SD tune

[catman3126]

I need help changing the stock tune in my LS1 that i put in my Jeep CJ7, I have not found where it is I see that there is Custom OS in the bins on my EFI Live but not sure what to do with it? is there a set of instruction on EFI Live's web site somewhere I have not found yet? thanks

[Taz]

Are you asking how to run the stock tune in SD mode, or how to use a COS ?


Regards,
Taz

[catman3126]

well whichever would be better to run without the maf and make the engine always run in closed loop? by running the stock tune in SD it would all out right? but yeah the stock tune in SD mode would be good what would the advantage be to use a custom OS?

[Taz]

Is the engine NA (Naturally Aspirated) or will it use a power adder of some sort (supercharger / turbocharger / nitrous) ?


Regards,
Taz

[catman3126]

Naturally aspirated and as of now stock engine with no more then a set of headers and a intake. How much power can be gained from.a well tuned SD tune engine?

[Taz]

Naturally aspirated and as of now stock engine with no more then a set of headers and a intake. How much power can be gained from.a well tuned SD tune engine?

With a NA engine there is no power output advantage caused by removing the MAF and running in SD. I prefer to use a MAF sensor whenever possible. The main reasons to run MAFless with an NA engine:

aesthetics - don't "like" the look of the MAF air intake system
engine compartment space - no room to effectively position the MAF
reversion / consistent air flow issues - MAF positioned too close the the TB while using a large cam (lots of overlap or tight lope separation angle)
Regarding tuning the engine after installing a free flowing cold air intake system and free flowing exhaust system ... yes, there will definitely be a power output increase.

How much ? ... depends on the increase (delta) of airflow, and the over all condition of the engine.


Regards,
Taz

[catman3126]

Ok thanks so how do I do the SD tune? Another issue is that I was never able to pickup a speed signal for the ecm and because of that it would never go into closed loop but by unplugging the maf it will run in closed loop, but by plugging the maf it runs in closed loop. So this is the main reason I want to go with SD or should I copy the spark table into all the tables so it is not in the semi limp mode?

[Taz]

At the point where specific information and your tune is necessary.

Are you running DBC or DBW TB ?
MAF - 3 wire Camaro style or 5 wire truck style ?
P/N switch - Camaro style or truck style ?

A VSS signal to the PCM is mandatory if you want to eliminate idle / driveability issues. I take it you are using a cable speedometer - from a sender on the transmission or transfer case ? An in-line pulse generator (that would provide a usable VSS signal) may be purchased for as little as $35.

Post your tune, and component description.


Regards,
Taz

[catman3126]

DBC camaro style and 3 wire. I have one of those inline signal generator and was never able to get it to work, so I talked to Novak conversions and they sent me another one and it didn't work. I talked to advanced adapters and they said that the speedo cable on the output of the jeep t case doesn't spin fast enough to make them work. now whether thats true or not I don't know. They sell a setup that requires the output of the Dana 300 to be changed so that a tone gear can be installed with a sensor on the side of the housing. I will post the tune tonight when I get home tonight. I know that by unhooking the maf it made a world of differents at for how the engine runs. now it seems to run like it should. before it would sometimes run decent and other times it acted like it derated and low on power. I would like to have the speed signal work but pretty much gave up on that. thanks for your help. I will put the tune up tonight.

[Chevy366]

I need help changing the stock tune in my LS1 that i put in my Jeep CJ7, I have not found where it is I see that there is Custom OS in the bins on my EFI Live but not sure what to do with it? is there a set of instruction on EFI Live's web site somewhere I have not found yet? thanks
Look here : http://www.efilive.com/index.php?option=com_content&view=article&id=130&Itemid=134 , AutoVe tutorial has a simple SD tutorial in it .

[slows10]

^^ I agree, I ditched the maf to try SD and used the AutoVe tutorial its easy to use. Since you are doing a transplant in a jeep a SD setup may work well for you.

[catman3126]

Hey thanks I found that this morning, so how do I know which custom OS to pic from the bins?

[slows10]

It depends on the os,what o/s are you running now? There is a tutorial on the efilive site that shows you how to switch to a cos and what cos to use depending on what base o/s you are using.

[catman3126]

ok sounds good I guess it will show how to pick the right one?

