Sporadic blowoff?

[NeoZer0]

Hey guys!

I just got my Talon's engine broken in after a complete engine and head rebuild and I seem to be having an issue with my blowoff valve. Its a Greddy type S and it was working before the rebuild however since the rebuild it seems to be working sporatically. I have it venting to atmosphere so I can really hear when it works however it only seems to work every so often. Now I'm only putting a max of 5 lbs of boost into the engine right now since I'm am still kind of Babying the motor but I should still get a good blowoff when shifting right? As far as I can tell all the vacuum lines are installed correctly and the IC and piping doesn't have any leaks.

FYI here is a list of things that were upgraded during the rebuild in case you want to know.

Engine bored .40 over
Wiseco 8:2-1 Pistons
Eagle H Beam rods
1mm oversized stainless steel valves installed w/bronze guides
HKS 264/272 combo
Fidanza cam gears
Spearco FMIC kit

 

[prplhz96]

well if you are only running 5 lbs. of boost, I believe that is not enough pressure to properly function a type s. Look into the single spring mod, where you take out the lesser pressure spring(inside one I think), I am sure that someone will correct me if I am wrong, but this should help your situation, 5 lbs. just seems awful low for that stiff spring in the type s. Good luck. BTW you gettin any compressor surge??????

 

[NeoZer0]

Well I'm only running 5 lbs right now. I'm slowly going to increase it as I increase the mileage on the engine. Before I had the engine rebuilt I was running 17-20lbs on my small 16g. So you don't think 5 lbs will open the blowoff?

 

[MindBlowin03]

Start by 'tuning' it the right way. Let your car idle(you want vacuum). Start with a hard setting and make sure the plunger is closed(look in with flashlight or feel with finger). Slowly loosen the bolt until the plunger starts to open while still at idle. When is does tighten it back a turn or two and your done.

You should have more of a whistle at lower boost blow-offs, but soometimes you will get a flutter(which is ok).

 

[nickrule99]

How are you running just 5 psi?

Theres no way your wastegate has a spring that small.....

 

[NeoZer0]

How are you running just 5 psi?

Theres no way your wastegate has a spring that small.....

The boost controller is set to its lowest setting (stock 10 psi) but I only allow 5 psi pressing on the gas. Anything more than that I let off the gas.

 

[NeoZer0]

Start by 'tuning' it the right way. Let your car idle(you want vacuum). Start with a hard setting and make sure the plunger is closed(look in with flashlight or feel with finger). Slowly loosen the bolt until the plunger starts to open while still at idle. When is does tighten it back a turn or two and your done.

You should have more of a whistle at lower boost blow-offs, but soometimes you will get a flutter(which is ok).

I understnd flutter, its ok....just not all the time. I think this is the answer I was looking for. I will adjust the blow off valve tomorrow and let you guys know the outcome.