Heads up for FAST 90/90 owners.

[ArKay99]

As some of you know I have been going through a lot of trial and tribulation with my setup since I put my car away for the winter about 9 months ago. Prior to that I installed a ported FAST90/NW90 in addition to rephasing my cam andhaving the heads milled to -.030". I had previously had an LS6 and ported 75mm tb on the car. It ran ok before I put it away, but upon taking it down it ran awful, wouldn't idle, would stall, etc. I had lot's of problems and tried as many fixes.
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I had stopped scratching my head and asked for ideas on this forum. ONe of the suggestions was to put it back to SD and re-scan due to the possibility of the MAF masking some issue. I did that and retuned my VE table, to a point. Yesterday I booked time on a Mustang dyno so I could do real world loading on the car and drove it on the dyno to set up my VE table without worrying about the LEO's coming down on me. I found that my VE table was still out of cal quite a bit and got it tuned in with 2 runs to fill the tables. It toolk about 1 hour of driving and tuning to do this. Then I plugged the MAF back in and re-tuned that to the VE table. That took about 15 minutes. Then I did a bonzai WOT throttle run from 1000 to red-line in 4th for PE. That got my AFR nailed in.
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The long story short, the car is amazing. It runs BETTER than stock. It idles with just a hint of lope, doesn't stall at all, has great throttle response, and is awesome at WOT. LTFT'd are withink 0 to -2% for now, more driving needed, but all I can say is I like my car again. I'm even taking the wife for a drive later today. The hell with the gas prices. I'm making ~30mpg with 4.10's :rockon: .
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This is just a thank you to the guys on the forum that helped with all the suggestions and ideas. Also, it's validation for the REQUIREMENT to have a solid VE table as the basis for your tune. What happened was I didn't redo the VE table after the FAST 90/90, and assumed the change would be linear and therefore could be compensated for with RAF adjustment. WRONG!
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I'm still very new to this, but I learned an awful lot by having gone through this last tuning experience, probably more than I should have, but that is the bonus from having a tool like EFILive.
Thanks again EFILive and the forum.

[heavyfoot]

Thanks for the update. May I ask how you achieved ~30mpg with 4.10's. I'm only seeing about 20 mpg.

[TAQuickness]

and may I ask how you finally got your 90 to seal up?

[ArKay99]

Thanks for the update. May I ask how you achieved ~30mpg with 4.10's. I'm only seeing about 20 mpg.
Instantaneous, flat level road, 55mph in 6th gear, reads ~28-30mph. Not an average or anything. Also, 11.3:1 compression with a .034" quench height helps, as do headers, vararam, etc. Average varies from around town = 11-14mpg, to highway ~22mpg.

[ArKay99]

and may I ask how you finally got your 90 to seal up?
Torque. I removed the gasket I made with the RTV and bought the rope gasket that FAST makes. I also used a set of FAST intake gaskets. They are a bit thicker. Then I used the GM tightening sequence, but went past the 106 in/lbs to 16ft/bls. I got it on tight. Not tight like the bolts won't move any more, but tight like 2-3 turns past the 106 in/bls.
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When I purchased the intake I had Tony Mamo port it for me. When he sent it back he said to torque it that way. I voiced my concern about cracking it, but he assured me it could take much more than that.
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I think it was always sealing, but the strange way the car idled and transitioned made me think it was leaking.

[frodo84]

So, you don't think the FAST gaskets were really necessary? I was going to use new LS6 intake gaskets with my ported 90 and LS2 ported TB. I'm going to start with my 28 lb injectors when I do the H/C job, just to make it easier to dial in, then go to 30 lb SVOs. I also am very new to this, and am trying to read as much as possible. I want to use the auto tune functionality so I will be putting in an LC-1...have you tried that?