[Sid447]

With a NA engine there is no power output advantage caused by removing the MAF and running in SD.
Regards,
Taz

You sure about that? :)

[joecar]

With a NA engine there is no power output advantage caused by removing the MAF and running in SD.
Regards,
Taz

You sure about that? :)There's a long thread on LS1Tech on that very topic, it contains evidence that SD and MAF produce the same HP and TQ.

Sid, I believe you have seen that thread.

:)

[Sid447]

Hi Joecar,

There's loads of threads on other public forums about this very thing as most are aware.
The problem is trying to sort out the reality, a person wouldn't know who to believe, as most claims aren't validated or carried out in an un-biased or correct manner.
Maybe in comparison with the later 85mm maf-sensor things would be different.

Using the older 75mm maf, same dyno and a trusted Australian race engineer with the same car, same tune (we had it set just like the HSV GTS single-spark tunes so we could fit or remove the maf at will).
Nothing, and I mean nothing was adjusted other than the physical removal of the maf-sensor; I was there the whole time and there was just the two of us.
It made a difference, the most pronounced was to throttle response.

It convinced me, especially after comparing drivability on the road. The nicest was when open loop, but run CL for sensibility sake.
I don't want to convince or change anyones' preset ideas of anything.
The response to Taz was of a friendly nature with humour intended; not to ridicule or start a game of verbal badminton.

I run SD because I think it's better and have no urge to change other peoples general opinion; if it's the same, then it's the same! (but different).

[Taz]

Hi Guys,I haven’t had much time for the Forum lately … mad rush here to get things done before the snow arrives … its late this year thank heaven !

No malice ever taken from your comments Sid … much like myself, you appear to sincerely wish to assist others. My primary intent in this thread had been to assist the OP with setting up a VSS input to the PCM, which is necessary to get the most out of any street driven tune. The thread then ran head long into switching to a COS prior to addressing pre-existing issues … at which point I was out.

I have not seen the post Joecar referred to, so my apologies if any of the following are repetitive. My first career was in clinical psychology, and I studied research methods and statistical analysis while in university (a very long time ago !). I retired from this field sometime ago, so I may be a little “rusty” on the absolute application of methods and analyses.

I believe Joecar and Marcin (and I’m sure others) have a background in pure mathematics, and would be able to correct any of my misconceptions.

Data collection and subsequent analysis (in this case a chassis dyno) must be valid and repeatable, and must address extraneous and confounding variables. Accuracy and precision are essential elements for scientific instruments (chassis dyno), and establish the internal validity of the measurements made by the instrument.

Accuracy - how closely an analytical result approximates the intended target.

Precision - how closely multiple results resemble each other.

Precision and reliability are similar, in that they are both indicators of repeatability.

An engine dyno has fewer variables to control, as compared to a chassis dyno. With a chassis dyno controls must be in place for any variable that may affect engine power output and also “rolling resistance”, these could include:

engine oil temperature
engine coolant temperature
intake air temperature
fuel temperature
transmission oil temperature
differential oil temperature
universal joint temperature
axle and / or axle bearing temperature
rear brake drag
tire temperature
After developing controls for all variables, the method of data collection needs to be considered. This may be:

5 dyno runs to warm up components
5 dyno runs with the MAF in place and enabled
5 dyno runs with the MAF in place and disabled (SD mode)
5 dyno runs with the MAF removed and disabled (SD mode)
This would be followed up by reversing the order of the dyno runs (with the exception of the warm up runs). The results would then be analyzed. Types of analysis could include an Analysis of Variance (ANOVA), an Analysis of Covariance (ANCOVA), and / or a Multiple Regression Analysis. These analyses would assist in determining if the difference (variance) was statistically significant (i.e. not due to the affect of extraneous / confounding variables).

If the results of this single case were deemed to be statistically significant, the data collection / analysis methodology would then be repeated employing a representative sample of engines … perhaps 10 (i.e. n=10). The results of this group would then be analyzed. This would then yield the ability to state, with a measure of confidence, that the results were or were not statistically significant.

