Forrest Nearing

guess maybe I've been overspinning this turbo...

the other day I took the AFC spring out of my pump to try to cover up what seems like a lean stumble at 2000+ in 2nd or 2300+ in 3rd if I lay into it at a zero load condition...

seems to have helped a little in 3rd...

helped show off the new stacks at the local get together (LOTS of smoke on demand at any time)

hurts acceleration if I floor it at too low an RPM, but I really didn't do that before

an odd byproduct is that I was seeing 45psi on the boost gauge... I had it set at 40 before.

so I played w/ the boost elbow. I got tired and gave up last night... the way I left it was if I rolled into the throttle slowly, I would see about 36psi max boost. If I floored it and let some smoke chug out, I would see ~39psi max boost.

EGT's seem to climb at about the same speed either way. if anything, they might be climbing slower now than they were before I removed the spring and I was running 40psi? maybe the new stacks dropped EGT's ever so slightly?

anyhow, just thought it was interesting.

Forrest

welder27

If the exhaust is bigger than the stock exhaust your EGT's will drop and your boost will go up. Reasoning is, the faster you get your exhaust away from the engine, the lower the EGT's will be because that hot gas is escaping and doesn't have time to heat things up. Because the exhaust is escaping faster, it's moving through the turbo faster, thus spinning it faster = more boost. The more boost pressure, the better. As long as your EGT's don't go above 1200* F you're ok. And you say you can make smoke anytime you want...that means you're getting enough fuel into the cylinders. Do you have a big air filter kit on it too? If not, that should be your next investment. You said there was a lot of lag in acceleration when you punch it...could be a lack of airflow.

Forrest Nearing

I went from 5" straight pipe to 5" stacks...

I peg my 1600* pyro on a daily basis

I believe the additional lag in acceleration is from dumping TONS of fuel at low RPM/zero boost... I've got a flat fuel plate and no AFC spring... IE, full fuel any time I floor the pedal