loss of boost. idea's?

[innrkid]

Last Monday at Autobahn while driving like a mad man keeping a Viper off my ass I started to lose boost. The gauge went the normal 12-14psi to around 8. I thought it was likely heat and went another lap and it dropped to around 6 and I pulled off the track.

I have visually inspected the vacuum lines and don't see an issue. I don't think it's the gauge because the 'seat of the pants' feel is diminished.

You guys have forgotten more about performance cars than I ever knew to start with. So I am throwing it out there. Any idea's?

This is my 07 Roush with TVS2300 blower.

Any help would be appreciated.

Click to read more...

 

[Zack]

Last Monday at Autobahn while driving like a mad man keeping a Viper off my ass I started to lose boost. The gauge went the normal 12-14psi to around 8. I thought it was likely heat and went another lap and it dropped to around 6 and I pulled off the track.

I have visually inspected the vacuum lines and don't see an issue. I don't think it's the gauge because the 'seat of the pants' feel is diminished.

You guys have forgotten more about performance cars than I ever knew to start with. So I am throwing it out there. Any idea's?

This is my 07 Roush with TVS2300 blower.

Any help would be appreciated.

Check the operation of the boost bypass valve first.
Sounds like it is opening under boost.
Do you have the valve hooked up to straight vacuum or a boost line?

 

[deviantlx]

boost is nothing more than a measurement of restriction. check compression and do a leak down test. sounds like a hurt motor.

 

[FirstWorldProblems]

boost is nothing more than a measurement of restriction. check compression and do a leak down test. sounds like a hurt motor.

Loss of boost and your first assumption is a hurt motor.....with no other signs of engine problems? Could be a dozen other things.

 

[Bob_Kurgan]

i would start by checking for belt residue.. the belt may have stretched and is loose... look for belt dust on surrounding parts.

 

[hj16]

My guess would be belt slip... is there a bunch of black, grimy dust in the area surrounding the supercharger belt?

 

[innrkid]

Check the operation of the boost bypass valve first.
Sounds like it is opening under boost.
Do you have the valve hooked up to straight vacuum or a boost line?

How would I check the operation of the bypass?
I don't know if it's straight or into a boost line.

i would start by checking for belt residue.. the belt may have stretched and is loose... look for belt dust on surrounding parts.

It does not seem like there is excessive dust. I will check this again.

My guess would be belt slip... is there a bunch of black, grimy dust in the area surrounding the supercharger belt?

I wondered about this when I put billet pulley's all around.

I don't think I have a hurt motor unless something happened under normal (well, track normal) conditions. Yes, I run the car at high revs for an extended period on the track but the motor still feels, sounds strong. I am going to try and keep chasing vacuum or slip problems before I decide the motor is hurt.

I'll say it again....you guys forgot more than I know. Any help is appreciated.

Thanks


******Edit****** I checked for dust. Nothing abnormal.

 

[FuelSlut]

i would start by checking for belt residue.. the belt may have stretched and is loose... look for belt dust on surrounding parts.

+1 this would be my first guess. I replace my blower belts every 5k. They stretch very easy.