Most people are familiar with a standard distribution curve (“Bell curve”) …. most often associated with IQ scores … mean of 100 … standard deviation of +/- 15. The tails of the curve (high & low ends) are not considered to be statistically significant. This means the difference between an IQ score of 162 versus 176 may not be statistically significant. The “confidence level” of such endeavours is generally established – often in the 2.5% to 5% range – meaning any difference in observed results that are equal to or less than this value, are not considered to be statistically significant.

In the graph you posted the engine made 335.5 HP with the MAF, and 357.5 HP without. This represents an increase of roughly 6.5%. An increase this small could easily be the result of extraneous and / or confounding variables. But, the curves themselves are most telling. The curves run loosely parallel and in good agreement (no statistically significant difference) until approximately 4000 RPM – where they begin to diverge. This coincides with the point in an OEM based tune where the OS switches from SD mode (VE table) to MAF mode (MAF table).

It is probably that the VE table (SD mode) was a reasonably accurate representation of engine airflow, while the MAF table was not. A rework of the MAF table values would have probably narrowed the observed results.In the end, a test using a single engine without controls in place for extraneous / confounding variables, amounts to anecdotal evidence not scientific evidence, and therefore cannot be relied upon.


Regards,
Taz

[Sid447]

Brilliant Taz,

Love the post! :)

[slows10]

If the air-fuel ratio was optimized during the maf run and it was still down on power to the sd run, you could play with the maf table all day long it would not change the peak power output. A log of the run watching a wideband could confirm it.Not sure how accurate the lamda reading on that sheet really is. Im just assuming that both the maf tune and sd tune were set up correctly. If they were than that data is pretty accurate. The problem is that we probably wont get all the data on the runs or know how the testing was done.

[catman3126]

Ok so where do I find the speed sensor that you have used TAZ? for 35$ I would try another one. also if I'm going to go with a Comp cam would the SD tune be better for that?

[Taz]

The problem with the VSS signal might be in your tune ... which you have yet to post. Do you currently have an in-line VSS generator (sometimes called a pulse generator) connected ? If so, what make / model and how many pulse per mile output (4K, 8K, etc.).

Post the details of your current VSS signal generator, and your tune, and perhaps there may be a no cost fix.


Regards,
Taz

[catman3126]

12336

[catman3126]

there is the tune im running right now i copied the high octane spark table into the low octane table so it has no choice but to use the high octane timing table and it sure made it run better and seems to have gained a decent amount of HP. i have tried all different pulses per revolution and doesnt seem to help maybe you will see something i dont Taz, thanks for helping.

[Taz]

Thanks for posting the tune ... still require the specifics of your VSS pulse generator, to adjust the tune file - after this I will repost your amended tune and applicable instructions to confirm the installation.


Regards,
Taz

[catman3126]

I know that when i spoke with novak he said to set the tune to 40 pulses but now its at 17 because i was trying different things to see if i could get it to work i was never able to get any kind of a reading i wouldn't think it would matter how many pulses it is set to wouldn't it just read wrong but still show a reading?

[Taz]

Neither of those settings will work. Does the pulse generator have threads on either side - such that the speedometer cable essentially passes through it ?

Does it have 2 wires coming from the body - that get connected to the PCM ?

Check any documentation that came with the pulse generator - should be something that states it is designed to produce 4000 pulses per mile (4K), 8000 pulses per mile (8K), etc.

Cable speedometers (in the dash) are usual calibrated for 1000 revolutions per mile - that is, they will provide the correct displayed speed and odometer measurement when the speedometer cable turns at a rate of 1000 revolution for each mile traveled. The number of teeth of the speedometer drive gear in the transmission (or transfer case) and the speedometer driven gear (in the sleeve that is inserted into the transmission) are factory calibrated to produce 1000 cable revolutions per mile.

Any change to gearing or tire size, must be accompanied by changes to the speedometer drive and / or driven gears - to retain speedometer accuracy. As long as your current cable speedometer is reasonably accurate, the VSS can be tuned to a reasonable level of accuracy also.


Regards,
Taz

[catman3126]

yes it is a pass through unit, all novak said was to set it to 40 pulses, and yes has two wires coming out of it. my speedometer is off by about ten miles per hour. reads slower then im going. i see that it is set to 4000, ppm i also see that when i change the pulses per rev it does not change the pulses per mile. i thought it did. maybe thats why its not working because its not jiving. what does the secondary pulses per mile mean? why is it so much higher then the primary?

