I'm interested in hearing from folks about your thoughts on the proper suspension upgrade. Looking to bump up the perf on my 03' C5.

 

Hi..I'm not going to say that any setup is better than the next but I'll tell you what i did. I had a stock base suspension car and added C5 Z06 sway bars, Z06 composite springs and Bilstien Sport shocks with a 3/8 tunnel plate, and lowered the car 1".. The improvement in handling and overall feel was dramatic to say the least. I have since upgraded the swaybars to the Phadt street Bars and the car feels even better... If I had to change anything, I would say that installing a set of coilovers from the start would have been the better way to go ( I will be upgrading to coilovers at some point)...
It all depends on your budget..

 

Your budget is the main thing.

SImple upgrade. C6 z51 wway bars and c6z06 springs. i like the z06 sway bars. then it gets more complicated as you can start upgrading alot of things but you need to follow a good "system" not just throw various parts at it.

Ideally a set of good coilovers and sway bars your up and running.

 

To the above suspension upgrades, you can add polyurethane bushings to the sway bars and control arms. Finish by adding aggressive alignment front and rear.

Roger T

 

A good set of delrin bushings, coil overs, T1 bars and the car will be a different animal. However, if you are not really driving the car, for most people, it would be a waste of money.

 

You can go simple,fairly inexpensive, and impressive. Replace shocks go to C6Z shocks or better Pfadt. Upgrade sway bars to Pfadt street bars. Change alignment to a street/race.
Or go for coil overs, sways.
If interested I might be selling my stock 04Z suspension. Complete front and rear springs, sways with links, 4 shocks. 13,000 miles on it when removed last year, mint shape never in rain.

 

First help us out by telling us what you want to do with the car. Do you want a car for autocross or track days? Or, do you want more crisp handling on the street. Finally, what suspension is on your car?

What are the roads like where you live? If you are in Michigan or the frozen north, you may not be as happy with a really stiff suspension as somebody in Florida.

What's your budget? You can spend thousands of dollars for the last bits of improvement, or you can get 99% of what you want for a very reasonable amount if you are smart.

There isn't any one upgrade that does it all for everybody. Let us know what you want from the car and we can probably be more helpful.

 

You can pick up new Eibach sway bars for around 230 shipped if you look around. I like mine They made a big improvement over my stockers and are larger and cheaper than C5 Z06 bars.

 

I went to Bilstein Sport Shocks and bought used front and rear C5Z06 sways with metal end links. Lowered car on stock bolts.

Very nice improvement in handling and was even commended by an HPDE instructor who drove my car at Watkins Glen Still very streetable too which is always a plus!

 

Thanks to all for your inputs, I certainly appreciate it.

SoloFast - It's a street application for the most part but I do plan on two or three track days as weather warms. She sits under cover while O'l Man Winter is busy hozing things up (Northern VA). Looking for more handling as a daily and enough stiffness (not overkill) to perform on the track as well.

All - Is there much of a performance difference between the Phadt Street, C5Z06 or C6Z06 sways?

 

 

For what you are doing it would serve you well to just upgrade to a C5Z06 package. If you start picking sway bars from here and springs from there you can easily end up with a package that has nasty oversteer or pushes like a pig, or it can be so stiff that you will need a kidney belt to drive it on any but the smoothest roads. Go out and drive a C5Z and see if it's about what you are looking for. If that's about right, then just duplicate it. It's probably the cheapest way to get a great handling package for a very low price.

If you get a set of C5Z springs and bars you will have a balanced package and you know the car will handle well and won't push or be tail happy. The C5Z is about as stiff as you want on the street, but it won't shake out your fillings on the roads where you live. Also, you can often find C5Z springs and bars for sale for a low price in the board from somebody who has done a big upgrade to coilovers. For what you are doing, coilovers are a waste of money, and going siffer on bars is a waste.

