What are you guys using for an IFR value with 42lb injectors??? I cant seem to get a straight answer in the PCM forum. Ive heard to use a single value for the whole table because when the vacuum is hooked up to the regulator it will "lean" the cruising around fuel down some vs your base pressure setting with the vacuum line off.

A little info about my car:

Im using a custom fuel system with sumped tank, aeromotive rails off a Mustang, and 13101 regulator. Im using this setup with a 5115 NOS dry kit for a Mustang that uses vacuum spiker to bump the fuel pressure up at the regulator on the vacuum port. Right now I am using a scared IFR table. My car is going pig rich as RPMS increase because I think im actually seeing that the injector is opening more as RPM increases based on the scared table. If I can eliminate the scaled table for one more constant and I can start to adjust fueling and have a more accurate A/F graph instead of going richer as RPMS increase. I know that right now im spraying through my MAF and it also will add fuel based on load.....I wil be moving the dry nozzle behind the maf and adjust my timing table accordingly because I will be getting fuel from a manual source off the nitrous kit itself with the spike of the regulator.

Any help is appreciated....I know once I get these last 2 things straightened out the car will pick up even more power.

Right now its making 616hp and 790tq with it going 10:1 as soon as the nitrous is activated...It stays that way all the way across...Not sure what its actually seeing with the scaled table either because the wideband graph doesnt read anything below 10:1..hehe

If I can lean it out I feel there is about 50-70 hp left in it...this is all on stock heads and stock shortblock btw. Cam only setup.

Mike

 

Check the specs on the rotary gerder.......AAAAHHHH I'm retarted I'm sorry.

 

if they are ford lime top 42's put the ifr at 5.5 all the way across and set your fuel pressure to 58 key on and pump priming.. engine off.

i dont know what this 'vaccum spiker' will do to your tune but off the gas should be close.

 

Thanks for the answer!!! First person to give an honest answer...

I have edit so I should make the whole table read that value then right?

Mike

 

WTF? dont make me kick you in your *** cheeks lol

Mike

 

how much does the fuel spiker raise the fp?
most ls1 cars boost regulators raise fp 1psi per psi of boost

 

5.5 is a little low IMO. I've still got some work to do on my offsets, but 5.9 w/ a base pressure of 4BAR (58psi) has my trims hovering around zero except at idle (about +5%, needs a little more injector on time).

Starting mid 5 range had me off the scale rich after starting w/ a dead nuts setup from the 8.1 marine injectors.

Just my .02 from getting the truck back up and running

 

5.5 is safe.. maybe -7% or so l trims.. wont hurt the tune a bit.

i ran 5.5 per cablebandit on a 1/1 regulator with svo lime green tops.. if you dont have those then i dont wanna guess.. maybe you have these ones matt is speaking of and they require a diff flow.. but yes it should be the same number if your regulator rises 1/1

 

Same ones i got, lightning injectors.

-7% is all good and fine, but when the trims zero in PE you get that 7% fuel back. If you trim the PE to get where you want to, it's about 7% leaner than you expect. If something happens fuel flow wise, voltage, etc and your trims manage to go back to zero or positive, now your PE airfuel is a magical 7% lean.

I like zero or slightly positive fuel trims simply because I know what the PE airfuel is gonna do then.

Just my preference.

 

my *** is about healed.That "new skin" rocks.

 

Yes it does...

Harlan and MM, yes they are the Lightning green tops...

Ill look into what you are working with Matt and I am assuming that im chaning the whole table to the one number you are mentioning...thats the only thing i dont guess has really been verified yet. Yes the reg...is 1:1

Mike

 

ive been wanting to know that to as i have a boost ref reg, but have the vac port unhooked cause i havent spent time to figured it out

i have HPT is this what i modify, those values are near 5.5 or 5.9? is that ls1edit units?

 

My understanding is that you will need to check those values you have by converting your number to G/sec....I think that is what Edit uses as the input vlue for that table. Looking at a table Edit uses Vacuum and Voltage to input in the IFR table. Not sure how to convert that to HPT stuff...Someone can chime in im sure.

Mike

 

ok that helps just convert lbs/hr to g/s
yup have close to the same values now.

 

What was your formula you used to do that..Post it up if you dont mind...its something i need to save for sure.

Mike

 

its in the conversion cal that HPT has
1 lb/hr = .13 g/s
1 g/s = 7.94 lbs/hr

 

Preciate that homie!!!!

 

V6 bird, we are running 42 green tops in ATVRacers car currently as well. I wil check out what we are running for an injector constant on his, although it is a stock returnless setup the ) kpa load cell should be equivalent to what you need

 

right around 6.0 looks like

 

Yep after fiddling around with some math numbers the other day it looks right about there is what im looking at as well... A little more then what Harlan suggested and not quite 6.1 seems to be what will be best on the money.