boost discharge

[N2HIPSI]

I just installed a lt-70 turbo today. I was out dialing it in tonite and had a weird thing happen. In 3rd gear at around 4500 rpm under full boost(16lbs) it was pulling great and then the boost just discharges and the car noses over. It was like a hose blew off, but it didnt. The egt's were 1446 at the highest. Any ideas?

 

[BlackBandit]

Can you still build boost?

 

[N2HIPSI]

Yes. I thought it was a hose or the wastegate rod at first, but I could immediatley make boost again.

 

[azgn]

you are probably blowing the wastegate open....even at low boost levels, that turbo moves a lot of air and you need some tension on the wastegate

try a bleeder in line to keep the pressure off until you want it to open

 

[N2HIPSI]

Thanks. I have a bleeder. Should I shorten the rod and close the bleeder down some or should I lenghten the rod and open the bleeder farther?

 

[azgn]

think I would take the bleeder out and see how much tension is required to keep the gate shut....typically, with a HD actuator, you can't run less than 18-20 lbs

if your bleeder is working correctly, you should be able to keep the rod fairly loose and control boost with the bleeder (up to 25 lbs or so)

 

[N2HIPSI]

Thanks, I'll give it a try this weekend.