Just as important as springs and bars are shocks and wheels. I'd get a set of Bilstein sport shocks since they are very reasonably priced and have almost exactly the same valving as the much more expensive 2004 C5 Z06 shocks. The C6 Z shocks are a bit stiffer and if you didn't upgrade springs and bars are a good choice. If you stiffen springs, bars, and shocks too much it can get uncomfortable on the street where you live with it most of time. Also the Bilsteins last forever, something you can't say about the factory shocks.

Get a set of OEM C5Z wheels, since they are very reasonably priced, and unless you spend a fortune you won't find anything lighter. Put a set of good tires on them, get rid of the run flats, get a pucka pump and a tire plug kit and put a bottle of goop in the back if you get a flat. A good set of regular tires ride a lot better than the run craps and the car will have grip that you never dreamed of. Spend the money you saved not buying expensive springs and bars on the wheels and tires and enjoy the car.

Finally, lower the car about 3/4 of an inch (and no more!!!) and put on a serious alignment (-1 to -1.5 degrees of negative camber in the front, a half a degree less in the back, and 1/8 of an inch of total toe in, front and back and all the caster you can get up front). This alignment will really wake up the car and you will be amazed how sharp it will be when you are all done. If you are going to run more than 2 track days a year, add an additional 1/2 a degree of negative camber all around to keep from eating the outside of your better tires.

That's about it. If you do that much the car will be awsome on the street, and will devour the track.... For a track day prep, add a set of front spindle ducts, some track pads and a change of brake fluid and you will be all set.

 

Delrin? Are they two piece bushings?

 

Couple good points covered.

1. Budget? Figure that out and stick to it.
2. Use of the car? No point in buying race parts if it isn't going on track
3. Current condition and alignment.

I think that last one is something that needs to be looked at. All the best parts in the world will not make a car work right if the wheels are not pointed in the right direction or things are worn out and broken.

Now let's say everything is in good working order right now I think the biggest bang for the buck would be sway bars. These are not going to impact your ride quality to much but are going to change the nature of the car in the corners more than any other modificiation right off the bat. Do your homework and see what might be good for you. We always liked the factory T1 race bars and modeled our G1 bars after those, and the same setup we worked with for our coil overs if you want to take things that far. Nice bolt on part, and it gives you a three way adjustable rear. All one piece so you don't have to worry about arms deflecting or breaking off.

If the car needs shocks I would do a set of Bilstein sport shocks.

Shocks, sway bars, alignment and get some track time in the car. That would be a darn good start....again given everything else is in good working order.

Of course if the budget allows then there are aftermarket leaf springs, different shocks, and coil over packages as well.

 

My car is driven on the street and occasionallly hits the autocross. I currently have the following (purchased in stages) and love it. It's very comfortable, and handles like a dream.
C5z51 springs
C5Z06 sways
Koni FSD shocks
allignment on the aggressive side of Z06 spec

If I were to do it all at once (and money were not as tight) I would probably go with a Pfadt coil-over and sway bar package. I drove one with those a while back, and was very impressed. It will cost some coin, tho.

 

Big difference and they are 3-way adjustable...

 

I dont mean to hijack or anything but since the thread is tailored for suspension upgrade I would like to know with the setup i have now what spring leaf i should go with. Its for my 01 AT4. I already have C6Z shocks and C6Z51 sway bars and metal endlinks. I got rid of the runflats and went with the Hankook tires. I would like to replace my stock spring leaves and was wondering with what I have upgraded so far what would be a good upgrade.
Also whatever i want to upgrade to I want it to be like kind of swap take the stock part and bolt on the upgrade without the need of major modification.
Its a street drive for now but I want to have it open to race a couple of times a year.

Thanks in advance

 

Exactly. If your going to spend money on sways get better ones. the C5 C6Z sways are a upgrade, but for a few bucks more get the Pfadts and you can grow into them and adjust if you need.

 

FYI, these don't fit. I think this meant to say C5 Z06 springs.

Peter