gear help

[willyj]

Need help on gear choice. 1/4 mile med. banking,lots of rain in Tn. lately so it has good grip but will go away later with temps rising.409 SBC 500ish Hp,currently 5.83 at only 7500.We dont want to go over 8000 rpm. Was thinking 6.20 which will prob go over 8000 and use chip.the driver thinks it will hit the chip too soon,I just dont know.Lots of folks say ole rule of thumb is for every .20 increase is app. 400 rpm. Yeah i know the leaders may be near 6.50 but our eng. cant stand the 8200-8600,oh UMP tires.

[cavemod]

I think you answered your question yourself .If 5.83 gives you 7500 and .2 in ratio gives 400rpm then 6.20 would be roughly 8300 so being as how you don't want to turn over 8000 then best choice is 6.00 which should be 7900 or stick with 5.83..What kind of chip rule you got 7800?

[willyj]

We do not have a chip rule. we dont want to go over 8000 for longevity purpose. we are leaning toward a 6.17 but unsure how long we would lay on the chip.thinking maybe someone on her has been in this crapshoot of a purchase decision before.I guess the q-change has an advantage in this situation.

[AJGARBER70]

Are you running clarksville?

[willyj]

AJG70, YES we are.

[AJGARBER70]

Then go to a 6.00 i have ran a 5.83 gear there a bunch and a 6.00 gear and always turned less rpm with the 6.00 you might turn 2-300 more rpm with the 6.00 than the 5.83 in hot laps but as the track gets slick you will turn less rpm with the 6.00 than you will with the 5.83 because you will have less wheel spin with the 6.00 good luck

[cassellracing24]

I have a 9" 3rd member built by JR Motorsports. It has a Ford case, Motive Light Weight 6.00 gear, Ultra-Light Weight Full 31 spline spool, New Timkin bearings with solid spacer (not crush sleave) New Short-Wide yoke, bought wrong gear, only 6 races on gear, paid $680 shipped. Sell for $450 shipped in JAZ tote to your door. If interested call & I will text Pic's if needed.

Brian (217)201-3640