Springs Rates 172 Ph1 Race Car

Wanted some recommendations for spring rates for a 172 Ph1 race car.
I have Leda coilovers on front & Leda dampers on back with beam springs. Springs are old Eibacs and way too soft. Ideally I would replace with new AST coilovers but as the Leda are in good working condition and I dont currently have the funds, I may as well get some DR Faulkner springs for now as a relative low level of investment.

My thoughts were 375 Lbs front & 500 lbs Rear (which I think equates to a 1000Lbs beam spring instead) ?

Appreciate your advice

Also wanted to confirm ideal ride height front & rear. I am running R888's & Rainsport 3's

The current front springs are 9". Not sure about the rear but the rear is probably too low and needs a bit of rake to front.

Flam686 said:

Wanted some recommendations for spring rates for a 172 Ph1 race car.
I have Leda coilovers on front & Leda dampers on back with beam springs. Springs are old Eibacs and way too soft. Ideally I would replace with new AST coilovers but as the Leda are in good working condition and I dont currently have the funds, I may as well get some DR Faulkner springs for now as a relative low level of investment.

My thoughts were 375 Lbs front & 500 lbs Rear (which I think equates to a 1000Lbs beam spring instead) ?

Appreciate your advice

Click to expand...

If it's a race car you want upwards of 500lb springs up front mate. Regarding the rear, it's a lever, so your 500lb rears will work out to be the opposite way around to what you're thinking due to the lever ratio. The wheel would only actually 'see' around the 350lb region.

You're going to really struggle tbh mate with rears unless you go full coilover. As a starting point though, jack the car up and place the rear on axle stands to allow the rear suspension to be on full droop. Then, measure the distance between the spring perch on the rear beam, and the top spring perch on the bodyshell/chassis leg. You now have the maximum distance that the suspension can travel without the spring becoming dislocated.

Due to the design of the rear inboard springs, you ideally need to have some custom wound if you want to start going up mega firm on the rates. I had a set done by Coilspring up in Sheffield, and they were spot on tbh. They engineer a few 'dead coils' into the rear spring to stop it from dislocating at full droop.

I'd say you realistically want to be fitting 700lb springs (upwards of at least) into the back end if you're going to race it.

Alternatively, just buy a set of Gaz rear coilover units and fit them as some of the guys who ran leda, now run Gaz. It will also give you a 1:1 motion ratio, so a 500lb spring, is a 500lb spring.

Thanks NLC
Yeah makes total sense. Will get some coilovers