piiraags

I have a MY 04 STI with PPP (305 hp). The problem is the turbo boost, when I start up the car the boost is no more than 0.4 bars. 10 minutes later the boost reaches max and is 1.2 – 1.3 bars, but when I start to race the car (go up to 6 k RMP), the boost falls down to 1.0 bars and stays there. I have tried to change the turbo, air flow meter and downpipe, but no result. Does anyone know what might be the problem?

Tidgy

its called the turbo running out of puff, or do you not mean it drops off all the time?

you'll tend to find that the boost will reach max then drop off slightly the higher up the rev range you go, and also the 0.4 is prob negative boost not positive.

piiraags

you'll tend to find that the boost will reach max then drop off slightly the higher up the rev range you go, and also the 0.4 is prob negative boost not positive.[/QUOTE]

The problem is that the turbo boost won’t reach the max boost (1.2 – 1.3 bars) once the engine’s temperature is in the mid range.

Also, there is no or little turbo boost when I drive thought city (rush hour) when I get to highway the boost doesn’t reach 1.0 bars, but as I get more incoming cold air the boost is 1.0 – 1.1 bars

StiX

iTrader: (4)

I have just fitted a boost gauge to my classic, which has been remapped to 1.25bar.

1st gear - don't notice any boost
2nd gear - goes upto about 0.5
3rd/4th - if full throttle thats when I see over 1bar upto the max (hard to be accurate but about 1.3).

All dependent on throttle and load.

1st and 2nd I have noticed I don't give it anywhere near full throttle especially around town, hence the no/low boost readings.

No throttle = -0.5/07bar.

New_scooby_04

iTrader: (4)

PPP will not permit anywhere near full boost untill the car is warm; it's a safety feature. You should be keeping the car off the turbo untill the engine oil is up to temp (anywhere between 5-10 miles of driving: thrashing a cold engine is a short cut to a rebuild!

Boost will naturally peak a certain point in the rev range and then tail off at the top end; no car that I know of holds peak boost to the red line.

Ns04