Roaring Forties Spring Rates

[Troy]

I know it's out there, but I just can't seem to find the info.

Looking at spring rates for a track-only RF, and for some reason thought that the fronts were heavier rate than rears. Most threads I find here for other manufacturers suggest heavier springs on rear than front.

Yes, my set up is different to other RF's, but was hoping for a base line to start from.

Suggestions?

 

[Troy]

Bump...

 

[David]

Don't know about the RF but AFAICT weight distribution is between 38:62 and 45:55. I'd not really be surprised that firmer springs are required at the back.

Generally seems to be 325-400 front 400-450 rear.

 

[40 Bud]

Some years ago (when Robert Logans name was permitted), I talked with Robert about this very thing. He told me his chassis engineer had told him they needed heavier springs in the front. Later when redoing my GTD's shocks and springs Steve Duck at RCD Suspension, Bilstein specialists, recommended the same thing. It seems that the working angle of the shock/spring set had something to do with it. As it turned out we used 450lb. units in the front and 350 lb. units in the rear. They have worked well and are good on the street as well as the track. When sprung the other way around the car twitched a little on heavy braking, now it is rock steady. I found Steve Duck at Race Car Dynamics a real help. You can contact him at [email protected] . They are in El Cajon, California.

 

[flatchat(Chris)]

I'll go along with Bud --100 lb softer at the rear --ie:- 650lb F and 550lb R --suits my application just nicely, that said, your geometry will dictate the actual #s.
A good front sway bar and double acting shocks will do wonders for the rest.
Chassis torsional stiffness knowledge is your basis