C5 suspension for street and auto cross
11-15-2006, 03:44 PM
#1
Burning Brakes
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C5 suspension for street and auto cross
Hi I have a 1999 C5 with about 50,000 miles on it and I was looking at replacing my shocks and maybe some other suspension components while I was under there. I cant have my car go any lower because the air dam already scrapes as I leave my driveway(its at stock height). I visit the auto cross track 4-5 times a summer and I was wondering if you could recommend a set up for me
Thank you peter
Thank you peter
11-15-2006, 04:09 PM
#3
Le Mans Master
The stock suspension is pretty good; a lot better than people think.
You didn't say if you were driving a coupe or 'vert. If a coupe, run with the top in; it'll add some stiffness to the chassis, which makes the suspension work better.
You also didn't mention tires. Tires are the largest performance factor other than the driver when it comes to handling. Also, make sure the car fluids are fresh.
HTH, and have fun on course!
Mike
You didn't say if you were driving a coupe or 'vert. If a coupe, run with the top in; it'll add some stiffness to the chassis, which makes the suspension work better.
You also didn't mention tires. Tires are the largest performance factor other than the driver when it comes to handling. Also, make sure the car fluids are fresh.
HTH, and have fun on course!
Mike
11-16-2006, 12:05 PM
#4
Premium Supporting Vendor
50K on Stock Suspension, What next?
Peter,
Greetings,
Before you up-grade, check on the rules, establish your goals and budget. Inspect the chassis and focus on any play in the suspenion. Your platform is very sensative (good) and worn parts (bad) will have a negative affect on the handling. Handling is a package, each part has it's function and needs to match/compliment each other.
If you just want to have fun and all is tight, then here is our take on building your package.
Sway Bars:
We find huge improvements on the Stop Watch... Anti-Sway Bars are the cheapest, non wear part you can install to improve lap times. we found 35mm (1.3/8' tubular) front and 24.5mm (1.00" tubular) rear are a great package. Polyurethane mid-section bushings and adjustable heim joint end links as a perfect choice.
Springs:
Composite or Coil-over. You have options, hard core ALMS/Speed series cars for the most part use the coil-overs, and have lots of them for varies rates. Technically, the C5 is not designed to support the cars weight on the shocks and when coil-overs are used on the street things happen. Composites are designed for the C5, will last the life of the car, will not wear out or lose rate like coil overs. With our experience we tailor the rates to match your goals, usage and abilities.
Shocks:
Bilstein Sports will work well and only firm the ride, not make it harse which is not fun. Additionally, Bilstein uses a shorter shock canister which will give you addition suspension travel under compression travel and if you have lowered the car helps re-establish lost travel. The Factory Z06 shock is very popular but a tad pricey. If you were to compare the shock dyno sheets they are very close to the Bilsteins and the Bilsteins are generally cheaper. Additionally, down the road, if you want to have the Bilsteins "custom tuned" their shock can be "re-valved" which is an added bonus.
Adjustable Shocks:
Koni has a new line of products targeted at the C5 enthusiast. The valving is a result of working "behind the scenes" with some of the top C5 auto-x ers to perfect the production product. Single or Double adjustable models are available. Pricing is surpricingly competitve for an adjustable shock. I would only recommend adjustable shocks if your long range goals were to require the track side tuning ability.
Bushings:
Control Arm bushings are a major wear part on the C5 suspension, especially if you drive aggressively. Front lower C-arm bushings "walk" out of the C-arms and the rear allow for torque steer. Our tests revealed a 50-55 durometer reading and when serverly loaded will change the toe setting by as much as .500" and camber change by 2.0 degrees. Not good when you are really working hard to go around corners. If properly installed polyurethane bushing are quite and dramadicly improve platform stability. Perfected for track use, using them for the street has been a good thing. I have yet to see or hear of failure on the street.
Tie Rod Ends:
HD Tie Rod Ends have a longer threaded shoulder which eliminates deflection when the platform is lowered. When brake rotor temps are high the ball stud packing with the HD will not distort like the OEM tie rod end.
Alignment:
It's the polish on your shoes. Once the suspension is assembled, the aiming of your sneekers (tires) can be worth seconds on a given venue. Alignment, ride height and scaling are a must.
Hope this helps....
PL
Greetings,
Before you up-grade, check on the rules, establish your goals and budget. Inspect the chassis and focus on any play in the suspenion. Your platform is very sensative (good) and worn parts (bad) will have a negative affect on the handling. Handling is a package, each part has it's function and needs to match/compliment each other.
If you just want to have fun and all is tight, then here is our take on building your package.
Sway Bars:
We find huge improvements on the Stop Watch... Anti-Sway Bars are the cheapest, non wear part you can install to improve lap times. we found 35mm (1.3/8' tubular) front and 24.5mm (1.00" tubular) rear are a great package. Polyurethane mid-section bushings and adjustable heim joint end links as a perfect choice.
Springs:
Composite or Coil-over. You have options, hard core ALMS/Speed series cars for the most part use the coil-overs, and have lots of them for varies rates. Technically, the C5 is not designed to support the cars weight on the shocks and when coil-overs are used on the street things happen. Composites are designed for the C5, will last the life of the car, will not wear out or lose rate like coil overs. With our experience we tailor the rates to match your goals, usage and abilities.
Shocks:
Bilstein Sports will work well and only firm the ride, not make it harse which is not fun. Additionally, Bilstein uses a shorter shock canister which will give you addition suspension travel under compression travel and if you have lowered the car helps re-establish lost travel. The Factory Z06 shock is very popular but a tad pricey. If you were to compare the shock dyno sheets they are very close to the Bilsteins and the Bilsteins are generally cheaper. Additionally, down the road, if you want to have the Bilsteins "custom tuned" their shock can be "re-valved" which is an added bonus.
Adjustable Shocks:
Koni has a new line of products targeted at the C5 enthusiast. The valving is a result of working "behind the scenes" with some of the top C5 auto-x ers to perfect the production product. Single or Double adjustable models are available. Pricing is surpricingly competitve for an adjustable shock. I would only recommend adjustable shocks if your long range goals were to require the track side tuning ability.
Bushings:
Control Arm bushings are a major wear part on the C5 suspension, especially if you drive aggressively. Front lower C-arm bushings "walk" out of the C-arms and the rear allow for torque steer. Our tests revealed a 50-55 durometer reading and when serverly loaded will change the toe setting by as much as .500" and camber change by 2.0 degrees. Not good when you are really working hard to go around corners. If properly installed polyurethane bushing are quite and dramadicly improve platform stability. Perfected for track use, using them for the street has been a good thing. I have yet to see or hear of failure on the street.
Tie Rod Ends:
HD Tie Rod Ends have a longer threaded shoulder which eliminates deflection when the platform is lowered. When brake rotor temps are high the ball stud packing with the HD will not distort like the OEM tie rod end.
Alignment:
It's the polish on your shoes. Once the suspension is assembled, the aiming of your sneekers (tires) can be worth seconds on a given venue. Alignment, ride height and scaling are a must.
Hope this helps....
PL
11-20-2006, 05:57 PM
#6
Team Owner
My car is a daily driver but I also run about six or seven autocrosses a year and a few road course days. I needed something that would improve handling without making the ride awful. My car is a Z51 that I upgraded with 04 Z06 front and rear bars and endlinks as well as 06 Z06 shocks, all from Fred Beans. It autocrossses much better and the difference on the road course was substantial. As has been mentioned, biggest improvement was a set of tires. i picked up a set of Z06 wheels in the FS section and some used V710's and its like night and day.
All of the parts were from posters or vendors on the forum.
All of the parts were from posters or vendors on the forum.
