Hi guys,

I'd like to know some important FACTS about the suspension upgrades. It is obvious that if you wana go fast, the stock suspension won't give you the conifidence and support. So, what upgrades are you guys doing?

I did Bilstein sport shocks & Hotchkis sway bars at the same time. I loved the ride for a while. But then it doesn't seem much in cornering. I don't get full confidence in cornering at higher speeds as some ppl do. Even some VW's, or ricers seem to corner faster. So, what's up? Do I need to upgrade to Z06 springs too? Most ppl who do shock & sway bars say they're experiencing amazing change in handling. Are they just bragging, or is it for real?...........

P.S: I do need new tires though, could that be it..

 

Those shocks and sways are a good street upgrade, but it will not turn you car into an instant road racer like some guys like to think. Figure out your tire problem before you do anything else, they are the most important part of your car.

 

 

 

I have a 98 coupe to which has been fitted ZO6 springs and shocks, and Bilstein Sport shocks. I have 2 sets of wheels and tires. One set is a all stock size OEM thin spoke set with Michelin tires, NON runflats. Fronts are slightly wider than stock tires and one size lower profile. The rears are stock.size. These tires drain well in rain, have reasonable adhesean, and decent ride. I have them mounted up in our winter rainy season, and they work just fine for daily driving, but I would not consider them beyond a 'all arounf' tire. I can break them loose with ease on lower speed corners and they drift with ease. My other set of wheels and tires are 3 piece modular wheels a full inch wider in the front, and again with wider lower tires up front to offset the natual slight understeer. On these wheels i have BFG KD series tires, which are nearly slicks in comparison to the Michelins, and also much softer with a much higher grip. With these tires and wheels, the car can corner at a much higher velocity than the Michelins before begining to slide, and when they do, they have a smaller range betwen grip and total slide. Read tis to mean much faster cornering, but with higher skill to drive at the upper limit. I also do not use the factory suggested alignment specs, but rather, have made slight adjustments to camber and toe until I arrived at handling characteristics that I found to be more predictable and 'better' with the wheels and tires I run. For the record, I do find the ZO6 springs to be just barely adequate, and the anti-roll bars to still be too soft

I only mention all this to point out that no matter what springs, shocks, and anti-roll bars you have on your car, ultimately it will be your tires that contact the road and that will have a LOT to say about how the car feels. Every tire brand and model has a different handling feel. There is almost universal agreement by this forums members that run-flat tires from just about any maker offer substandard grip and harsher ride, a looser in both categories. The phrase often mentioned is "Run-Crap" tires!

Your current setup has soft springs, pretty stiff anti-roll bars and OK shocks, but I beleive the ration of spring to bar stifness is not so good. You must also adress tires, SERIOUSLY address them. There is no 'best tire' which is why I have to keep 2 different sets for different use and weather.

There is a section of the forum set aside for road racers and autocrossers. Some of what you see there on suspension setup and tire selection may translate to a general use street car, but not most of it. Race cars are aligned to suit specific tracks and really fast corner turn in. If you set up a road car this way, it will be way too twitchy. Also the springs and bars you would use on a road race track, which has higher speed corners, and long straights, will be QUITE different from a setup for autocrossing in a tight corner layout where you never et over 45 MPH, but are cornering a max speed virtually 100% of the time.. So called "DOT" race tires may well be DOT rated, but are not suitable for roadgoing use, They will last only a VERY short time, perhaps as few as a 100 miles or so., clearly a bad choice for the road. Even the KD series tires I use only last about 10K miles and for most people that is not enough life for a very expensive tire, but if you want higher cornering speeds and confidence, it is part of what you have to pay the piper. Goodyear and Pirelli also have some sticky tires, but I do not know specifically the range of tire sizes they have.

It takes a LOT of balancing work to set up suspension and handling, and everthing you do will intereact with everything else. The whole thing is a giant balancing act. It will take some money and pleanty of research to learn and eqperiment, but it IS possible to make the c5 coupe and vert handle very well indeed, compared to a stock setup.

Good Luck,

 

I know you can make a C5 handle better, and it might be apparent on an autocross or roadhandling course, BUT for most of us folks on the street, .95 g or better handling is WAY MORE PERFORMANCE than we will ever need or use!

 

.95 G ? I don't know if my car's doing that, or even how to measure it.

FiberglassFan: Thanks for the detailed/informative reply. So, do you have the Z06 shocks, or the Bilsteins... can't have both. ... lol. Seems what changed my ride was the fact that I made a lil change to the Hotchkis sway bars. The rear bar has 3 holes for endlinks. When I originally got it installed, it was on the OUTER holes. Then I read somewhere that as you use the Middle or Inner holes the suspension gets tighter and more appropriate for cornering. So, I changed it to the most inner of the 3 holes, cuz I wanted to use the Hotchkis to the MAX for its benefit.

My personal experience: I have nearly bald "run-craps". With STOCK shocks/sway bars, car used to slide every time I turned or even in straights... AFTER I got the Hotchkis sway bars & Bilstein sport shocks - I was amazed . NO MORE Bumpy ride. NO MORE Sliding. NO more loosing control. I LOVED the shocks more than I've ever imagined . When the car went over bumps, instead of landing in a bumpy/bouncy way (stock), the Bilsteins made it land as if it landed on Cotton - really soft, and it landed in a way where it settled down slowly - NOT bouncing down and up, and down. Just went up, and then settled down once (slowly, in a plush way). The ride was like a luxury car, but didn't slide and HELD the GRIP strong even on bald run craps. However, I felt a little banking affect when cornering, so I went to the inner holes on sway bars-------------------- After I changed to the inner holes, the ride is back to harsh (as the stock shocks were), very bumpy, jittery. It seems like the shocks are Old and given up already. No more Plush ride And I'm not sure if inner holes (compared to the outer holes I had before) has made any difference in cornering ability.

