slaserj

Hey all! After my last post regarding the MKTurbo car, I've fixed pretty much every initial issue that car came with. MAP sensor onboard the MS3PRO was reading 20 kpa off at all pressures, so replacing that brought everything back to where it's supposed to be in terms of tuning ability. I've scrapped the old fuel tables, and redone it with the correct pressure reading. Idle works well (still some ironing to do here, but it works), and it runs pretty well.

I had a strange issue today though, when working on a boost issue. Car didn't want to go above 8psi after fixing the MAP sensor. Note, my Boost Control settings did not change. Worked on it a bit yesterday, but no luck. Previously, my open loop boost control table was set to 40 on the topmost row (100%), and 31 on the next row (90%). Today, first run, car was about 175 deg CLT and I didn't log it. Still having the same issue, I set the top TWO rows to 40, and tried again. Car went easily into overboost protection at 190kpa, and freaked me out a bit. I lowered the top 2 rows down to 32, and ran again. Back to maxing at 8psi with full throttle. So, I slowly eased the top two rows up to 38 and 40 respectively in increments of 2, and each run it still maxed at 8-9 PSI with no noticeable changes. What gives? is 1% on this enough to make that much of a difference in boost? Is there something else wrong with my tune that I'm missing? Appreciate any and all help here, and I apologize in advance if I missed something I was supposed to read that is causing issues with this. Cheers all.

Attached are the current tune, and a log from a pull I did. The boost can clearly be seen plateauing.

Panici

How is your MAC valve plumbed?

slaserj

Hey all, fixed my boost issue. Huge thanks to Jumpster74's post here: https://www.miataturbo.net/build-thr...2/#post1624767

Changed the MAC valve frequency, and all is well. Hitting 12psi reliably now, and life is good (for now).