illegal87

It is the non-lockup type on a 87' IROC. I just put it in today. The roads are wet cause it is raining. Could this be the reason? If it was dry would it hold another 750 rpm? people say that torque has alot to with stall speed. I understand that, and I do have just a 305. Although that little hoe with the TPI makes alot of torque.

Willie

iTrader: (1)

I think you're confusing brake stall with flash stall. Brake stall is essentially a function of how good your rear brakes are and on our third gens, they are awful. It is the point where engine torque overcomes your brakes and starts spinning the rear wheels. The 1300 stall you're getting must be brake stall.

When you "flash" the throttle, the engine rpm's rise quickly. Flash stall is the point where the converter actually starts transferring torque to the driveline.

I'm curious why you chose a non-lockup unit. You may know this already, but be prepared to experience a noticeable drop in gas mileage and higher running transmission temps.

For example, I currently have a Precision Industries converter that has a brake stall of about 2,000 rpm's (my rear brakes suck) and a flash stall upwards of 4,000 rpm's. It is a lockup unit.

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Willie

Supercharged 1987 305 IROC-Z, Daily-Driver, Emissions-Legal.
Paxton (6-psig): 12.57 @ 111 mph.
Paxton (6-psig) & 50-hp nitrous: 12.04 @ 114 mph.
ATI D1SC (10-psig): ?

http://willie.camaro-firebird.org/

1987 "20th Anniversary Commemorative Edition" Z28 Convertible -- Super Chevy Show Class Winner, 1998.

[This message has been edited by Willie (edited March 28, 2001).]

AlkyIROC

Also the rated stall on the converter will vary depending on how much torque is put out by the engine. That same converter behind a 400 will stall higher.

My car has a "3800" stall converter and I can only hold the brakes to 2400 with a 383.

The only way to can see how much stall the engine can put into the converter is with a transbrake. This will lock the transmission in first and reverse gears preventing any power out. You can then bring then engine up to full throttle and the transbrake will hold allowing the converter to build up to it's stall. When the transbrake is release, the reverse pressure is dumped allowing a high rpm launch. This is hard on driveline parts and not recommended for street use. It would be like reving up the engine to 4000+ rpm with a manual tranny and dropping the clutch. U-joints and ring & pinion teeth don't last long especially with our tiny parts.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
461 Big Block installed and ready for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley