Drag Racing Discussions > Front Engine Dragsters

Rear wheel width

(1/3) > >>

masracingtd1167:
I have been using a 12 inch rim with my 12 inch tires but I have a set of 10 inch rims that are super light . Just wondering if any one else has any experience with this ? The tires are the Goodyear 2585's Thanks Bill

GlennLever:
Look the tire up on the manufacture web site and they should tell you what rim width you can use with the tire.

dreracecar:
Go with the 10"  reason is that on the burn out the sidewalls will square up and the contact pattern on the surface will be even. Going with the 12" the tire will triangulate and concentrate harder in the center of the tire surface

JrFuel Hayden:
Bill, for years we ran 12" tires on 10" rims, but as we started running below 7.20's I found we needed a 11" rim, mostly for the finals at Bakersfield when the sun went down and the track cooled off. Then as we made more power, we were using the 11"  D2585 combo more based on the tire speed I saw on the RacePak computer. So then I made-up a 12"/ D2585 combo for declining tracking conditions. The wider rims also were needed not only for the start-line, but also when the car would move around at half track. The wider rims kept our 60' times 1.01 - 1.04. The down side of wider rims is the tires will not grow as much, so the MPH is lower. As a matter-a-fact one of the Heritage J/F racers racing the lightest car [1355#] & running with the smallest motor [ 387ci ] doesn't like to run 12" rims because of the slower MPH, but then again he's running canard wings to try to get a hold of the track around the 1/8 running on his 11" rims. 
BTW we run 5 3/4 to 6 1/4 lbs of tire pressures, and launch at 6,000 to 6,400 rpm. I had Bogart widen our 10" rims to 12" because we don't use the 10" anymore, only the 11" or 12".
So, use your light 10" rims until you have traction issues, because racing a JrFuel type car, you need tire speed to keep the motor in the RPM it will work best. Case-in-point if your 60' are above 1.15, use the narrower rims and raise the launch rpm, and maybe lower your tire pressure to increase your tire speed. As you lower your tire pressure the tire will concave in the center and run more on the edges. To confirm that check your tire temps right after your run, going across the tire tread with your temp gun, you can see the temps are higher on the edges. I always check the tire temps when I pick-up the race car after a run. I also check engine temps just before final staging and after the run, so I get an idea what to change for the next run.
I can see Bruce has good results with his blown alky SBC on 10" rims using 33" tall tires [ I think] because he's making different power at different points in the track than our injected alky 400 ci SBC's.
Glenn's point about asking GoodYear what rim to use, is a good idea, but for the D2585's their chart says 12" rim, and they are conservative suggesting wider rims for more traction. GoodYear has told me "use rims only 1" on each side of the tire size", ie 12" tire use no less than 11", and no more than 13". Racers still have to decide what combos work best for them.
Feel free to call me with any questions, 805-444-4489
Good Luck racing,
Jon 

Paul New:
Great information Jon!

Navigation

[0] Message Index

[#] Next page