I have an audi tt 225 quattro with apr cat back exauhst, software, dv, and intake. I just got a boost gauge installed, and i noticed i spiked to 20+ then fell right down to 11, figuring i was going into soft limp mode, i put on a 4.7 volt 1 watt diode today. I know i had it hooked up correctly as the other way caused a funny idle. I drove down the street, and i still drop to 11 and somtimes i only go up to 11 and never reach 20+ so its the same as before.

Any other suggestions as to what may be wrong or what to fix?

boost leak? ... my vacuum reads in the 20's so I know thats good

Timing to far advanced?

Detonating?

Not running 93 gas and only running 91? ... 93 not available in AZ

N75?

 

None of the above. It is normal. It is a small turbo and they dont hold boost well. As for not reaching 20psi, that is also normal, its called load. If you want to hold boost longer, get a mbc/ebc.

 

I have the k04 turbo, and my friend has the same car with a 180 k03 turbo with software, he spikes and holds in the 20's

Am i not limping when it jumps down to 11?

 

does it spike and then goes strait down to 11psi or does it taper down to 11psi? taper is normal

whatchip are you running?

 

It will hold at 21 22 for a few seconds then quickly drop to 11 for the remainder of each gear, unless it is being funny, then it goes up to 11 and holds nothing more, which really is disappointing.
I have this nice hard pull for a second, and then just nothing for the rest of the gears. My buddies 180 apr car is faster, APR SAID THATS NOT POSSIBLE, AND SAID I WASNT CHIPPED!!! Well i obviously am since it wouldn't be hitting 22 psi right.

I have an appointment today at 1:45 to have an APR dealer hook up to their laptop and tell me what software i am running, since i bought this car used i have no idea what the guy before did to it.
If its a 93 program i need to have it re mapped to 91 since that is my gas down here. what else should i have them look for?

 

Thats about it. You probably have some crappy chip if thats the way its running. But just remember that at about 5k the boost starts to drop of fast.

 

so how do i keep it higher crank the waste gate? n75j? mbc?

 

mbc. But just remember, a small turbo will not make boost in higher rpms. With turbos you have to pick a target rpm range (low, mid, high) and suffer the others.

 

Thanks for your help. I am going to get mbc and see if i can squeeze out some more. should i crank the waste gate for more boost in the higher rpms though?

 

not unless you want to replace the turbo soon