I am running MS1 v3 with wickedesi's board mods and the fairchild alternatives to the vb921. My buddy John (aka J. panther) has been running MS on his boosted mx3 for a while now and is very confident in his tuning skills. We took the car out to do some street tuning. I have the wastegate set to 10 psi. After about 3 hours of driving around my car finally feels like a factory turbo car.... If not better! I wanted to be on the safe side so we stuck with low 11 AFRs and about 19 timing @ WOT. The car moves out for being on 10 psi! I was very impressed and pleased with the tune. I drove about 2 days on this tune (full and p[art throttle). Well I hop in my car to go to work today and all is well.... car still pulls like a train. I go through my work day and start heading home.... I decided to do a boost pull on my street and the car started breaking up as soon as I hit 10 psi.... I took a look @ the wideband and wot was lean (15.7 afr). I had this same issue happen to me once before and It was the open loop settings. My overboost protection is around 17 psi. NOTHING HAS CHANGED SINCE THE TUNE! I havent hooked my laptop back up to the MS since my boy tuned it. BTW the car is full built w/ a gt3076r. LMK what you guys think.... I will post up a my MSQ if one of you guys would like to look @ it. Thanks in advance

Are you using the wideband correction or autotune as you drive? Target VE's off? I would turn off the correction once you have a nice tune and retune when needed -if not doing it already.

Close to maxing injectors or fuel pump?

I'm just throwing out anything that could cause the condition.

Originally posted by wickedtalon
Are you using the wideband correction or autotune as you drive? Target VE's off? I would turn off the correction once you have a nice tune and retune when needed -if not doing it already. Close to maxing injectors or fuel pump? I'm just throwing out anything that could cause the condition.

Autotune is disabled, Wideband correction is off. It should be running off the map only with no correction factors. The injectors are 850cc injectors and they were @ 50%. Walbro 255lph rewired, aeromotive 1:1 and fuel pressure set to 42 psi @ idle.

Gotta think about common turbo problems also. Might want to check for a possible boost leak.

Originally posted by bullettdsm
Gotta think about common turbo problems also. Might want to check for a possible boost leak.

No boost leaks! We started from scratch again. We re tuned it for 19psi falling off to 17...... HOOOOOLLLLYYYY CRAP! I did manage to destroy something in the bell housing/tranny. Once again the project is put on hold until I fix these issues.

A little late, but I am also using the Fairchild ignition transistors (with MS2E). I was scared because they are not current limited, so I started with a low maximum dwell (2.2 ms). That was fine up to 6 psi, but would start to break up at 10 psi. The wideband would jump from 11.X to 15-16.X. I increased the dwell to 3, 3.5, 4, and 4.5 ms until it was completely gone at 15 psi on a GT3071.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire