Thread: Ported blower and threw on a 3.4 - less whine, same power and 8 psi

Originally Posted by sco77

Your BBV is having problems, your belt is slipping, vacuum leak, or you have a high KR condition.

If the belt is slipping should there be belt debris on the pulley?

Originally Posted by Twizted 1

Mine holds 20-22 HI of vacuum at idle.
Wire resistance looks to be off though.

I am thinking the wires resistance (while possibly contributing to the misfires) wouldn't affect the boost I should be seeing?

No debris on pulley so i doubt belt is slipping. The bbv seems to open fully when i rev it. Yesterday i couldnt make more than 7.2 psi. I am thinking my port job totally mangled the blower performance??

Pics of port?

A FUNNY SCENE FROM GONE IN 60 SECONDS - YouTube

Don't have pics of the port, wish I had of taken some but I basically extended the lines down, took the bolt bosses out & formed probably a less than ideal perfect triangle with acute edges at the bottom. I really didn't take out that much material although it could have been a smoother job.

Get the proper belt size for your pulley.

When you removed those bolt bosses, did you shorten the bolts? Did you use anerobic sealant on the mating surfaces of the rotor pack and some Teflon on the two lower bolts? Is the S/C gasket new? You may have a minor vac leak that turns into a sizable pressure leak under boost.

Sent from my SkyRocket

Figured out some stuff:

Belt - I am running a 660 which is for a 3.3-3.7 AND running a larger tensioner pulley - so things are as tight as they can be!
SC - I shortened bolts to pretty much line up with the porting job. Could not find anaerobic sealer but the stuff I used worked mint. I didn't put sealer on any of the threads as I figured just air was in that area - no leaks & its been 500km
I did notice some miniscule breaks in the vacuum line that runs from the MAP to the BBV solenoid? Anyway, I also measured the vacuum at the FP rail tee - it was about 17 whereas the Aeroforce was reading 20.5ish which is taken from the MAP I think.

Going to look at the remaining vacuum lines. Can I jam the BBV open manually & see if boost changes? That would point to a vacuum problem or is there more going on there?

If the BBV lines are cracked and dry rotted then they need replaced and that would be your issue right there.

You can replace it with universal rubber hose...it works.

Do that and report back.