Injector data...its ALL what its cracked up to be!

[Redline Motorsports]

Well this weekend I had the opportunity to see whats really involved in collecting the all important "injector data" we so often talk about online. Over my career as a calibrator I have had my share of issues with poor quality injectors, lack of data and bad data. Now that I have a good understanding of how critical it is AND the effect it has on drivability and overall performance I'm not looking back.

We flowed a few different sets of injectors that are currently being marketed and its quite concerning to say the least. Many people think that as long as they have the size of the injector they are all set...wrong answer! Some of the things that are critical are;

Injectors stability and predictabilty at pulse widths below 4.00 ms
Overall injector flow rate (static flow)
Consistency between sets of injectors
Proper spray pattern

The above items noted above where all observed this weekend. We also ran some stock unmodifed sets to compare to and observed the effects of "drilled" injectors, especially when not done correctly.

The tests performed where done using the SAE J1832 test methods which is the test method that all injectors in the OEM world are tested by. Its a very specific test which includes using a certain fluid as well as warming up the injectors for so many cycles before testing.

Its a decathalon of testing! I was quite surprised to see how some of the injectors are completely uncontrollable at low pulse widths. This now confirms why a few cars we tried certain drilled injectors on where very hard to get good fueling control. According to SAE the injectors must be within 3%...the injectors we tested where closer to 12% off.

I am not at liberty to discuss which injectors we tested but if your injector supplier doesn't test with the SAE standard and you claim to be good calibrator your wrong...


http://www.youtube.com/watch?v=OCWX3r1h2Cg

Those who haven't read this write up will have a better idea of what we experienced during our tests

http://www.calibratedsuccess.com/Assets/Documentation/WhosGettingDrilled.pdf

Howard

[swingtan]

Agreed!

I've only worked on a few cars with non std. injectors, but those that provided the full injector details made tuning very easy. Injector Dynamics for example provide the required injector data to suit tuning with EFILive for their injectors. This includes the small pulse adjust values that are critical to light load tuning.

Simon

[mowton]

Not trying to open an Injector war :), what are your feelings on the Bosch Racing 127 Lb/hr injectors being offered from the "other" injector supplier?

Thanks,

Ed M

[slows10]

^^ Did you get all the data required to set your tune up with these injectors? If you did not, then you probably already know the answer to that question on the 127 lb injectors. I saw these cost $115 bucks each on their website. If they did not come with data that is crazy. Can a similiar set of ID's be bought for the same price? EDIT I just saw that id 1000's are only $3 more each.

[swingtan]

It all comes down to what Howard has posted and the injector data. Bosch make good injectors, so do other manufacturers. Providing you are getting a properly matched set and the tuning data is provided, then you should be able to knock out a decent tune.

[J.Abbott]

Howard,
Thank you for the video. It is awesome. We did open a can of worms and other things that need to be looked at. For instance has anyone really though about how important the spray pattern is. For example it is easy to say we can adjust for it in the wall wetting settings, but as we watched this and asked questions, what about the tables we can't really control. Like what effect does it have on IVT since that is modeled. Very important questions and what is more important is that the injectors stay as close to the original pattern as possible.

[eficalibrator]

Cool video montage, Howard. Did I mention that Dave and I were in the middle of editing my new fuel injector video last night when you called? I'm thinking that the performance industry is just now waking up and smelling the coffee with regard to actual injector behavior. The more we can educate everyone, the more the sport/hobby can progress as a whole. The people feeding consumers bad data are going to start getting weeded out pretty quickly if they don't get on the bandwagon with the rest of the automotive industry and start testing using established procedures and generating valid data.

[Redline Motorsports]

Not trying to open an Injector war :), what are your feelings on the Bosch Racing 127 Lb/hr injectors being offered from the "other" injector supplier?

Thanks,

Ed M

No wars Ed! It is what it is...we the consumer don't manufacture this stuff but need the right data to make it work. I haven't worked with that injector directly so I can't really comment. We could "assume" that since its manufactured by Bosch and its unmodified by the outside world that its been engineered to work. This being said....if we can get the data according to J1832 we would be in good shape!

Howard

[Redline Motorsports]

Howard,
Thank you for the video. It is awesome. We did open a can of worms and other things that need to be looked at. For instance has anyone really though about how important the spray pattern is. For example it is easy to say we can adjust for it in the wall wetting settings, but as we watched this and asked questions, what about the tables we can't really control. Like what effect does it have on IVT since that is modeled. Very important questions and what is more important is that the injectors stay as close to the original pattern as possible.

I know we talked about these issues this weekend and we may never have the ability to compensate but many of those tables are effecting emission requirements as EVERY molecule of fuel has to be accounted for. I think the bigger of the issue is the spray pattern, especially what we saw on the bench, that can have a major effect on the drivability. Fuel blasting on the intake port wall that was suppose to hit the intake valve can show up as "tip in" issues and lambda recovery after the throttle has been put back to steady state.

My brain is still swollen from all the data this weekend....

HT

[eficalibrator]

Just a small slice of the bigger fuel injector video I'm working on...


http://youtu.be/JZmV10pFsCM

Click on the "More Info" button at the top right to see my description as well.

[ScarabEpic22]

I have just worked on stock injectors so far, haven't had a need to modify the IFR, pw, etc tables yet. But, a few people on here have really stressed the importance of this data (Howard, Greg, Joe, others Im forgetting) and after seeing this, it just makes me even more of a believer. Over the years, Ive watched guys struggle to get their tunes dialed in on this site and it usually ended up being their modified injectors.

ID has made it really easy to get the correct info, Ive never personally used their stuff (yet), but since they provide all of the data to plug into a tune it makes a tuner's life a lot easier!

[mowton]

^^ Did you get all the data required to set your tune up with these injectors? If you did not, then you probably already know the answer to that question on the 127 lb injectors. I saw these cost $115 bucks each on their website. If they did not come with data that is crazy. Can a similiar set of ID's be bought for the same price? EDIT I just saw that id 1000's are only $3 more each.

Yes, all injector data was supplied and seems to be working as far as "perceived" SPA (idle/low PW stability) and IFR (no obvious large transitions off the "supplied data" line). I don't have a problem with science and testing, but it seems the results state that only IDC does high flow injectors worth buying.....but because of liability, actual comparative data to specific injector p/n results can't be released!

