I Can't Hold Boost With My PowerBastard Brakes.

[motorhead]

Yep, at 2psi (stock gauge) or 1.5 psi (VDO) it starts a-spinning the tires. The converter stalls to ~2000rpm and bingo: tire spin.

This is on the street, with regular Comp T/A VR4s. The car has the S-10 wheel cylinders, aluminum drums, and fresh shoes. It also has one of the proportioning valve by-pass switches for added pressure to the rear brakes... I just haven't got it working yet (previous owner install).

I figure it should ideally hold 4-8psi on the street. But I guess not On slicks at the track it holds 4-6psi pretty well... a 10psi launch would be nice.

Any suggestions?

TIA,

 

[TurboDave]

Only if there's absolutely NO heat in the rear shoes!!! If you do a burnout without a line lock, you're screwed.

Also, 2,000 rpm and only 1.5-2# of boost tells me it's a WAY too tight converter.

How well are the rear shoes adjusted? Adjust them out until you can just barely get the drums back on.

 

[motorhead]

Originally posted by TurboDave
Only if there's absolutely NO heat in the rear shoes!!! If you do a burnout without a line lock, you're screwed.

Also, 2,000 rpm and only 1.5-2# of boost tells me it's a WAY too tight converter.

How well are the rear shoes adjusted? Adjust them out until you can just barely get the drums back on.

1) Since this car is being used for "road racing" it isn't getting another line lock on the front... the one for the rear is staying on because I am too lazy to pull it and bleed the brakes.

2) It is a tight convertor. It is a non-lock up unit... as is the transmission. And I hate it. With a passion. But this was necessary to keep rpm & heat down to a minimum on the highway. Yes, I have an oiler cooler too... but the bloody car also has 3.73 gears. [It is staying this way until next year when I go to a manual trans. Yes, a manual trans, and lower numerical gears. Needa the top speed. Yes, I will get the manual transmission to work effectively with a single turbo... it is called an expensive goal ] <- Shouldn't hijack my own threads

3) IIRC, the drums are set with alot of "drag". But I can have them double checked.

I guess making that "switch" work is my best bet to bigger boost holdage.