Visit The Dirt Forum for More Information

Author Topic:   Gear Ratio For 3/8 MIle Track
Raceman17
Dirt Maniac

Total posts: 165
posted March 17, 2005 03:08 PM  
Hey I was wanting to know a good gear ratio to run on a 3/8's mile track. Im using a 350 in 2nd gear with a 3.73 in the rear. so The total rear ratio is 5.66. The car is just spinning out of the corners. We a limited to 235/75/15 DOT tires. I installed a posi in the rear thinking that would make it better. It did but, I am still getting a lot of tire slip. Any suggestions. Also the track is always VERY dry slick.
Thanks

I-B-RACIN
Dirt Maniac

Total posts: 132
posted March 17, 2005 04:13 PM  
I always ran a 2.73 rear gear and 200 or 350 turbo trans in first gear. Dont know if there is any advantage to running second gear in trans and highr gear at rear..I ran about 6300 rpm

Steve Dupree
Dirt Freak

Total posts: 316
posted March 17, 2005 04:18 PM  
most people we know run like a 6.20 final on that size track. We run a 6.50 a very seldom have that problem.

racer17j
Dirt Forum Champ
Total posts: 5390
posted March 17, 2005 07:27 PM  
We're not allowed to run any weight in the car anywhere so I know the rear percentage is no where close to being more than 50%. Its proabbaly more like 47%. And yes the driver has been trying to easy onto the gas to stop that wheel spin. So it would be a good idea to change the gear? Thanks

M1
Dirt Freak

Total posts: 257
posted March 17, 2005 10:59 PM  
could also try some softer springs on the back to get it to transfer some weight onto the rear tires. we race on a dry slick a lot, and I use the weakest springs I possibly can. we are also not allowed to add weight, PLUS we cannot lock the rear end, so its tough.

racer17j
Dirt Forum Champ
Total posts: 5390
posted March 17, 2005 11:34 PM  
Right now I have a 200 on the LR and a 225 on the RR. Should I go down from there? Would "REAL STOCK SPRINGS" be better
Thanks

AtomicPunk
Dirt Maniac

Total posts: 130
posted March 18, 2005 07:56 AM  
Switch the rear springs, you want the car roll over onto the RR. Both Speedway and Midwest Motorsports offer stock appearing (pig-tail) style springs in various rates.

petordragon
Dirt Maniac

Total posts: 167
posted March 18, 2005 11:30 AM  
get your cross weight right and that will help alot. right front and left rear should have the stiffer of the two spings for that end of the car.

Raceman17
Dirt Maniac

Total posts: 165
posted March 18, 2005 11:37 AM  
LAst week at practice I switched the two around. Putting the 200 lb on the lr and the 225 on the rr. I talked with a buddy of mine who works in Nextel cup and he suggested I do this to try and set the car down more on the lr. So when I go into the corner, the lr would not want to transfer ALL the weight off of it to where I would still be pulling some from the LR. Should I change the springs in the back to softer rates? Right now, the ride hight is about 10.5 inches across the back with those "speedway STOCK APPEARING" springs.

M1
Dirt Freak

Total posts: 257
posted March 18, 2005 12:08 PM  
We are not allowed to use those kind of spirngs, so I wouldnt know. We have to use stock springs, so I have never even had mine rated. I use the saggiest ones I can!!

My home track we arent allowed to add weight, but i also race at another track (superior speedway) and we have to weight 3200. I just add 65 pounds right above the rearend and Im over by 25#'s after a feature

I use a 22 gallon cell and have the battery in the back. I also have never had mine on a scale (other then weight in at Superior Speedway) but going off of tire temps we took one night, I get the right hotter then the left rear, and with a one wheel wonder, thats pretty good.

petordragon
Dirt Maniac

Total posts: 167
posted March 21, 2005 09:24 AM  
I use the saggiest ones I can!! LOL that's funny don't care who you are argh argh!!!!

Back to the Archives