Quote:
Originally Posted by J Tyler
Well, I should clarify. The rear goes into negative camber geometrically (if you put the car on a lift and compress the rear, it's plain to see that), but in the real world of bushing flex, subframe bushing flex, deflection of various supports/bushings/bearings, roll center movement, etc, it's tough to say. From looking at pictures, it looks like the suspension goes into negative camber geometrically like I said, but the whole car rolling negates that affect and can sometimes end up with the rear in positive camber during roll (especially if your rear springs are soft like our V3's are). Also, we're going to start playing with rear ride height (we've been running it too high) which will change our dynamic roll center movement and what camber the rear ends up at in roll; so all of my/Berk's assessments on this may get thrown out the window! But here's what I see so far:
Ex of what the inside suspension does in roll (somewhat high rear ride height):
Outside suspension in roll:
^That's running about -1.8* static in the rear. We lowered the rear recently which should give us some more (which is what I want). Haven't re-aligned the car yet. Your -2.1* sounds about right... it may put power down better with a little less camber, though. It's tough to say without driving it on a track and then looking at the tires, but I know we've been at -1.8* and I want more.
For a street car, you're probably worried about tire wear. But for a track car, you do want quite a bit of camber, especially with radial tires. Ideally, with these cars, I think you'd want to end up with a little more negative camber in the front than in the rear, because the front really loses camber geometrically and the rear doesn't. |
Thanks Jeff. Everything you have said tells me that my set up in the rear isn't too bad. Yeah ideally I want to get a bit more power down ability, but I also want good cornering grip. I think the only way to solve this opposing requirements is to get new wheels that will also wider tyres while retaining the camber.
I will have to play around with things a little on the next few track days. My car is not a street car in the sense that it doesn't see many street miles. So I am not concerned about tyre wear at all.