Hitman227

Just like the title states, except maximums will be implemented (suspension / headers / gears), with tires as the variable.

alextz

THe current SCCA SSP Solo National Champion is Joe Tharpe in a 2003 C5 Z06. So Id say its pretty good!

Cant change the gearing in SSP.

momo20

from the events i go to..and see mostly c5z's as compared to the other vettes i would say they are right at home on the tracks

Solofast

The place to ask the question is on the Autocross and Road Racing page in the general section of the forum. That's where the real racers hang out.

Hitman227

Can't change the gearing what the **** that sucks! I really do not want to go SSM unless I really have to. I thought transmission and rear end gears blah blah are all inclusive with the status.

Supercharged111

Why would you want to change the gears? I love having the legs to do ~105 in 3rd and ~145 in 4th. There are some long tracks where you'd run out of 5th if you had 3.73s.

GeorgeZNJ

The Glen and VIR immediately come to mind.

AverageVetteNut

Yeah, and Joe won SSP this weekend @ the Dixie match tour as well.

Agreed, why would you WANT to change the gearing in these for autocross?

Hitman227

Well the reason for this setup in regards to the gears is to have the mechanical advantage for different situations, such as short tracks long tracks or medium tracks. As far as I know gears are ok in SSP as is rear end or trans. If not then I won't have gearing in reference to the street.

alextz

No gear change in SSP, (we are talking SCCA SOLO II Autocross classing here right?)

I still dont know why you would change gearing from a C5 Z06. It is geared perfectly for Solo II.

Hitman227

Alright, here's the deal, SP allows only certain mods in addition to the Stock Class, which is as follows:

15.10.R (SP)
Limited slip differentials are permitted. This permits locked differentials,
either by design, welding, or mechanical means. Differential
cases, internal differential parts, and axle stubs may be machined as
required for clearance and installation to the extent that material may
only be removed, not added, and the exterior of the case may not be
altered in any way. This machining may serve no other purpose. Any
other modifications or substitutions to accommodate the installation
of the limited slip differential must meet the requirements of 15.1.B
and 15.1.C.

15.1.B (SP)
Street Prepared vehicles may only be modified in excess of Stock
Category rules in the following ways. Any modification not specifically
authorized by the Stock Category or Street Prepared rules is prohibited.
No unauthorized modifications are permitted in order to accommodate
authorized modifications (e.g., non-stock hood scoops or
holes necessary for carburetor clearance). Structural modifications,
such as the addition of members known as “jacking rails”, are not
permitted unless specifically authorized herein.

15.1.C (SP)
Equipment and/or specifications may be exchanged between different
years and models of a vehicle if:
(a) the item is standard on the year/model from which it was taken,
and
(b) the years/models are listed on the same line of Appendix A (Street
Prepared Classes).
The updated/backdated part or the part to which it is to be attached
may not be altered, modified, machined, welded, or otherwise
changed to facilitate the updating/backdating allowance. Standard
factory installation methods, locations, and configurations are allowed.
The updating and/or backdating of engines, transmissions,
transaxles, and/or unibodies must be done as a unit; component
parts and specifications of these units may not be interchanged.
Cars not listed in the Street Prepared sections of Appendix A may
not be updated/backdated until approved by the SEB and published
in the official SCCA publication.

13.10.L (Stock)
Limited-slip differential, transmission and differential ratios, clutch
mechanisms and carburetion, fuel injection or supercharger induction
systems must be standard as herein defined.

So, you are right, no gears in SSP. F****** B****!

Ok, I'm going to have to make some changes. Or, move up classes to SSM, which I might implement.

Supercharged111

Didn't realize this was auto-x at first, thought it was road racing. Do you already have gears? I don't understand why you're so hung up on them, I really doubt changing them will make you the class ringer. If you're losing to less powerful cars, mod elsewhere.

Solofast

You could change to other gear ratios offered for the C5 from the factory. That is if automatic cars had something different that you wanted to use, you could. Something like a very tall rear axle could be used so that you could run most of the course in first gear. Some folks have done that to good effect over the years. Other than Pro Solo events getting off the line isn't that important in most autocross events so there is some latitude, but no, you can't drop in a set of 3:73 rear gears in a C5 legally in the SP class if it wasn't offered from the factory.

