mcar00

I'm sure there will be many different opinions, but I'm wondering what front and rear spring rates guys who road race with coilovers are using. Looking more for race car set up's as opposed to those vehicles set up for street/track.

Also, is the spring rate dependant on the brand of coilover or is this truly an apples to apples comparison? I understand that those with downforce may use more spring rate so if you can clarify why you chose the spring rates you run that would be helpful. I'm particularly interested in the front to rear relationship.

Thanks!

Gman57

The way I understand it....... It works as a system shock rate and spring rate= total package call Randy @ DRM that's my perfered supplier/builder

RacePro Engineering

Mike,

We need a little clarification here. I can not imagine any road race car that could be considered "dual purpose", if by that you mean street duty.

Ed

mcar00

Ed you're exactly right. What I was trying to get at is that I'm not really interested in cars that are used dual purpose for street and track but only dedicated track cars. What I was trying to avoid are spring choices that are softer because the car has to perform street and track duty. In other words, track set up's only.

Sorry for any confusion.

RacePro Engineering

Mike,

Following are a couple of recent good threads dealing with the subject.

http://forums.corvetteforum.com/auto...-on-front.html

The following started out as a question about aero, and around post # 12, morphed into a pretty good discussion of spring rates and F-to-R balance, with aero.

http://forums.corvetteforum.com/auto...th-a-wing.html

As you guessed, guys here will have all sorts of answers, so look for the opinions that are supported by sound reasons.

Ed

mcar00

Interesting thread. Thanks for pointing it out Ed.

95jersey

Running 700/600 coil over and it is VERY stiff. I would say overall it feels much stiffer than T1. The car barely leans even under extreme G loads. There is no discernable dive under braking. Car just remains flat no matter what you throw at it. I can't imagine going much more even for dedicated race applications, also it is a bit of a killer on bushings.

You could try 750/650, but anything higher than that and it may not work on the bumpy tracks or in wet conditions. Remember a 700lbs coil over is stiffer than a 700lbs leaf spring.

mcar00

I've been running 900/700 and my car is stiff as well. I use it primarily at Sebring which is not very smooth in places. I found that by softening up the shock settings I could eliminate that bouncing feeling going down the straights.

A lot of guys run softer springs in front vs. the rear and I'm basically just trying to make sure I'm not missing the boat here.

RacePro Engineering

If we can discuss spring rate for a second --

Mike,

I missed this portion of your question both times:
Spring rate is simply how much force is required to compress a coil, OR to bend a leaf, exactly one inch. It is expressed in pounds. So, a 500 pound spring will compress, or bend an inch for each 500 pounds of pressure exerted DIRECTLY ON IT.

Here we need to be careful with terms, because 700 pounds is always 700 pounds, and one inch is always, and forever, one inch. What makes the coil spring "appear" stiffer to the Corvette chassis is the manner in which it is integrated into the suspension geometry, as opposed to the leaf. Without getting into a completely different discussion here, when we move from leaf to coil, we alter the MOTION RATIO, and the same 700 pounds of SPRING RATE feels stiffer.

Ed

VGLNTE1

i am wonderingthis also. If i hit a bump at about 150mph, it feels as the T1 rear shock bottoms out because of my full wing in back.

Pfadt Racing

On our Competition coilover setups we use a stiffer front spring rate. Ultimately a stiffer rear rate is a trade off for ride quality on our street and dual use coilover packages. With our competition FeatherLight Generation Double Adjustables we know that users are looking for track performance at the expense of ride quality, and can design damper package around a higher front spring rate. Our FeatherLight Double Adjustables are a great example of this, we start the spring packages included with that kit at 700 Front 600 Rear. It's pretty stiff, and on the upper end of what we would consider streetable, but they work very well on track with race tires.

kentz06

On my car 700F/600R =

Dean