[Colorado Bill]

Somebody posted torque multiplication numbers for various stock converters a few weeks ago, but I can't find that discussion. The talk of generic vs. Pontiac specific converters got me wondering about my setup, though.

I'm using a Hurst Trophy Taker, rated 400-600 rpm over stock, 3600 lbs, 400 with 228/236 @.050. At 3500' elevation, best 60'times:
2.39 with 2.73 gears, 26x8.5 slicks
2.14 with 4.10 gears, 26x8.5 slicks

The engine and trans came out of a '70 GP (may the Black Shark rest in peace), 350 hp rating, 2.93 gears. No 60' data on the GP, but there was definitely a delay between idle and the powerband with the new cam and stock converter. I changed to the Hurst converter when I swapped the drivetrain into the new car, so I don't know how the stock converter would work with the lighter weight and the gears.

So finally, my question is, could my stock GP converter work as well as or better than the Hurst with less weight and the 4.10 gears? Or should I stay with the looser converter because of the cam? I'd like to try one of the custom units I've read about, but the price is right on these two.

[Colorado Bill]

Somebody posted torque multiplication numbers for various stock converters a few weeks ago, but I can't find that discussion. The talk of generic vs. Pontiac specific converters got me wondering about my setup, though.

I'm using a Hurst Trophy Taker, rated 400-600 rpm over stock, 3600 lbs, 400 with 228/236 @.050. At 3500' elevation, best 60'times:
2.39 with 2.73 gears, 26x8.5 slicks
2.14 with 4.10 gears, 26x8.5 slicks

The engine and trans came out of a '70 GP (may the Black Shark rest in peace), 350 hp rating, 2.93 gears. No 60' data on the GP, but there was definitely a delay between idle and the powerband with the new cam and stock converter. I changed to the Hurst converter when I swapped the drivetrain into the new car, so I don't know how the stock converter would work with the lighter weight and the gears.

So finally, my question is, could my stock GP converter work as well as or better than the Hurst with less weight and the 4.10 gears? Or should I stay with the looser converter because of the cam? I'd like to try one of the custom units I've read about, but the price is right on these two.

[Half-Inch Stud]

Get rid of the off-idle bog first.

[Half-Inch Stud]

I posted Stock Converter Torque Mult values several weeks ago...a mere faded cloud of numbers now.

[Colorado Bill]

Half-Inch:
What I meant by a bog off idle was that putting a bigger cam in the GP killed the bottom end with high gears and the stock converter. I could feel it really start to pull between 2500 and 3000, but it took awhile to get there. I don't have that problem with the current setup--I was just wondering if the stock converter might be a better choice than the Hurst now that I have about 400 lbs less car and low gears. Maybe I just answered my own question--don't mess with it if it works.

[Half-Inch Stud]

OK.
So, the converter being the only Horsepower issue [at the driveshaft]. When the Throttle is mashed wide-open....
I assume the Engine can respond with gobs of torque. I'd call that a "tall pedal feeling"

If you have that, then you would use the higher stall converter for the best 60' times. Even with the lighter car.

Issue becomes how little slip the converter has at the end of the track. These days the converters [including <10"] can be expected to have little slip.
Sooo, you decide if the higher stall converter is efficiently coupling like some other design claim.

No more guessing needed. [I run a 10" on the street with a puny cooler]