[catman3126]

one other thing novak said was that to make then engine run right the speed reading didn't need to be right it just needed to see a speed reading to run right. so even if the calibration wasn't perfect it would still help me get the engine running correct with the maf plugged in wouldn't it?

[Taz]

... my speedometer is off by about ten miles per hour. reads slower then im going ...

Cable speedometer calibration is a ratio. If the speedometer reads 40 MPH when the actual vehicle speed is 50 MPH, it will read 80 MPH when the actual vehicle speed is 100 MPH. It will never read a constant 10 MPH slow - unless the speedometer needle in the gauge has been moved or bent.



... to make then engine run right the speed reading didn't need to be right it just needed to see a speed reading ...

No. The VSS signal sent to the PCM should be as accurate as is possible. The VSS input will have an affect on many driveability tune parameters - stationary idle, non-stationary idle, low speed surge / buck, etc.

I must admit, I am a little frustrated with this thread. I have asked several times for the specifics of the VSS generator being used - have never received an answer - only echoes of incorrect tune parameters. The EFILive Forum is dedicated to assisting enthusiasts with tuning challenges. The role of the person posting the question (requesting assistance) is to provide detailed and specific information regarding the issue. The role of the Forum body is to synthesize possible solutions to the issue at hand.

Limited information leads to multiple possible solutions. No information leads to little more than guessing. Pick up the phone, call Novak, and ask.

Attached below are 2 tune files - one set up for a 4K VSS pulse generator, the other for an 8K. Try the 8K tune first (commonly used) - if the logged VSS speed is about half of the actual vehicle speed - then try the 4K tune.

Ensure that the VSS Low signal wire from the the pulse generator is connected to PCM connector C2 (Red) pin 20, and the VSS High signal wire from the pulse generator is connected to C2 pin 21.

I enjoy contributing to the Forum and helping others - you never know who will become a future Chip Foose - but sound advice requires sound information.


Regards,
Taz

[catman3126]

First off Taz I really apprieciate all the help from you and others hear. I appoligize for not getting the information from the generator as I will have to call Novak, i do however remember asking them one time about it and all the guy said was he had a place in cali make them up for them, I will try to call Novak tomorrow and see if I can get some more information about it. all it says on it is "Masstech" and some numbers TR8-2525-2 and a written in pen number of 2090. I will try to upload a photo of it and see if that helps maybe someone has seen one or used one.

I have one question about the tune (not questioning anything you've done just curious and wanting to learn) I'm curious as to the fiinal drive ratio being 1.000 and 2.000 on the tunes.

[catman3126]

1234612347 Here is the generator

[Taz]

No worries ... the older you get, the more time speeds up ! Like many people, I don't have much "leisure" time (that's what the missus calls my Forum participation !) and I like to make the most of it. I opted for early retirement from my previous career field - but that didn't last long. I am currently employed full-time (to maintain augmented health / medical coverage), operate a small automotive business full-time, and also provide consulting services on a per diem basis.



... I'm curious as to the finial drive ratio being 1.000 and 2.000 on the tunes ...

In a vehicle with a cable driven speedometer, the displayed vehicle speed (on the speedometer) has been calibrated for tire diameter and gearing via the ratio of the speedometer drive gear and driven gear - to produce 1000 revolutions per mile traveled. If this same data (tire diameter & gear ratio) are also input into the tune file speedometer segment (Speedo Calculator) - it will affectively recalibrate the initially accurate mechanical calibration - making the VSS input to the PCM grossly inaccurate.

When using a VSS pulse generator with a cable speedometer vehicle, simply adjust H0101 (Pulses per mile) to the pulse output of the VSS generator. How you arrive at 4000 (4K), 8000 (8K), or any other figure is irrelevant - you may set the gear and tire size to any value that will allow you to arrive at the correct pulse per mile calibration for your particular VSS pulse generator.

I elected to configure your tune file such that if your VSS generator produced higher pulses than 8K - you would be able to apply a simple multiple to the gear ratio parameter.

Once you install the VSS pulse generator, let us know if you get it working.


Regards,
Taz