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nitrorocket
August 21st, 2006, 03:27 AM
Some people have asked questions on how I have tuned my twin turbo 1000 hp stock cubed LS1with 96 lb. Injectors to run and idle on ONLY 93 octane.
I was completely new to LS1's and tuning with EFILIVE. I asked some pretty simple questions when I first started and had lot of difficulty first eliminating ALL torque management. Luckely I did not get banned for trying this on my own. I have now been answering PM's and emails on a regualr basis, so I thought I would share some info on commonly asked questions.

I am by no means an expert, but here is some ifo that might help you out.:D

Well, my setup is this:

Base fuel pressure is set at 45 psi and being that I have a streetcar, I wanted to have low fuel pressure to not overwork the pump. This has also greatly improved the overall flow rating of the pump by running such a "low" fuel pressure. I am over 800 rwhp with no fuel delivery problems.

I also do not use the boost reference on the fuel pressure regulator. A couple reasons for this is the ease of tuning, there are less fluctuations and inconsistencies in the tune with just a set static pressure. Also, again, being a streetcar with extreme amounts of boost, I do not want a mishap. I left the boost reference line off because if it were to ever fall off or fail under boost, fuel pressure would drop about 5 psi and the motor would BLOW UP! If the reference is connected, it taxes the pump harder, which lowers overall fuel delivery and heats up the fuel more then necessary. I did not need more flow from a 96lb injector anyway!

As far as the boost reference goes for idle, it makes NO difference. Idle AFR was almost not affected at all by the 5 psi decrease in fuel pressure.

There are 3 key things that affect idle tuning as far as getting consistent lean idle AFR.

IFR table can be tweaked (lowered) in the high vacuum ranges to trick the pcm into thinking the injectors are larger then they really are thus lowering PCM commanded pulse width at idle. This can be done at certain KPA(vacuum) levels that you need a smaller and faster pulse width.

SMALL PULSE ADJUST table can have “–“ numbers put in to actually subtract pulse width under the pcm commanded pulse width. This works well, up to about -.3 to -.4 where the injectors seem to not pulse at all and the car will want to die.

PULSE WIDTH VOLTAGE COMPENSATION table can be adjusted to not command as much additional pulse width by lessening the numbers in certain KPA(vacuum) levels that you need a smaller and faster pulse width.

Some of these mods can affect other parts of your tune INITALLY but can be corrected after data logging to see final changes. It took me a small combination of all these “tricks” to get the car idling correctly. These tricks also allowed me to have lean AFR on throttle deceleration where it normally wants to run rich due to the motor still spinning fast while the throttle blade is closed creating a really high vacuum pulling fuel from the injectors.

For boost tuning with the 3 bar,You simply set the 105 KPA on both the MAIN VE and the BOOST VE tables to match, from there you scale the boost ve table to about 50% richer(or whatever you feel comfortable with) to the last column. This will be way off but that doesn’t matter, you need a log first anyway.
Make a run into a small amount of boost while LOGGING and see how much richer the table is from 105 kpa on up. If it is getting richer by say 5% in each progressing column over what you want the AFR to be, then calculate the amount you need to lower the very last column and rescale the entire map from side to side and then top to bottom so the AFR does not progressively keep getting any richer or leaner. If you concentrate on making the map so the AFR is consistant, tuning will be easy. All you then do is richen or lean the entire map till you have the AFR you want, the whole chart will at least be consistant. This can be time consuming, but focus on this first a little at a time.


All this assumes you already somewhat know your way around the software pretty well. I hope this helps someone with a similar setup!
:)

foff667
August 21st, 2006, 04:29 AM
:cheers: its amazing how far you came in as little time as you did surpassing many in knowledge to be blunt. Also more amazing is you've again showed even JUST using the stock hardware can more then get the job done almost every time.

joecar
August 21st, 2006, 04:58 AM
Nitro, you have done well, good job, mate. :cheers:

redhardsupra
August 21st, 2006, 05:32 AM
good info, good job!

what kind of injectors are they?
care to post your final tune, to see how the settings worked out for you?

Tordne
August 21st, 2006, 05:36 AM
Nice one mate!

