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Author Topic:   gears
chevelle
Dirt Full Roller

Total posts: 71
posted May 31, 2004 10:59 PM  
am running 4.11 gears in second gear(350auto). was told last year to aim for 6.30 final ratio. now find out the fast cars are running around 6.00 and turning about 1000 more rpm than me. I've been turning around 5500. If I changed to a 6.00 final would this make me faster, and up my rpm? or do my problems lie elsewhere?

ruggs66
Dirt Maniac

Total posts: 193
posted May 31, 2004 11:17 PM  
if you are not running 6500 rpm with the 6.30s, your rpm will be less with 6.00 gears.

sounds like you need some more hp. from your engine.

what do your rules allow for engine specs & what cam are you running?



19J
Dirt Freak

Total posts: 370
posted May 31, 2004 11:17 PM  
It could make you faster but also how is your handling? Thats a big factor. More rpms dont mean faster all the time. What is the powerband of the cam? You want to make sure you have the right cam for the track and rpm range and motor etc.. You can try more rpms and see how it goes

racer17j
Dirt Forum Champ
Total posts: 5390
posted June 01, 2004 02:53 AM  
running 350 .030 over, limited to a .420 lift cam am running a howards .410 lift cam. with springs that are supposed to good up to a .490 lift, accel hei, have to run 205 15s all the way around.

19J
Dirt Freak

Total posts: 370
posted June 01, 2004 11:59 AM  
Whats the HEI module at? If its stock then there is part of your problem. Another thing what kind of carb are you running? If your running out of carb you arent going to turn anymore rpms. No matter how much gear you put in thats all you have. There is a such thing as too low of a gear. It wont pull you down the straights and it only does so good in the corner.

ruggs66
Dirt Maniac

Total posts: 193
posted June 01, 2004 12:23 PM  
what intake & carb? 2 Or 4 barrel?

is that the 222 @ 50 with 106 lc cam?

we tried that cam in a purestock 305 with poor results, but we have to run a stock 4 barrel intake & stock exhaust manfolds.... car would turn only 5800 rpm, changed the cam & now it will pull 6400 rpm.

chevelle
Dirt Full Roller

Total posts: 71
posted June 01, 2004 05:36 PM  
yep that would be the cam. a two barrel cast intake with a rotchester that another driver ran last year and it was rebuilt late last season. also have to run restrictor plate. the hei module is whatever comes in the accel distributor. the cam range is 2400 to 5400, oops just looked that up, so it looks like a cam change may be in order. Any suggestions, would like to stay legal, would also like to try another track with a 15 inch vacuum limit.

[This message has been edited by chevelle (edited June 01, 2004).]

ruggs66
Dirt Maniac

Total posts: 193
posted June 01, 2004 05:43 PM  
that cam is slowing you down I would bet.

we tried that cam in 2 different low comp 9.5-1 engines & it was a slug. Charles at Camcraft has some really good lift rule cams.

ruggs66
Dirt Maniac

Total posts: 193
posted June 01, 2004 05:46 PM  
http://www.camcraftcams.com/


J3
Dirt Maniac

Total posts: 188
posted June 01, 2004 06:53 PM  
For all of yall running up to 6500 RPM's, what cam are yall running? What RPM does the cam say it will pull too? Is it bad to turn your motor more than what the cam says?


ruggs66
Dirt Maniac

Total posts: 193
posted June 01, 2004 10:07 PM  
the RPM range on the cam card is Not exactly where the cam will quit pulling. They will prolly go another 500 rpm or more than advertised.

It depends on the whole engine package with the intake & carb & exhaust manifolds or headers that you are using.

it will be a big slug if your running a cam thats too big for the rest of your engine combo.

we use a cam that says the RPM Range is 800-4800 & we can almost get 6500 out of it. our purestock class runs 305 chevys.

most of the time if you don't have enough power out of the corner your cam is prolly too big for your setup.

sometimes Less is More!

racer17j
Dirt Forum Champ
Total posts: 5390
posted June 03, 2004 04:58 PM  
[QU. if i do deside to head over there i'm gonna run a 6.88
---------------------------------------------thanks racer, I've been quietly monitoring this post and I agree with you. We run on a 3/8 med bank trk. I run a 373 rear gear with a saginaw 3 liner trans in 2nd gear with 90"
tires. I calculate that at just over 700 final drive and turn 6600 to 6900rpms on avg depending on track conditions

------------------
Light it up, Baby!

racer17j
Dirt Forum Champ
Total posts: 5390
posted June 18, 2004 06:02 PM  
Changed motors ran 3/8 track not sure of rpm cause tach was on the blink. But was able to keep up. When I had the cam degreed the guy said we had the cam 90 degrees off, had it lined up dot to dot, with number one on tdc. Said he had to redrill and move the pin or something(will tear it down this week). Kind of thinking he may have got the cam off just enough to cause the problem.

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