All of the following is on an '04 G35 swapped to a CD009 6MT:


Hey guys,

Would love to pick everyones brain. I decided to stick with my G18s and just turn up the juice, but I think I've got a boost leak-- let me know if this makes sense.

Went from AT to MT with an HKS SSQV, there is no adjustment on an HKS (famously) but it was the only BoV I could really use with my AT and not stall at low RPM.... Now I was stalling at Low RPM when I moved to a MT.

We drilled a VERY small (3/16" ish) hole in my throttle body, and it cured my car diving for 300 RPMs everytime I hit the clutch (and ultimately stalling my car in a lot of situations).


So recently: I upgraded my wastegate springs, took the OLD HKS SSQV off and put a Tial 50MM with appropriate spring. I could only run about 16.5 PSI on the dyno and made 589 torque and about 575 HP ( No dyno sheet to show you)... Now when I drove it, the BoV sound was delayed by fluttering / surge.

I THINK, that hole in my TB is messing with my vacuum and boost at high boost, and now that my BoV has adjustability, I can use that instead of a hole in my TB.

Thoughts?

 

Mine flutters too, I also have a tial. And on my other car I have a blitz bov, also flutters. As long as it's holding boost when u go full throttle then it isn't a bad leak if any, try the old starting fluid trick to find the leak maybe ?

 

I'm really trying to figure out if I have one.

It seems strange that you change a wastegate spring to allow 20+ PSI and only gained 1.5 on the dyno.

amirite?

 

Too many variables to figure this out over the Internet. You should be able to push the 18Gs to 700 whp DJ.

 

Fair enough, I don't disagree... Just seeing if anyone had any ideas.

 

Well 20+ psi will grenade your motor unless it's built to the guild