Why am I overboosting with just an intake and a bov?

[rb26dett]

I just got my GST a couple of months ago and I don't know much about DSM's...I used to be a Honda guy. Anyway...here are my list of mods before I ask my question. Injen intake, Apexi mechanical boost gauge, Autometer EGT and A/F gauges, Greddy type S bov, and hard IC pipes. I installed my boost gauge first just to see what I'm running stock...and it was at 12 PSI. Then I installed the intake and the bov and the IC pipes and my boost jumped up to 15 PSI and sometimes 17 PSI...it scared the s**t out of me. First, is this normal to be boosting this much with just an intake and a bov and hard pipes? I read that stock boost is about 14 PSI. I also bought a Hallman manual boost controller, but I'm scared to install it because I don't want anymore boost. I was hoping to just boost around 13 or 14. What can I do to lower my boost? And yes, I am recirculating my bov and all my installations are correct as far as I'm concerned. Please help a newbie out. Thank you in advance.

 

[Coldandafraid]

what year of car is that? Im guessing 2G, and that you replaced the leaky 2G BOV with a non-leaky BOV. That would account for increased boost. Go ahead and install the MBC anyways... bypass the BCS and your boost will go down a little... then turn it up again with the MBC.

 

[rb26dett]

what year of car is that? Im guessing 2G, and that you replaced the leaky 2G BOV with a non-leaky BOV. That would account for increased boost. Go ahead and install the MBC anyways... bypass the BCS and your boost will go down a little... then turn it up again with the MBC.

Yeah...it's a 2G (1997)...but is the boost supposed to jump up to 17 like that? And also the MBC will help lower it? I was afraid it might make it increase the boost. Thanks for the quick reply. I'll install the MBC tomorrow...I'll keep you posted.

 

[Coldandafraid]

the stock BSC bleeds off some pressure, so the boost goes up to open the wastegate. So, if you install the MBC and keep the BCS out of the loop, then the boost will go down a couple PSI... that is, until you turn it up again with the MBC.

 

[VBGSX]

Yes it's normal.
Mine did the same thing. Jumped to 16-17lbs
As was mentioned above. Leaky BOV and better non restrictive piping.

 

[igs]

Spiking to 17 psi is normal. Mine spiked to 20 psi with the stock bcs. A manual boost controller will fix that problem.

 

[rb26dett]

You guys were absolutely right. I installed the Hallman MBC today and my boost pressure went back to stock. Thanks for your help guys.

 

[midnght]

Please update your profile for your vehicle.

It will help you greatly in the long run. You won't have to listen at things that don't effect you.