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Author Topic:   1/2 mile gears
Oldsmobile13
Member
posted October 22, 2001 04:32 PM
i run 5.83 most of the smallblock chevy`s run 6.0


jammin
Administrator
posted October 22, 2001 06:55 PM
hrspwr, if you run 6.00 gears on a half mile track with a small block chevy, your gonna put the pistons through the hood at about 11,000 rpm.

jammin


Oldsmobile13
Member
posted October 22, 2001 07:17 PM
most of the smallblock chevy`s are turning about 6800 to 7200 rpm. my ford is twisting about 5600 with the 5.83 gears. if i had a windsor i wouldn`t hesitate to run 6.0 gears. 1/2 mile medium bank 24 second laps
we are running manual trans with 1-1 high gear. these gears are for the rear.

[This message has been edited by hrspwr (edited October 22, 2001).]

jammin
Administrator
posted October 22, 2001 07:31 PM
I run 5.83's.....long 1/4 mile.....turn 65-6700.....no way in the world.



jammin
Administrator
posted October 22, 2001 07:33 PM
Olds......43's will get ya in the neighborhood of where you want to be. Most of the guys here are running them on the long 3/8 mile stuff....so, your close.

jammin


hrspwr
Member
posted October 22, 2001 07:40 PM
ok boss you caught me i`m lying. i am spending time to help but i`m lying. why? to mislead some guy on the other side of the country. seriously, our tack has 900ft straits and has a rep of being very fast but brutal on motors. i have 5.83s in my nine inch and a 3 spd manual. most of the chevy`s run 6.0 -1. i am not lying.


phelps
Member
posted October 22, 2001 08:03 PM
A guy I helped last year ran 6.13's on 3/8 & turned 6500. You must have some real tall tires to get by with those gears on 1/2 mile.


jammin
Administrator
posted October 22, 2001 08:18 PM
Guys, I am sorry, I made a mistake.....he is right on the gearing...I have my head stuck in modified mode.


jammin


hrspwr
Member
posted October 22, 2001 08:50 PM
thanks boss, thought i was goin more nuts than usual.


racer17j
Member
posted October 23, 2001 01:10 AM
i was gonna say jam 95% of the cars around here are running 6.0 with the same tire and turning somewhere in the neiborhood of 6000 the others are running 5.86


jammin
Administrator
posted October 23, 2001 01:11 AM
You guys give me some slack....mod minded here...lol


jammin


Oldsmobile13
Member
posted October 23, 2001 01:54 AM
1/2 mile low banked dry slick
with a 90" tires w 6.00 i hit 6200

5.83 is common for the Street Stocks which usually run a 86-88 tire. they turn 6000-6200

5.63 - 5.83 is common for nights which are dry slick and 6.20 when the track is heavy.(hasnt been heavy in at least 4 years)

find a gear that will keep you 300-500 RPM below your max. You always have to factor in unwanted wheelspin.

to definitly keep it under 6000
Id start with 5.63


Oldsmobile13
Member
posted October 23, 2001 06:04 PM
what are you tipp'n the scales at olds. we had a car was 2800 on the track run same tires as you 205/70/15 6.0 gear the lowest i have heard of guys running in final drive was a 567 but they ran 79 in tire roll. hey widebody what size tire gives you a 90 roll they must be pretty big


Oldsmobile13
Member
posted October 23, 2001 11:25 PM
the 90" tires are a d60 hoosier 11" wide.
i run these when i run w pro-stocks

when i run street stock ive run:
235/70/15 thats 88"
225/70/15 86"
255/60/15 85"
225/60/15 81"
235/60/15 82-83"

the imcas were getting around 81-82"

we also found that mixing tires did funny things for the handeling of the car. like with a mischilen on one side and a bfg here and a cooper there. the all reacted differently and at different rates. stick with one brand. michelens have weak sidewalls, gives them a nice ride but suck for racing and definetly dont mix imca bias tires with radials tires.

I like the imca tires for the dry slick when they can get heat into them, for a tacky track the cooper cobras worked better.

plus my car only had 4-5" ride height with the 82" tires, i hit everything on the track.
my dynamic suspension(frame rail) was hard to adjust. not that the track was rough or had any holes in it(according to the track oficials)
hope this helps a bit!!


ryan
Member
posted October 25, 2001 12:04 AM
How do you figure tire roll?
I have 255/70/15


racer17j
Member
posted October 25, 2001 01:42 AM
with a tape measure or a stagger stick put the tape at the middle and run it around the tire till it meets then read it i use one of those little 50 centers you can get at the hardware store don't try it with a big tape it's not as accurate. we have alway used this method if you want to do it like olds here do it the same way but devide the roll by 3.14 ie my 205/70/15 81 in roll 81/3.14= 26. wide body we noticed that with the diferent tires too we now run kumho 795 series tires and love them um


phelps
Member
posted October 25, 2001 10:10 PM
What track do you run in Kansas Olds?


Oldsmobile13
Member
posted October 26, 2001 02:48 AM
hey wingwhere are you from?is that with the 350 carb or the old carb. and those cars are about 2500lbs right ? i know our stockcars are here


phelps
Member
posted October 27, 2001 07:51 AM
We run at Jetmore Kansas


wingnut
Member
posted October 27, 2001 04:08 PM
i was looking thru some old mags and found a cirlce track with a gear formula in it in case anybody is interested. it worked out for me right on the money only thing is if you don't have an ieda how fast the average speed is it realy does you no good lol
max gear=(tire diamiter)x(rpm's at red line)/(336 x max speed in mph).. i figured 26 in tire 6200rpm 80 mph came out to be 5.99


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