Gears: 4.10s or 3.90s and why?

[SilverStateZ06]

I am making about 400 rwhp. Sometime this year, I plan on installing the Cartek X package. Based on my mods (see sig), with the X package (expect around 450-460 rwhp), what gears should I run?
I am taking the car into the dealer next week to have my Cartek clutch/master/slave put in (the pedal has not been returning when shifting under a load). Enloe, another Corvetteforum member, tells me the differential has to come down to replace the clutch. Since that is the case, I might as well have them put the gears in now.

As for what I intend on doing with the car, I drive it daily to and from work (sometimes on the freeway and other times on the surface streets). I like to blast at the drag strip every now and then (Las Vegas Speedway or other Pacific Street Car Association tracks). I have a buddy with a new Cobra who needs an butt-whipping (he is making 460 rwhp and five hunred something torque). Someday, I would like to get into autocross and maybe even run the Silver State Classic.

I have thought of installing an NX kit and spraying 100 to 150 horse instead of the heads and cam.

Thanks in advance for any advice.
:s :Roll

 

[SilverStateZ06]

Hey guys, I KNOW someone here has gears in their car.

Can you help a brutha out with some advice?

 

[c4c5specialist]

HI there,
I can only give you the advice that I have seen, due to working on some of the Cartek cars, with the package you state you want.
There are no real downsides to this mod that you want.
What you will get is better acceleration off the line.
Just remember, warranty on the transmission is void, when you do this, heads and cam, or nitrous, or anything of this magnetude.
So with that, they drive very well, and I have not seen problems with this mod.
Although, I do not recommend changing rear gears, on a stock vehicle.
Allthebest, c4c5

 

[SilverStateZ06]

Thanks for the info.

I think I might go with the 3.90s - more room to grow.

 

[SilverStateZ06]

So I called Andy today at A&A to order my 3.90 gears. I tell him that I have an '02 Z06 making about 400 rwhp and that I want to blast on the drag strip once in a while with my CCW drag kit.

He tells me that I should not get the gears. He says because I have an m12, and because first and second gears are too close, that I am better off with 3.42s. He goes on to say that he has a Z, and could put any ratio he wants in it, and that he does not run 3.90s or 4.10s.

I know he knows more about Corvettes than I do, so I am now wondering whether I should just leave the gears alone, or get 3.73s.

What do you guys think?:confused

 

[BigRed]

I think your guy knows what he's talking about. Especially with a Z06 Id be careful using "Drag" gears because of sacificing the streetablity of the car. Id listen to your guy man.

 

[SilverStateZ06]

Decided to go with 3.73s - best all around gear - thanks for the input

 

[Ling_650vette]

3.73s are probably the best all around gears you can get as far as street/drag goes...

Not trying to make you realize you made the wrong decision, cause 3.73s are probably a damn good thing, but imo, i think you'll be limited more by the IRS then the gears themself. Lingenfelters TT 427 put down around 850rwhp and ran a 8.95 @ 150 on the 3.42s.

As far as the drag racing goes, w/ the 3.73s your 60' and 1/8th should be a touch quicker, depending upon if you get traction or not...hopefully, everythings faster, and you enjoy what you got!

 

[vet346]

All,

If your going drag race with the 3.73's, and use stock tires your going to have problems with traction. If your going to go with Drag Radials or ET streets get the harden shafts.

Just my .02 worth.

Ernie

 

[rwd]

Rear ratios are more of an issue with 4-speeds than 6-speeds. The Z first and second gear ratios are short, anyway, and sometimes selections come down to whether they'd require an extra shift in the quarter or not.

In any case, you'll be shifting more, and the highway rpm will go up, mileage will go down, and the engine will experience extra wear over any given amount of miles.

If you go with aftermarket tires to gain traction, you'll be putting additional shock loads on the driveline that could cause problems, and strengthening one area will just allow it to transfer force to another.

It's a vicious circle, but that's racing.