And has others have mentioned, 2nd gear in a C5Z is about as perfect as you can get for an autocross car. Very seldom do you ever need third, and most of the time you have enough torque to put the tail out of line if you push the pedal all the way down, even at relatively low speed. So you have all the power you can effectively use. Sometimes you can bump the rev limiter in second, but seldom do you upshift, you just hold it and usually you are on the brakes right about then so it's not a worth upshifting and downshifting. Only once in a great while will you need first gear at all, it's almost entirely run in second.

If you put in a set of shorter gears you are going to be running out of second gear and be between second and third all the time. That would be miserable.

Shorter gears work at the drags, but not really an advantage in solo events.

Hitman227

That's interesting and I see what you're saying in regards to the gears. However, what I am implementing will allow me to throw in a set of gears and still have the advantage of stock gears. More specifically, 7000 RPM limiter with 3.73 gears gives me about the same in reference to the limits as the 6500 RPM limiter with regular gears. I can still use the limiter in terms of speeds and not have to worry about running out of gear because the limits will be the same.

Solofast

I agree. Grip and cornering speed is far far more important than the little bit of extra punch that you think you will get from a gear change. The reason is that coming off of a corner in second, you always have to squeeze in the power and you can't use all the power you have anyway. And that's my experience with Hoosier DOT tires. Unless you are running pure slicks and have two drivers to get them really hot, you can't put down all the power that's available in a stock Z. Getting 10% more torque for a couple of seconds when you can finally floor it, isn't worth much in this game.

I could see an advantage in pushing up the rev limiter to 7,000 with the stock 3:42 gears, because then you would probably never have to shift into third except on a really fast course, and if you were in first you could get a bit more usable range out of it. But if you push the pedal all the way down and the back end gets loose you don't need more gear.

Spend the money on a set of serious shocks, wheels and sticky tires, and seat time and you will be a lot faster than if you spent it on gears.

JMHO, but I've been doing solos for 30 years..

Moto One

The Problem raising the valve limiter to 7000 is that the valve train isn't capable of keeping up. I seen competitors at nationals that have raised their rev limiter and brake valve or valve spring.

Mark

Hitman227

That is not good news if the stock Z06 valvetrain cannot sustain 7000 revs! I'm thinking even 7200 or greater, without having to move classes to SSM.

Hitman227

So I am going to have to move classes, SSM is my new class (thank you, thank you). SSM allows for valvetrain, gears, engine modifications, illegal in SSP.

With springs retainers pushrods and super powerful lifters, I should be able to pull 7200 concernlessly, without even having to run titanium connecting rods (wish me luck!).

Supercharged111

I hate to keep beating this dead horse, but you're going to waste a lot of money to not go fast. If you're modding the car the way you are because it's your all around fun car and that's what makes you happy, so be it. I have many-a-debate with myself over spending track money on headers, cam, ported heads, and such. Will they cut my lap times? Barely. Even less so in auto-x. Will the extra pull and noise put a smile on my face? Hell yes. If you're hoping to mod a car to he max, head out there and dominate, I think you'll be sorely disappointed as the loose nut behind the wheel is often the biggest holdup. I'm just making some WAGs here, as typically the more experienced auto-x/racing types don't ask such questions about the rules, but let me be clear in that I do not intend to offend you in any way with this post so please don't take it the wrong way. You haven't really let on you level of experience or current car mods. I realize what's been said isn't 100% on topic, but we are trying to keep you headed down the right road if getting better at auto-x is what you want.

Solofast

Roger Johnson, (5 time SCCA National Solo II champ and more nationals wins at NCCC conventions than you can shake a stick at) tells this story often...

He went out to his first couple of regional SCCA autorcosses. Got beat pretty bad, like 4 seconds... Winter came along and he did all kinds of mods to the car (some of them decidedly illegal).... Came back the next season... Went to the first event and he felt the car was definitely much faster.. Looked at the time board... He was now getting beat by more than 6 seconds...

Went home and stewed it over, those cars shouldn't have beaten him at all, let alone so badly... Decided it must have been the driver, went to work on the nut behind the wheel, and the rest is history..

Work on maximizing grip and put in a balanced setup that is known to work, and work on your driving before you start doing a lot of mods. There's two reasons for that. The first is that you will learn to drive a properly set up car, and you won't develop a lot of bad habits driving around a car that has funny handling. The second is that you'll progress faster and learn more and you will then know that if you made a change, was it a positive change or not. Believe me in that while you may be a good driver, there is no substitute for experience in this sport.