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Author Topic:   Gear Selection
rfriellymotorsports
Dirt Full Roller

Total posts: 44
posted August 03, 2005 06:46 PM  
What rear gear would be good for a 4/10 mile dirt track .....rpm's need to stay around 7200-7400

GO 24
Dirt Freak

Total posts: 366
posted August 05, 2005 01:51 PM  
Tough one, kinda depends on how wide the corners are, the typical groove of the track along with the actual track conditions. When we run a 4/10th 608 seemed to be our baseline (kinda on the high end though).

rfriellymotorsports
Dirt Full Roller

Total posts: 44
posted August 06, 2005 06:58 PM  
quote:
Originally posted by GO 24:
Tough one, kinda depends on how wide the corners are, the typical groove of the track along with the actual track conditions. When we run a 4/10th 608 seemed to be our baseline (kinda on the high end though).

Somebody said a 529 or 523 is good ....the corners are about 200 feet with 20 degrees of banking...i got it on a 614 now but nevere run it on that big of track...but runs good on the 3/8s...

GO 24
Dirt Freak

Total posts: 366
posted August 09, 2005 07:32 AM  
Hmmmm, on a 3/8th were in the 650 range, is your ring/pinion a 4.86? If your sure on the ring/pinion I'd ask one of the front runners when you get to the track and at least you'll be in the correct range. We turn our steel spec motors 7200-7400 rpms whereas a IMCA spec maybe add another 200 pts and a 700hp full blown another 400.

rfriellymotorsports
Dirt Full Roller

Total posts: 44
posted August 09, 2005 08:52 PM  
quote:
Originally posted by GO 24:
Hmmmm, on a 3/8th were in the 650 range, is your ring/pinion a 4.86?

It is a FORD 9" rear end my winters (4.86)quickchange is broke BAD broke at that so i have my 9" under it now....CHEAPER AT present to buy 5.29 @ 149.00 dollars than repair Quickchange.(EST> REPAIR $450)...POOR BOY RACING THE REST OF SEASON!......if you are running your car on the 3/8ths w/608.....I may try the 614...then..whats the worst i can do BREAK....

GO 24
Dirt Freak

Total posts: 366
posted August 10, 2005 07:45 AM  
yeah I hear ya. Good luck!

rocket36
Dirt Freak

Total posts: 209
posted August 12, 2005 08:14 PM  
it doesn't matter whether your ring and pinion in a quick change are 4.86 or 4.11, it just means that you will require a different quick change gear set to achieve the same desired final drive, in go24's example 6.50 is the final drive. you do need to know which ring & pinion you have so that you can read the gear chart correctly and select the right gear "set" number.
i know go24 will know this but i thought i'd just add this for some of the newer guys as they often get confused.

RCRacing #08
Dirt Maniac

Total posts: 121
posted August 15, 2005 11:17 AM  
i KNOW THE GEAR SET......BUT MY QUICK CHANGE IS OUT OF CAR IT IS BROKE ....I GOT MY FORD NINE INCH NOW.....WITH A 614 GEAR....BUT HAVE A 529 I WAS GONNA TRY IT ON THE 4/10 BUT WILL SEE WHAT THE 614 WILL DO WITH ME RPMS....

TBROOKS
Dirt Roller

Total posts: 14
posted August 16, 2005 10:20 PM  
GO UP TO LEFT CORNER WHERE IT SAYS MENU CLICK ON IT AND GO TO TOOL BOX, THERE IS A CALCULATOR IN THERE THATS VERY HELPFULL. WE RUN A SUPER LATE MODEL ON 4/10 TRACK AND WE RUN A 570 TURNING 8000 WITH A GERTE MOTOR.REMEMBER 7 POINTS ON A GEAR IS 100 RPM. GOOD LUCK

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