matty

I drove my friends 03 zo6 all night on saturday. In fact he insisted that i beat the crap out of it. I must say i am very impressed with the car. I knew it would accelerate like an animal...but thats not what shocked me! I couldnt get over how the car handles. Despite the fact that it feels big (bigger then my rx-7), i must confess that i enjoied the handling over my 7. It seems to me that the car corners flatter yet is WAY more comforatable over the bumps. My car is just too harsh. I bet i could drive the 7 faster but the harshness needs to be fixed.

My understanding in regards to handling is that there is a particular trade off...you want flat cornering and responsive handling you get harshness. But the Z06 handles insanely well while still being a comfortable ride. I cant understand it. Anyways my question is how can i upgrade my 7 to handle as comfortable as the Z06 does while still being able to cut up corners nice and flat. My current suspension mods are eibach springs (ala pettit, progressive rate), koni yellows, and pettit antisway bar. The rest on the suspension components have 41k miles on them.
In hind site, i would have never bought the progressive rate springs. They just allow way too much body roll. I was planning to go ground control coilover conversion soon. Will this increase harshness though?

DamonB

All of us chasing the Z06 in SCCA Super Stock can tell you the Z06 is no joke; it's an excellent and well tuned car. Kudos to Chebby.

How to make your RX-7 do that? I dunno. Just be observations (not real evidence) I suspect the Z06 has much more anti-dive and squat. That's a pretty fundamental thing you can't just tune out of an RX-7 as it requires complete geometry changes. The stock Z06 dampers are also very good units.

matty

i am guessing that the zo6 uses softer dampners then 7 while the springs are stiffer, no??
Thats why i was thinking of going coilover conversion...keep the shocks on full soft and 550/450 spring rates. Should be a level handling car with some softness in damping. i dont know...u know alot more then me.....?

M's

if anything i'd say the opposite. the stiff springs will make it pretty bone jarring.

ptrhahn

iTrader: (9)

Actually, the harshness of ride owes alot to the valving of the shocks, and less to actuall spring rate than you might think.

Koni Yellows don't offer the nicest ride around, but i noticed that i actually thought it was better with coilovers (500/400) than w/ Eibach pro-kits (linear rate).

redrotorR1

Corvettes also run leaf springs, which leave the shock independent to resist suspension travel. Is this why the Z06 rides better? I dunno.

ptrhahn is right on about the Koni Yellows. The valving in the off-the-shelf version is not-exactly-comfortable for the everyday driver. Throw in some stiffer springs that are probably not well-matched to the Koni valving .. and voila ... hello bone-jarring ride. I have been told that stiffer spring rate matched with proper shock valving can actually make the ride quality better.

Most of these popular aftermarket coilover kits (Tein, JIC, etc.) are fairly well tuned, and enough members here have commented on how much better the car rides. I suspect that if you were to spend the dough on some quality coilovers, you could achieve similar results to what you experienced in the Z06.

rynberg

Don't the 03 Z06s run those new magneto-rheological shocks? They adjust much faster than adjustable shocks of old and supposedly ride better than the 02s but handle better.

Also, I'll add my comments in about the Koni's valving just not matching up with stiffer aftermarket springs. You can read my comments in my HKS springs/Koni shocks review (just search using my user name).

I'll be going with JIC coil-overs next year to see if the ride/handling will improve. More importantly, I'd like to run a stiffer suspension without lowering the car so damn far. The HKS Springs claimed a 0.6" drop up front--they lied. It's more like 1"+ and I'm getting some rubbing on the right front now. Grrrr....

Brentis

Drove a car with JIC's flt-a2's and it drove very nice and predictable. It had crappy tires on it, but I still felt like I could throw it around better than my car + it didn't have the jarring feeling when hitting rough road patches.

That is what I'm going with unless someone can convince me that GC's or M2 coilover kits with Koni's or GAB's feels as good for less $$$

CCarlisi

I believe the track on the z06 is considerably wider. Wouldn't this allow for a lower degree of body roll than a FD with comparable shocks?

DamonB

Here are a few pics from Divisional #2 hosted by the SCCA Texas Region at TMS. All three cars running race tires, shocks and front sway bars. Granted I was pitching the car a little here to try and stay in the gas, but you get the idea.

DamonB

All things being equal body roll is less with a wider track. Cars actually roll about their front and rear roll centers which are a function of suspension geometry and the center of gravity. Because of this you cannot compare the amount of roll a car will have by just looking at track width on different cars.

...and shocks do not control body roll; springs and sway bars do. Shocks support no weight on the vehicle, only the springs do that.

Brentis

That's odd- is the yellow z06's mirror folded in?

Damon - it looks like your rear is rolling much more than the front.

