JETSWU87

I attended my first autox this past sunday, and had a blast.

The car is a '99 FRC with mods in sig.

It has 61k miles, i'd like to replace/upgrade the shocks as im still original. Going to go with bilsteins sports. Also the brake pads. I've heard nothing but great things about the HP+ pads so far, however im curious to know if the brake dust is corrosive. I dont mind if they are dust heavy, but i dont want them to eat away the finish of my wheels.


Next thing is the 1999 z51 cars differ from the '00-'04 z51 cars with sway bar size. I plan to just pick up a set of z06 bars. My main concern is should i just change the actually leaf springs too? I read here http://corvetteactioncenter.com/spec.../suspcomp.html

That the z51 and z06 front spring is the exact same, at least for that 2004 model year, however im finding it hard to find info on my 1999 model year. The information in the "Weights, measurements, ratios, strengths, etc " thread but theres so many different numbers.


So as i see it now with the info i HAVE.

change the sways to z06
change the rear spring to z06
bilstein sports
Hawk HP+ pads.

This should stop some of the "squish" the car has, and if i decide to run race rubber....i could without worrying about the tires rubbing in hard corners from soft suspension? I'm going to run street tires with the car until the tires are the thing holding me back from being faster.

Also changing the sway bars to another factory bar shouldn't throw me into some insane class right?


Thanks for any help,

Vinny

rhneff

You don't mention what organization you're autocrossing with, so WRT classing my suggestion would be to first read their rule book before making any further mods to the car.

Mods you've done already would put you in ASP with SCCA, in which case springs can be changed to any aftermarket as long as they're the same design/configuration as stock, and the sway bars are free meaning you can use any or none. You might want to look at the Pfadt bars, for the adjustability.

WRT the Hawk pads, my experience is the HP+ dust is highly corrosive and if not cleaned off frequently will damage most aftermarket wheels - at least it did with mine. I've had better luck with Carbotech - better modulation and braking power, and much less of an issue with dust.

beerkat

FYI Grassroots Motorsport magazine has been doing a setup on the FRC over the last couple of issues. You might fine it useful. It is being setup for NCCC autocross.

JiminVirginia

If you're going to be stuck in ASP, as seems to be the case, I would think you need a more aggressive plan. As it is, you're going to end up with a more or less stock Z06 set up--that is, Super Stock, like mine, only with less horsepower. Your car will be quicker, but you'll never be competitive in ASP, where you'll be compelled to race because of your intake and use of non-OEM springs. It might not matter much at first, but you'll get frustrated with your set up as you get into the sport and develop your skills and get that itch to keep up with the other guys.

What to do, then? I'm in a similar predicament, as I've got a Super Stock ZO6 that I'm thinking of developing into an ASP car.

Even stiffer springs and bars, fore and aft, for one thing. And wider wheels and sticky tires to match. That gets you to 90 percent of where you want to go.

Just another point of view....

JETSWU87

well the springs would be OEM, just from another car. Does that not count?


I'm unsure of what events ill be running, there's so much i dont know about the sport and all the background information.

JETSWU87

Well guess ill be buying tires way sooner then expected.

Passenger side rear tire has a nail in the middle of the sidewall.



After doing about 2-3 hours of research, i want a tire i can street drive and autox in. But wont wear out in 10k miles either.


It's between the Kuhmo MX, and the BFG KDWII....

The knock on kuhmo's is that after a few heat cycles they just are hard. However i have not read much on the KDWII on how they perform for extended periods...


ideas? Need to make a purchase very soon, as the car is down until new tires.

VetteDrmr

There's a big difference between the KD and KDW tires. The W stands for "wet", and, being the current owner of a set of old style KDWs, I would *not* use them in an autox.

The knock on the MXs is a mixed bag. All tires get hard after a number of heat cycles, and with you just getting started I think you'll do just fine with the MXs.

HTH, and have a good one,
Mike

JETSWU87

Thanks for all the info guys.


Well the rim size is already a problem as im running z06 wheels.


Also there is a national back order on MX's in the 295 size....3-5 weeks. I cant wait that long as i need tires now, so im just going to get wide ovals for my street tires. Firestone up the street from me is giving me a very fair deal out the door. I'll get something for track time also so i dont burn those up at the track/autox.

JETSWU87

Well the reason i was getting new tires so quickly was because of that nail in the sidewall.

After the guy at firestone was done doing to job, i went over and looked at the tire in question.....The nail didnt even go all the way through

So i easily could've waited for MX's to come off of back order. Oh well, didnt want to pull the nail out prior and end up needing to tow the car.

Got the tires installed out the door for $972 w/road hazard. Pretty fair i think.

VetteDrmr

Maybe a bit more than the MXs, but not a bad deal.

Now, keep us informed about your autox events!

Have a good one,
Mike

JETSWU87

eh only about 16 bucks more for wide ovals vs mx's on tirerack for the 4.


I signed up to a "cone clinic" at richmond dragway July 28th.

Also ordered a set of bilstien sport's that will be on the car before then. Should be fun, hopefully wont tear up the brand new tires that much

jpasterjak

At this point, I'd approach things slowly when it comes to modifications. It sounds like you have a good set of tires, and a good set of shocks on the way, so from there, I wouldn't even worry about hard parts for a while. Our '99 FRC Project car only has a set of Koni FSDs, and a set of Kumho 710s for the autocross and it's a regular FTD contender at local NCCC events.

At this point, I'd concentrate on driving, and learning the ins and outs of fine tuning the suspension. There's a ton of performance available absolutely for free just in a proper setup. Corner weighting and alignment settings can make huge differences in performance and driveablility.

Taking an autocross class is also a good move. If you're relatively new to the sport, the last thing you need is to overcomplicate things by swapping a lot of parts. When your abilities reach the level that you know what those parts do dynamically, and know instinctively what effect changing them will have, that's the time to start wrenching.

Good luck in your endeavors. If you have any questions, don't hesitate to ask.

J.G. Pasterjak
Grassroots Motorsports
Classic Motorsports