Powerglide question

[TwinT66]

I`m running a glide in my backhalve car.I think I`m blowing thru the converter.On the Felpro in the recorded runs there is no RPM drop during the shift.The rpm starts at 7000 and ends at 7500.It just looks like a strait line.The gearing in the glide is a 1.75 then 1.0.Running a 9inch converter.Also to determin the stall speed on the brake I can hold the car up to 7500 and at 25+ psi on the brake.So I think the converter is too loose.This whole combo is on a twin turbo v6.
Thanks again
Tony

 

[KEVINS]

Yep, I'd say your converter is a bit on the LOOSE side! We had the same problem on a friends truck. The shift light was set at 6500 but it was suppose to be a 5000 stall. As soon as he'd let go of the t-brake the light would mementarily come on. It would run 9.4's @ 136 all year long. We finally switch converters and it went 9.0 @ 148 first run! According to TCI it was not the converter, though

ks

 

[TwinT66]

On first run on the car it went a 8.90@154 with a 1.31 60ft.
The car felt lazy down low.So it looks like went I switch the converter the car should pick up mph I hope.
Thanks again
Tony

 

[KEVINS]

Here's a formula that I use for gearing my cars:

RPM = (336 x mph x gear) / Tire diameter

For the tire diameter you can measure from the axle centerline to the ground then double that measurement and this will be closer to the "actual" tire diameter while it's rolling. I have always found it within 200 rpm. If your RPM is more than 300 rpm then I'd say the converter is slipping.

hth's
ks

 

[TwinT66]

Thanks KS, This is what I came up with:
336 x mph x gear / tire
336 x 154 x 390 / 33 = 6115
I was crossing the line at 7500 so I think I`m off by 1300 rpm
Thanks again
Tony

 

[KEVINS]

OUCH!!! Yep something is WAY OFF!!

Good Luck!

KS