Anyone knows what's goin on here? Anyone has the same set up as mine and knows what I'm talking about? Will changing over to Z06 springs make a worthwhile difference ($450-$500 or so)? Thanks again...

 

The post by FiberglassFan was pretty thorough, but here's my experience..I have ZO6 springs, Hotchkiss bars, and Bilstein sports. I love the ride on the street where let's face it we spend the vast majority of our time (most of us anyway). It's stiff, handles well and not too harsh. I participate in track days and autocross. The car handles very flat and it's very predictable which is important if you want to drive it home at the end of the day. The other upgrades that I will consider are coilovers ($$$) and T1 bars. The T1 bars will make it pretty stiff for street driving (or so I've been told). Good Luck and have FUN!!

To answer your last question, yes the springs are worth the money. Each of the components take care of different parts of the suspension puzzle.

 

Your tires are definitely holding you back. They are your only contact with the road. Everything you do to improve your suspension is done to improve the tires contact with the road.

Your first order of business is to get some good tires. Stay away from runflats as the stiffer sidewalls will hurt your cornering ability. Also, are you running stock sizes. If so, you might want to look into upgrading to Z06 size rims and tires.

The next step is to get a good alignment. Something a little more aggressive than a regular street alignment but less than for HPDEs or auto-X.

This will help a lot.

You also need to realize that since you have an automatic you are at a disadvantage to cars with manual transmissions since you cannot control when your car shifts. If it shifts in a turn it will unbalance the car somewhat, which means you have to compensate by going slower.

 

Its quite obvious that I need tire, maybe sooner than later. And yeah, I agree that a lil aggresive alignment is what I'd get. And I'm hoping that'll take care of most of the issues I "feel" I'm having. Though Z06 springs would be nice to have, it is so absolutely, neccessary to have them? ($$) I know most ppl don't have 'em. But a lot of ppl brag about the Bilstein sport shocks, and sway bars (generally Z06 sway bars). With these 2 mods, they CLAIM to ride on rails . I have the same shocks and Hotchkis bars (more stiffer than Z06's).

My main concern is that the ride is not so plush anymore as it was when I put IN the new sway bars & shocks. What happened? My tires were just as bad even then. Its been hardly 3K miles since I made the change. Within that 3K miles, the ride is not plush at all now.

 

this is weird because my 97 is all stock suspension with sumitomo tires and I can into and out of street corners pretty good without sliding. When I drive my brothers 01' cobra, I realize how great my suspension is in the vette because that cobra s all over the place around turns.

and i have a z06 rear swaybar sitting in my garage waiting to be installed, but it's sounding like it's not going to do much for me.

 

I have to be honest, I have not read all the posts above...

I will only add that springs will change the car. I did shocks/sways and it was better, but as soon as I put the springs on it was a completely different car. Instead of gliding through the turn, it felt like it pointed, and you actually had a sense of it rotating vs. vaguely guiding it through.

This is all with Z06 springs/bars and Bilsteins. Now, obviously that setup isn't race-ready, but it's pretty darn good on track.

if you're looking for a track monster (or looking to say you drive a racecar on the street), go with T1 stuff. If you are looking for a good solid handling car for the street that does damn well at the track, I'd say Z06 stuff. Just my opinion based on the cost/benefit I went through myself some time back.

And the post above is also right regarding tires - runflats will tend to skitter through turns since they are so stiff. This will make a world of difference too.

 

One thing that hasn't been mentioned is whether your car is lowered or not. If you lower your vette on stock springs, you reduce the amount of travel your suspension has, giving you a bit of a harsher/bumpier ride. If you cut the bushings, that will cause the ride to be even harsher.

Having a lowered car adds another wrench to the hunt for the perfect suspension setup. Although lowering your car does give you the advantage of less roll and can be a bit benefitial on a roadcourse, it generally gives you a harsher ride. Coilovers seem to be the best way to have a lowered vehicle and keep a firm but comfortable ride, depending on your adjustment settings.

I currently have my vette lowered on Z06 shocks/sways but stock springs. The ride is great on road course, I do about 3-4 HPDE events a year but its a bit harsh on NYC pothole ridden streets. I may get the Z06 springs in the future to see if that helps or just wait a bit more and get adjustable coilovers.

 

As Alex1217 noted if your car is lowered, and your signature shows your car is lowered by 1 inch, that could lead to a harsher ride on the street. Might be a good idea to put it back to stock height. The Hotchkis are very stiff. If I recall correctly, they are about 2 times stiffer than the Z06 sways. Could be a be much if you only plan to use the car on the street. Might want to consider selling them off and putting on Z06 sways (with metal end links) and get the Z06 springs. I had a Z06 suspension on my 01 coupe and while the ride was a little stiffer than the Z51 suspension I felt it was worth it for the much improved handling.

Not sure that going to stiffer springs with your current set-up is going to help your ride quality on the street. Probably make it worse since it will just make your suspension stiffer.

Hope this helps