[Redline Motorsports]

Nice job and thanks for the story! Once again starting with the basics pays off. I am learning with this tuning stuff that too much thinking can ruin the tune! During my quest to learn tuning I have read and disected so much stuff that it had drove me nuts. After slowing down the thought process it all started to make sense.

Again the VE is the foundation of it all and needs to be as close as it can get. Keep us posted on how the car continues to act!:cheers:

Howard

[TAQuickness]

Torque. I removed the gasket I made with the RTV and bought the rope gasket that FAST makes. I also used a set of FAST intake gaskets. They are a bit thicker. Then I used the GM tightening sequence, but went past the 106 in/lbs to 16ft/bls. I got it on tight. Not tight like the bolts won't move any more, but tight like 2-3 turns past the 106 in/bls.
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When I purchased the intake I had Tony Mamo port it for me. When he sent it back he said to torque it that way. I voiced my concern about cracking it, but he assured me it could take much more than that.
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I think it was always sealing, but the strange way the car idled and transitioned made me think it was leaking.

How many passes did you make on it?

[ArKay99]

How many passes did you make on it?
I made 4, then checked it once more, then I tweaked it a few days later. I guess the gaskets compacted. I know you've been going through a lot to get yours to seal. As you know I didn't use their orange O-ring at the throttle body either, I made one from RTV and cranked that down too. So far so good.

[ArKay99]

So, you don't think the FAST gaskets were really necessary? I was going to use new LS6 intake gaskets with my ported 90 and LS2 ported TB. I'm going to start with my 28 lb injectors when I do the H/C job, just to make it easier to dial in, then go to 30 lb SVOs. I also am very new to this, and am trying to read as much as possible. I want to use the auto tune functionality so I will be putting in an LC-1...have you tried that?
I don't know about necessary, as a matter of fact a friend of mine has one on his car and used his old LS6 gaskets and has no problems. I liked the FAST gaskets for my app because I thought I had a sealing issue and used those because they are a little thicker and therefore would give me more room for error.
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I don't see how starting with 28lb injectors, then switching to 30lb injectors would make it easier to dial in. I went with my old 28lb setup and when I did my h/c I put the 30lb injectors in and calculated the table from the flow rate then put the tune in.
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Autotune rocks. I had my VE dialed in with two passes of 'driving around' on the dyno. Then one pass for the MAF, then PE. I used BEN tables for the VE and MAF, then did a WOT for PE using a map I made for RPM vs, AFR. Then I figured the percentage difference for the AFR from wht I measured to 13.2:1, dialed that in, did another PE run and verified it. All I need to do now is tweak my idle transition, and get my spark a bit smoother.
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I use a PLX , a very nice unit with pre-built PID's.

[ArKay99]

Nice job and thanks for the story! Once again starting with the basics pays off. I am learning with this tuning stuff that too much thinking can ruin the tune! During my quest to learn tuning I have read and disected so much stuff that it had drove me nuts. After slowing down the thought process it all started to make sense.

Again the VE is the foundation of it all and needs to be as close as it can get. Keep us posted on how the car continues to act!:cheers:

Howard
I sure will. I'll probably come back here shortly asking how to fix something I noodled up. A little knowledge can be dangerous ;) , but I move slowly, one param at a time.

[joecar]

...it's validation for the REQUIREMENT to have a solid VE table as the basis for your tune...
:cheers::cheers::cheers::cheers:

[frodo84]

Originally posted by Arkay99 "I don't see how starting with 28lb injectors, then switching to 30lb injectors would make it easier to dial in. I went with my old 28lb setup and when I did my h/c I put the 30lb injectors in and calculated the table from the flow rate then put the tune in."

I guess I thought it would be one less thing to do when initially firing up the motor with new heads/cam, intake and ported tb, larger MAF, etc. Maybe not, that's what I'm doing here, trying to learn. Thanks for your help!