Would have been a whole lot easier to just click the 1000HP Tune button in the EFILive Easter Eggs - thats how I'm trying to get my power :muahaha:

nitrorocket
August 21st, 2006, 05:36 AM
I am using Delphi injectors. I have a few things to button up. I have been screwing aroung between open and closed loop to try to get perfect driveability. When I am finished and the new tune is complete, I will post it.

nitrorocket
August 21st, 2006, 05:37 AM
I never saw the 1000 hp tune button? Dang! I did all this for absolutly nothing?

Tordne
August 21st, 2006, 06:26 AM
I'm afraid so - but it is all experience :)

BTW, I'm still fighting my injectors. I think I have this magical spot around 1.8ms pulse width where below that they just don't work :frown: DFCO will be my only hope me thinks.

nitrorocket
August 21st, 2006, 06:50 AM
What injectors are you running?

Tordne
August 21st, 2006, 07:01 AM
SVO 42's (Green Tops). But I have a stock bottom end. I think I had a blocked stock injector and had these sitting there so thought I may as well give them a go. Surprised I can't get below a ~ 1.7ms pulse width, but that seems to be the magic number.

1998ws6
August 21st, 2006, 09:00 AM
How do you acount for the injectors getting smaller under boost? Or does the EFI live custom OS acount for this in the IFR table? Or do you just tell the pcm that it has more airflow than reality, and acheive the additional fueling in that manner?

Either way, 1000hp on a stock pcm hardware is an impressive feat.
:)

nitrorocket
August 21st, 2006, 10:38 AM
Tdorne... have you tried subtracting .2 from the small pulse adjust from a 1.70 commanded and below? This WILL knock the pulse width down to 1.50. when the pcm is commanding 1.70 or below.




If a boost reference regulator is not used you must scale the IFR table proportionatly to compensate, not just put in a standard value all the way down. That is how the pcm knows to add or subtract more fuel based on manifold pressure.

TAQuickness
August 21st, 2006, 10:56 AM
I've been working on a similar issues with the SVO 42's. Seem like at 1.7 or less IPW, they just quit flowing.

You can see it in the logs, as things get real lean real fast like. I redid my minimum pulse so I get no smaller than 1.8 and that seems to work well.

nitrorocket
August 21st, 2006, 11:02 AM
What fuel pressure are you running? You should not be rich with that injector if I am getting a 96 to idle lean??? Have you played with the IFR??

Tordne
August 21st, 2006, 11:06 AM
I'm waiting on my fuel pressure sender to arrive as we speak. But I'm guessing around the stock 58psi range.

TAQuickness
August 21st, 2006, 11:17 AM
What fuel pressure are you running? You should not be rich with that injector if I am getting a 96 to idle lean??? Have you played with the IFR??


Have I played with it??? I've beat it up against the wall :D

I have 63 psi at idle, drops to 53 under WOT. This condition usually occurs under light decel (not enough to engage DFCO) with 63 psi fuel pressure.

Tordne's car is stock in the fuel department (other than the injectors) and demonstrates identicle behavior.

Seems the 1.8 pulse is a tad too much and cause's a slightly rich condition - BEN's around .94 and at 1.7, it goes very lean, BEN's in the 1.20's. makes me think the SVO's don't support a small pulse width very well.

nitrorocket
August 21st, 2006, 12:05 PM
What is the cobra fuel pressure??

TAQuickness
August 21st, 2006, 01:51 PM
What is the cobra fuel pressure??

Not sure. Good question though (KISS) ;)

I scaled the injectors using 43.5 as rated. BEN's didn't change afterwards

Delco
August 21st, 2006, 02:38 PM
The SVO pintle injector has no where near the low end control the delphi plate injectro has , you can get big plate injectors down to about 1ms without to many issues , getting a pintle injector below 2ms is a headache.

We stopped using the Ford SVO injectors about 2 years ago due to these issues.

Tordne
August 21st, 2006, 02:42 PM
Where do you get your Delphi injectors from Delco?

TAQuickness
August 21st, 2006, 02:44 PM
The SVO pintle injector has no where near the low end control the delphi plate injectro has , you can get big plate injectors down to about 1ms without to many issues , getting a pintle injector below 2ms is a headache.

