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-   -   6500rpm stall converter tooo loose? (https://www.racingjunk.com/forums/showthread.php?t=33614)

happyfast 07-07-2013 09:01 PM

6500rpm stall converter tooo loose?
 
the motor is a 706 CI big block Chevy. The trans is a Powerglide. It makes maximum horsepower at 7000 rpm and maximum torque at 5600rpm. I think most people would recommend a 5600 rpm stall converter.the last car I had had a similar motor hp range, similar converter and I tightend the converter to 5500stall and it did not speed up the car or drop the et at all. So what are your thoughts would make any difference to change it?

hammertime 07-08-2013 04:18 AM

Need to know more about what car its in, weight, trans, rear gear and tire ? and what type of racing do you do?

6500 is pretty standard now days, most are even higher.

happyfast 07-08-2013 09:11 AM

[quote="hammertime"]Need to know more about what car its in, weight, trans, rear gear and tire ? and what type of racing do you do?

is 6500 pretty standard with a peak horsepower @seven thousand Rpm? How interesting. the car Iis a Top Sportsman 63 split window tube chassis vet made by Spitzer in 1995, tires are 32 inch paddle tires for sand drags..I am guessing the car weighs about 2600 pounds without me in it I am a hundred sixty pounds.powerglide has standard gears,the rear gear ratio is 410.
I really appreciate the help. I only get to run this car a few times a year and it is not enough time to iron it out by just test and tune.I shift at one and a half seconds which is usually about 6,900 rpm and I finish the 100 yards at 6500 rpm.I am happy with the ET which is 3.6,s but I want to understand the car better.I am assuming that because it is not finishing at a higher rpm that I am wasting some power through the converter ,perhaps could use some lower gearing, but wanted some information from someone with more experience than I have

hammertime 07-09-2013 05:58 AM

Knowing it needs to accelerate quicker for a short distance, 5500 is to tight, but 6500 is on the loose side. 6100-6200 would be a perfect middle ground. A 8" converter would also accelerate and be the quickest in a situation like this.

TheRabbit 07-09-2013 01:48 PM

[quote="happyfast"]

Originally Posted by hammertime
Need to know more about what car its in, weight, trans, rear gear and tire ? and what type of racing do you do?

is 6500 pretty standard with a peak horsepower @seven thousand Rpm? How interesting. the car Iis a Top Sportsman 63 split window tube chassis vet made by Spitzer in 1995, tires are 32 inch paddle tires for sand drags..I am guessing the car weighs about 2600 pounds without me in it I am a hundred sixty pounds.powerglide has standard gears,the rear gear ratio is 410.
I really appreciate the help. I only get to run this car a few times a year and it is not enough time to iron it out by just test and tune.I shift at one and a half seconds which is usually about 6,900 rpm and I finish the 100 yards at 6500 rpm.I am happy with the ET which is 3.6,s but I want to understand the car better.I am assuming that because it is not finishing at a higher rpm that I am wasting some power through the converter ,perhaps could use some lower gearing, but wanted some information from someone with more experience than I have

Honestly the max torque at 5200 looks low rpm's for that motor. The 6200 converter is fine. That's what I use to run with my NA setup. That's higher than you need to launch tough. With paddle tires and as light as you are you can launch a little higher than I can but not that much higher. Also the track you run on makes some difference to that too. However, even when I run paddle tires 3500 to 3800 is still the magic #. If it's sandy much more rpm's and tires go down before they go forward. Don't be scared to try to lower your launch rpm's

BTW You would be a good bit faster by not shifting at all. I run a glide that has 2nd gear taken out completely. I run low gear all the way, but you can't be scared to turn the motor hard. 8,200 to 8,400
is my normal rpm max with 2 kits on. On motor I use to turn 7,600 - 7800.

happyfast 07-09-2013 04:38 PM

thank you for the response everybody, rabbit that truck is awesome

TheRabbit 07-10-2013 01:50 PM


Originally Posted by happyfast
thank you for the response everybody, rabbit that truck is awesome

Thanks. I read your original post but didn't reply because these guys have a lot more experience and know more about normal drag racing than I ever will. I started smiling as soon as I saw "32 inch paddle tires..."

jtortorete 02-22-2014 07:19 PM

Happyfast

What converter did you end up putting in your car? Stall wise that is? Who's converter? What was the converter efficiency in percentage?

I am doing something people do not do. I have a 632 in a 2500 lbs with driver car. I run a 1.98 planetary, and short shift a tight converter. Greatly improved my 60 ft's and MPH-ed like a bitch.

JT


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