Ive got 50# injectors, a BAP feeding a heafty head and cam, forged low comp 6.1 with twin turbos. I still can't dyno peanuts over what the stock motor did with turbos. 525-560hp 535 tq. Am I at a limit which would require larger fuel lines, rails and even larger injectors to cross? I seem to have read of much higher #s before that is necessary
You're in the ball park for needing fuel line upgrades. I dyno'd in the low 500's on a Mustang dyno when I was running out of fuel volume and that was with aftermarket rails. It sounds like you need a new line from the tank forward along with rails. Contact MOL at Show and Performance, he builds fuel line kits based on whatever you need. Don't forget to look at your injector duty cycles too. My AFR was OK, but my injectors were running static so there was no longer any control to adjust fueling with.
I may be having this same problem...From 4000 to shift my car is pulling about ~8-10 degrees KR...AFR is 12.4...no matter if I add fuel to the table or pull timing i still get ~8-10 KR. Adam/Ralph, what injector size were you running? You think my injectors may be the problem, or is it the stock fuel system capacity? As you know, i'm N/A. My injectors are from a GM super charged GTP V6.
I think I'm still running the SRT4 Stage 1 injector, but to be honest I'd have to check. I've had at least 3 sets of injectors on it and I know I have 2 sets in my spare parts stash.
Kyle if you have fuel issues it will be the injector.....you should have plenty of room on the stock fuel lines and pump N/A.
Okay, good to know...now, how can AFR stay 12.4, shouldn't i see an increase in air volume with RPM and see my AFR going lean if I'm maxing out the injector?
^^ WOW, thanks Ron...i wasn't sure Erik knew what he was talking about, you reassurance put it over the edge for me.
i am still running the srt 4 stage 1 injectors i think that's the set in there right now. definitly agree. all the proof i need right there. hahahahahaha
Yes, they said the 50# were running above 80% duty cycle. I didn't realize that mechanical upgrades, i.e heads, cam were limited bythe same. I was a bit suprized to see dyno #s barely higher with upgraded internals and turbos than what I was getting with turbos only on stock 6.1. seems Iv'e read much higher results with stock fuel sys before. Thanks for the help
Hal, stage II injectors?. I thought the 50# ers supplied with the STS turbo kit were stage IIs. What about fuel line and rail restrictions? Don't forget, I already have a boost-a-pump.
Logging with the Predator go into the Injector control section and choose AVG Pulse Width.......that will log the duty cycle of the injector......anything over 19,000ms and you are out of injector.
The approximate limit of the 5/16" line is about 600rwhp on a boosted app with about a .65 BSFC. To the OP, how much timing have you added to your setup since going low compression? Are you running the same boost? What is your AFR? To the guy with the knock retard... It sounds like false knock. Who built the motor for you? I see false knock in some forged stroker motors a lot. There are a number of reasons why you could be losing injector control. One of which is a static injector. You need to log your injector pulsewidth to know for sure. There are a number of things that could be going on in the tune or PCM that create a static injector condition when the injector is not in fact maxed out. How much total timing are you running when the KR event occur. What is your knock sensor threshold voltage set up at?
