Steering response....

[CGM2SSRS]

Alright. We know our car has a little under steer problem.(weight considered)
For those of us that live for the twisties, what are you going to do to improve it?
My thoughts are to eliminate the staggered tires, not knowing if I want more narrow tread in back or more up front? Kind of a trade off? Going negative camber to off set outter edge tire wear will help a little as well. I really don't know how much of an improvement specific to steering response I'd get going with coil over system? A slight drop front and back with a stiffer spring rate is going to help but I don't see it helping much without sacrificing the ride quality?
Opinions?

[Rusky]

check how much toe-in you have

[CGM2SSRS]

What, are there no SCCA or IMSA guy's in here?

[Rob@WretchedMS]

well, there are a few things that you can do to improve handling, and help with the understeer.

1. Caster Adjustment, the Camaro comes from the factory with no Caster adjustment. We however have an upgraded bushing, that comes with Caster washers (modification of the bolt holes required)

2. Camber will help, though much more than 1 degree and you risk tire wear issues.

3. Sway Bars, we will have adjustable front sway bars available soon, and have an adjustable rear sway bar available already. having the adjustability will help setting up the car a lot.

4. Non staggered tires are better for road racing

5. increased coil rates with a lowered stance for a lower CG.

6. not for oversteer/understeer so much, but the bushings, especially in the rear of the car will help the feel and control of the car a ton. The rear sub frame bushings allow the rear cradle to twist under hard driving, and this can effect the confidence you have in the corners, as well as the traction.

hows that for a start.

[Doc]

Get rid of the staggered setup; go with same size rims all the way around... 8, 8.5, 9" wide, whichever you prefer. I'm probably going to go with 8.5's. Reduce unsprung weight to improve suspension/steering response. I'm going to do this with lighter rims and brake rotors. The setup I'm going with I'm estimating will save about 18 lbs of unsprung weight per corner.

As Rob from Wretched said, adjustable sway bars; but if you've never setup a car before I highly recommend you do some research on this so you don't mess up the handling. Think safety first; if you aren't sure, don't mess with it until you are sure what you're doing. Make small adjustments and test; do one thing at a time so you know what adjustment had what effect. Noobies will make all kinds of adjustments at one time, then go out to test and not have a clue what adjustment did what or what's working/isn't working and why. Be patient when setting up a car for handling.

You can go to all kinds of levels of handling and performance, just depends on what you want to do, how you're going to use it, and what you want to live with. You can make it handle like a Formula 1 car but then you'd need a kidney belt and mouth protector to drive it on the street; you'd feel the paint in a crosswalk when driving over it. What's your intended use?

For a decent street machine I'd say lighter rims, brake rotors, sway bars, better bushings. If you want more than that look into coils, spring rates, etc. but that's more involved and complicates the setup process. You'd be surprised though at how much you can accomplish just with adjustable sway bars and better bushings; try that first.

Or better yet tell us what you're looking for in performance and how/where you're going to use it.

[Info@PeddersUSA.com]

Pedders has done a serious amount of R&D on the ZETA platform. Several things to discuss:
1. Staggered wheels and tires will increase understeer. so go with a oversized equal tire on all 4 corners a 275 is a easy tire to get in
2. The back end needs to be approx 15mm lower than the front. This will help significantly
3. Increase negative cambers in the front
4. reduce front toe or even go slightly toe out
5. Increase sway bars
6. Lower the front and rear and increase coil rates

These are a couple of things to think about.

mike
dms

[Wolverine]

Strut tower bars! Why did they put the hood prop on the strut tower? I also wonder if a strut tower bar would clear the hood and the engine?

[CGM2SSRS]

Thanks Doc. Primary goals are as I indicated in the first post. Try to minimize the OE ride quality while maximizing steering response. IE; losing the under steer.
My driving will be primarily fair to poor road back road condition. I noticed you are anchored in Cali. If you know roads such as the Silverado trail in Calistoga, St. Helena, Middletown area those are the style roads I live for. I will also be looking at track time at Lime Rock in CT and hope to be able to visit Watkins Glen in NY. If I were in CA, I'd be looking to get on my favorite track in the world. Laguna Seca.
I have a fair amount of suspension geometry so no worries of rookie exuberance. I agree if you don't going in, you could really FSU by the reason you explained.
My counter to your points will debate gains through weight loss specific upgrade and cost effectiveness as opposed to outright upgrades?
Breaking that down, reducing the unsprung weight means a brake rotor upgrade and wheels swap. Would I realize more improvement say keeping the weight, taking that money and investing it in say a set of coil overs? I think the other upgrades you mentioned are,"done deal" stuff needed to achieve my need.

Thanks for your your .03 there Mike. I did enjoy our lengthy phone conversation last week.

I also agree with you wolverine. As far as I know, nobody has even been going hard on designing a STB for the cammy yet?

opinions? Thanks!

