Fluctuating boost levels, 3 BAR.

[Jtrain]

Hey guys,

You know, I'm really starting to enjoy this ride. But I can't seem to be able to solve a small mystery I've got.

When I'm under high load situations in medium boost @ 3-4.5k RPMS (Say you put half peddle after taking a turn and getting up to the speed limit) You can hear everything working right, except for you can physically actually hear HEAR the boost levels going from 10-14PSI with the peddle position in the same place. (I have confirmed this by extrapolating the information from data logging)

It's jerky and doesn't feel healthy. I've talked to my tuner about it and he doesn't seem to think it's related.

Am I running too much boost? Do i need a better wastegate spring or something? I've been screwing with turbo cars for a solid 10 years and can't for the life of me figure out why this thing continues to do this.

If I can fix this, I'd probably buy this lease out. It's like a grown up SRT8 (For half the cost) At the very least I'd feel better about spending a few grand on an exhaust.

MODS:
K&N Drop
170 tstat
.030 gap (1 step colder I believe)
3 BAR
SCT Tuner.

[glock-coma]

Have you checked for any codes that haven't triggered a cel? Sounds like a boost leak at one of the hoses.

[Jtrain]

i hold 18-19 psi just fine at wot. Boost leak doesn't sound viable. No codes thrown.

[AJP turbo]

Pm me your email....i would take a look at the datalog if u want...maybe you have found a hole in the tune....i wouldnt bother with the wastegate spring..very unlikely its a physical hardware problem.....my guess is tune related

I would really try and compare it to any previous turbo car...the tuning is ridiculous funny things can happen when u try to force a result...in an attempt to make the power delivery consistent and reliable the tune is so complicated

See if u can post a log

[Jtrain]

Will do bud.

I tend to agree. I don't want to put my tuner on blast here. He's a good dude, the AFR and everything looks right to me... But if it's a hole-- it's biiiig

[AJP turbo]

Will do bud.

I tend to agree. I don't want to put my tuner on blast here. He's a good dude, the AFR and everything looks right to me... But if it's a hole-- it's biiiig

Yep, no need to put a tuner on blast...there are so many strategies that it's  not far fetched at all to see cars have a different response from time to time...ive heard that from more than one professional tuner

[Jtrain]

Just so everyone can clearly see what I'm talking about

i hold 18-19 psi just fine at wot. Boost leak doesn't sound viable. No codes thrown.

Boost is Green. Pedal position and RPM are the others.

[AJP turbo]

Read my email....they tend to tip in hard...if u held that pedal longer it will level off...wastegate dynamics need time to regulate