You also need to buy the 14mm adapters for the LS3 setup which is another $100.

As I am not setup to perform all these tests, I ask the question again, has the Bosch Racing 127 injector been tested and how did they perform? Competition goes along way in keeping our prices in check for aftermarket toys :)

Thanks,

Ed M

[Tre-Cool]

could be a market for someone with the right tools and a website.

allow people to buy injector data for different tuning software, allow for calculation adjustments based on fuel pressure etc.

[JOHNBOY]

Darn right it matters!

I shake my head sometimes when people show up at my place wanting a tune up and with all the money the spent the skimped on injectors. There was time when I would try to make it work. I had varied levels of success with that. In the cases you can not get a handle on the tune up the person leaves and even though they brought sub par parts you are to blame in their eyes. A good chance your reputation ends up suffers do to word of mouth or posting the internet because the owner can not fathom how this is their fault.

After figting some of those mystery injectors and taking Greg's class I now take the stance that I simply will not tune it if I do have useful data on the injectors.


This issue will really come into focus when people start modifying Direct Injection engines. We already see it in the diesel world. Dynamically matched and mapped injectors are way more money then then ghetto honed out stockers. But I have found it best do require high quality injectors or I will not touch it.

Sure seems to work out for me.

[minytrker]

I have seen first hand what wrong injector data can do. I re-tuned a boosted stock LS3 that had tons of issues and 99% of them were from the injector data being wrong.

[Meister]

Here is another great example of good injector data. 2009 Corvette Z06 with 430CID motor, ported LS7 heads, Magnacharger with Injector Dynamics 850's, return fuel system with regulator. Using ID supplied data and making changes for the return system with regulator the maf curve was left virtually stock and fueling was bang on 95%. You will also understand from the article that injectors are not created equal. You can have the best data in the world but if the injector is crap the car will run like crap

[eficalibrator]

could be a market for someone with the right tools and a website.

allow people to buy injector data for different tuning software, allow for calculation adjustments based on fuel pressure etc.
Unfortunately, there just isn't a good business case for doing single sets. This process takes a bit of time. It's enough time that I can't even offer this injector characterization service to individuals at anything near a "cheap" price. It literally takes most of a day to run the complete procedure (all pulsewidths and voltages) on a single set. The rate I would have to charge for my consulting time for an entire day exceeds what most people here expect to pay for the dyno tuning itself. My accountant won't let me work and use my resources for free, so I have to at least make something.

Plus, what happens when I run all the tests only to find out that the set of injectors you sent me are either:
1) not matched
2) have too much shot to shot variability to be used with confidence
3) don't match the flow rate the seller quoted you
4) have data that results in a negative offset that you can't even apply to a GM control system, nullifying any possibility of actually using said data

There is a good chance people will be upset with my data because it means they spent money on bad parts plus money to me to confirm they're bad, PLUS more money to buy good parts and more data in the future.

Alternatively, enough of the injectors get characterized for a dirt cheap price and I would work myself right out of a job. I'm not so worked up about this because characterizing injectors is not how I pay my mortgage, but my accountant still won't let me work for free. If you are an injector reseller who is interested in shipping me a significant quantity of a single part number, we can probably work something out.

[Redline Motorsports]

Want to know how much is behind injector data characterizing?????

Closing Time (CT)
Inductance (L)
Coil Resistance (R)
Dynamic Flow (Qd)
Dynamic Flow Calculated (Qdc)
Dynamic Flow Rate (Q)
Dynamic Flow Temperature Shift (Qtd)
Dynamic Flow Vacuum Shift (Qvd)
Dynamic Minimum Operating Voltage (DMOV)
Dynamic Set Point (PWxx)
Dynamic Set Point Flow (Qsp)
External Leakage
Flow-Offset (Y)
Insulation Resistance (IR)
Linear Flow Range (LFR)
Linearity Deviation (LD)
Maximum Overload Voltage
Opening Time (OT)
Operating Voltage Range
Period (P)
Pulse Width (PW)
Pressure Drop Ratio (PDR)
Repeatability
Slope (m)
Slope Approximated (ma)
Spray Pattern
Stability (S)
Static Drop-Out Current (I/S-OFF)
Static Flow Rate (Qs)
Static Minimum Operating Voltage (SMOV)
Static Pull-In Current (I/S-ON)
Time-Offset (X)
Working Flow Range (WFR)

Get with the program or be left behind!

Howard

[myws6formula]

what I find interesting is I wanted to make a post asking where people are coming up with there injector data and I saw this post.

? does that mean most are just changing the flow slop and leaving the rest of the tables stock?



I want to install my GTP injectors in my return fuel rail and I have found variations on the data and they are stock injectors! even the ASA tunes seem to have conflicting data. I feel like I am almost shooting from the hip going off any of the data I have found.

[JOHNBOY]

what I find interesting is I wanted to make a post asking where people are coming up with there injector data and I saw this post.

? does that mean most are just changing the flow slop and leaving the rest of the tables stock?



I want to install my GTP injectors in my return fuel rail and I have found variations on the data and they are stock injectors! even the ASA tunes seem to have conflicting data. I feel like I am almost shooting from the hip going off any of the data I have found.
Yep. That sure makes it interesting does it not.

Here is an example of data Injector Dynamics provides. http://www.injectordynamics.com/ID1000%20-%20GM%20Characterization%20Tables%20-%20EFI%20Live%20-%203-29-2011.xls

[Redline Motorsports]

what I find interesting is I wanted to make a post asking where people are coming up with there injector data and I saw this post.

? does that mean most are just changing the flow slop and leaving the rest of the tables stock?



I want to install my GTP injectors in my return fuel rail and I have found variations on the data and they are stock injectors! even the ASA tunes seem to have conflicting data. I feel like I am almost shooting from the hip going off any of the data I have found.

Yep...now the real calibrators are going to start gaining yards on the tuners.........By the time you narrow down the guys outside of the OEM world that really get this......there aren't many...the buy a laptop and order an ego concept is slowly getting torn down...

This isn't rocket science...just tested methods and comprehension..

Howard

[eficalibrator]

This isn't rocket science...just tested methods and comprehension..

Actually, a big part of rocket science revolves around getting correct air-fuel ratios in order to deliver enough thrust to break gravity. What we're doing here isn't fundamentally different. ;)

[J.Abbott]

Greg,
Did you have a hand in that Corvette and rockets commercial?