[Info@PeddersUSA.com]

One of our Camaro modders is redesigning a different billet hinge that will eliminate the hood shock. Then we will have room for a STB. But putting on a STB without substantial suspension mods may look good, but you will not experience any gains.

mike
dms

[Doc]

Originally Posted by CGM2SSRS

Thanks Doc. Primary goals are as I indicated in the first post. Try to minimize the OE ride quality while maximizing steering response. IE; losing the under steer.
My driving will be primarily fair to poor road back road condition. I noticed you are anchored in Cali. If you know roads such as the Silverado trail in Calistoga, St. Helena, Middletown area those are the style roads I live for. I will also be looking at track time at Lime Rock in CT and hope to be able to visit Watkins Glen in NY. If I were in CA, I'd be looking to get on my favorite track in the world. Laguna Seca.
I have a fair amount of suspension geometry so no worries of rookie exuberance. I agree if you don't going in, you could really FSU by the reason you explained.
My counter to your points will debate gains through weight loss specific upgrade and cost effectiveness as opposed to outright upgrades?
Breaking that down, reducing the unsprung weight means a brake rotor upgrade and wheels swap. Would I realize more improvement say keeping the weight, taking that money and investing it in say a set of coil overs? I think the other upgrades you mentioned are,"done deal" stuff needed to achieve my need.

Thanks for your your .03 there Mike. I did enjoy our lengthy phone conversation last week.

I also agree with you wolverine. As far as I know, nobody has even been going hard on designing a STB for the cammy yet?

opinions? Thanks!

Ah, a racing man.

Are you going to weekend race or go official SCCA? If official, you'll have to comply with the rules for the class you're entering which will dictate what you're allowed to do and stay "legal" within your class. If weekend/fun runs, then go for what your budget and will desires. For track, get a set of light 18" rims if you can find some that fit over the brakes; Falken or whatever racing brand tires you prefer as a "racing set" so you don't thrash your street wheels. Obviously, low profile tires to improve steering response. If you're going to casual race and want to stick with street rims and tires, get a lighter 20" street rim; I'm going with 3-piece forged. For tires I'd say Falken 452's or something close that will be reasonably affordable and a good performer. Unless you have a deep wallet, Pirelli's get expensive to replace every few months if you race often. The Falken's are about half the price. You can get 452's for about $185 in stock sizes versus $350 or more for Pirelli's.

Check out racingbrake.com for lighter rotors and steel braided brake lines. Do those first before doing springs/suspension mods. DMS above from Pedders had good comments about suspension mods. Get the suspension and chassis set up before adding power; it's much easier to setup when you aren't trying to harness gobs of power too.

I'm looking into a carbon fiber driveshaft which will reduce about 50 lbs of weight and improve engine response and drivetrain efficiency. Should be in the $800-$1000 range and be a good mod for street and track.

You can also do little things like titanium fasteners everywhere it's feasible to reduce pounds, remove the electric motor system in the seats and replace with stock seats or even go with a racing seat if you seriously race.

Reduce weight and balance; key areas for good performance. Makes it much easier and fun to drive a car that responds the way you want it to. Nothing is more frustrating than fighting a slug of a car that just won't freaking hold the corners. You can add power later. Many guys make the mistake of thinking they just need power to go fast and then can't understand why they aren't competitive. Power is useless if you can't control it.

Are you going to make a journal for your project? I'd love to follow your progress!

[CGM2SSRS]

I will probably keep this thread as a place to record upgrades and such.
I shared seat time with a friend in SCCA in the mid 90's.(69 Boss 429) To rich for my blood now. I will be once a month at a track though. So serious yes, crazed, no. I will not get down to counting ounces to cut weight. Though I agree if crazed that is mandatory. I like the driveshaft upgrade. That will be at the top of the secondary upgrade list. I've ARH LT's with cats n x pipe ordered. I will likely go with the vararam CAI. And a tune for power in the initial upgrades. Suspension is next. Rob will be hearing from me soon. I will take you advise on a lighter track set of wheels. And a set of track tread. I will be driving it to the tracks. With a chase/tool/parts truck of course. Thanks Doc!

[Doc]

Originally Posted by CGM2SSRS

I will probably keep this thread as a place to record upgrades and such.
I shared seat time with a friend in SCCA in the mid 90's.(69 Boss 429) To rich for my blood now. I will be once a month at a track though. So serious yes, crazed, no. I will not get down to counting ounces to cut weight. Though I agree if crazed that is mandatory. I like the driveshaft upgrade. That will be at the top of the secondary upgrade list. I've ARH LT's with cats n x pipe ordered. I will likely go with the vararam CAI. And a tune for power in the initial upgrades. Suspension is next. Rob will be hearing from me soon. I will take you advise on a lighter track set of wheels. And a set of track tread. I will be driving it to the tracks. With a chase/tool/parts truck of course. Thanks Doc!