DamonB

They are. Some drivers like to do that so you can't look behind you. As when you're driving the course and *think* you hit a cone it reduces the temptation to glance behind you and see if a cone is down or a worker is running. It also keeps the race tires from throwing rocks into the mirror; that happens on the Z06.

I'm hard on the brakes and turning at the same time, that's why the right rear is practically completely unloaded. This pic is a good comparison of the cars, they are all braking hard and turning. You get to see chassis dive and roll at the same time. If you look closely at the right rear tires where they touch the ground on both Z06's they are nearly unloaded too, but their total amount of chassis movement is well controlled.

Mahjik

iTrader: (1)

Sorry, not to muck up the thread, but it cracks me up to hear people bash Vettes until they actually drive one.

Brentis

Back when the 02 z06 came out I went and drove one and scared the salesman shitless. The only thing that really appealed to me was the acceleration. I came fairly close to buying one at invoice, but the rackety seats, the damaged window molding, and other fit & finish problems, coupled with the fact that I thought it was too stiff for a daily driver kept me from getting it.

Oh yeah - there was a small dent on the roof - a brand new car with 71 miles...

I was also looking at a new M3 - decided on neither and got two cars - a gs400 and a rx-7 - best of both worlds for me.

ptrhahn

iTrader: (9)

DamonB,
No wonder you have trouble keeping up w/ Z06s if you have to run the stock wheels... they ought to at least allow you to run the '99 17" sizes... jeez, back in '92 a 225/50/16 was a high performance size, now it comes on family cars. Z06s run 295/40/18 rears (or similar), right?

DamonB

In the stock classes for SCCA autoxing you must run the stock size and offset wheel (1/4" allowance). So any wheel is legal as long as it is the same size and offset as stock. Yes, the 10" wheels on the Z06 kill us, but so does the 405 hp and that small block Chevy torque That's my biggest disadvantage; the Z06 launches beautifully out of slow corners while I have to churn the boost.

In stock classes you can change the front swaybar, the shocks (not springs, they must be stock), the exhaust behind the catalytic converter and run on race tires. That's it.

I can bump into other classes that allow more mods, but that is not my interest right now. Basically every other class I bump into the car is still not competitive as the Z06 would still be there. At some point you have to realize you have a 10 year old car and can't be competitive forever. If you look at the times the well driven stock class Z06's are turning in national SCCA events it's pretty astounding, they beat the majority of modified cars as well. I have posted times that would trophy in classes that allow more mods than I have, but yet finish near the back of the pack against all the Vettes. All the same I still enjoy chasing them

matty

noone hear is bashing vettes....is that a general statemnt?

Mahjik

iTrader: (1)

OMG... Don't get your panties in a knot. It's just a general statement. If you search this forum for threads about Z06's and Vette's, people bash them. Usually when someone actually drives one, they have a different opinion. I didn't quote anything about you bashing a Vette because you didn't.

matty

It seems my questions have been answered....thanks!

..and i dont have a problem admitting that a car with 10yr newer technology and one that costs 55k can out handle my 20k..but i will take him in straight line races....

matty

whoa man u are aggressive today...my panties are fine...i just wasnt sure if you directed that to me or not...i usually have a very competitive tone when i post on other cars...i wasnt sure if you picked up on that at some point.

thats all man

DamonB

You should add the to your sig!

Brentis

...my panties are fine... lol

i agree though matty - vettes suck. lol. all that delco engineering and the gmc tahoe steering wheel. argh.. with that said - it is likely the *only* american car I'd buy. pretty sad that our we are the #1 nation and our cars have the styling, fit and finish, and reliability that they do.

Hell the vette had to copy styling cues from the nsx and rx7 to get what it has and they are ten year old cars. They were so busy copying the rx7 and nsx that they forgot that pop-up headlights were actually something of days past.

It's sad. I wonder how many years it will take Chevy to make a SMG transmission now that they've been out for 2+ years. It's sad - I'd love to be proud to own a corvette, but they need to get ahead of the game.

redrotorR1

Actually, only the regular '03 C5's come with the magneto-rheologic shocks. Z06's still come with (correct me if I'm wrong) Bilsteins factory shocks ... which are pretty damn good from the factory anyhow. From the articles I've read about the magneto shocks, the ride is better but the handling aspect has yet to be proven. It's probably not as good ... yet.

Damon, too bad they didn't grab pictures from the offset chicane in the middle of the course. The picture on my trophy was taken in that section. I remember how bad the body roll felt .. and the picture shows it. Eehhh.

DamonB

Popups were outdated in 1993 with the FD too. The 300ZX had no popups...The C5 has popups for the same reason reason the FD does; they were already established styling cues for the cars.

I still insist the C5 followed a nice path is its design progress. It is not an FD copy other than being a 2 seat sports car.