[Redline Motorsports]

Can't we all just get along?....

[slowhawk]

I like how people finally caught up with testing injectors at the low pulse tables.
This isn't new but is new in this market. Will make life easier if the correct data is provided for each injector you buy.

[ASNUPHIL]

Hi Guys,
Remember, the spray pattern should be at the top of the injector data characterizing, otherwise the rest of it will be pretty much redundant, good luck!!

Phil Ellisdon - ASNU.

[joecar]

Hey Phil @ ASNU, welcome to the forum :cheers: :cheers:

[Redline Motorsports]

Hi Guys,
Remember, the spray pattern should be at the top of the injector data characterizing, otherwise the rest of it will be pretty much redundant, good luck!!

Phil Ellisdon - ASNU.

Phil good point. But I assume the characteristic parameters that we have control over will still stand as is and tables like Stomp Impact Factor (Dynamic Fuel Control) will clean up the mess. I agree that if the pattern is really messed up then its a bigger problem.

From what I've seen on the flow bench, every injector (meaning as a group) had a different spray pattern....therefore fuel mass entering the combustion chamber will vary regardless of the items like short pulse adder, offsets, etc...I'm not convinced that we have enough calibration control with EFiL to truly address this. It's also starting to split hairs and something on a OEM level for emission compliance that is effected.

Will be interesting with DI (Direct Injection) on what is needed to be adjusted when fuel isn't even in the intake port anymore!

Howard

[minytrker]

Howard,

So are you going to flow test every injector on each vehicle you tune? How are you going to handle tuning injectors you dont have all the data on?
I agree the correct data makes life alot easier, Im not denying that but Im sure you tuned thousands of cars like myself before all this "new" data came into play. I'm not disagreeing or picking on you just curious. Feel free to PM me if you dont want to discuss this on here.

[Redline Motorsports]

Howard,

So are you going to flow test every injector on each vehicle you tune? How are you going to handle tuning injectors you dont have all the data on?
I agree the correct data makes life alot easier, Im not denying that but Im sure you tuned thousands of cars like myself before all this "new" data came into play. I'm not disagreeing or picking on you just curious. Feel free to PM me if you dont want to discuss this on here.

There really is no sense in running every set of injectors through a cycle like this. I just want to be able to buy an injector from a supplier where the are consistent. Once we acquire the data just match it to that brand/model.

I pretty much have data for every injector WE use that covers us from stock to 1800 HP so my library is good. What I am doing now is revisiting some of the prior data to the recent stuff and making changes.

Usually our customers that are looking for packages will just trust us to supply the injectors that make the package work properly. The guys that come in with odd ball junk.....we just use the best judgement we can in getting them dialed in. Cars that have consistent issues we just tell them to pony up and do it right.

Any injector manufacture that thinks they will be successful in selling injectors for the GM world without supplying data is in for a hurting as people realize its importance.

HT

[minytrker]

I'm on the same page now, makes complete sense. I sold my shop in 2009 and sometimes forget that most people are building the cars they tune. I just tune cars so I am at other shops mercy alot of times. Unfortunately alot of shops dont have your view on things, it would make my life alot easier if they did, lol.

[ASNUPHIL]

Hi Howard, Hi Joe, (thanks),

I enjoyed the video Howard, nice, hope you enjoyed playing with the machine.

In answer to your question, Yes, to a certain level if you are looking at injectors as a group and on a production vehicle, but we would never recommend this for a performance engine, what we condemn on performance can quite often be acceptable for a production vehicle, but now, even they are going to have problems.
As we progress in to direct injection, you will see more and more importance placed on the performance of the spray pattern rather than the flows, the system running sequentially can adjust the fuel delivery per injector, but if the spray pattern is out of shape, the system cant handle this and compensatory adjustments are made by the long and short term fuel trims, but I do say COMPENSATORY, not corrective adjustments, so eventually the problem manifests until the system reaches its tolerance levels and flicks the engine check light on and in some cases, puts the engine in to limp more.

So sprays are going to be more and more important and it will be down to the technician doing the testing to decide as to what is acceptable and what is not.

In your video, you had 4 injectors, with two different spray patterns, were they the same injectors, if so, which ones did you decide were the correct ones?

Back to your question, I always cross one bridge at a time with injectors. First you are looking for the flow to be correct, both dynamic and static, if you have an unacceptable difference (after ultrasonic cleaning) then that injector needs replacing before wasting any more time on it. Please note, we get people calling up saying "my injectors wont run at 15,00 or 20,000 RPM, what is wrong with them, do I need to replace them? NO! They are not designed to run at that level so they wont, so don’t replace them, if they run correct at 10,000 rpm, they are fine.

Once we have a matched flow set, then we look to match the sprays. If you are using quality (Bosch) injectors, you generally find their sprays are matched, unless the injectors have been produced to a budget rather than a requirement, which many O.E. injectors are. Again, if the spray does not match to an acceptable level, it will change the air/fuel ratio in the air track and an imbalance will follow. Many production car injectors are built to a budget, therefore the system is set up to accept the level produced, allowing the oxygen sensor to try and balance it out as much as possible till its out of warranty or changes hands. We know that quite a few injectors are built with a limited life expectancy, with replacement being the only option, you will start to see many of the later generation re-man injectors being thrown back because the car has a hot start problem.

So, if we have the correct flow, correct spray, they don’t leak, they all perform correctly through a drive cycle and the spray pattern is correct for the manifold, THEN we can start to fine tune the engine with the characteristic data we have available.

Many people would not realise, but a coil pack failure can be a result of poor injector performance, if the injector is not delivering the correct amount of fuel or distributing and atomising it correctly, the KV’s increase and the coil works harder which in some cases will rapidly shorten the life of the coil. Simple answer, replace the coil, 3 months later, the car is back with the same problem, replace again, 3 months later, back again. Don’t find the problem, find the cause of the problem.
Regarding Minytrker’s comments, that seems to be option now facing everyone, which is why I designed my injectors the way I have.

One top quality core injector with the option of 15 different flow rates, with each flow having a predetermined spray pattern to match.

This way, the only variance required is the characteristic changes in pressure or voltage, but now with many of the new generation of injectors, the flow does not change much above 14.5 volts, as the materials now used in the injectors reach saturation and voltage increase make no difference, lower voltage will and does.

So, with all the data available and ready to use, it’s as simple as falling of a log, or tripping over an injector as we say in ASNU.

Hope this is helpful.


Regards

Phil

[eficalibrator]

In your video, you had 4 injectors, with two different spray patterns, were they the same injectors, if so, which ones did you decide were the correct ones?

Surprisingly, the right two injectors are STOCK LS3 units. Yes, they have a "pencil stream" upon inspection. Theoretically, this isn't so fantastic for mixture homogenization, but in practice it seems to work very well in the GM engine. This is likely because of a longer distance between the injector tip and the spray target on the back of the intake valve. Wider and more disperse cones would likely increase the impact factor upon the port wall and require their own adjustments to the transient compensation tables. The moral here is that a pencil stream isn't 100% bad as long as >90% of your fuel is getting evaporated and mixed prior to combustion.


Once we have a matched flow set, then we look to match the sprays.

This is my approach as well. Specifically, in that order! I need actual fuel mass delivery to be on target, then I get the right amount placed in the correct position to promote good combustion. Give the choice between poor mass control and and poor distribution, I generally tend to prioritize mass control since I have the ability to adjust X-Tau compensations for different wall wetting characteristics. If I don't get the right mass in the first place, the whole system chases its own tail.

In a race application, we just want both correct right from the start and pay a little extra to get the right injector that does both!

[ASNUPHIL]

So we don’t get at crossed purposes, I am talking about Performance and Racing, where you I believe, are talking about general Production EFI.

In any engine, throw fuel down the throat and it will burn, how efficiently that fuel burns is the difference between Race engine and Production.

I don’t disagree with you that the pencil system works in a production engine, but early 2000 legislation on Emission Control and the need for better Fuel Economy being the driving force behind these changes. I am sure you will agree that it’s certainly not the best option for a performance engine
And that you can certainly improve even a production engine with just a change to a better performing set of injectors, even cleaned ones!!

But this is old hat, now its all about Fuel Droplet Formation (FDF) and now we have the multihole injectors replacing the pencil sprays, giving smaller droplets of fuel, which will mix better in the air track and burn better, giving the additional boost of performance to the afore mentioned Economy and Emissions requirements.
Denso have a very nice 12 hole injector.

For Performance, If we look at early prestige production cars, they were fitted with fuel injection for performance, from the first K-Jet systems, where they had a 35° cone spray, the early D-Jetronic on the early Mercedes injectors had 25° sprays. The early F1 Fuel Injected Cosworth engines had cone sprays firing atomised fuel down the mouth of the trumpets.
In Performance, its always been about Fuel Quantity, Fuel Distribution and Fuel Atomisation, in that order, nothing has changed in those requirements, its just the change in education of the market as Fuel Injection went from Prestige Performance/Racing to aftermarket production and emission controlled engine management systems.
The newer players entering in to the FI business over the past 15 years, they saw mostly pencil spray injectors and the reasoning of spraying fuel on to the back of the valve and accepted that this was the norm. Saying that, ASNU has been working in the USA for over 25 years and only these guys have been educated on spray patterns, everyone else seemed to ignore them, but now more and more are becoming aware of the spray patterns importance.

Here is a scenario worth thinking about, using some of the fuels around: Fuel hitting the inlet vale can cause sticking vales and valve stem guide wear, the non atomised fuel runs in to the combustion chamber, sits around the piston and washes the bores, fuel is now in the oil and can damage the bearings, un-burnt fuel carbons up the exhaust valve, gums up the EGR valve, lacquers the Lambda and slows the response time and finally clogs up the catalyst exhaust.
I wonder how many people have changed Lambda’s & EGR valves, replaced Cats, rings and valves and never thought about what caused the problem in the first place.

In my 30 years of Testing & Servicing Fuel Injectors, I have Tested and Serviced Injectors on every continent, I have seen some horrendous problems caused by the FUEL when the injector had pencil sprays, in Europe in the 90’s, there were issues all over the place because of these injectors, BMW, Ford, Citroen/Peugeot, Jaguar all had major problems, but as the fuel improved, so the problems decreased, then they switched to multi hole injectors. The wetting the walls issue was always caused buy wrong design for the application, be it spray distribution angle, injector position and spray pattern atomisation.
Air charging down the manifold is like going down the tubes at Wet N Wild, it does not sit in the centre without touching the walls it runs down them, to get the best out of a performance engine you need the fuel to be in an atomised form ready to meet the incoming air, this is what multi hole sprays do.

Now we have Ethanol in the fuels, it will be interesting to see the long term issues the Injector/Fuels combination has on the engines.

I was asked once to sort out an injector problem on a new “Limited Addition” vehicle at a large vehicle manufacturer in Europe. When I looked at the set up, I saw the problem and asked why they were using this manifold with this injector in this engine?? The combination was completely wrong, their answer was: we have lots of these manifolds, lots of these injectors and lots of these engines, a “Limited Addition”
So don’t believe everything the VM’s tell you.

Again Greg, my comments are about injectors for Performance and Racing.

[Redline Motorsports]

Here is the future of checking spray patterns!

Phase-Doppler interferometry (PDI) is another type of instrument that can be used to measure the drop-size distribution of the fuel sprays. Phase-Doppler systems perform measurements at a point in a spray. This is accomplished by monitoring the light that is refracted by the individual drops of a spray that pass through a small“probe volume” that is illustrated schematically in Figure10. This is a very small volume that is defined by the intersection of two, or more, focused laser beams and a precision optical slit, or spatial filter. Wherever the probe volume is positioned within a spray, the complex refracted light signal from an individual drop that passes through that volume is interpreted, classified and, if it passes a series of logic tests, is converted to an accepted drop diameter and placed into a cumulative database. This database yields the drop-size distribution for that location at the end of the test. Unlike the laser diffraction method of measurement, other locations in th espray are not interrogated while data at that location is being acquired. Typically, the probe volume is sequentially positioned at numerous sequential locations in the spray, yielding a measured spatial variation in spray characterization parameters.The individual measurement locations are specified to be along a specific straight line, which is designated in SAEJ2715 as the radial scan line, and which normally scans the distance from the injector centerline to the outer spray boundary. As a result of having to index the probe volume through numerous positions in the spray, phase-Doppler testing is significantly more time consuming than laser diffraction testing. The key drop sizing parameters obtained using PDI are the drop-size distribution curves at key points within the spray, the SMD and the drop diameter that corresponds to the 90% cumulative volume point on the drop-size distribution curve, D
v90.


