Can anyone explain to me why the rear wheel allignment specifies a toe in? The front are at zero -- what does it do in the case of the rear wheels? Maybe it's one of the reasons the rear tires wear so much faster.

Any insight appreciated. Thanks.

-Michael
'05 Nightfall Blue Short answer: to keep the back end of the car from becoming the front end of the car. I would think it should be toe out or zero in the rear and toe in for the fronts. Lotus may have set it up to have more understeer the way you have it. They don't want newbies losing the rear when they get cold feet.

I haven't realingned my Elise yet, but from my experience a little toe in gives you better turn in and grip (preloads the sidewalls for faster set) and toe out in the rear gives the rear end a "four wheel steer" effect (faster carving).

There are lots of threads on this so just search "alignment" I would think it should be toe out or zero in the rear and toe in for the fronts. Toe out in the rear. Not recommended unless you're suicidal. Toe out in the rear. Not recommended unless you're suicidal.
Exactly......unless you just drive in a straight line. There's also a lot more to the suspension geometry than just the static settings.

In the case of the Elsie, the toe-link is behind the upright of the wheel wheels. When the car is in a tight left turn for instance, the body roll will tip the car to the right. This raises the right wheel, and lowers the left wheel relative to their static positions. This in turn, causes the right wheel to turn in, and the left wheel to turn out (aka, bump steer) helping the car to turn just a bit better - a bit of rear wheel steering.

There are lot of things going on with the suspension geometry that is not apparent until you start considering all the dynamic positions of the suspension. I have a lot of toe out up front. And I actually ran with toe out in the rear for a while. Once we got the ride heights fixed, though, it became, umm, treacherous. I went basically toe neutral in the rear for the rest of the year, though, and liked it. Many said it would be undrivable that way, but it wasn't. However, I did run an extra stiff front bar and a ton of negative camber in the back to settle the car down. It was a spectacular setup that three different National Champions said was outstanding. However, it left me with little adjustability is low grip situations, so I plan to retune it next year. What these guys said. Toe-in keeps the rear in the rear. ...the toe-link is behind the upright of the wheel wheels. When the car is in a tight left turn for instance, the body roll will tip the car to the right. This raises the right wheel, and lowers the left wheel relative to their static positions. This in turn, causes the right wheel to turn in, and the left wheel to turn out (aka, bump steer) helping the car to turn just a bit better - a bit of rear wheel steering.
Great explaination, Tim. I can actually visualize that.

Almost all RWD setups are meant to have Toe in at the rear wheels. Otherwise the "push" driving force of the rear wheels creates too much rear wheel steering effect under power.
Might work in very slow (acrobatic -autoX type or even lower) speeds

FWD racecar setups mostly use Toe out in the rear b/c there's no driving force to "steer" the rear axle, so you want the rear end to "come around" in a corner and you "pull" it out with the front wheels' drive.
Well... you guys sure know your $#!+ -- now I know a little more too. Thanks! Toe out in the rear. Not recommended unless you're suicidal.
I've actually had toe out in the rear by accident and it wasn't near as nutty as I thought it might be ..... just not a very "fast" setup is all. what happen if it's zero in the rear, just like the front? Almost all RWD setups are meant to have Toe in at the rear wheels. Otherwise the "push" driving force of the rear wheels creates too much rear wheel steering effect under power.
Might work in very slow (acrobatic -autoX type or even lower) speeds

FWD racecar setups mostly use Toe out in the rear b/c there's no driving force to "steer" the rear axle, so you want the rear end to "come around" in a corner and you "pull" it out with the front wheels' drive. what happen if it's zero in the rear, just like the front?
You're more likely to spin. Happened to me, but there are too many variables to blame it on my alignment at the time. A slight toe out in front and toe in the rear will help the car transition on turn in and rotate. The more toe (in or out) combined with the degree of camber will determine how fast and where your tires wear. There's also a lot more to the suspension geometry than just the static settings.

In the case of the Elsie, the toe-link is behind the upright of the wheel wheels. When the car is in a tight left turn for instance, the body roll will tip the car to the right. This raises the right wheel, and lowers the left wheel relative to their static positions. This in turn, causes the right wheel to turn in, and the left wheel to turn out (aka, bump steer) helping the car to turn just a bit better - a bit of rear wheel steering.
There is also a benefit to toe in with regard to initial turn in.

Imagine the tire tryiing to "turn" inwards, with the left tire trying to go right and the right rear tire trying to go left. When the driver says to the front wheels, turn left and the weight transfers to the right side, the right rear tire is already trying to turn left. The huge benefit is that the rear of the car will want to follow the front, rather than continuing in a straight line. Transient response is greatly improved.

I purchased one of the first NSXs in our area. I drove it a bunch, autocrossing and tracking it. I put a bunch of miles on it and wore out the rear tires quickly. Honda replaced them, thinking the alignment was off. Then I wore out that set.

There was a class action lawsuit against Honda for the premature wear on the rear tires! (I wanted to testify on Honda's behalf! What a bunch of hooey! This is a performance car with performance tires. Where do these people think the performance comes from?) Anyway, Honda settled and we all got three sets of free rear tires.

The turn in and stability of the NSX was amazing. A car before its time, much like the Elise.

Michael