why do you change from a -34 from a -31

or from a std to a -31

are -34 for T34 turbo's or do you get them to run more boost?

just selling mine now and someone is emailing me about it, but i cant answer any of his questions,

 

I have just changed my -31 to a -34 when i recently changed to a greys conversion running 31psi max peak.
From what i can make out is that a -31 will not hold the wastegate closed at this sort of pressure,so a -34 is needed which is stronger.

regards mark

 

cheers

so do you change from a -31 to a -34 so you can run more boost?

or change to a -34 cos your changing turbos ie from a T3 to a T34?

 

its got fook all to do with how much they can hold..............people seem to get a -34 cos they think "its a 34" so it must be better than a 31.....i've used both and i prefere a -31...(my opinion).....smoother feel to the car...

 

-34 can hold shut against more boost, than a -31 as already said, has a stronger spring and can take more preload.
tabetha

 

cheers peeps

 

Thats how i thought it worked i think you could use a -31 but the preload would too much and not the correct application...i just bought a -34 as my -31 would not hold the wastegate to my required boost level...i fitted a -34 and preloaded it to hold 31 psi,worked out at half a hole on my -34,but when i preloaded my -31 to half a hole it only held 22 psi.

mark

 

....sound like it was fooked.............i have the same boost as u on a t38 and my -31 is fine..............also know that Grove use -31's on 500bhp t4 cars with no probs................