on my setup im loosing about 1.5psi from 7000rpm up on my datalogs...i presure checked my setup to 30psi..and i have no leaks...im stumped
quick run down of my setup
lsvtec 81.5mm
sls ramhorn
tial 38mm with 1bar spring and hallman mbc running 17.5psi
60-1 82ar stage 5 ex wheel
3''dp/exhaust
2.5'' charge pipes
crome pro/p28
any ideas why it would loose a bit of boost?

 

DID YOU MAKE SURE YOUR BOV ISNT LEAKING?

 

it didnt leak when i did a persure check..and i checked it up to 30psi..and im only running 17.5psi

 

[QUOTE=turbo boost;38784882]
tial 38mm with 1bar spring and hallman mbc running 17.5psi
[QUOTE]

Its not the intake side that's the issue, its probably the exhaust. Specifically, the wastegate's valve seal. Occationally the valve seal will allow extra exhaust pressure into that lower port, which will open the valve further than it should. Boost will drop as more exhaust is routed around the turbine. If the turbo has been pushed very far (top right of it's efficiency map), it will simply from being out of breath.

 

^^^^ what he said ^^^^^

 

[QUOTE=HiProfile;38786725][QUOTE=turbo boost;38784882]
tial 38mm with 1bar spring and hallman mbc running 17.5psi
is there anyway i can correct this?

 

yeah either wastegate seal breaking
turbo running out of breath
or too much overlap in your cam tune, that won't show up till the turbo starts to run out of the ability to over flow that...

the 3000GT guys (on race gas ad drag events) would run regulated vacuum (rather than boost) to their gates to hold them shut, peaking out from ~28 psi to ~32 psi at the top of the rev range so the wastegate leakage (especially if u have a small turbine housing like theirs) is a significant problem ...

you could try to go up to an ~18psi spring and retune your cam timing...

 

im running gsr cams and there set to 0,0...i wouldnt think the turbo would be out of breath at only 17psi 404whp?...maybe the seal is leaking on the wg tho..ill check it out