My car has great instant boost off the line. It never has the boost drop that I would expect to see when the second turbo and under hard accel the cars seems to fall flat on it's face and generate no power on the top end.

I suspect that the second turbo is not operating properly. I replaced the vacuum lines and now I'm in the process of testing solenoids, etc. Here is my question though....

Can I hurt anything if I force the flap between the two turbos and take the vehicle for a test drive to see if my diagnosis is correct? I'm sure it will feel laggy off the line but at the upper end I will feel more power if I cam correct that my vacuum flapper is sticky or not operating.

I wish I understood more about these but I'm learning!

 

Yep, you can do that no problem. Car won't care if that flapper is open.

Dale

 

Check under car below the turbos that all actuator arms are still attached to the flapper in the exhaust manifold.

 

Will do... thanks.... That will narrow down my problem and I will check the arms on the manifold.

 

Hi there,

I have always liked this guide for boost trouble shooting - its systematic and outlines what each part does and why.

Troubleshooting

All the best, Rusty