Losing turbo pressure

[Mr.Salas]

Hi all,

I'm having an issue with the turbo pressure (Boost pressure).
Seems when i'm doing WOT, the pressure falls from 1.2 bar to 0.7 bar.
What i mean is that it peaks 1.2 bar @ 5000 RPM and drops off around 0.7 bar.

What could the problem be?
Boost leak, wastegate problem or in need of new turbo's?


Thanks

[kiteman]

Hi all,

I'm having an issue with the turbo pressure (Boost pressure).
Seems when i'm doing WOT, the pressure falls from 1.2 bar to 0.7 bar.
What i mean is that it peaks 1.2 bar @ 5000 RPM and drops off around 0.7 bar.

What could the problem be?
Boost leak, wastegate problem or in need of new turbo's?


Thanks
Sounds like you have a soft boost pipe perforated. Thats what I'd be looking for first.
I had the same problem way back + mine peaked at 5000 RPM also.
Check all the soft hoses before you look elsewhere.

[elnevio]

Standard tubs?

I think you'll find that they just can't provide that level of boost to the red line, normally.

[Davezj]

it doesn't sound too abnormal to me,
maybe a bit low to drop to 0.7bar, it depend what it does normally.
standard tubs should hold boost to about 5500rpm and then they tend to run out of puff and pressure drops off as the rpm rises to the red line.

[Mr.Salas]

Yes, they are still the standard turbo's, but they used to hold the pressure good until redline
The pressure normally drops a little, but not as it does now.

I replaced almost all of the intercooler hoses with new 4ply aftermarket sil hoses, I still need to replace the stock rubber hose at the Y section and the rear turbo 90 bend hose.
I will check if they are leaking and replace them with new hoses.

[Davezj]

sound like you need to do a boost leak test.

[kiteman]

If you know someone with a smoke pro, it will find a leak rapidly.
http://www.youtube.com/watch?v=4-abu6wPMbg

[97vr4]

I have the same issue with mine
Don't think the turbos are efficient at high rpm
I get 1.2 bar and a drop to 0.8 over 5500rpm
The turbos are Sooooo small
don't think it's a boost leak issue

[Davezj]

If you know someone with a smoke pro, it will find a leak rapidly.
http://www.youtube.com/watch?v=4-abu6wPMbg

you pesky man, i am going to have to go out and buy a disco fog machine and fittings to make one of those smoke testers, what a good bit kit. i have been trawling ebay for a cheap one and they are out there. i found a good youtube video which basically shows you the way the system work and it basically a disco smoke machine out put from that goes to a T joint and you connect compressed air to the T joint and the out put of the T joint goes to the car inlet pipework and it blows smoke under pressure into the inlet pipe work.

the proper gear you link to is going for about £750 on ebay