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-   -   gearing ? (https://www.racingjunk.com/forums/showthread.php?t=22361)

Tod74 11-28-2008 04:35 AM

HE said he had 14x 32 hoosiers.

dparker 11-28-2008 05:26 AM

Try this rpm/mph calculator. In your case type in the mph, gear, and tire size then click the mph its pretty close. These calculators are a good tool when your thicking about gear changes.
What the tire says on the side (14x32) means almost nothing. It just gives you a ballpark figure.
To get a true tire size, take your roll out and divide it by 3.1416 and that will give you a exact tire height. Your 105 rollout, 105/3.1416=33.42

http://golenengineservice.com/calc/calcrpm.htm

http://www.1bad69.com/calc.htm

Tod74 11-28-2008 06:07 AM

Wow that calculator isn't even close for mine...does that mean the converter is too loose? I have 32 x14 goodyears and the rollout I think is 102. Last time out I was right around 67-6800 at the eighth and my mph was 110. I have a 5.14 rear gear.

dparker 11-28-2008 06:16 AM

Sounds like your converter is not locking completely up. These equations are usually within a couple of hundred RPMs. Supposedly your converter never fully locks up. But should be 95% locked up on the big end.

Tod74 11-28-2008 06:20 AM


Originally Posted by dparker
Sounds like your converter is not locking completely up. These equations are usually within a couple of hundred RPMs. Supposedly your converter never fully locks up. But should be 95% locked up on the big end.

Converter was built for a smaller motor that I had previously...it had very few runs and I figured I would just try it...It is a COAN 8" and he told me the same thing...just try it and let him know how it did and go from there. It was built for a 454 this is a 540 makes a lot more torque. I have never tested how high the converter goes with this engine but I did with the smaller one. It went 5400 behind the 454.

bjuice 11-28-2008 03:34 PM


Originally Posted by dparker
Try this rpm/mph calculator. In your case type in the mph, gear, and tire size then click the mph its pretty close. These calculators are a good tool when your thicking about gear changes.
What the tire says on the side (14x32) means almost nothing. It just gives you a ballpark figure.
To get a true tire size, take your roll out and divide it by 3.1416 and that will give you a exact tire height. Your 105 rollout, 105/3.1416=33.42

http://golenengineservice.com/calc/calcrpm.htm

http://www.1bad69.com/calc.htm


:wink: ...there ya go !

my 17x33's with a 101 roll out is actually only 32 inches tall

john858 11-28-2008 03:54 PM

Brian,what kind of slicks do you run? Tod i did the same thing just tried the converter i had & ended up having one built. warning thought when you get one that works it shows all your other problems :lol: of coarse i went from sbc ,176 glide to alittle bigger combo :lol: .thanks again guys your the best.john

bjuice 11-28-2008 06:30 PM

M/T
Jegs Part# 672-3088

Tod74 11-29-2008 12:12 PM


Originally Posted by john858
Brian,what kind of slicks do you run? Tod i did the same thing just tried the converter i had & ended up having one built. warning thought when you get one that works it shows all your other problems :lol: of coarse i went from sbc ,176 glide to alittle bigger combo :lol: .thanks again guys your the best.john

I'll have one built just as soon as I destroy this one. :lol: I paid $900 so I'm using it. I already asked COAN about reworking it to this combo he said no dice...said try it and see but if it was too loose I'd have to go with a 9"

dparker 11-29-2008 12:19 PM

Dang Todd this is Racingjunk.com sell yours and get a 9" that you want. Hect your car might scare you with the right converter.


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