vance.dykes
Well-Known Member
call Rick at A & A trans he has different gear sets for the 727 and they work great .when he first open he was one of the first to offer something for us mopar hard liners. ALL MOPAR OR NO CAR.
Trap rpm should dictate your gear ratio, tire size and to some extent torque converter. Where are you at rpm wise in the traps?
I would lower rpm shift light if you want it to shift at lower rpm
IMHO
Mike , maybe time to look at gearing . Doug runs a 4.1 iirc . The lower gear will let you run a little longer through the gears plus lower trap rpmOn a 140.04 run I was trapping 7200 thru the lights. 4.56 gear, 32" tall tires with 105" rollout and a 5500+ converter....and this was with the restrictor plates set to reduce airflow thru the twin Dominators by 50%....so...I would guess with the carbs opened up all the way it is going to be closer to 150mph at, of course, a higher rpm thru the traps.
And, sure, I will set the shift light to about 6000 because I do want to shift at 6500.
That is big time slippage, nearly 11%
Doug
How do you calculate the slippage....I have never had to address anything like this before. ThanksOn a 140.04 run I was trapping 7200 thru the lights. 4.56 gear, 32" tall tires with 105" rollout and a 5500+ converter
ThanksIn decent air; 4.30, trap rpm 7200@148, 31.5 diameter, 98.5" rollout, flash 6000
http://www.wallaceracing.com/mobile/converter-slip.php
Doug
Hey Chris, what's the weak link in a Torqueflite? I keep hearing that they can handle more than 1000 horses....I tried a power glide for 1 weekend and it was the biggest disappointment ever.
I thought my Torqueflite wouldn't handle 1180hp at the time.
Went out 1st time with the Torqueflite and ran 8.57@160.
But the 4th pass I smoked the clutches.
Pulled it out and wasted $5700.00 on a ATI Powerglide.
Went 9.11 next outing.
Only to find out that the Torqueflites Griner valvebody was defective.
Got it fixed and put the Torqueflite back in.
Ran 4 years without any problems.
Now new combo is 1275hp and going to try the Torqueflite still and see if it can handle it.
I did remove the low gear sets.
A& A low gear sets cant take 900 ft.lbs of torque
The record was set by Gary Wolkwitz (8.22) in 2015 and recently reset by Bucky Hess (8.20) both run proflites (904 guts in a 727 case made by Protrans)the reason why you hear about these things has nothing to do with cost
a long time NHRA world record holder
was a 426 hemi mated to a 2 speed power glide.
today I'm sure that has changed a bunch..
Protrans built my 727 and its 4 years old with 100’s of passes and has been 8.19/177 in a 3450 pound Dart with 10k miles on it 4 time Dragweek participant. The ET was achieved with 21% converter slip.call Rick at A & A trans he has different gear sets for the 727 and they work great .when he first open he was one of the first to offer something for us mopar hard liners. ALL MOPAR OR NO CAR.
The Pro trans stuf is nice. I freshed a few for people last year. Dave is great to work with. I'm very fortunate to have Joel here local That builds agreat unit as well. When you recorded 21% slip was it due to using a low axle ratio? Or is it intentional? We saw that much slip with our street turbo car running a 2.76.Protrans built my 727 and its 4 years old with 100’s of passes and has been 8.19/177 in a 3450 pound Dart with 10k miles on it 4 time Dragweek participant. The ET was achieved with 21% converter slip.
You are correct in your assement of rpm range. The converter has to put the engine in its sweet spot. Most often that will be flash stall somewhere between 500-1000 rpm below the shift point. Currently mine is about 800 below (7000 shift/6200 flash). My bet is it could still be a touch looser. When raising the shift point the flash stays at the same rpm.Doug, is converter choice more related to horsepower, or rpm?
(Example, a 7000 converter wouldn't do me much good with an engine shifted at 6000, even if I made 1000 hp, which I certainly don't, lol)