1985 Reynard spring rates

[JWMotorsports]

I’ve got one of the few ‘85 Reynards still running the factory push-rod setup.

I know there’s a lot that goes into determining spring rates, and I know I probably don’t have all the info, but I’ll list what I have and hopefully someone can help with a ballpark idea.

I’m currently wearing out end plates and bottoming out at Mosport (CTMP) in turn 1 and turn 5 because the front end drops so much (Turn 1 no brakes, Turn 5 all the brakes!)

Ride height:
Front 75mm
Rear 85mm

40/60 front/rear
50.1/49.9 cross weight
229/224 front
346/344 rear

Hoosier Bias ply tires:
Front – 20.5 x 7.0 – 13 R60A - 43164
Rear – 22.0 x 8.0 – 13 R60A - 43285

Current spring rates (as written on the springs, not tested)
Front: 420
Rear: 550

Here’s the lean in 1 doing 175kmh


Would 50-100lbs make a big difference? Or is +200-250 going to be what it takes?

Thanks!

[BruceRace]

Droop Limiter?

[teamwisconsin]

What kind of bump rubbers are you using? And are you close on your gaps? (Bump rubber to shock body)

If you like the way the car handles with those setup numbers and you just want to limit the amount of travel at the front you could use some packer to prop it up. It can come with some side effects but personally I'd start there if you are happy otherwise.

[tlracer]

I had a 1600 Reynard 85F (back in 1987) and there was a weird geometry with the rear pushrod suspension. If I recall correctly, the original bellcranks gave an unusual (falling?) suspension rate.

The factory issued update parts to correct it, but these resulted in poor rear grip, that needed a very soft rear ARB. Even then, we ran the front ARB very stiff, but it was never really 'right'.

The factory's next offering - which went onto a number of 85's and got carried-over onto the original 86 car was a kit that replaced the rear pushrod setup with rockers. I p/x'd it for an Van Diemen instead!

Based on that experience, I would agree with Ethan - packers could be the way to go if you're happy otherwise.

[jchracer]

I had an 85F as well. My conclusion was that the weird rear geometry resulted in side loaded deflection and dynamic toe-out....a truly scary thing at speed. I made up new rear lower control arms and moved the pick-up point on the lower upright to a more conventional location centered on the upright and the car became WAY more stable when cornering. Perhaps dialing in bunch of compression bump steer toe-in could help as well but I chose to correct the root problem. YRMV.