We stopped using the Ford SVO injectors about 2 years ago due to these issues.


Would this be a similar style injector as the racetronix 32's?

Delco
August 21st, 2006, 04:40 PM
Would this be a similar style injector as the racetronix 32's?

Yes , the 32lb , 62lb and 95lb are all plate injectors , racetronix are a good source and priced competitively

TAQuickness
August 21st, 2006, 11:07 PM
Dunno. I can honestly say the Racetronix is not a bad injector, but I would be hard pressed to put another plate-type injector back into my bird. Low end drivabiltiy, or streetability, was markedly improved when I swapped from plate to pintle.

Not doubting the plate's ability to control low pulse width's. But I do feel like pintle has the advantage for my application.

nitrorocket
August 22nd, 2006, 12:30 AM
If you scae the injectors to 43.5 you should correct your fuel pressure to 43.5. You will definetely need some retuning, but you need to run them as they are intended if you want them to idle correctly. Or, look on the Vette forums for some used z06 injectors from a 427 zo6. Thos are like 33 arent they?? You are N/A??

TAQuickness
August 22nd, 2006, 03:07 AM
If you scae the injectors to 43.5 you should correct your fuel pressure to 43.5. You will definetely need some retuning, but you need to run them as they are intended if you want them to idle correctly. Or, look on the Vette forums for some used z06 injectors from a 427 zo6. Thos are like 33 arent they?? You are N/A??

Per the spread sheet, 43.5 psi rated, 42 lb/hr rated, 63 psi actual.

I am NA, but 33's won't cut it. If memory serves, the Racetronix 32's came out to ~36 lb/hr at 58 psi and were ~ 97% DC. The 42's are currently maxing at 67% DC.

I have contemplated using the C6 Z06 42's, given the known injector tables for them, but I'm not sure I want to get into the fuel rail, manifold, & wire harnes issuses associated with the swap.

I think a little further tweaking of the minimum pulse widths may yeild the desired results I'm looking for.

nitrorocket
August 22nd, 2006, 03:22 AM
It is your call, but I would highly recommend lowering your fuel pressure. You are working the pump harder as well as forcing the injector flow more fuel at idle by running 20lbs higher fuel pressure then it is rated for. I bet the idle would clean right up. Just for kicks, lower the fuel pressure to 43.5, reascale the IFR and see what idle does while sitting in the driveway or around the block. If the idle does not get better, load back in the old tune, but at least you will know!

Dirk Diggler
August 22nd, 2006, 03:47 AM
Dunno. I can honestly say the Racetronix is not a bad injector, but I would be hard pressed to put another plate-type injector back into my bird. Low end drivabiltiy, or streetability, was markedly improved when I swapped from plate to pintle.

Not doubting the plate's ability to control low pulse width's. But I do feel like pintle has the advantage for my application.

I also seen the same thing after going form Racetronix 32 to the SVO 42's

TAQuickness
August 22nd, 2006, 03:52 AM
It is your call, but I would highly recommend lowering your fuel pressure. You are working the pump harder as well as forcing the injector flow more fuel at idle by running 20lbs higher fuel pressure then it is rated for. I bet the idle would clean right up. Just for kicks, lower the fuel pressure to 43.5, reascale the IFR and see what idle does while sitting in the driveway or around the block. If the idle does not get better, load back in the old tune, but at least you will know!

I'll have to go back over you original thread on lowering the FP. Sounds like it would be worth a shot.

emarkay
August 22nd, 2006, 04:46 AM
Hmmm, I recall there's a hidden button in the Tuning software for just this sort of thing... ;)

nitrorocket
August 23rd, 2006, 12:24 AM
TAQUICKNESS

I went with an aftermarket Aeromotive regulator and rails due to the high fuel requirments I have when wide open. It would cost you the $150 for rails, $150 for regulator and then some Misc. AN connections. I would look for someone with a good reg mod for the stock regulator first though.

nitrorocket
August 23rd, 2006, 12:26 AM
Pics::

nitrorocket
August 23rd, 2006, 12:43 AM
Pics::

TAQuickness
August 23rd, 2006, 03:47 AM
Nitro - I don't think your pipes are big enough.

Very nice set up there.