Advice on stall speed for new combo

One of the most critical areas of a automatic race car

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supernova
Posts: 2552
Joined: Sat Feb 02, 2008 7:35 pm
Location: Ft.Worth Tx

Advice on stall speed for new combo

#1 Post by supernova » Wed Oct 08, 2008 6:58 pm

Hey Marty,
I'm in the process of building a new car. It is a 1972 Nova. This car is a full 14 point roll cage, drag radial tire (275-60-15, class rules), 4.30 rear end gear, 525 c.i. bbc, power glide (1.76), on nitrous (200-250 shot). The motor made just over 1000 hp. on the bottle and right at 900 ft. lbs of tq.
The 900 ft lbs of tq was at 5000 rpm's and the 1000 hp was at 7000 rpm's. Too much power hence the new car. I have run this motor in a 1973 nova not built like this new car and was wondering if a converter change is in order to go faster. The new car is definitly a race set up and the 73' was a street car more or less. Not near what the new car is.
I ran a 3500 stall in the old car and got 3800 out of it (street converter).
I was thinking of going to 4800-5000 stall. I have the timing and nitrous controls that it will take to run this kind of power on the small tire so that is not a concern.
Any advice would be helpful.

Thanks
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

Marty Chance
Posts: 193
Joined: Fri Sep 19, 2008 6:34 am
Location: Cheney, KS

Re: Advice on stall speed for new combo

#2 Post by Marty Chance » Thu Oct 09, 2008 7:28 am

This may not be the answer you are wanting , but you should make some passes on the new combo and get some DATA LOGGING on the car to see how the converter is working with the power plant , this means you will need something on the car that records at least engine rpm going down the track , some msd boxes have this capability built in , or auto meter makes a tach that will download to a computer or we have a data logging system on our web site that starts at $588 and records engine rpm , driveshaft and battery (www.racingconverters.com ) and can be added on to one piece at a time until you have a full blown data recording system . I tell you all of this because you may not need to buy a new converter , your old one may work great like it is or may only need to be fine tuned but we need some data on how it is working to know what may need to be done to it. If your converter stalls 3800 on motor it will about 5000 with the nitrous
Neal Chance Racing Converters
Home of the World's Fastest Automatic Doorslammers!
www.racingconverters.com

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supernova
Posts: 2552
Joined: Sat Feb 02, 2008 7:35 pm
Location: Ft.Worth Tx

Re: Advice on stall speed for new combo

#3 Post by supernova » Thu Oct 09, 2008 8:39 am

Thanks for the advice.
I don't have a data logging system now but am putting one on the new car. Will check out your site and look at your data logging systems. It would be nice if I didn't have to buy another converter as the one I have was $1200.00.
Blackhoodmafia!!!! :mrgreen: :mrgreen:

1972 Nova SS
572 C.I. BBC

Best to date: 1/8
et: 5.28
mph: 134
new wt. 3340 lbs

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