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Discussion Starter #1
I'm having some trouble with a fresh powerglide, I believe may be charge-pressure related. I'll try to be brief-

New car, "poorboy" street car. 2700lbs raceweight, Junkyard LQ4 with bolt-ons, fresh 'glide, some spray, 275 tire.

Transmission and converter was purchased from a builder in the south. not here to bash, service has been OK, but shipping parts from Alberta to Texas especially with our anemic Canuck Buck, gets expensive really fast. so, hoping to get it fixed here at home.
Trans is stock case, GM pump, 1.76 gear, turbo spline. BTE valve body with brake, -6 cooler ciruit

trans seems to function ok, EXCEPT-

1) converter is very tight. spec'd 3800rpm, the thing struggles to get to 2800 on the brake. Engine starts ok until hot, then starter struggles to turn the motor. Odd for a low-squeeze junkyard LS....
2) first race out we made 6 passes before the trans split the case across the back- in the reverse piston area. I swapped the case, also swapped to a higher-stall TSI spragless converter i had laying around from previous car. off to the next race....
3) Second race- the TSI converter is getting to about 3400rpm...still tight, was expecting much more stall rpm based on experience in other car. Made it five rounds before wiping the thrust out of the engine.
4) Swap engine (identical setup), also install a new PTC converter spec'd for this setup, approx 4200rpm. On fireup, once again the converter seems very tight. against the brake, car struggles to get to 3000rpm. have not called PTC yet as its long weekend...

All converters had nice engagement into the back of the engine, about 1/8"-3/16" clearance to the flexplate and slid nicely into the crankshaft pilot.
Checked line pressure at servo cover. around 210psi in gear cold, just over 200psi warm. Didn't check above 3000rpm.
Cooler line pressure- bottom line never over 50psi at any rpm. top hose slighly less.
I took the pump apart today, the input shaft is a nice looking aftermarket piece- solid, with a single teflon seal. After surfing here a bit, i went looking for an orifice installed in the converter charge circuit...can't seem to find one.

so, here's the question- is it possible to have excessive converter charge pressure even though the cooler circuit does not have high pressure? how would a fella confirm such a thing?
 

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Very possible to have a charge problem. If its apart with no pressure test it will be hard to tell what the problem is. If you want to ship it out, I'm in the same country at least.


Hutch
 

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Discussion Starter #4
thanks for the quick responses

jakeshoe- hard against the brake, all three converters, between 42- 48psi on the bottom hose (2800-3400rpm)

I would love to send to you Hutch, I'm really hoping to run the car one more time (Sept 11/ 12) before winter...perhaps after that...
 
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