Boost vs. RPM

DIGItonium

This is weird, so bare with me.

Typically I can get about 5 PSI steady at half throttle around 3-4k RPM. It ramps up quick. Then it maxes out around 8-9 PSI steady around 6k RPM at full throttle.

Then there are times I have to flog it and can't get much power as if it is held back. In 2nd, the boost gauge slowly ramps up in sync with the tach to redline, but it doesn't max out at 8-9 PSI. It feels like the ECU is limiting the time to "fully" open the throttle, but limits how wide to open as well. I notice this after a warm start, and it gets a little better after a few minutes. Then there are times the "problem" comes back, and I can't get the car moving even with additional pedal travel.

I did get the brake switch replaced a few months ago, and I was able to get the car to scoot crazy fast in 2nd. Max boost picked up well before 4k RPM instead of ramping up slowly. The < 2k RPM slow pickup or hesitation is coming back. I recently filled it up with non-ethanol fuel, and it seems to improved response and reduced minor roughness at idle.

Just curious since I don't have a datalogger for turbo boost.

[EDIT] Forgot this might have to do with the ECU throttle tables. I'm still running the canned tune from GTM. My car never got dynotuned after the kit was installed. Possibly need updates to the throttle tables.

__________________