Ok running a 12/60 ? And going up to 12/63 should that bring it higher in the rpms ?? This is my dyno sheet
Gearing
- Thread starter Bigred28
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racing promotor
Moderator
yes if not gear bound now, should increase rpm by 300
What do you mean by gear bound ?
racing promotor
Moderator
You way off on gearing, the gearing combo would warrant 7500 rpm when you only want 6500 rpm would be an example, a lot of times when this happens you won't get true tach readings, I've had guys pull 6 teeth already and gain rpms. That's why if with the 12/63 it's worse were saying try the 14/66.
racing promotor
Moderator
If it's gear bound now It will not increase rpm with the change.
Can you explain what the front driver does in the grading would be very helpful.. from changing for a 12 to a 14 what would that do
racing promotor
Moderator
That would equal lowering rear gear by 8 teeth, with leaving same number rear gear.
You don’t think lower the rear gear to a 58 won’t help any ?? All this information is helpful guys thank yall
racing promotor
Moderator
If it's gear bound doubt 58 would show any difference, a 56 might show slight difference.
racing promotor
Moderator
Do you have a 13 front driver ?
Ok thank you will let y’all know Saturday
I’m in the Pryor trying to get one our supplier is limited sometimes and runs out
alvin l nunley
Site Supporter
This shows you how much RPM you need to gain to be going the same speed with the gear change.
OVALTECH1
Site Supporter
if it was checking out in the heats on a 14/67 and the track came in for the feature I wouldn’t have dropped to a 13 driver. I would of stayed on the 14 and put a 65 on the rear. Or just leave it as is. Now it the track totally went away and it became a drivers race.... then maybe that 13 combo would of worked. Just my 2 cents
racing promotor
Moderator
If I'm reading it right he didn't drop to a 13 driver, he stayed with the 14 /67 but was thinking of increasing rear gear, if so that was you mistake you should of pulled 2 off rear, unless track changed big time, then the difference was tires.
alvin l nunley
Site Supporter
Something else to consider; what did the air density do? I don't recall you saying what the timeframe was. When the sun goes down, I've seen the air density go up, 5 to 7 points. I'll guarantee you that will make a difference in jetting.
What about this scenario; you were tuned just right for the heat, everybody else was tuned rich for the heat. If the air density had gone up, you would be lean and everybody else would be tuned just right. That's a possibility, as remote as it sounds.
Not going to a smaller axle gear could have compounded the problem. One or two teeth on the axle goes a long way.
What about this scenario; you were tuned just right for the heat, everybody else was tuned rich for the heat. If the air density had gone up, you would be lean and everybody else would be tuned just right. That's a possibility, as remote as it sounds.
Not going to a smaller axle gear could have compounded the problem. One or two teeth on the axle goes a long way.
It lugged down in the feature to 6500 I need to go up on gear to bring my rpms back up
racing promotor
Moderator
What were your RPMs in the heats ?