[Boosten ya]

Originally Posted by Ryridesmotox

That build looks sic dude. I have the same injector issues as you do since the cobalt ss uses a 2.0 DI motor. I'm not sure how your HPFP works but ours is a cam driven unit. We currently have 2 options, a new set of cams with a different fuel pump gear to turn the pump faster, or a 5th injector in the intake manifold. Our EVAP system uses a port right in the middle of the intake mani directly behind the throttle body. Its perfect for putting a 60lb injector in. For me, it would allow me to run straight E85 instead of having to mix it. I'm not sure how your car responds to E85 but mine will demand about 2300psi of rail pressure from 3000-6000rpm (on my e85/91 mix tune) and the car will only be able to provide about 1000psi rail pressure or less until like 4500rpm. I can't get enough fuel in the cylinders. Having the extra injector would allow me to get enough fuel in there based on boost levels. Just cruising around, I would run on the DI only, then if I needed the extra go juice, the 5th injector would get me there. There are a bunch of cobalt guys trying to do a dyno day this summer, I'll let you know when it is so you can get a run on the rollers, I think they are talking like $50 for 3 pulls on it but I don't have all the details as of yet.



I'm not sure what tuning software he is using (I'm sure he said earlier in the thread) but most will show peak airflow numbers, That is what I usually use as the guess for peak power at a given RPM. When I tune for my E85/91 mix tune it I get ALOT of airflow from like 3000-5000 RPM, my torque band looks like an LS block V8.

Sweet yeah let me know man.

Yes we have a HPFP that is driven by the exhaust cam. Our release valve opens at around 1950psi, ptp has a RV that holds to just under 2150psi. We have fuel pump internals that get us to 2k psi no problem but thats it.

I wonder if a new exhaust cam with bigger HPFP lobes would work for us.