Hey guys I have just installed a greddy prospec II recently and the boost falls off at high rpm..what would cause this?

 

in a lot of cases its normal for the boost to drop at higher rpm by a couple pounds, especially with a few mods and a stock turbocharger. basically saying the turbo isnt as efficient as it could be to hold boost through the rev range.

 

The turbo has been upgraded to a t04 with series 5 exhaust housing

 

bro my stock S5 turbo fall of hard out. will crank 11psi till about 5500 then fall off to about 7psi by red line. Ive got a 3" turbo back exhaust and 3" inlet. what gives aye. wheres my solid 11pounds from 3000 to redline

must be a shitty turbo

 

wow mine like holds 14.1 psi until 5500 and than drops to 5 psi by red line.....but mind u i have a turbo manifold leak

 

oh real I thought iu as the only one..I get 10 pounds then it falls away

 

Apparently the S5 and probably the S4 turbos cant flow enough and just fall away at hi rpm

 

yes mine does the same thing as wel... ill be at like 10 then it will drop to like 5 but i also think i have a manifold leak as wel..

 

yep ill be at like 12 and drop to about 7psi....