# Problem with boost! Help Please! Imortant!



## agratise (Nov 18, 2004)

Hi,

A Friend of mine has a Nissan 200 SX with 170HP, it has a stock turbocharger. Just to let you know what i'm talking about! I don'z know the exact type of car or engine! I guess you know it...

the Problem is that at a RPM of about 5000 the boost falls down from 11psi to 6psi and we do not know why that is! Is there a stock blow off? could that be damaged? Or what do you think?

The other question is: Is it possible to change the stock blow of with a HKS for example? I'm not sure if the 200SX Charged version has a sensor which messures the masses of air (dont know the name in english, sorry!)! If thats the case, i can not install a blow off, which just blows the air out, i need one which puts the air back into the intake... is that right?

Thank you guys,

Greetings form germany,
philip


----------



## Rathi134 (Jul 11, 2003)

agratise said:


> Hi,
> 
> A Friend of mine has a Nissan 200 SX with 170HP, it has a stock turbocharger. Just to let you know what i'm talking about! I don'z know the exact type of car or engine! I guess you know it...
> 
> ...



sounds like the usual reason, vacuum leak


----------



## agratise (Nov 18, 2004)

Rathi134 said:


> sounds like the usual reason, vacuum leak


where should we start looking for the leak? Is there a typical place to look first?

What about the blow off valve, can we change it to a HKS?

Thanks!


----------



## NotAnotherHonda (Aug 7, 2003)

you can always get a greddy, or some kind of blow off that you are suppose to recirculate


----------



## Zen31ZR (Mar 24, 2004)

You might also be outrunning the fuel pump. Check for a clogged filter. Turbos "unspool" because there is a lack of the hot exhaust air to drive them, which can be caused by a lack of fuel to promote proper combustion, or the wastgate is fully open. A "vacuum leak" will not cause this, there is no "vacuum" under boost. Any intake leakage would generally be painfully obvious above about 5 psi.


----------

