So i've been working on tuning my 08 MR for a few days and i got almost everything dialed in exept for the boost spikes that occures when i up shift at WOT.
I currently have my lower bound ignition table at -2* from my actual high octane ignition table and it still will spike 3~ PSI when i shift at WOT, could Mivec have something to do with it?
I can make single gear pulls and the boost stays flat till redline so i know is not WGDC related...
Mods are:
FP Red ported with FP 18psi wastegate
GM 3 port
Ported EX manifold
AMS DP, test pipe
Buschur crossflow catback
ETS FMIC, hot/cold IC pipes
AEM intake
FIC 1100's
walbro 255

 

well, i've tried everything i can think of so i'm goign to put the OEM wastegate on the FP Red and see if that helps.

 

I am having the same problem as you. What makes it worse is that my target boost is 26.8 psi and during SST upshifting, that additional boost spike cause it to exceed 30psi resulting in clutch opening

I'm not inclined to enable the ASC Off, SST Off fix at this point as I prefer to keep it on for safety reasons.

Maybe Bryan can chip in here and offer some advice?

 

i tried the OEM wastegate but i didn't help at all.
i also did a few pulls with the WGDC table flat (40% across) and it still does it.

 

That is interesting. I can hold 26psi flat across 2nd to 5th gear, even in shifts.

What ROM ID? Can you post your lower bound / timing / boost tables?

 

it's a 08 and ROM 52690122

 

personally I would ZERO out the -6.2, -5.4 an -4.6 entries in your TBEC.

It's probably not the problem, but doesn't help the situation...

 

I have +10 in -6.2 reducing to +1 at -0.8

I have no issues with shift boost spikes. Something else is going on here. He is not showing any WGDC correction in the logs.

I have a feeling it's just too little timing but I'd love to see it be something else.

 

yep but you zero out your max upward yeh?

 

I do, but so does he after looking at his rom.

 

Correction intervals? what are they set at?

what Load/Timing are you dropping to on gear changes? Have you logged just rpm timing and load to get the best resolution?
I have been trying to help out someone with this problem a little and all my suggestions have fallen flat on their face, so i am also very interested in a fix

My own tables look similar enough to those and i too have no issues with spiking.
As Bryan said, the timing looks kinda low... I've never looked at boost through the gears until i had everything else tuned so i don't know if this would affect it?

 

Brian helped me with some tweaks that helped.
I originally lowered the timing and richened the fuel because i was afraid of what was happening, not knowing that this on it self would make the problem worse. As of right now, I've increased timing by 3* and have my lower bound timing set 2* lower and I'm "only" spiking ~2 PSI.
To answer you questions, the loan goes up when i up shift. This also doesn't help the problem because you tend to have lower timing values the higher the load is and no, i haven't tried to log just RPM, load and timing but it's very clear that the timing is dropping so I'm just working right now on having less of a drop.

 

oh, correction interval set to 2.
But if your wondering if i'm getting upward correction at the upshift, i'm not.

 

^Cool
what i have tried, is messing with the timing map...

so on the right (higher Load) , the columns with Load you never reach except on upshifts - in those cells i keep the timing more or less the same, or just drop by 1*
(so you get less timing drop at gear change)

obviously you need to log extensively to ensure you never hit those Load cells under normal WOT in ANY gear - as you would want timing to fall with Load under those circumstances, as a general rule.

so the timing map ends up looking a bit weird... but for an SST it seems to work.
not sure if anyone else does this, or versions of it??

 

I'll have to try that