In interpreting the results of drop-size measurements, itis important to remember that automotive gasoline fue lsprays are pulsed sprays. The highly transient nature of a spray pulse is obvious, even with simple visualization using a strobe light. Although the drop-sizing statistics that are detailed in the SAE J2715 document are all based upon time-averaged measurements made over the entire injection event (in fact, over a large number of consecutive injection events), there are some PDI and laser diffraction instrument packages that can perform time-resolved drop-size measurements. This time windowing has the additional capability of measuring only during brief time intervals within an injection event. This specialized equipment can differentiate between leading edge drops and trailing-edge drops, and can separately measure the sizes of the main spray drops and the sac drops. However, such specialized equipment options are quite complex in application and interpretation. An additional consideration is that many PDI and laser diffraction instruments remain in service that do not have the time-windowing option. One of the goals of the new J2715 procedures was to have an equipmen trequirement that all spray laboratories could meet, and a test procedure that was not overly complex in configuration and interpretation. Hence, after much discussion by the GFISC committee, there was a consensus that all of the drop-sizing tests in the SAEJ2715 document would be time-averaged, with the time windowing option turned off if the drop-sizing equipment has such an option. With the exception of spray-tip penetration, this also applies to all of the other tests within the document. Controls on the air-purging rate of the spray enclosure are specified to prevent the measured, time-averaged results from being excessively
influenced by the residual spray droplets.

[joecar]

...

Many people would not realise, but a coil pack failure can be a result of poor injector performance, if the injector is not delivering the correct amount of fuel or distributing and atomising it correctly, the KV’s increase and the coil works harder which in some cases will rapidly shorten the life of the coil. Simple answer, replace the coil, 3 months later, the car is back with the same problem, replace again, 3 months later, back again. Don’t find the problem, find the cause of the problem.
...Very good point.

I've seen secondary ignition waveforms showing different kV among cylinders on same engine (lean mixture is more resistive, producing higher kV).

[joecar]

Some interesting reading involving laser interferometry, Howard.

[ASNUPHIL]

Howard,
That is the ultimate in spray pattern analyzing, as the growth of GDI increases, so the need for better atomization analyzing will increase, but the need for the basic workshop will never be that specific I am sure. It does make interesting reading and gives a good insight to what standards the VM’s and the injector manufacturers are expected to meet, it can only get worse.

We have built machines for laser applications to measure Fuel Droplet Formation (FDF) for a number of Automotive & Aerospace test facilities, the Automotive was for Emissions, the Aerospace was for consumption, with a brief to measure the FDF to ensure they burn as much of the fuel as possible.

With any of the SAE data, its all designed for production vehicles, not modified Sports and Performance. What I find strange is that if you take any of the injectors from Bosch Motorsport, none of them have a straight spray pattern, none are designed to atomize on the back of the valve, they all have a spray pattern option of between 15 - 70°, either in a twin or conical spray pattern and they do know what they are talking about.
(http://www.bosch-motorsport.de/en-US/literature/en-US/Injection_Valve_EV_6_Datasheet_51_en_2775912459.pd f)
What is strange is that when a certain “Injector Specialist” in the USA tells everyone that a straight spray is the best spray, everyone believes it??? Even some of the most respected Tuners have followed the same path, preaching the same belief, but I am sorry, they are wrong.

In Sports and Performance Injectors, I think Bosch have greater knowledge and experience than anyone, so I would trust their advice first.

A change is coming, people are starting to realise that you may not need all that fuel that the 2000cc injector is supplying if you have the correct spray pattern to suit the flow.

I am sure my comments have and will annoy a number of people, but they are not intended to do so, they are fact and they are correct.
ASNU has worked with Fuel Injection Specialist in over 60 countries for over 25 years, we are approved and recommended by Robert Bosch and we only wish to offer the best support and advice possible to our ASNU owners, but in this case, I feel I needed to get involved outside our network.

Maybe we can get one of the design engineers from Germany over to PRI this year to give a presentation, that would be interesting.

I hope this helps rather than antagonise.

[Redline Motorsports]

Howard,
That is the ultimate in spray pattern analyzing, as the growth of GDI increases, so the need for better atomization analyzing will increase, but the need for the basic workshop will never be that specific I am sure. It does make interesting reading and gives a good insight to what standards the VM’s and the injector manufacturers are expected to meet, it can only get worse.

We have built machines for laser applications to measure Fuel Droplet Formation (FDF) for a number of Automotive & Aerospace test facilities, the Automotive was for Emissions, the Aerospace was for consumption, with a brief to measure the FDF to ensure they burn as much of the fuel as possible.

With any of the SAE data, its all designed for production vehicles, not modified Sports and Performance. What I find strange is that if you take any of the injectors from Bosch Motorsport, none of them have a straight spray pattern, none are designed to atomize on the back of the valve, they all have a spray pattern option of between 15 - 70°, either in a twin or conical spray pattern and they do know what they are talking about.
(http://www.bosch-motorsport.de/en-US/literature/en-US/Injection_Valve_EV_6_Datasheet_51_en_2775912459.pd f)
What is strange is that when a certain “Injector Specialist” in the USA tells everyone that a straight spray is the best spray, everyone believes it??? Even some of the most respected Tuners have followed the same path, preaching the same belief, but I am sorry, they are wrong.

In Sports and Performance Injectors, I think Bosch have greater knowledge and experience than anyone, so I would trust their advice first.

A change is coming, people are starting to realise that you may not need all that fuel that the 2000cc injector is supplying if you have the correct spray pattern to suit the flow.

I am sure my comments have and will annoy a number of people, but they are not intended to do so, they are fact and they are correct.
ASNU has worked with Fuel Injection Specialist in over 60 countries for over 25 years, we are approved and recommended by Robert Bosch and we only wish to offer the best support and advice possible to our ASNU owners, but in this case, I feel I needed to get involved outside our network.

Maybe we can get one of the design engineers from Germany over to PRI this year to give a presentation, that would be interesting.

I hope this helps rather than antagonise.

I don't think you should worry about people giving you shit! This is your world that we are invading and we appreciate your views and information. Unfortunately us guys on this level don't have all the knobs to twist like you do but we've made great strides in getting better control over the final fuel mass.

It's become very fascinating to see how detailed the injector world is and how fine it's analyzed...

All this has continued to ruin an already poor sleeping pattern!

Howard

[joecar]

Does anyone here sleep...!?

[ASNUPHIL]

Thanks for the compliment, well I will take it as one anyway. It is entreating and it's good seeing tuners proving that small changes can make a big difference.
As we increase the amount of fuel delivered in street performance vehicles, the more defined we have to be in the injectors performance, it's getting more interesting by the week now that we have GDI, which we have been doing since 1997.
I respect what you guys are doing and hope my comments are useful.

As for the sleep, when you have guys in Australia and Japan who are getting up as you are going to bed, well it's hard not to contact them when they have urgent questions, emails have become a time consuming pain, it's easier and quicker to pick up the phone, no matter what time it is. Thanks.

[mowton]

Howard and all,

This is all great reading and makes alot of sense to this engineer at heart. So where does that leave us tuners who don't have access to all the sophisticated test equipment or time to research all the options out there. Is there someone or group who has our back?:help::help: I think my takeaway on this is if you pick from Bosch or IDC you should be OK. The major issue with re-drills is <2ms non-linearity causing major issues in idle and light cruise tuning along with varianility from injector to injector at >2ms even though they are "flow matched"

I assume they (Bosch and IDC) will continue to keep up with the technology and support "the little guy" with the best injector designs/styles for our projects.

Thanks Howard, Greg and Phil for your time and effort and having the desire to bring this to us.

Ed M

[eficalibrator]

Phil,

If I am understanding you correctly, you are asserting that as we go to very large injector flow rates (i.e.: 800+cc/min) we are more susceptible to lost fuel issues due to poor atomization? I know that our first priority needs to be the carbon balance for flame control, but if we are not evaporating and cleanly burning all the fuel mass that is being injected, that opens the door for further discussion of mixture preparation that has an impact upon combustion. Lost fuel can skew our downstream lambda measurements or at the very least force us to "bake in" some error to calculated airflows if one makes the ASSumption that 100% of injected fuel is burned. It seems that you might have some data showing that this might not be the case in some high flow rate injector applications (regardless of manufacturer) if the spray pattern and distribution are sub-optimal.

[ASNUPHIL]

Gentlemen,

Again, I would like to reiterate that this topic can be talking about two different programmes, those being Production Vehicles and Performance/Motorsport Vehicles..
Let clarify any arguments people may have about spray patterns, they are like everything else on a vehicle, they are built to specification, either to a Technical requirement or to a Financial budget. Take a guess as to which one has the best, top quality products on it and which has the cheapest bulk buying products possible on it?

Production Vehicle
Lets take the production vehicle, all built to a budget, with all the component being a target for cost saving buy the buyers. The injectors are a great example, the Bosch EV1 is now only special order and costs a fortune for quality versions from Bosch.
When a VM orders 35,000,000 for a production programme, saving $0.05 per injector means a saving of $17,500,000, so in an injector manufacturer has to make an injector $0.05 cheaper, then they have to start looking how to make it cheaper if they want the order.

The pintle valve of the EV1 was ground to a 1 micron tolerance, reducing the tolerance would change the characteristic of the spray, to which the VM would either have to accept and make adjustments in their design to accommodate the changes if they want the injector at the price or pay the price if they want the quaility. The words "Quality" and "Cheap Prices" have never been a statement from a manufacturer, you can have either, but not both.

As demands in emission regulations increased and pressure to reduce the price to the VM’s grew, injectors changed. In Bosch they went from the EV1.0 to the EV1.3, then to the EV6 and now to the EV14. This was the results of demands for progression in injector designs, productions and costs. As I am sure everyone is aware, the changes from EV1 to EV14 are huge, just take the cost saving in not using the metal body, add to that the savings in copper wire of a coil of the EV1 to EV6 to EV14, its a huge cost saving.


Bosch now have an injector rolling of the production line EVERY 3 SECONDS. The changes in designs mean that in theory that although they are making more injectors, their profit per injector has possibly reduced, which (this is only my own assumption) means the plant are possibly making the same money as 20 years ago, this is called progress.

Now we have gone from the EV6 to the EV14, cost saving are really being squeezed, the injectors are now the most important component in the controlling of exhaust emissions, so not only are they expected to be produced to a cost, they still have to perform to a standard for emission control.

Injectors are designed to ATOMISE IN FRONT OF THE VALVE, NOT ON IT.
Atomising in front of the valve gives the best chance of getting an even air/fuel ratio prior the mixture going in to the combustion chamber, ensuring the best possibility of even combustion, resulting in best possibility of even Idle, Economy and Emissions.
Using the inlet valve to atomise the fuel is a cheap option that limits the possibility of achieving the best results, yes it works, but is not an idle standard and one that covers up the inadequacies of the injector being used.

With multi production vehicles, injectors are in the most, designed to a cost and standard, which could be described as a “That will do” level, that increases as the standard of vehicle improves, I don’t think I need to explain the differences.
Now we have Multihole injectors, which are designed to produce Fuel Droplets to an average of 160 microns for production vehicles, if the manufacturer can laser cut 2 or 4 holes rather than 6 or 12, then they will make huge saving, we know the cost of laser cutting.

If an injector is produced to a standard such as SAE for a production vehicle, then IT WILL WORK, but if you ask if it could be improved, then the answer is YES, if you ask is it the best injector for the application, then the answer is possibly NO.

Now we have switch from Simultaneous to Sequential Injection, we will start to see the injector’s performance become even more critical, especially the quality of the spray pattern, sequential systems can compensate for fuel delivery discrepancies, but not the discrepancies in the spray patterns and that is an issue we are already seeing with GDI direct injection.

I have been testing injectors all over the world for over 25 years, no one in the world has seen as many different injectors for production vehicles and the problems due to manufacturing as I have and believe me, there are some really terrible production injectors in use. One well known VM’s and an Injector Manufacturer produced a range of injectors with a limited life expectancy, they were destined to fail and did, but some would last long enough to surpass the warranty period, then it becomes the owners problem, nice!! So lets not use a cheap OE injector, designed to do a job to a minimum as an example to which all injectors should be measured, that would be a serious mistake.


Performance/Motorsport Vehicles
OK, let’s now look at Performance/Motorsport vehicles.
What we all know is that this market not only uses the best, they demand the best as they all want to be the best, but that costs money.
If we take ANY Performance/Motorsport vehicle, if they want the best, they wont use a production version of anything on their vehicles!!

