Rear gear for 6060 swap

RYAN97812 said:

Why bother having a 6 speed if you'll only use 5? You don't "optimize" gears for an overdriven gear (.74 in the 6060) in a car that you are doing 1/4 drag racing. Intended power, et, trap speed and tire size is what you use to determine the best rear gear for each application. 4.11's fit the bill perfectly for me. Made the swap and would never look back.

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A because the gear spacing is crap between 5th & 6th for performance use (big rpm drop puts you out of the powerband). But if you are just drag racing, your are never going to see 6th anyway. Are you even planning to see 5th?

No. 5th gear would be useless on the track as its overdriven. My specific set up will put me at 7500-7600 rpm going through the traps in fourth. Hence optimal. \
As for the street I use them all. 6th gear on the highway at 75 mph and 1900 rpm nets me 26 mpg with the 4.11's. With the stock 3.73's 6th gear at 80 was only 1500-1600 rpm, was a dog to try to accelerate at that speed and loaded the motor on hills etc. so it rendered 6th gear useless. 5th in the MT82 was the same as 4th in the 6060. No way you would be rowing 5 gears making 900+ rwhp and have that trans survive no matter what upgrades you did to it.

RYAN97812 said:

FYI for gear swap cruise control doesn't work after installing them. I have to flash BCM still for gear change and that should take care of it as CC worked in all gears after swapping trans

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I have a whipple flare...that should be able to accomplish correct?

Tommy V said:

Hey man i know this is a different subject,but i know u have been running the rxt clutch for some time now.I didnt want to go that route but looks like i dont have a choice with the power i have if i want a clutch that will last.How is your rxt holding up so far and have u ran it at the track yet with some sticky tires.Thanks for any input.

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Absolutely no issues at all with the RXT...none. I have not been to the track but have MT S/S 305/35/19's on the rear and they hook very well.

Well my gears did not arrive. The box from Summit was the install kit only. US Gear does not have a lightning series 4.11 gear option any longer for the IRS...:shrug:

Thought i would update this. Finally got the 4.09s in. While doing the gears I also put in a Wavetrac torsion, replaced the DSS 800 shafts with FRPP 1400 shafts, and did BMR BK051 lockout bushings.
First thoughts - this gear ratio is perfection with the TR6060. I no longer have any drivetrain noise
No thuds, no clicking, nothing. The car ran good before with the 3.73s ,however i was experiencing a couple of issues. One was normal driving from a dead stop sometimes i would get stumbling if the rpms were not up high enough. I was also experiencing a hesitation just before going into boost....both of those are gone.