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Author Topic:   final drive ratio ???
hotstock15
Member
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.


racer17j
Member
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


Whitelightning
Member
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.


hotstock15
Member
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.


Baxter00
Member
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
Member
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!!!

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Just a little crazy!!!!!!


bigcitycowboy
Member
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.


Eljojo
Member
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.


outlawstock17
Member
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....


dirtracer7
Member
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).]

ctfarm
Member
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


bigcitycowboy
Member
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.


wermm
Member
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


Raz_900
Member
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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