warmfuzzies

Question, If the turn in with progressive springs is less than sharp as some have suggested, would going to the RS -ve camber offset this somewhat?
I'm trying to evaluate what setup to go for when I change my springs, but am still quite unsure about what to do.

TIA

Kevin

Ruairidh

Can I also add to Kevin's question by asking what folks experience of the additional tire wear in road use with RS negative camber at the rear?

joey bagadonuts

The change in wear is minimal. Think of it. If your stock camber is zero, then you should see even wear across the tread; now add 2 degrees of negative camber and you'll see a bit of a slant from outside in but nothing dramatic. The tires pictured below ran approx 5K miles with -2 degrees.

In regards to using camber to sharpen turn in, IMHO the difference will be neglible vs. linear springs. When you turn into a corner, you're often on the brakes or at least the front wheels are loaded up. The forward weight transfer compresses the springs and gets you to the firmer part of the coil. The negative camber alone will assist with turn in but the benefits are comparable whether you're running linear or progressive springs.

Perhaps someone else can clarify the benefits of linear springs but it seems the reduced lateral weight transfer during corner exit would allow you to get on the throttle sooner ... which is the object of the game.

Bill Gregory

RS camber is roughly minus one degree of camber, and you shouldn't notice any particular wear in street use.

In terms of sharpening up front turn in, you wouldn't believe the difference monoballs in the front a-arms, along with cup 'forks' in the steering, make on turn in. Major difference versus stock, and that's based on street experience. Track in late March.

On springs, Joey hit the nail on the head....progressive springs are good to learn on at the track, as they help you learn to make smooth transitions. As you advance your driving skills, and the speeds you apply those skills at, you really want to return to linear springs (or linear with helper), so your suspension doesn't have to move through the progessive portion of the coil to take a set in a turn.

warmfuzzies

Thanks for the replies guys,

I really wasn't considering the track days as an issue, more like trying not to lose the turn in I enjoy now on the road, plus trying to get some degree of comfort on the poorly maintained roads over here.......
I guess compromise isn't an answer.

Thanks

Kevin.

ThomasC2

To much toe-in or toe-out gives you more tire wear than negative camber. I run with a little more than 2 degrees camber and I can't see any uneven wear.

Ruairidh

Kevin, I've just had a Roock coil over set up put on my car (progressive springs), and ride height set to RS spec with neg camber at rear. P-Zeros all round.

Now I've no point of reference for what new shocks with the old ride height/alignment would feel like) BUT I will say that - in road driving - the new set up is a great great improvement in feel (glued to the road), turn in response and go-kart control. Hence my only concern was for the wear on the rear tires.

joey bagadonuts

Yes, after I posted, I thought this may not be a track question.

Given your driving conditions, I think you're right to go with progressive springs but that's not necessarily a bad thing. The key to great handling is keeping contact with the road. With stiff, linear springs, driving at speed on bumpy roads would not only be uncomfortable but simply treacherous.

The other aspect of good handling which is often overlooked is the effect of well-matched dampers. That "glued to the surface" feeling Ruairdih alluded to is produced by the shocks. Whether you're attacking bumpy straights or diving into a turn, the firm rebound valving eliminates the float or excessive weight transfer evident in worn dampers.

So while a street coilover system may seem like a compromise relative to a pure track setup, the design is actually optimized for the surfaces on which you drive. In short, you're getting a better setup for the way you use your car.

Bill Gregory

As mentioned, it's important that the shocks are matched to the springs, however, my experience doesn't support the characterization that stiff linear springs are treacherous. I have 600 lb linear springs in front and 700 lbs in the rear, with custom valved Bilstein struts/shocks, with digressive valving. Granted, an individuals comfort level with a suspension is very much a personal thing, which varies person-to-person. The stiffer suspension is quite streetable on my dual purpose 964, although it might not be the most comfortable for a relaxed cross-country trip.