Gear bound help!!

Halfsack Mike

Halfsack Mike

Member
Ok, last night's race came to be. Had a new 212 predator hemi with a 2 disc EC clutch with a 13 driver and a 58t axle sprocket. (My usual gear setup) the 212 has a new ARC billet flywheel, a .021 low side jet and a .033 main jet, and valve last is set to zero. Track is an 8th mile flat dirt oval. Halfway down the straights I was floating the valves. So I began taking rear gear out of it down to a 55t. Made no difference whatsoever. However I won my heat race and placed 2nd in the 20 lap feature. I believe im gear bound. But I never had this issue before. Should I go up a tooth on the driver?
 
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Halfsack Mike said:
Ok, last night's race came to be. Had a new 212 predator hemi with a 2 disc EC clutch with a 13 driver and a 58t axle sprocket. (My n usual gear setup) the 212 has a new ARC billet f p wheel, a .021 low side n jet and a .033 main jet, and valve last is set to zero. Track is an 8th mile flat dirt oval. Halfway down the straights I was floating the valves. So I began taking rear gear out of it down to a 55t. Made no difference whatsoever. However I won my heat race and placed 2nd in the 20 lap feature. I believe im gear bound. But I never had this issue before. Should I go up a tooth on the driver?
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If you have to remove two teeth on the rear, change the driver.
I never go below a 60 on rear gear.
 
When you say you’re running the Predator class I automatically assume the traditional Predator class with the governor intact, or the new rule for Ducar with the RPM limiting coil. If that’s the case I’d bet you were not floating the valves but hitting the limit on the coil. The first time I ever ran an Lo206 that exactly what I thought. If that’s the case, keep lowering your ratio until the problem goes away.
 
1fasttiller said:
If its a truly stock Predator, it shouldn't be turning more than 5200-5300rpm tops. Drop gear until you are at that RPM peak or just under. We've won some very large predator races turning them 4900rpm peak.
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It is one hundred percent stone stock.Except for the modifications I have listed.Which are the low side jet main jet valvelash set and governor removal
 
Halfsack Mike said:
Ok, last night's race came to be. Had a new 212 predator hemi with a 2 disc EC clutch with a 13 driver and a 58t axle sprocket. (My usual gear setup) the 212 has a new ARC billet flywheel, a .021 low side jet and a .033 main jet, and valve last is set to zero. Track is an 8th mile flat dirt oval. Halfway down the straights I was floating the valves. So I began taking rear gear out of it down to a 55t. Made no difference whatsoever. However I won my heat race and placed 2nd in the 20 lap feature. I believe im gear bound. But I never had this issue before. Should I go up a tooth on the driver?
Click to expand...
Billet flywheel makes a big difference with these motors.
Either drop rear gear, or go to a larger front gear. Try to keep the rear at around a 50 or 60, with whatever front gear you have.
Personally id drop the rear gear and keep the 13 to see if i could be around that 50 before id make the change to a 14 front.
 
Halfsack Mike said:
I do. 5k by the middle of the straights. Which is why I was taking gear out of it. But I'll be adding a tooth to the driver and go from there
Click to expand...
Yep, you're on the right track. You can achieve what you're after either way, by adding a tooth to the driver or going closer to a 50 rear. Depending on the track it may be beneficial to stick with the 13 and change rear sprockets to get the ratio you're after. Some people say a smaller driver pulls better out of the corner on a tight track, and I can somewhat agree with that. Also, I assume you're running stock valve springs? It will float the valves pretty much anywhere over 5k, so you're gonna want to aim for slightly less than that at the end of the straights unless you can switch to 10.8s which will gain you a 2-300 rpm cushion.
 
SoCo Tire Treatments said:
Billet flywheel makes a big difference with these motors.
Either drop rear gear, or go to a larger front gear. Try to keep the rear at around a 50 or 60, with whatever front gear you have.
Personally id drop the rear gear and keep the 13 to see if i could be around that 50 before id make the change to a 14 front.
Click to expand...
Won't i need a mini gear setup for that?
 
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