C4 geometrie road/track car
10-10-2012, 04:14 PM
#1
Three Wheelin'
Thread Starter
C4 geometrie road/track car
Hi guys,
here are my numbers, would like to see yours and hear your comments ....
Rear
camber - 1.55
toe left & right +0.13 degrees
total toe +0.26 degrees
Front
castor + 3.52
camber - 1.51
toe left & right + 0.12 degrees
total toe + 0.24 degrees
Konstantin
here are my numbers, would like to see yours and hear your comments ....
Rear
camber - 1.55
toe left & right +0.13 degrees
total toe +0.26 degrees
Front
castor + 3.52
camber - 1.51
toe left & right + 0.12 degrees
total toe + 0.24 degrees
Konstantin
Last edited by kos11-12; 10-11-2012 at 05:06 AM.
10-11-2012, 03:33 AM
#5
Burning Brakes
in the rear, i´ve nearly the same numbers.
in the front, i´ve a little more camber, but under 2° and nearly zero toe (total toe must be +0.05). It turn´s in much more directly with the increase of camber and the tire wear gets much better with zero toe...
in the front, i´ve a little more camber, but under 2° and nearly zero toe (total toe must be +0.05). It turn´s in much more directly with the increase of camber and the tire wear gets much better with zero toe...
10-11-2012, 06:35 AM
#7
this was my alignment settings that worked well ...
rear
camber -2 (max we could get)
toe in 1/8 in
front
camber -2
caster +2 (max we could get)
toe in 1/8 in
surprisingly close to the 9m tips!
EDIT -> obviously I'd go with the 9m tips .. I was just surprised that mine were quite close .. i must have some good research on the forum here many months ago! .. read this ...
https://rennlist.com/forums/964-foru...re-set-up.html
https://rennlist.com/forums/964-foru...n-h-and-r.html
rear
camber -2 (max we could get)
toe in 1/8 in
front
camber -2
caster +2 (max we could get)
toe in 1/8 in
surprisingly close to the 9m tips!
EDIT -> obviously I'd go with the 9m tips .. I was just surprised that mine were quite close .. i must have some good research on the forum here many months ago! .. read this ...
https://rennlist.com/forums/964-foru...re-set-up.html
https://rennlist.com/forums/964-foru...n-h-and-r.html
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10-11-2012, 09:37 AM
#8
Three Wheelin'
C4 w
Billy HDs
H&R Green/Purple
Ride height is ~RS (spring seat adjuster allows ~10mm lower on front and ~25mm on rear)
21mm Rear ARB
Geo'd to "RS" by GT One
Rear:
Camber -1deg 21min
Total Toe +0deg 30mins
Front:
Caster +3deg 56mins
Camber -1deg 05mins
Total Toe +0deg 27mins
Road performance is very neutral. Slightly vague turn in and understeer in certain conditions - both probably linked to managing weight transfer front to rear, so partly my inept driving, but not entirely. My feel is it needs more front camber (caster too but I think its set to max already) and maybe more rake. Sounds like losing the front toe in might help too.
Track performance with only limited reference points (~10,000 road miles, a day at Spa, one lap of Nurburgring (old tyres 16inch) a day at Donnington (track day tyres 17inch)). Very neutral again, with the 17s tyre temps even across the tyre. I do notice that the smoother my driving style the more the natural understeer manifests.
The softness of the setup is the limiting factor atm, I don't think you can get too scientific about it with everything wobbling about, I'm tempted by a set of H&R ARBs for next year and maybe some new bushes.
I'm surprised that folk haven't found a base point setting for the C4 that differs from the C2 over the years. I guess they are tracked more rarely and the ones that are have varied setups.
Billy HDs
H&R Green/Purple
Ride height is ~RS (spring seat adjuster allows ~10mm lower on front and ~25mm on rear)
21mm Rear ARB
Geo'd to "RS" by GT One
Rear:
Camber -1deg 21min
Total Toe +0deg 30mins
Front:
Caster +3deg 56mins
Camber -1deg 05mins
Total Toe +0deg 27mins
Road performance is very neutral. Slightly vague turn in and understeer in certain conditions - both probably linked to managing weight transfer front to rear, so partly my inept driving, but not entirely. My feel is it needs more front camber (caster too but I think its set to max already) and maybe more rake. Sounds like losing the front toe in might help too.
Track performance with only limited reference points (~10,000 road miles, a day at Spa, one lap of Nurburgring (old tyres 16inch) a day at Donnington (track day tyres 17inch)). Very neutral again, with the 17s tyre temps even across the tyre. I do notice that the smoother my driving style the more the natural understeer manifests.
The softness of the setup is the limiting factor atm, I don't think you can get too scientific about it with everything wobbling about, I'm tempted by a set of H&R ARBs for next year and maybe some new bushes.
I'm surprised that folk haven't found a base point setting for the C4 that differs from the C2 over the years. I guess they are tracked more rarely and the ones that are have varied setups.
10-11-2012, 09:45 AM
#9
Three Wheelin'
Hmmm, if I wind down the front by another 5-10mm the -ve camber will increase (obviously) what will happen to the toe in; more or less?
My mental pic of the relationship between the steering rack and the hub say the toe in would be reduced.
Might be a quick way to test the "more front camber, less front toe in" theory.
My mental pic of the relationship between the steering rack and the hub say the toe in would be reduced.
Might be a quick way to test the "more front camber, less front toe in" theory.
10-11-2012, 03:53 PM
#11
If you strart from RS heights, you shoud have the first ~10/20 mm of suspension travel (lowering) during which you should have positive to neutral bump-steer; after that, it becomes negative bump-steer (toe out).
10-11-2012, 03:59 PM
#12
Kos,
If it's in degrees, I'd say you're right at the back, but, if I were you, I'd reduce the front toe to 0, or very close to that.
Can you increase the caster to around 4? If I remember correctly, my car is around that...
Ciao
If it's in degrees, I'd say you're right at the back, but, if I were you, I'd reduce the front toe to 0, or very close to that.
Can you increase the caster to around 4? If I remember correctly, my car is around that...
Ciao
10-11-2012, 04:15 PM
#13
Three Wheelin'
Thread Starter
yes I thought the caster could be better... 4 to 4.5 ...
OK it seems that the front toe needs improvement...
I was wondering if the C4 needs a different tweaks than the C2
ride height is RS or lowe , standard sway bar 1992, KW V3 with stiffer front springs
10-11-2012, 06:47 PM
#14
Right, go for max caster (I think it should be around 4,2)!
Don'd go below RS heights, otherwise you'll suffer negative bump-steer
C4s suffer understeer, so I'd use a bigger rear bar.
Ciao
Don'd go below RS heights, otherwise you'll suffer negative bump-steer
C4s suffer understeer, so I'd use a bigger rear bar.
Ciao
