Quote:
Rallytwit wrote:
When I was using the car for Auotcross (Gymkhana) and roadracing the -1.5 degrees of camber worked fine. This was with Yokohama A08R tires, the outside 1/2 of which are almost like slicks.
The suspension settings in the comp prep manual work well, I'm not a big fan of huge amounts of negative camber as it always seem to make a car darty under heavy breaking. Also note I tend to be the king of trail braking at track days I'll have students and intermediate drivers that will complain about understeer in their car but I won't have an issue.................now I do have a buddy whose a former SCCA national champ and he runs a ton of negative camber on his Autocross Civic, the car is not real powerful so he tries to be on the gas as often as possible and the oversteer keeps the car rotating while on the gas. The car is undrivable as a street car. (if you brake and turn it will snap spin)
Tom
the suspension settings in the comp manual are designed for a very limited mod class that ran on cross plies.
the amount of static camber you need depends on:
1) suspension design, spring rates and camber curves of the bump travel of your setup.
2) the speed of the events you are entering. low speed events like gymkhanas won't require as much camber as a high speed race circuit
3) the type of tyre you are using. a semi slick or R spec tyre or whatever you call them in your neck of the woods tend to like a minimum of 4 degrees for circuit work. low speed stuff will be much less sensitive to camber. a normal road tyre won't respond as well to increased camber - they don't have the grip to generate the loads to require much camber.
the best way to determine how much camber you need is to measure tyre temps straight after a run. if the outside is hotter than the inside you don't have enough camber. you're only really working the outside of the tyre. you want to use all the tyre for maximum grip. its better to use a pyro to get a few mm into the tread rather than surface temps that cool off much more quickly before you get a chance to measure them.
camber doesn't make a car darty under brakes. that's more associated with scrub radius problems, or worn tension rod bushes. or just the fact that you're comparing it to a fwd car that always exhibit lift off oversteer! brake and turn in hard and of course it will just want to rotate. that's not due to camber, that's due to its fwd-ness! apples and oranges to a rwd car. but alot of fronties use trailbraking (you do have to moderate the pedal effort as you start to turn) to reduce their inherent underster tendancies. it sound slike that SCCA Civic had a very aggressive setup.
what camber does do to a datsun 1200 is make it turn in alot better and generate a little more mid corner speed. The improved turn in response is very noticeable just from getting a degree or so more camber. it can also prolong tyre life on the circuit by using the whole tyre surface rather than overworking the outside half.
I've done the development path from road car to road/race compromise to full track car. You really notice the improved turn-in from increased camber straight away on good semi slicks. Just going from the 2.5 to 4 degrees as I did made a massive improvement to initial turn in and a noticeable improvement to mid corner grip.
if you had more camber you might not need to trail brake as much as you do to get it to turn in. 1.5 degrees is what we would recommend for a performance oriented road car on normal street tyres that never sees the track. or for the back of a rwd race car! most dirt rally cars will run more front camber than that!
castor helps but its no substitue for static camber on a 1200 strut front end. for a track car 1200 you want as much of both as you can get. but castor doesn't help that much - you typically only use a maximum of 17 degrees lock on the track. You don't get much dynamic camber gain from your castor from that little steering angle. castor has bigger impacts on other factors.
for circuit work most R compound radials like a minimum of 4 degrees static camber. more for higher speed tracks. Autocross would be a bit less due to the lower speeds and less sustained cornering. but around 2.5 to 3 degrees would not be over the top at all.
Transfer
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