Boost drop locking the converter

[DougsfastZ]

Over the years with the stock turbo, I fought a bit of boost creep locking the converter in 3rd gear. I got it under control with a GN1 external DP and wastegate. Recently I swapped the stocker for a TE45A and ran across the opposite issue.

Now I have a 3 degree boost drop locking the converter in third. It recovers faily quickly, but I have no clue why the boost would drop.

Any idea what the cause would be?

Thanks,

Doug D

 

[Quick6'n'-K.C.]

Possible that the motor is bogged down and the rpms drop with the convertor locked. You have less exhaust coming out with the lower rpm.
Thats why you get less boost.

Lock it at a higher rpm / mph and it will be less of a drag on the motor, and your boost might stay up higher.

When do you lock it? 83mph?

BW

 

[DougsfastZ]

Possible that the motor is bogged down and the rpms drop with the convertor locked. You have less exhaust coming out with the lower rpm.
Thats why you get less boost.

Lock it at a higher rpm / mph and it will be less of a drag on the motor, and your boost might stay up higher.

When do you lock it? 83mph?

BW

I lock it at 73, right after it goes into 3rd.

Maybe because the TE45A is a bit big for a stock heads/cam car?

Thanks

 

[TurboDave]

That's pretty low. I lock mine at 88. Still produces good mph and doesn't bog the car.

 

[Quick6'n'-K.C.]

After Daves response, try locking it higher and see what you get.

And my opinion, yes the 66 1050cfm turbo is too big for stock heads and cam.

My blue limited has that turbo with a 214 erson flat tapped and some good ported heads.

9psi is too much on drag radials at 50MPH. Maybe it needs new tires or the boot comes in too quick.

Get a cam, you will have less detonation.

BW