So when we are looking at injectors, why are we trying to use a production injectors for a Motorsport application, if it were that easy, Bosch would not go to all the trouble of producing a range of Motorsport components, including injectors. Yes you can adapt some injectors for Performance/Motorsport applications, but trying to use some of their designs is not the idea answer.

Again, if someone want injectors to meet a budget, then don’t complain when you cant achieve what you expect, it’s the same with mapping ECU’s, some you can make an engine sing and dance, others are limited in what can be done with them, if you buy cheap or something that is not the best for the application, you only get what you pay for, it goes across the board.

Ignorance is not an excuse, but if you are being feed the wrong information, then this is a problem. People visit sites like these and trust “experts” giving their advice, but if the “expert” is giving bias information, then that is not fair and they WILL be found out, it’s only a matter of time before someone puts the question to the test and finds out the truth.

Air being driven down the inlet track runs down the walls, if atomized fuel is fired into the incoming air BEFORE the inlet valve, you will achieve a much more balanced and combustible Air/Fuel ratio.

This will give a better combustion process with more of the fuel being burnt that in turn will deliver a better performance from the engine in the shape of Throttle Response, Torque Curve, and BHP. Improved Fuel Economy will come from more power for the same usage.

Why tuners and users would choose inferior components when they are spending so much money to achieve so much performance, it’s a false economy.
Again, the ECU’s with sequential systems are more expensive, but if a owner and tuner really want to get the best out of an engine, this is the best option, but you have to have a quality injector and the injectors characterisation data to go with it.

FDF (Fuel Droplet Formation) Fuel droplets burn from the outside in, (looking a bit like the sun), they are possibly only in the combustion chamber for fractions of a millisecond before they are drawn out on the exhaust stroke. Any droplets not completely burnt, (and you will never burn 100% of the fuel delivered in a manifold injection system) is wasted fuel. The aim is to make the fuel droplets smaller and lighter, so they mix easier with the incoming air and will burn quicker and better in the combustion chamber.

The ASNU Performance Injectors have been specifically designed to achieve this, with Multihole Sprays with the relevant spray angle to match the flow.
Single hole spray pattern cannot achieve this and atomising on the back of the valve is not the idea process for maximum performance.

I hope this clears up any misunderstandings between the use of injectors used for Production and Tuning/Performance/Racing.

[joecar]

Where should an injector's open/close events be located in relation to the intake valve open/close events...?

[ the intake valve will be closed for some of the time that an injector sprays ]


Does the shape of the spray pattern require any modification of this...?

[ASNUPHIL]

I think this says it all.

Customers comments:

Nispro Performance

13772Due to cold start and tickover problems with the Subaru, we have been looking for a modern high performance injector. Thanks to our sponsor ASNU Fuel Injection the JapPerformanceParts subaru is now running modern 600cc injectors which has made a huge improvement. We've had it on the rollers and tweaked the map a small bit and she is now running very smoothly @ 510 BHP. We will be looking forward to working closely with ASNU in the future!

[J.Abbott]

Crap, I leave for a week and look what happens. I have found some interesting data a
On some stock injectors from other applications that also do not work for the GM stuff. Way more advanced then what I ever initially thought.
Phil, I will be starting to flow the injectors this week.
Howard, talk to you in Carlisle.

[ASNUPHIL]

ASNU Injector Solutions Programme.

Gentleman, i thought you might like to see one of our Injector Solutions for the Ford Focus ST170, which has the 650cc Simens Injectors and not a lot of room or movement.

The customer had mxed out the Siemens at 95% and required some 750cc that would be a straight swap that would perform. No Problem!
ASNU Injector Solutions have the answer, now please tell me that this is what a spray pattern SHOULD look like.

I am only 25 years in this business and see more injectors than most, but if i am wrong, please let me know.

If anyone has a problem finding a solution to an application, let me know, we can help.1380413805

[ASNUPHIL]

By the way, there is no trick photography here, what you see is what you get, unlike some other one floating around.Phil.




ASNU Injector Solutions Programme.

Gentleman, i thought you might like to see one of our Injector Solutions for the Ford Focus ST170, which has the 650cc Simens Injectors and not a lot of room or movement.

The customer had mxed out the Siemens at 95% and required some 750cc that would be a straight swap that would perform. No Problem!
ASNU Injector Solutions have the answer, now please tell me that this is what a spray pattern SHOULD look like.

I am only 25 years in this business and see more injectors than most, but if i am wrong, please let me know.

If anyone has a problem finding a solution to an application, let me know, we can help.1380413805

[JOHNBOY]

Ok I am going to bring a little life back to this thread. I have question for Phil, Greg, Howard, and anyone else.
What effect does fuel pressure have on all this?
The standard operating pressure for the LS is 58psi (4bar). Now I have ID1000 injectors and am considering running one fuel pump instead of dual stock style pumps for simplicities sake. Using Magnafuel 4303 without a controller. This is a turbo charged engine with a boost referenced return style fuel system. Magnafuel reccomends using 35psi (2.4bar) as my base pressure. They say this will keep load on the pump down and have plenty of room to meet my 800hp base goal.

The difference in the Flow Base easy enough to calculate.

But what happens in the other tables and settings?
I would guess the the minimum pulse would stay the same along with the break point.
Would the small pulse adust change?
What about the voltage adjust? If manifold pressure effects it surely fuel base pressure does?

[Meister]

Ok I am going to bring a little life back to this thread. I have question for Phil, Greg, Howard, and anyone else.
What effect does fuel pressure have on all this?
The standard operating pressure for the LS is 58psi (4bar). Now I have ID1000 injectors and am considering running one fuel pump instead of dual stock style pumps for simplicities sake. Using Magnafuel 4303 without a controller. This is a turbo charged engine with a boost referenced return style fuel system. Magnafuel reccomends using 35psi (2.4bar) as my base pressure. They say this will keep load on the pump down and have plenty of room to meet my 800hp base goal.

The difference in the Flow Base easy enough to calculate.

But what happens in the other tables and settings?
I would guess the the minimum pulse would stay the same along with the break point.
Would the small pulse adust change?
What about the voltage adjust? If manifold pressure effects it surely fuel base pressure does?

