SWB suspension set up

[Alex Webster]

Many of you know that I am running a 67S in historics here in Australia, and I am now seeking some input as to some of the set ups that fellow racers use in regard to shocks, torsion bars and sway bars.

My car comes in at around 1000kg or 2200 pounds, has to run on 60 profile rubber and is restricted to 205 width on 6 inch rims, running R compound tyres.

Currently the car has a pretty standard set up with slightly harder shocks, and loves to drift! Turn in is good, mid corner can get a little unsettled, but exit is good with a little oversteer, however the rear does light up the inside depending on how hard you push it. You tend to have to feed on the trottle to compensate for this which is slowing mid corner speed.

I feel that I can now start to set the car up harder and a little more 'racey' as I have grasped the car and taken it basically to its limits in current suspension format.

Engine specs are about 170bhp. Gearing is AFMSX - or will be very soon, currently running Z top which is standard 67S 5th.

I have faith in our mechanics here with the wealth of experience but keen to learn more personally so I know what others have used first hand

[Schläfer]

however the rear does light up the inside depending on how hard you push it. You tend to have to feed on the trottle to compensate for this which is slowing mid corner speed.

Hi Alex,

Are you allowed to run a limited slip/torque biasing diff? It'd certainly help the inside wheel losses.

David

[304065]

Alex,

It's impossible to have too much spring rate in a torsion bar 911. We know that one of the motivations for the factory switch to coilovers for the RSR was the availability of higher spring rates. Therefore, I think you would be well advised to throw everything you can into it: 23/31 is a proven combination. You will need revalved Bilsteins to match.

Of course you must ditch the old SWB front suspension and use an SC or Carrera setup with "A" or "Wide A" calipers, so obtaining Bilstein inserts should not be a problem. Make sure whatever struts you have use a wedge bolt, not a threaded one, as the latter is a death trap. The valving rates for the Bilsteins are a closely guarded proprietary secret among chassis tuners certainly in the USA.

Smart Racing Products or Wrightwood's "Charlie Bars" are the best, but my understanding is that the Charlie bars have a long lead time, whereas with SRP, you just call them. There are interchangeable bar thicknesses that you can use to tune the ARB rate but my advice is go with the big ones.

Of course none of this will work properly without the complete monoball setup front and rear and some good bushings. Currently, the WEVO roller-bearing spring plates are only available for LWB cars, so you are stuck with Sway-A-Way with a set of Chuck Moreland's Polybronze Bushings. These are a much better alternative than plastic.

When it's all done, BE CAREFUL your first few times out. The car will feel like it is bouncing across the surface sideways. You will have to adjust your driving style to compensate for the changes in the suspension, but if all goes well, the car should be faster.

Good luck!