dprantl

I've seen spikes of 0.8 and 0.9 on my non-X50 '03 @~1,000ft above sea-level. A spike of 0.9 will settle back down to 0.7 if you stay in it long enough.

Dan

"02996ttx50

funny, as i'm just above "sea level" and i see spikes of 1.4 on occasion, and yet i *usually* back off before the car will.

i'm not half the swimmer i was once in my youth lol

r6vr6

I replaced my broken OEM Bosch diverter/blowoff/cutoff valves with the OEM supplier Wagner versions. They howled some and they also let the car over boost when going off throttle. I saw 1.4 bar a time or 2 and decided that was enough. (My car has a Tune and normally maxes at 1 to 1.1) They got sent back to pelican and I ordered a set of evoms billet unit. Might be worth looking at those.

"02996ttx50

agree i also have evoms dv's. no honking and seemingly indestructible.

spikes to 1.4 are not a big deal with a 1.3 7200 tune

but then that might well be ( is? ) roughly equivalent in terms of *overboosting* to a stock k16 spiking to .09 lol

OEM+

So a bit of an update for those who care or anyone who may search for this in the future:

Took it to Moorespeed in Austin and they replaced the boost control valve. I just picked it up, romped it pretty hard on the toll road and it never went above .7 so it appears I'm happy!

Had them flush the brakes, too...pedal seems a bit softer than before...but it always seems pedal feel changes after every flush, and we own multiple cars that I've driven all this past week, so I honestly don't know if its in my head or what. But the car stops, so woo.

But yes, there is the update.

dprantl

Just wait. Do a bunch more romps and you may see a spike again. It's not a problem, so don't worry about it.

Dan

NCdog

My TT is new to me so I'm trying to learn as much as possible, so this thread prompted me to check out the bar reading. I'm not sure from reading these responses whether my car is OK or not - can I get some conclusive answers?

My car was chipped at some point (NAIS stage 2, sport exhaust), but I had it checked at a NAIS dealer and it is running the factory settings currently.

So I went out and mashed the throttle in 3d gear for the first time(oboyoboyoboy!) and I saw 1.1 boost at 5-6000 rpm.
I''m at sea level.

Sound OK?

Third-Reef

Going over boost as you chop the throttle is to be expected the way the TT is set up. the pressure sensor is before the throttle plate so the cylinders are not seeing it. Same as when you are tooling along at 1/8 throttle and the boost gauge shows .2 bar. The sensor befoer the throttle plate is seeing .2 bar but the intake runners are not seeing any boost.

Macster

Chopping the throttle, lifting off the throttle abruptly, may result in some over boost as you state but I have not observed this.

I do see boost peak/max out at 0.7 bar (or sometimes higher under special -- at higher elevation -- conditions) then decrease some as RPMs rise.

Under steady throttle at highway speed -- which could be the "1/8 throttle" you mention -- I have observed the boost showing 0.1 to 0.3 bar but I believe this is real boost because concurrent with the appearance of boost I can feel the car react to the boost. The reaction is not severe but real nonetheless.