sonicraze

Just got my first euro car, a 01 225 tt coupe.

First thing i did was get it chipped (apr). After chip I was getting 20 pound spikes falling to 18, then 15, then at 5k down to 10! Apparently this is normal but the car can do 20 to redline just fine. The apr chip just doesn’t boost as high as others to save on "engine wear". Screw that, i got it chipped so i could drive the **** out of it till it breaks and i can rebuild with more power.

So a friend helped me install a profec b v2 i had from my last car. We left the stock boost controller (n75) plugged into the harness but caped of the pressure and wg side of the valve. Car seemed to respond well, we did lo at 15 and high at 20, neither droped more than a pound or 2.

On the way home i had the ecu throw itself into limp mode and die on the freeway. Apparently the car doesnt like the n75 not seeing any pressure. I called a few local shops and they all said it was a bad idea to use a mbc with a chiped ecu but couldnt tell me exactly why. I then called apr (makers of the chip) and i got the guy to admit that its not bad, just untested.

Alot of people say its a bad idea to use a ebc even inline with the n75, that i will have "problems" but cant tell me what. At the same time ALOT of people are using this home depo thing called a "boost machine" to get a few higher pounds and to ctrl the wg creep.
Link


Isnt this thing just a MBC? if so, then why would i have any problems running a ebc the same way as this is bein used by 100's of people? inline before the n75

1st post, friend told me this was a good forum for advice and help.

Thanks ahead of time.

.RTErnie

He's my bitch...so help him out

MooreBoost

People use MBCs on flashed Evo's all the time.

Works fine.

.RTErnie

Ive personally been in the TT... The profec B is working just fine...the car boosts different EVERY TIME. sometimes it spools perfect...some times it hangs up at 10 psi and feels like staged boost....some times it will fluctuate severely...some times it hits 20psi solid and sticks. Its NOT characteristic of the EBC....I know because I had it in my car.

the stock solenoid/actuator is called the N75...it has a signal port from the intake manifold...and out port to the wastegate actuator...and a source from the inlet pipe to the turbo(intake pipe...not charge pipe)

we capped off both ports and left it hooked to the intake.

wired up the profec B and routed the vacuum lines.

worked flawlessly for like 20 pulls. parked it...drove it again...started acting up...fluctuating...stalling at 10psi...st00pid inconsistent ****. IDK what it could be.

GA-AutoFab

i'm not sure what a 225 tt is but seeing you talk about a N75 i'm going to assume its an audi tt. if it is don't they have a little k03 turbocharger? If it does I highly doubt it will hold 20psi to redline. even if it has a K04 I don't think it will hold 20psi to redline either. but i'm not 100% sure if were talking about the same car or not.

Everyones Hero

The diagram looks like it sets up a WG bypass w/ something that looks like the bleeder valves people use for the AFC hack. It allows pressure to go through to whatever is on the other side of the "pressure relief" and "pressure regulator" valves.

So hard to understand something when you can't see it first hand.

edit: I have a feeling that the reason they don't let you go to 20psi and hold it to redline using their chip is because they didn't tune it for 20psi, hence why it's "untested."

platinum00

If you want to keep the N75, you can try running different N75 Vavles. There are a couple, depending on the motor i think the stock one is a "F" valve, the one to get is the "J" or "H" valve or also known as the N75 race.

The "H" holds more boost then the "J". You can find these on a S4 or from ECS tuning.

The computer in the 1.8T motors is extremely intelligent and if your not running the correct software you can "overboost" with the "H" valve and be thrown into limp mode.

Im pretty sure to remove the N75 completely and get the car to run right you need standalone. Not 100% sure on that.

vwvortex.com is your friend.

platinum.

.RTErnie

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by platinum00 &raquo;</TD></TR><TR><TD CLASS="quote">If you want to keep the N75, you can try running different N75 Vavles. There are a couple, depending on the motor i think the stock one is a "F" valve, the one to get is the "J" or "H" valve or also known as the N75 race.

The "H" holds more boost then the "J". You can find these on a S4 or from ECS tuning.

The computer in the 1.8T motors is extremely intelligent and if your not running the correct software you can "overboost" with the "H" valve and be thrown into limp mode.

Im pretty sure to remove the N75 completely and get the car to run right you need standalone. Not 100% sure on that.

vwvortex.com is your friend.

platinum.

</TD></TR></TABLE>

thank you. I knew the ECU was freaking out, but I couldn't figure out how it was controlling boost.,..or making it "expletive" up. Maybe retarding a TON of timing..IDK. I will look into the S4 N75's...etc