Spring rate advice Options

[BlueRidge914]

I’d be grateful for some spring rate advice for my vintage race 914.
It’s a narrow body 2L six, 205/50 tires all around. Front torsion bars with adjustable sway bar. Rear is Bilstein Sports with adjustable spring perches, and a fixed sway bar.
My personal preference leans to a relatively softer spring all around.
Any recommendations for both torsion bar size and rear spring rate?
Thanks!
Gavin
VARAC #58

[slivel]

I believe that you get performance gains by going as stiff as possible but not so stiff that you are bouncing over rough pavement. Stiffer helps to prevent front end dive under braking and rear end squat under acceleration while keeping the balance close to what the chassis has statically.

The tracks that I frequented were pretty smooth and I did not feel like changing out my suspension from track to track. Final race configuration for my car had 450 front and 400 rear. The car and driver are now retired and I have softened the suspension by using stacked springs giving me a progressive rate.

For what it's worth, I'll attach my spec sheet and a suspension worksheet.
 1975_Porsche_914rev16.pdf ( 69.19k ) Number of downloads: 61

 Suspension_for_914_world.pdf ( 200.22k ) Number of downloads: 46

[campbellcj]

I believe that you get performance gains by going as stiff as possible but not so stiff that you are bouncing over rough pavement. Stiffer helps to prevent front end dive under braking and rear end squat under acceleration while keeping the balance close to what the chassis has statically.

The tracks that I frequented were pretty smooth and I did not feel like changing out my suspension from track to track. Final race configuration for my car had 450 front and 400 rear.

Mine was set up for primarily track use along similar principles and IIRC has 22mm hollow 911 t-bars and 350 rears (may be 300 or 325). Very flat and stable on track (or canyons), but nearly intolerable for street use.