I'm going to do almost exactly the same setup on power upgrades. For track rims look into Enkei RPF-1's. They have them in 18 x 8.5 and they weigh 18.3 lbs. The stock 20" rims weigh 32 lbs so that would reduce unsprung weight by 14 lbs just for the rims alone. Each pound of unsprung weight saved has the effect of reducing car weight by 20 lbs, so saving 14 lbs has the same effect as reducing 280 lbs of vehicle weight. Only thing I don't know is if the RPF-1's will clear the brakes but if they do it's a very popular racing rim. Falken makes a 235/40x18 Z rated tire that weighs about 26 lbs and costs about $155 each. You could have a full set of race tires for that rim size for under $700. The stock Pirelli P-Zeros that come with the car weigh 32 lbs each.

If you go with the 2-piece racingbrake rotors which are 9 lbs lighter, the RPF-1's in the 18's which are 14 lbs lighter, and the Falkens in that size which are 6 lbs lighter, you're saving a total of 29 lbs of unsprung weight per corner. That's the equivalent effect of reducing your car weight by 580 lbs. Do that first, then get the suspension set up and you'd have a great handling car.

Good idea on the "mobile pit". Sounds like you're familiar with the process. This should be a fun car to race!

[CGM2SSRS]

Originally Posted by Doc

I'm going to do almost exactly the same setup on power upgrades. For track rims look into Enkei RPF-1's. They have them in 18 x 8.5 and they weigh 18.3 lbs. The stock 20" rims weigh 32 lbs so that would reduce unsprung weight by 14 lbs just for the rims alone. Each pound of unsprung weight saved has the effect of reducing car weight by 20 lbs, so saving 14 lbs has the same effect as reducing 280 lbs of vehicle weight. Only thing I don't know is if the RPF-1's will clear the brakes but if they do it's a very popular racing rim. Falken makes a 235/40x18 Z rated tire that weighs about 26 lbs and costs about $155 each. You could have a full set of race tires for that rim size for under $700. The stock Pirelli P-Zeros that come with the car weigh 32 lbs each.

If you go with the 2-piece racingbrake rotors which are 9 lbs lighter, the RPF-1's in the 18's which are 14 lbs lighter, and the Falkens in that size which are 6 lbs lighter, you're saving a total of 29 lbs of unsprung weight per corner. That's the equivalent effect of reducing your car weight by 580 lbs. Do that first, then get the suspension set up and you'd have a great handling car.

Good idea on the "mobile pit". Sounds like you're familiar with the process. This should be a fun car to race!

Someone has already been doing their home work! Your ahead of me Doc. Your unsprung weight reduction tips up there are something that everyone that can afford, should seriously look at if they intend to power mod their car. Whether straight line or road course those initial upgrades will drastically improve the cars agility and handling characteristics. Comparatively to the bolt on power gains. I know it's hard for some to translate UNSPRUNG weight loss to actual power gain, but it is fact. I know it's not as,"sexy" to gain power by weight reduction, but just think how the added bolt on's will feel after the weight loss.
Thanks again Doc,good stuff!

[UsedTaHaveA68]

Originally Posted by Doc

I'm going to do almost exactly the same setup on power upgrades. For track rims look into Enkei RPF-1's. They have them in 18 x 8.5 and they weigh 18.3 lbs. The stock 20" rims weigh 32 lbs so that would reduce unsprung weight by 14 lbs just for the rims alone. Each pound of unsprung weight saved has the effect of reducing car weight by 20 lbs, so saving 14 lbs has the same effect as reducing 280 lbs of vehicle weight. Only thing I don't know is if the RPF-1's will clear the brakes but if they do it's a very popular racing rim. Falken makes a 235/40x18 Z rated tire that weighs about 26 lbs and costs about $155 each. You could have a full set of race tires for that rim size for under $700. The stock Pirelli P-Zeros that come with the car weigh 32 lbs each.

If you go with the 2-piece racingbrake rotors which are 9 lbs lighter, the RPF-1's in the 18's which are 14 lbs lighter, and the Falkens in that size which are 6 lbs lighter, you're saving a total of 29 lbs of unsprung weight per corner. That's the equivalent effect of reducing your car weight by 580 lbs. Do that first, then get the suspension set up and you'd have a great handling car.

Good idea on the "mobile pit". Sounds like you're familiar with the process. This should be a fun car to race!

So let me get this straight. The Enkei wheels are 14lbs lighter a piece. 14x4=56lbs. 56x20=1120lbs.

Falken tires weigh 6lbs less per tire. 6x4=24. 24x20=480lbs.

2pc rotors are 9lbs less per rotor. 9x4=36. 36x20=720lbs.

1120+480+720=2320lbs.

You mean to tell me that by removing 116lbs of unsprung weight from my car, it will handle/brake/accelerate as if I had removed 2320lbs of sprung weight? Does anyone else find this just a tiny bit flawed? I think you're off by a factor of 10. I've always read/heard that for every one pound of unsprung weight removed, it's like removing 2lbs of sprung weight. My car handling like I removed 232lbs of weight sounds slightly more realistic than 2320. Otherwise I'd be driving an Ariel Atom!