LSwonderfull

I was contemplating gearing the rear in my Z28 to utilize 5th in the 1/4, anyone try this and can the trans(t56) handle say 435rwhp this way?

82cetuner

iTrader: (9)

youd need 4.56s if not more to actually need 5th. especially if your car can rev higher than stock

LSwonderfull

yes i am asking if 5th gear holds up at this power level?

jmd

iTrader: (4)

The two-piece countershaft can be a liability if the counter parts aren't shimmed properly and depending on power level. Should be fine at 435 na hp but the fork pads will be the first thing to go with ham-fisted shifting.

You're also going to have a case of diminishing returns with regard to time spent shifting; to finish at redline in 5th and have a well matched 1st/rear gear ratio is going to take more than a bolt-on type setup.

LSwonderfull

Thanks,this is good info, i planned (on paper) to gear the 9" with 5.80 gears to get lightning shifts, and with 28" tires will turn around 6500 in 5th at 125mph. The multiplication will lead to shifting every gear as fast as you can.Launch will be on a 2 step at peak torque. This will take the load off the Ram clutch setup i have and believe it or not the motor will still turn around 3k at hiway speeds in 6th.

85MikeTPI

iTrader: (9)

The extensionshaft engagement lugs or the main shaft cluster splines will give out after a season of abusing 5th in this way...

BADD SS

iTrader: (4)

I see no benefits to this, and you will probably go slower...adding yet another shift...

87__TA

I had been year before last while using 26" slicks trapping at 142.. Car went faster using 5th as opposed to riding limiter by about .05 for me.. It held just fine for the season.. Now trapping 146 with 28"s in 4th..

VandykeT/A

New 5.0s with 373s are geared to shift into 5th but I don't see to how its beneficial. When I hit 5th in my car it feels like you dropped a elephant through the back glass.

redtan

iTrader: (5)

Yeah because their 5th gear is still not an overdrive, it's at or above 1.00:1.

T56 5th gear is an overdrive, or below 1:00:1 and that's why your car fees like **** in 5th gear.

I agree with this, why would you purposely gear your car to have to use an overdrive gear in the quarter mile? Not only do you have to shift an extra time, but 5th sucks for acceleration. Gear your car to hit the traps towards the end of 4th and that's where you'll have the best success.

Slowhawk

iTrader: (12)

The gear can handle that power no problem but the shift fork/syncro can not handle the fast shift. Better off staying with 4 gears.