3.90s for M6
06-16-2009, 06:26 PM
#22
Race Director
3.90's are the way these cars should have come from the factory. They make 6th gear usable on the highway at legal speeds. I'm at 520RWHP with tons of low rpm RWT and still love the 3.90's. I've got local friends with everything from bolt on's to 425RWHP and they all love the 3.90's in their cars.
06-17-2009, 12:21 AM
#23
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I placed an order onlie for about 1300. Then the core is about 700 and then you have TAX, shippng charges and labor.
Not a cheap MOD, but bolls to the wolls when it come to haulin bass.
They have my oder on hold due to the fact I am out of the country for a while. Come to think of it, I've seen deals to have them installed and else for about 1500, not sure though.
Not a bad route...
Not a cheap MOD, but bolls to the wolls when it come to haulin bass.
They have my oder on hold due to the fact I am out of the country for a while. Come to think of it, I've seen deals to have them installed and else for about 1500, not sure though.
Not a bad route...
06-17-2009, 10:32 AM
#24
Melting Slicks
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..in my M6 coupe, couldn't be happier. 6th gear @80mph is turning 2700rpm's. 3rd gear is the power gear; all kinds of grunt now. Most of my local tracks (waterford, grattan for example) are 3rd gear tracks, with some 4th and 5th if I get the rythm right. You'll be running higher in the rpm band though; keep an eye on oil temps and be damn sure you're running the recommended 'one quart over' on the oil to prevent starvation.
Whatever rear set you go with, pay attention to the alignment of the gear set during install, and follow recommended break-in procedures for the type and manufacturer of your gear set. Grenading a rear end in these cars can be very costly!
Whatever rear set you go with, pay attention to the alignment of the gear set during install, and follow recommended break-in procedures for the type and manufacturer of your gear set. Grenading a rear end in these cars can be very costly!
06-17-2009, 12:14 PM
#25
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06-17-2009, 12:26 PM
#26
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If you doing any HPDEs 3.90s and 4.10s suck, why too much shifting, which then over heats the transmission. and some times, you just dont need to shift.
Most HPDEs are run in 3 and 4th gears with a 3.42 rear end. Occatiannly down to 2nd for a tight corner or traffic into a corner and even more occationally 5th gear for high speed long straights.
Drag racing is a different thing. Here you need quick acceleration.
Have to decide what you want to do ??
One diff does not work for both too well.
Most HPDEs are run in 3 and 4th gears with a 3.42 rear end. Occatiannly down to 2nd for a tight corner or traffic into a corner and even more occationally 5th gear for high speed long straights.
Drag racing is a different thing. Here you need quick acceleration.
Have to decide what you want to do ??
One diff does not work for both too well.
06-17-2009, 01:52 PM
#27
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I've had 4.10's for a few years now and it is a blast on the street. Shred the tires at will. Don't know how they are for the track. Great mod! Do the tunnel plate and shifter while you are at it.
06-17-2009, 09:38 PM
#28
Safety Car
Thread Starter
If you doing any HPDEs 3.90s and 4.10s suck, why too much shifting, which then over heats the transmission. and some times, you just dont need to shift.
Most HPDEs are run in 3 and 4th gears with a 3.42 rear end. Occatiannly down to 2nd for a tight corner or traffic into a corner and even more occationally 5th gear for high speed long straights.
Drag racing is a different thing. Here you need quick acceleration.
Have to decide what you want to do ??
One diff does not work for both too well.
Most HPDEs are run in 3 and 4th gears with a 3.42 rear end. Occatiannly down to 2nd for a tight corner or traffic into a corner and even more occationally 5th gear for high speed long straights.
Drag racing is a different thing. Here you need quick acceleration.
Have to decide what you want to do ??
One diff does not work for both too well.
06-17-2009, 10:24 PM
#29
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Keep with the 3.42. Put the money to other things, like more track time
any mods for HPDEs, should go to safety, seats and harnesses PLUS larger coolers, radiator, oil cooler, transmission cooler, brake cooling, better brake pads.
after 5 1/2 years on my 03 the best mod I did to my car in the first year was the oil cooler accu-sump combo and transmission cooler in March of 04. This was after my 3rd hpde.
I now have 24,000 track miles out of 29,000 on the car.
I have many other hp enhansers too, but that was before any HPDEs were done.
any mods for HPDEs, should go to safety, seats and harnesses PLUS larger coolers, radiator, oil cooler, transmission cooler, brake cooling, better brake pads.
after 5 1/2 years on my 03 the best mod I did to my car in the first year was the oil cooler accu-sump combo and transmission cooler in March of 04. This was after my 3rd hpde.
I now have 24,000 track miles out of 29,000 on the car.
I have many other hp enhansers too, but that was before any HPDEs were done.
Last edited by AU N EGL; 06-17-2009 at 10:27 PM.
06-17-2009, 10:30 PM
#30
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When you take a look at the tracks you run, and in which gears, then go and figure what it would be with 3.73 or 3.90 and or worse 4.10s, it just not worth the time and cost to change diffs.
06-17-2009, 11:05 PM
#31
Le Mans Master
Pick up the phone because the 3.90's are calling 
06-18-2009, 04:24 PM
#33
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06-18-2009, 05:11 PM
#34
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How about this, Go over into the Autocross and ROAD RACING forum part of CF and ask
or do a pole on which diff?
3.42
3.73
3.90
4.10
See which gets the most votes.
again this is for road racing track days, not drag racing. TWO different types of racing.
or do a pole on which diff?
3.42
3.73
3.90
4.10
See which gets the most votes.
again this is for road racing track days, not drag racing. TWO different types of racing.