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Author Topic:   RPM help!
Jimhobby02
Dirt Full Roller

Total posts: 69
posted April 14, 2002 10:46 PM
Tongight running on a 3/8 medium to high banked dirt oval I could only turn about 4500 or so. I have a high performance module and coil. My final drive is a 6.56 with a powerglide. I had the pedal to the floor but could not keep up!

redneck racing
Dirt Freak

Total posts: 276
posted April 14, 2002 11:59 PM
From what ive gathered on this site id say it could be gearing alot of the guys are saying for a 3/8 track you should be around 6.20 i ran a 6.27 final on a 3/8 track it seemed to be great ran it on a 4/10 and could only get her to 5000 rpm but did manage to hold my ground but barely some of it also could be cam but im no expert here. Eddie

hesseracing
Dirt Full Roller

Total posts: 55
posted April 15, 2002 08:21 PM
the gear is probably your main problem. also are you running a alternator. if not you aint getting the total possible voltage out of the coil.

racer17j
Dirt Forum Champ
Total posts: 1565
posted April 16, 2002 02:15 AM UIN: 54865418
was it haven't a hard time getting there or did you just hit it and nothing power wise. your gears might be a problem but it's not going to make you run low rpm it wouls make you run more if you are running pretty tall tires you should be alright with that gear. i would go thru your carb and make sure it's tuned right

WesternAuto17
Dirt Freak

Total posts: 248
posted April 16, 2002 08:42 AM
If everything else is correct, too much gearing isn't going to cause the car to quit accelerating at 4500. Too much gear would cause you to quit accelerating at like 6500 or 7000 because you're out of the power band. However, 6.56 is pretty high.

Sounds a lot like a carburator or electrical problem. I had 2, not 1 but 2, bad brand new Proform HEI's go bad last year. They would start to cut out at 5000rpm or so. That could be a problem. I switched to a Holley module and it cured it.

nWoracing
Dirt Roller

Total posts: 17
posted April 19, 2002 10:12 AM
I run on a 3/8 track.I also run a powerglide
transmission.I run a 4.10 rear gear.I turn about 7000 rpm's.What gear do you run in drive or low????I run my car in low gear.
Where did you get you cam from????Be sure you got what you ordered.I ordered a competition cam from summit,I thought I was getting a racing cam.I got a cam for a station wagon.Watch what you get.I got burned
You might have too!Check it out.
Adios,
Ron Carpenter

RangeRover
Dirt Maniac

Total posts: 174
posted April 19, 2002 10:35 AM
Your situation instantly reminded me of a problem a buddy had at the track one night. He wouldn't turn the rpm that he should have and consequently was signigicantly low on power. The problem turned out to be that his timing pointer had moved and he didn't have a feel for where it should be, so he thought he was setting it at 35 degrees total advance when in fact, as you know, he was way short. If this isn't your problem, it's something to be aware of.

Another thing on your cam; is it possible that it was installed retarded? It's easy to do with the three-position timing chains and it would sacrifice low end enough that perhaps with large tires the car can't make it to the higher rpm. That's a pretty low gear, though.

Jimhobby02
Dirt Full Roller

Total posts: 69
posted April 19, 2002 02:34 PM
I run a 1.76 low gear on my powerglide. I am starting to wonder about the cam install or the valve settings. I found a leak at the base of the carb. I replaced the gasket and got rid of the run on problem I was having. I will check the timing in the morning but after that I am stuck.

racer17j
Dirt Forum Champ
Total posts: 1565
posted April 19, 2002 07:58 PM UIN: 54865418
if you has a vacume leak on the bottom of the carb that would explain your problems that would make you way lean causeing your over heating and inturn that should fix the top end problem .funny how something so simple as a gasket can cause so many problems

Jimhobby02
Dirt Full Roller

Total posts: 69
posted April 21, 2002 03:10 PM
I found several reasons for my RPM problem. The first thing was the carb gasket had a leak. The carb was not properly tuned, the timing was off, and last but not least the rear end ratio isnt what I thought it was. Thanks for all the suggestions.

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