JJ01769

I cranked up the boost on my 7 yesterday and it ran fine. This morning I noticed it sounded like it was back spooling at the same time the blow off valve went off. It didnt do it as I turned the boost back down. Any help on how I can get rid of it so I can crank up the boost a bit?

slpin

iTrader: (9)

your BOV is not capable of releasing the increased amount of air fast enough
either get an aftermarket bov, or lower your boost... your pick...

JJ01769

I have an aftermarket. Im running a Greddy Type S

slpin

iTrader: (9)

try loosening the nut?

RETed

How much boost are you running?


-Ted

JJ01769

8 at low boost, 13 at high on a to4b turbo.

RETed

What brand BOV?

Are you running a "T" in the BOV vacuum line?


-Ted

JJ01769

Its a Greddy Type S. No tee, Im just running a straight line from the manifold.

RotaryBuddha

iTrader: (4)

"my stupid question for the day"

does it make a difference?

Ottoman

depending on the brand of BOV and stiffness of the spring.. different bovs work in diff ways

HKS SSQ is a pull type for example.. with a high and low valve..

greddy type S is good for lower boost/street apps(quick response, but limited to how much air it can vent through it's "mouth")
Greddy Type R is the big **** for high boost apps (but isn't responsive enough for low boost/small turbo's)

RETed

Yes, it does.

If you're running the BOV off the "branch" of the T, you don't get as much vacuum, and the BOV either will not open or open too late.
This causes compressor surge which will kill the turbo prematurely.


-Ted

RotaryBuddha

iTrader: (4)

well the T goes to my microtech and greddy type s bov. from the intake mainfold just to the left of the bac valve. kind of like this one but the pressure sensor is now a microtech.

RETed

If you're going to use a T, put the BOV on the straight side and use the "branch" for your pressure sensor.


-Ted