I have a 02 SS M6 and I need some help with gear selection. Should I go with a 3.73 or 4.10 a setup. I currently am running a a slp lid, smooth bellows, flowmaster catback, 125 shot of nitrous, and I am running a 12.5 @116 in 1/4 mile. I get no traction at all do to the fact I lowered the car 1 inch at all 4 corners. I also plan on lower control arms and relocation brackets with some Nitto drag slicks. I want to get the car to the 11.7 range so back to the original question, with all the above stuff done to my car which gear selection will most likely get me to my goal of 11.7 or better.

 

What I've always heard is go 4.10 with a M6 and 3.73 with a A4. The 4.10's will provide better acceleration and will still be fine as a daily driver due to the six transmission gears.

 

4.10's and 26" slicks if the car is a daily driver and need excellent driveability
4.30's and 28" slicks if you want alot better drag times and you are willing to give up a little MPG to do it
4.56's and 28's for all out drag car

any way you go be prepared for a rear upgrade in your future

 

cool thanks, for the replys.

 

4.10s are great on an N/A M6 car, but on the nitrous with 4.10s, you'll have to go into 5th. I know from experience, sucks, haha.

3.73s might be the best bet for a nitrous car.

 

What is your shift RPM?

With 4.10's, street tires, and the trap speeds your running now, you'd be at 6,200rpm at the traps, in 4th gear. If you plan to run faster, even with a 26" tire, you will run out of rpm and be forced to shift into 5th, as noted above. With the 3.73's, you could make it to 125MPH before you had to shift into 5th. 4.10's and a 27" tire would put you at 120+ MPH at 6,200RPM.

You figure your trap speed, plug in your max RPM, pick a tire size and type that give you the required traction, then put the data in the calculator to see what gear ratio puts you at max RPM, in 4th gear, at the end of the 1/4. You don't play with gear ratios to control traction - you gear the car for its capabilities, and put the tires under it that give you the required traction.