I have a 2003 Z06 with a 427 C5R engine and am running a 3.90 rear end. Is there anyone else running this particular combination of grunt and gears? Due to "challenges with traction" in first through third gear - in dry weather - I am considering a move back to either a 3.72 or the original 3.42 rear end with HD splines. Any comments? I have not tubbed this car yet as it would involve moving several amps as well as doing all of the tubbing. Thanks Guys and Gals!!!
I would definately go with a taller gear.
You would loose some torque, which you have too much off as it is, and trade it off for more road speed per gear, which you can use.
Those lower gears are good if your after 1/4 mile times with ET streets, or D/R's at minimum. Useless with that kind of power on anything less.
Tubbing isn't the best solution if your looking for traction.
Look at going with a R compound tire like the Nitto 555RII.
__________________ 2006 C6 Z06
Sorry bro, can't advertise for non site vendor in your sig Lingenfelter 427 CID 616 BHP : Caravaggio Full Leather & Alcantra Interior : PHADT Coilover & Sways
No Doubt has a car similar to yours. When he was having his diff gone through, he did some research and chose a 3.42 gear, he could have selected any ratio at the time. Trust me, the car has no problem getting moving with those gears!My ride in a LPE427!
If he doesn't chime in, shoot him a pm. I'm sure he would answer any question you have about it (or anyting else!).
Changing back to 3.42's is a good suggestion with that much power, but IMO it will not improve your traction problems. If any thing it may worsen your traction. My reason is you will be in the torque band longer.
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__________________
Never argue with an idiot. They drag you down to their level then beat you with experience.
Changing back to 3.42's is a good suggestion with that much power, but IMO it will not improve your traction problems. If any thing it may worsen your traction. My reason is you will be in the torque band longer.
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A taller gear will in effect lower his torque at any given rpm, and gain HP (how fast he can go in a given gear). This will make the car less likely to 'break loose'.
Granted a taller gear won't solve is traction problems, but it will help the car not break loose as easily (less torque at any given rpm).
Those 427ci engine are torque monsters.
ScD:
What are your racing usages? Road? Drag? What tires? Or, is this "strictly street"?
Many street-only folks are running the stock 3.42's, with great results. Drag racing, with "suitable" tires can get away with a shorter (bigger numeric) gear. Road racing, again, will be course-, and tire-dependant.
With power-adders, 427's often run 3.15's on street tires, just to help harness all that extra torque at lower speeds.
If you notice the specs of LPE's 2nd Place SuperCar Challenge 427 TT in the Car and Driver event, this past June (results/specs on C&D's website), their car was running 3.15 gears...and was DEFINITELY traction-challenged...
__________________ PowerPro01 sez "STAY TUNED"................ GarettO's the SigGod! "NOTHING Matters...until you CARE..." Bob Gibson If RACING was EASY, they'd call it WINNING ! Anonymous
Last edited by PowerPro01 : 11-22-2004 at 03:30 PM.
Good evening.... New to the forum. I have a 2003 Z06 with a 447 and I'm currently running a 3.73 rear with 550 RWHP and 550 RWTQ. 1st ,2nd , and 3rd are a waste as I'm sure you already know. I run a 345/30/19 (tubbed) and didn't notice much of a difference with the 3.42's or the 3.90's. I'll be increasing my HP and torque next week so I will keep you posted if I have to change my ratio as well. It's all a matter of trial and error IMO. Good luck.
Last edited by Antivenom 447 : 11-26-2004 at 01:47 AM.
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