DragStuff

i am wondering if i will pick up with a 9-inc conv. as of now, i have a 8-inch that flashes to 6500-rpm off the brake,and has about 8-10% slip, my combo is a n/a 565 motor,shift at 75-7600-rpm cross the traps at 7500-rpm at 150mph plus.its not blowing through the conv. now,but was just wondering if it will help, or will it be a waste of $$$,thanks in advance.

I could be more accurate with an answer for you if i had a dyno sheet on the motor and a data log of a run, but here is some general information. The lighter weight 8" is going to have the potential to be faster if set up correctly for your car , but if you are bracket racing the 9" has the greater potential for consistancy in that the larger fluid coupling has a faster rate of lock up and the larger converter holds more fluid so it does not effect the viscosity of the fluid as quickly as the smaller 8". With all that said , the 8" could be set up for your car and work great with out the expense of a new converter.

thanks marty

when i made this last post, i had not dyno'd the motor,now i have some dyno info,the motor made peak hp@7400 rpm.975 hp, and made peak tq@6200 rpm 775 ft lbs,now with the 8-inch it flashes off the brake to 6500-rpm shift @ 7800-rpm, fall back to 6700-rpm. for next season i am thinking of trying a 9-inch conv.my questions are,is the flash stall too high for my peak tq/also with the given info, would a 9-inch conv. work better??thanks for any info.

forgot to add its a t-400 with a griner brake,and has 4.10-gears,car weighs 3500-lbs, and is a ladder bar car,mostly heads up type stuff,not really a brackett car fwiw. also the conv now is a tci 8-inch with a c-300 plus stator if that helps also?

For heads up racing with the 3 speed trans , it sounds like the converter is very close. And with the peak torque @6200 i would be surprised if the 9" was faster. I would like to see a data log on a run to make a final decision , but it sounds like your 8" is dialed in pretty good.