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Author Topic:   final drive ratio ???
posted September 24, 2003 11:42 PM
hey everyone this is a great forum. This is my 1st post on here. I am considering running a new track that is a 1/2 mile in size.I have a 2800lb camaro which we call hotstocks in north texas.the track I race at now is a 1/4 mile in the racing groove. I currently run a 7.27 final drive. I need some ideas on what ratios would work on the 1/2 mile track.It has sweeping turns and has a pretty good banking. Any help would be appreciated.

posted September 25, 2003 12:28 AM
i take it that you are running some pretty tall tires on the rear from the l;ooks of it you might want to be in the 6.33/6.50 range

posted September 25, 2003 03:31 AM
most guys at my track (1/2 mile dirt) are running anywhere between 6.00 & 6.33, I myself run a 6.20. The purestocks are running a little less gear like 5.72 or something.

posted September 25, 2003 03:48 AM
oops. I guess i should have added my tires are 89 to 90" tall on the right side.

posted September 25, 2003 10:04 AM
Most drivers down at Devil's bowl which is a 1/2 mile run anywhere from a 6.00-6.50.

jhon hollomon
posted September 25, 2003 01:05 PM
WOW!! The guys that run street stock where i'm from run about a 5.43 to a 5.67 on the half mile with the taller tires and they turn some r's!!!

Just a little crazy!!!!!!

posted September 27, 2003 12:36 AM
i race at a 1/2 mile dirt track in street stock. the most common gears are 6.33 and 6.50. i run a 6.33 with a 90.5 roll-out tire. i turn about 5600-5900 rpm. depends on track conditions. with that tall of a tire, u might to get alittle more gear,like 6.50, or try getting a smaller tire, like 84-86 inches maybe. i just changed tires recently, to get alittle more rpm in the corners. hopefully it works. good luck and let us know how its does.

posted September 27, 2003 07:05 AM
I too gotta say "WoW" I run a 6:20 on a 4/10 and we BOOK! You guys running 6:33's on 1/2 miles--have you guys got low hp motors? What kind of lap times are you turning? I wouldn't think of running my 406 with anything taller than a 5:67 (85" tire)on a half mile.

posted September 27, 2003 07:14 AM
i'm with you eljojo. i run a 6.20 on a 3/8's and i'm all over the 7400 rpm rev limiter getting into the corners. 84 1/2" rear tires....

posted September 27, 2003 11:09 PM
I run 5.67 86" tire 7000 @ the end of the straight .Most others at this track run 5..14 ---5.43 with 84" tires don't know there rpms.oh yea its a 1/2 at the inside rail 5/8 in the middle.

[This message has been edited by dirtracer7 (edited September 27, 2003).]

posted September 28, 2003 12:18 AM
You've got to gear the Devil's Bowl for the back straight.It's an uphill climb from #1 to the middle of the back straight.6.20-6.50 is the preferred gear.I've ran as low as a 6.90.8400 R's

posted September 29, 2003 12:39 AM
well yea our engines are really stock we are only aloud stock parts. 360 max cubic inch. stock stroke. 160 pump compression max(9.5-10 to 1). 485 hydraulic cam max. cast iron intake and exhaust manifolds, HEI's, and a 2 barrel carb. no port work anywhere.

posted September 29, 2003 05:43 PM
sounds like the rules at my track, I run 6.20 and turn 6400 on a 1/2 mile track that looks like two drag strips with a u-turn at each end. I also run the American Racer 245's

posted September 30, 2003 08:50 AM
Must be nice to have rules that'll let you run a motor to handle 7000-8000 rpm!!!

Most stocks at my track run 4.88 to 5.43 with 86" tires. We're turning aroun 6000-6400 with 5.14s. I did run the last race with 93" tires and 5.67s turning 6500-6700. Unless you're motor can handle 7000+, I wouldn't go over 5.67/5.83. Plus, turning 7000 with a cam meant for 6500 will make you slower. Make sure you match the gear/rpm to the cam/powerband.

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