ZRConekiller

Figured it was time for an update it has been a very busy spring and lots of rain. The car received all new super pro bushings, ss brake lines, Hawk HP Plus pads and hoosiers a7's 315 35 17 on all 4 corners factory wheels (Please save me your wheels are to small if you would like to donate 2 17x11's that will fit the front of my car that would be great . Sorry I didn't have time for hardly any pictures but we did get to put the car on the scales with half a tank of fuel which really surprised me as far as cross weights go. So far we have had two events the first it was 5 degrees celcious and rain in a small parking lot a good friend had an incident which really made me check up in the video. The second event was at our normal spot an old runway on a military base it was 20 degrees celcious. Its a great venue but it really is important to have a co driver to keep the a7's hot they would get nice and warm on my first run than by the time I got back out they just weren't there. I am still figuring out the car with new bushings and a7's the results are not anything to cry home about but at the end of the month we have a great event at another air strip and I have my co driver lined up so fingers crossed! Now what I can tell you is this the car feels very tight and responsive. The old bushings were so shot it was scary but its amazing how tight the car feels, Second ss lines and hp plus pads are fantastic the car really bites now and will actually slow itself down. Now the a7's when they get warm they are incredible you can really feel the car change in steering inputs etc even with the big 315's on a 9.5 inch wheel the car turns in fantastically. We were allowed passengers today and my friend with a very well prepped ssp c5 z06 says the two cars felt almost identical he figures if he was on fresh hoosiers he would nose me so im happy with that. I'm going to try and link some videos from Facebook but if it doesn't work ill post them later now on to some terrible pictures Except for the ones our fantastic photographer took at the bottom! (Kevin Doubleday)
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Dominic Sorresso

Try installing the Vette2Vette No Flex chassis stiffener.

Tom400CFI

Don't. They add weight and won't improve the performance of the car.

Dominic Sorresso

Are u saying for competitive events or all around driving? I have them on my ZR and love how the chassis feels so much more solid having significantly reduced chassis flex.

Tom400CFI

Competitive events.

Objective numbers are different than the subjective feel that a stiff frame provides. A stiff frame FEELS better, so people say/think; "the car handles better". Subjectively -the way it FEELS, it "handles better". Put it on a track though, and it won't make a difference in the numbers.

Dominic Sorresso

Tom,

Can u elaborate further on why that’s true? Is it the weight penalty? Seems like all the chassis stiffening that is done to race cars would suggest otherwise. Perhaps the V2V isn’t the right kind of stiffening, but I’d like to understand better.

ZRConekiller

I have looked at the stiffening system but I don't really think that is where to start the car needs bigger sway bars and heavier springs next at least in my opinion. I plan to tighten up the nut behind the wheel this year.

Tom400CFI

Dom, you'll have to consult an engineer for a more precise and accurate answer, but I can suggest three things:
1. There is a story where GM took a 3rd gen Camaro, ran a road course with it, then cut the roof off (rendering it a "wet noodle") and ran the same course. Times were unchanged.
2. We know that stiffer frames are able to provide a better quality ride feel -you don't feel the movements of an undampened spring
3. Compare objective numbers of C4's and C5's; they're very, very close -yet the C5 is 4x stiffer in torsion! The frame stiffness doesn't translate to better objective numbers.

You should read the "Frame Tech" thread.

vettehardt

Careful with your sway bar choices. My dad installed the larger front bar, and it made his car push worse than a Z already does. He had it on for one weekend and then took it off. You would have to make sure the rear bar mates to the front bar to keep the handling balanced. You might be better off getting shocks before bars.

JoBy

This is my understanding about chassies stiffness.

I agree with Tom that a stiffer chassie does not automatically make tha car handle better or manage better times on the track.

The whole car, suspension, springs, shock absorbers, anti sway bar, tires, weight distribution and chassies is a system.
The most important thing is to maximize friction between tires and road. When the first tire starts to loose traction then you are at the limit.
When you for example turn or go over a bump you load up the system and all these components together affect how the forces between tires and ground changes.

Chassies flex act as a part of the suspension. The problem is that is is not a part that you can tune.
If you for example lift front left and right rear tires. With a stiff chassie and stiff anti sway bars and springs the other two wheels will be in the air. With looser springs and anti sway bars all wheels will be on the ground.
With a loose chassie it does not matter what springs and anti sway bars you use. The chassie will flex and all tires will be on the ground regardless.

What I an trying to say is that a stiffer chassie will give you a larger tuning window for the other components.
If you need that larger window to get the most from the tires is another question.


ZRConekiller, good job, but one thing is bothering me. Put the rear wheels on the correct side

ZRConekiller

JoBy yeah we were rushing to get the car together hence why the wheels were backwards lol. Improving the chassis is the next step I really want to buy a z51 spring and bar set next to try. I read over on the registry someone was doing this in the mas area with some success. The crippling factor for these cars is that the mold is broke at hypercoil so as far as aftermarket stiff springs were SOL. Lets face facts its not economical to make a new mold for these cars. Ideals next year id like z51 springs and id like to try the big bars front and rear from vansteel. I really want to stick with leaf springs but if I go coilovers the car is headed in a CAM S direction with 200 tread wear tires. We have another event tonight so well see what happens.

93Rubie