[ArKay99]

I guess I thought it would be one less thing to do when initially firing up the motor with new heads/cam, intake and ported tb, larger MAF, etc. Maybe not, that's what I'm doing here, trying to learn. Thanks for your help!
I don't know how much help I am, I mostly echo what I've learned from those before me and a little of my experience. I don't know if you know the formula for scaleing injectors, so at the risk of being redundant here is the formula I use.


From RC Engineering:
__________________
\ / New Fuel Pressure
\ / -------------------- X Injector Flow Rate
\/ Old Fuel Pressure

In order for this formula to work you have to know what fuel pressures are involved. There has been some controversy as to what fuel pressure Ford uses to flow the SVO's. Some have used 43.5psi, and some have used 39psi.
I used 43.5psi for mine and it worked out fine, i.e. no weird VE table numbers to make up for inaccurate IFR values. At least once I figured out what I was doing with my 'SD' tune.

So I set my table like this:
My injectors came with a flow sheet and the middle value was 30.597lbs/hr.
I assumed 43.5psi for my old pressure and 58psi for my new pressure and plugged the values in.

So I got: sqrt(58/43.5) * 30.597 = 35.330372....lb/hr
When I convert that to kPa and grams/sec to fill in the table I get:
sqrt(420/315) * (30.597 * 0.125997881) = 4.4515520... grams/sec
the (0.125997881) is a factor to convert lbs/hr to grams/sec.
the value 4.4515520 goes into the 0 cell in the IFR table.
Then for 5kPa in the table which is 5kPa VACUUM I add 5kPa to the 420kPa value for: sqrt(425/315) * (30.597 * 0.125997881) = 4.477970....
and I fill the table with each result of incrementing the 420 and adding the next kPa value to it until it's filled. That will be your flow values. I tried it with the stock values and they were very very close. Although air pressure is standard atmosphere = 101325 Pa = 101.325 kPa I used 105kPa as 1 atmosphere because that's how the table is laid out and used 4bar as the multiplier for 58psi and 3 bar for 43.5psi.

[joecar]

That's the correct calculation :cheers:, what you did can be expressed as (for unreferenced regulators):

flowrate = R0 * sqrt((FP + BARO - MAP)/P0) = R0 * sqrt((FP + VAC)/P0)

where:
FP = fuel pressure measured at rail
P0 = injector's rated pressure
R0 = injector's rated flowrate

i.e. the pressure term is the absolute pressure difference across the injector;
(during flow testing/rating, the injector has BARO on each end,
so the pressure difference is (P0 + BARO) - (BARO) = P0).


This is what the spreadsheet calculates.

[ArKay99]

That's the correct calculation :cheers:, what you did can be expressed as (for unreferenced regulators):

flowrate = R0 * sqrt((FP + BARO - MAP)/P0) = R0 * sqrt((FP + VAC)/P0)

where:
FP = fuel pressure measured at rail
P0 = injector's rated pressure
R0 = injector's rated flowrate

i.e. the pressure term is the absolute pressure difference across the injector;
(during flow testing/rating, the injector has BARO on each end,
so the pressure difference is (P0 + BARO) - (BARO) = P0).


This is what the spreadsheet calculates.

OMG, there IS a spreadsheet on the conversions tab. I could have put that into the spreadsheet, created a new one, and been lazy and had EFILive do it for me. :master: The good thing is, it wasn't all that hard. Like I said, even though I've been using EFILive for a while, I'm still a noob in lots of places.
Thanks for the tip.:rockon:

[joecar]

This is the link to the spreadsheet on RHS's tuning website: http://www.allmod.net/hpt/injectors.xls

Edit: the spreadsheet is good, but now that you've done it manually ("handraulically"), you've learnt valuable knowledge. :cheers:

[TAQuickness]

This is the link to the spreadsheet on RHS's tuning website: http://www.allmod.net/hpt/injectors.xls

Edit: the spreadsheet is good, but now that you've done it manually ("handraulically"), you've learnt valuable knowledge. :cheers:


:D:D I like that