I was running some numbers on how much my converter slips.

Right now I trap 128 MPH at around 6800 rpm with a turbo 400 (1.0 ratio 3rd gear) ,3.73s gears, and 28 nch tires. In theory, the car should trap 151 mph. So..... 128/151 MPH give about 16% slip. Is this to much????? Any opinions would be welcomed.

 

Seems a little high. Assuming 1" tire growth I get 157 @ 6,800 for your combo. If your trap is 128mph I estimate ~18% slip (29/157). Mine is a bit less than 12%. What does your converter stall at?

Rich Krause

 

Rick,

I can foot brake to about 2800 RPMs. The convert flashes to about 4500 ish on takeoff.

 

Seems high. I usually see less than 15% except for extremely high stall situations. Is it a new converter?

Rich Krause

 

It was a new converter. Maybe two dozen passes on it.

 

actually your final gear ratio is a 1.1 not 1.0 and you can go to www.prestage.com and go to the carmath section and figure out your MPH but it looks like youll be maxed out at 138 but with a 1inch tire growth youll get 143 I hope this helps

you can go directly to it here

http://www.prestage.com/Car+Math/Gea...H/default.aspx

 

If a TH400 has a 1.1:1 top gear that's big news to me. What is the source of your information?

Rich Krause

 

Hmmmmm..... my TH400 has a 1.00:1 3rd gear.

I was running 28" QTPs, 3.73's, TH400 and a convertor that comes up to about 3,000rpm on the foot brake, and flashes to 5,000rpm with an 800 ft-lb launch. Slip was measured at 10.5%. Tire growth was estimated at 0.50" at 128mph, based on hitting the leading edge of fender at anything over 120mph.