Overboosting with both stock and chipped ecu's....

[JD797]

So something's been feeling off lately with the boosting, I really started to notice when I got the thing chipped and didn't see much of a difference (APR 93 octane). So, sure enough, after finally installing my boost gauge yesterday, I got some interesting readings... chipped mode spiked at ~19 psi, and so did stock mode. So then I swapped back in my stock ecu, and sure enough, same thing. 19ish psi spikes. Any idea of what the problem can be? I'll be able to VAG it in a few days but am trying to get some kind of idea...

[soccerplayer01]

possibly a race valve on there? i no i'm overboosting ever since i put my valve on w/ the giac ecu.

[RolledMySTi]

Are you spiking and holding at 19 or is it spiking and dropping? If it is dropping what is it dropping to? You may have already had a chip on the car.

[JD797]

it stays in the 16-20ish range for a second or so, but never holds at the peak, jsut goes up to there then goes down, and i dont think it was previously chipped as the turbos were replaced under CPO by the previous owner less than 10k miles ago, and I had a shop check it out before I bought it and they didn't notice anything

[JD797]

And I put 710N DV's on there myself as well as the 034 TBB (with stock clamps), which has popped off once before before I chipped it, had to tighten down the clamps more

[SilverSurferS4]

I think the car was originally chipped bro... what your describing seems perfectly normal for a chipped s4... spike at 18-20psi... then taper down towards redline...
considering you didnt notice much of a difference before and after the chip.. leads me to believe it was always chipped... im thinking if you hit 16psi on a stock programmed ecu the car would go into limp mode or something perhaps..

[JD797]

possibly, but they wouldve had to have had it chipped in the last 8k miles, and not before the turbos went, otherwise audi wouldve never replaced them under CPO, thats why I don't think it's the ecu. some people have suggested a wastegate line problem...

[00s4slvr]

the giac ecu, the dealer cant even tell that its flashed unless they do the programming there, so even if it was chipped it is almost 99.9% gonna get fixed under warranty becuase audi would never know...

[JD797]

eh i still doubt it, the car doesnt feel like it pulls as much as when I first test drove it

[BurnAll4S4]

log it. my apr gauge is off by a lot (reads 24 and its at 21). i thought i was overboosting too before i actually logged it and saw the gauge was just off.

[nateS4]

I would say flashed, It is hard for a dealer to prove that a car is chipped. And if it was flashed with say GIACX and you just had APR installed, then it is going to feel slower.

[JD797]

yea, someones letting me borrow their vag today, but i havent really used it, what do i log and how? Also, is there any way to tell if the ecu is chipped or not?

[SourDieselS4]

generally you would hook up a boost guage and see how much boost your making

Increased top speed and redline too?

[JD797]

nvm, I found a slight tear and covered it up, chipped is very fast =D hahahaa

[team_soy]

a tear where?

[JD797]

on this black hose coming out the left side of this diverter valve looking thing jsut under the n75

[JD797]

if you pm me your email i can send you pics if you want