You are going to use the value at the base pressure you are running (whatever you decide it is) and use that for the entire table. This will work assuming you are using a regulator with a vacuum line on it. Your min pulsewidth and small pulse values will stay the same.

[eficalibrator]

Pressure will have a noticeable impact upon injector offset as well as linear flow rate. The short pulse phenomena are the question here. If this were a Ford, we'd be looking at applying a similar Bernoulli correction to the low slope as we did to the high slope for the change in pressure. Since GM uses a time adjustment to correct for short pulse errors, this requires a bunch more math and interpolation _or_ a whole new set of characterization tests at the new pressure. The latter would be my preferred method.

[Meister]

Pressure will have a noticeable impact upon injector offset as well as linear flow rate. The short pulse phenomena are the question here. If this were a Ford, we'd be looking at applying a similar Bernoulli correction to the low slope as we did to the high slope for the change in pressure. Since GM uses a time adjustment to correct for short pulse errors, this requires a bunch more math and interpolation _or_ a whole new set of characterization tests at the new pressure. The latter would be my preferred method.

Well said. I have always done this maintaining the factory base pressure. Injector Dynamics, if asked nicely, would be more than happy to provide this data for you if they have time available. If you will have enough range in your fuel system to keep 58psi I would do so.

[ASNUPHIL]

Hi John,

Before you do anything with the fuel pressure, take your injectors along to an ASNU owner and have him flow them at 4 bar under the Auto Cycle, this runs the injectors at 3, 6, 12mS @ 600, 2500, and 5000 RPM, look at them and see what a difference it will make to the spray patterns and the flow rates, the droplet will increase in size dramatically for when they are run at 4 bar, you will certainly have a difference with the air/fuel ratios compared to when they are run at 4 bar pressure, they do not have an orifice plate, so the fuel relies on the seat to distribute and atomize the fuel and lower fuel pressure will change the spray pattern characteristics.

You need to be sure you want to do this modification and have all the issues attained to the change. My suggestion is that when you are sure you can get the basics right, then you can start adjusting for the injectors characteristics.

Hope this helps.

[ASNUPHIL]

138511385213853John,

What you need is the data like this that we now supply with our ASNU Injectors, we have the data at 3, 4 & 5 bar settings.

What you need to decide is where you make the settings, for example, look at the 12v data, you will see that the delivery at 1.4mS is minimal, increasing at 1.5mS and then getting a full belt @ 1.6mS, now do you set your parameters as the injector is opening, part open or fully open?

1.4 0.15
1.5 0.73
1.6 2.75

You also need to be sure what the linear range is for the injectors at the pressures you are planning to use.

[slows10]

Ansuphil, Where do we/I go for injector pricing and available sizes and styles information?

[JOHNBOY]

Thanks guys. Your confirmed what I thought. Strike one on the the Magnafuel tech guy LOL. I have no plans of running fuel base that low. Injector Dynamics provides wonderful data for there product at 58 psi. That is what I intend to use. I know I could simply ask them to help if I really wanted to change the pressure base. I really see no need to change the base pressure/ Things said by the tech at Magnafuel got me thinking and I figured this was the best place to get some answers.

[PRAY]

This is great stuff. So for us non smart guys trying to become better than your average tuner, is there a link to adjusting all the injector tables and what they do? Also, everyone keeps saying to get the data on the injector from who ever you get it from. How does that data translate to adjustments in the injector tables in EFI live? Sorry for the "beginner" questions in such an advanced thread but I am just trying to learn. Point me to a tutorial or thread and I will gladly read away. Thanks.

[Redline Motorsports]

Pressure will have a noticeable impact upon injector offset as well as linear flow rate. The short pulse phenomena are the question here. If this were a Ford, we'd be looking at applying a similar Bernoulli correction to the low slope as we did to the high slope for the change in pressure. Since GM uses a time adjustment to correct for short pulse errors, this requires a bunch more math and interpolation _or_ a whole new set of characterization tests at the new pressure. The latter would be my preferred method.

Well stated....

[eficalibrator]

Time for another lesson, gents. Today, we learn about how some fluids change properties with aging. Particularly, the injector test fluid provided with some stands. I ran a test to back up some of my original data and got some interesting results. I grabbed the very first set of injectors that I tested on the stand, a set of STOCK LS3 Bosch ev14 units, all of which matched very well on the first test. I ran them again under the same conditions (13.4v, 400kPa) and got different results:
14012
Moral of the story? The provided fluid has a limited pot life in the test stand and changes with age and usage. How rapidly does it change? I'm not sure, but I don't like ANY change here since it makes scientific comparison very difficult when I can't reproduce the baseline test. I have a few more things to check, but the next step will likely be to drain the test stand and refill with a known test fluid. Next up, an actual batch of N-Heptane, which is what we probably should have been using from the start on this bench... Good thing test grade N-Heptane is only ~$200/gal. :wallbash:

[ASNUPHIL]

Greg,
well done for pointing this out, so many people do not think about the fluid and the changes in it's make up that occur when you are flowing injectors straight from an engine, the fuel will contaminate the testing fluid, by how much and how soon depends on the amount of use the system gets and it's especially important if you are carrying out OE comparison testing.
Of course, in the factory the injectors are new and their is no contamination of the test fluid, but where the testing guys like yourself are doing, it's very difficult to ensure all the gasoline has been removed from the injectors unless you ultrasonically clean them prior to testing, which would be my recommendation.
As you rightly pointed out, Heptane is expensive, so using the ASNU Flow Rite is a cheaper option, but as you have said, experience now shows you that you will now need to clean the system and replace the fluid and ensure all the injectors are as good ASNU before testing them.
For those doing non oe comparison testing, like normal injector testing and servicing, the fluid is ok as your main aim is to ensure all the injectors are performing the same.

A very valid comment and one that everyone carrying out oe comparison testing or characterisation of injectors must take into consideration and ensure they maintain correct fluid specifications.

Phil.

[joecar]

Hi Greg,

Your pic shows the mass flow has changed (does that indicate the density of your test fluid has changed with age (why did it change...?)...?), but what about the volume flow...?

[eficalibrator]

Good question, Joe. I actually took volumetric measurements in the burettes. Mass flow was calculated from volume, so what you see is a change in volumetric flow, which was converted to mass flow. I did not weigh the fluid directly, so I'm not honestly sure how much the specific gravity has changed over time. All I really know is "the fluid has changed with age".