cant boost more than 14psi

[matt31]

a friend of mine has a bmw with a rb25det in it. its got a hybrid turbo and is supposed to be able run 18psi,

problem is we cant get it to go over 14psi no matter what we do, btw its controled by a bleed valve. anyone heard or experienced

anything like this.

[skyline33]

well there is a boost cut i think at 14 psi

[matt31]

no dont think thats it hes got aftermarket computer, no boost or speed limiter

[Guest Nismo_Freak]

Check the actuator ... perhaps its getting stuck?

[Guest MRE]

When I installed mine we found that there was a little brass lug with a very small hole in the it inside the pipe.

My guess is yours is still in there.

The hole is small enough that I recon it would limit the boost to about 14psi, sort of a safety thing, I suppose.

[Revhead]

I've also heard the factory BOV leaks over a certain amount of boost... ?

[matt31]

we ran a cupple of tests where we replaced the restrictor with one with a smaller hole and when that did nothing we blocked the acuator completly thinking the boost should in theory just keep getting higher, but still exactly the same result. i found this really weird.

[MM2death]

If the map sensor reads over 14psi, the standard computer will say i've had enough...boost cut.

If you bleed the line going to the map sensor, you can trick your computer.

[matt31]

no its got a haltec ecu so cant be the boost cut

[MYGTST]

check your boost guage insnt stuffed

[matt31]

dont think its the boost guage cause i would still notice the extra power gained as i continue to wind the bleed valve further and further

[r32-25t]

try pulling the wastegate line off

but back off if the boost goes crazy

if that works look at replaceing ur bleed valve

and haltec can have a boost cut programed into it

[matt31]

ok thanks for the info ill try some more tests and see how i go.

[Guest MRE]

Squeeze the tube and see if the brass thingy is still in.

[Steve]

Could be getting wastegate creep? Perhaps the acutator spring is stuffed.