E30 M3 CABs

[fabe]

i have this for camber adjustment


and custom made control arm bracket with PU bushes for increase castor.. will attach some photos later.

handling is sharper with the custom made control arm bracket together with all the other suspension mods (IE swaybars, APEX springs, pillowball camber plates, pillowball rear mounts). The ride is firm but handling is pretty neutral.

Off topic, this is one of the shots of my car going sideways at the Sepang F1 Circuit in the wet due to not-so-good rear street tyres.

[ecpreston]

That is why you toe-in in the first place. More toe helps turn in on cornering. On the rear, toe-out is preferred so that under acceleration they push/pull in.  However on some racecars, they even toe in the rear as it really makes a car corner. Basically a driven wheel is toed out, non-driven are toed in, making all things neutral when driving.

I'm afraid you've got this all backwards. At least for a BMW. Having toe-out on either end of a modern car with decent suspension (I don't know about stick axles), RWD or FWD makes that end inherently unstable. As in, it responds to changes in steering more quickly, and doesn't like to go straight. Toe-out improves turn-in. Toe-in is for stability.

Toe out on the rear of a track car is downright scary as the rear end doesn't want to stay behind the car. Only in an autocross car, and most likely only FWD would you ever want toe out on the rear as it helps the rear rotate. But it's a no-no at high speeds. Slight toe-in, or zero on the rear is usually a good starting point. For a pure street car, even more toe in.

Slight toe-out on the front is more common, as it improves tun in. Sure, the car isn't going to center quite as well, but it's fine even for a daily driver. For a track car, a good starting point on the front is 0. Autocross, definatly toe-out. For a pure street car, you do a bit of toe in on the front so it centers well, and like you said, at speed, the wheels turn out ever so slightly, almost to 0.

Anyway, back to the topic. Offset bushings. Go for it. Caster is good.  

[sheepdog]

I'm afraid you've got this all backwards. At least for a BMW. Having toe-out on either end of a modern car with decent suspension (I don't know about stick axles), RWD or FWD makes that end inherently unstable. As in, it responds to changes in steering more quickly, and doesn't like to go straight. Toe-out improves turn-in. Toe-in is for stability.

Toe out on the rear of a track car is downright scary as the rear end doesn't want to stay behind the car. Only in an autocross car, and most likely only FWD would you ever want toe out on the rear as it helps the rear rotate. But it's a no-no at high speeds. Slight toe-in, or zero on the rear is usually a good starting point. For a pure street car, even more toe in.

Slight toe-out on the front is more common, as it improves tun in. Sure, the car isn't going to center quite as well, but it's fine even for a daily driver. For a track car, a good starting point on the front is 0. Autocross, definatly toe-out. For a pure street car, you do a bit of toe in on the front so it centers well, and like you said, at speed, the wheels turn out ever so slightly, almost to 0.

Anyway, back to the topic. Offset bushings. Go for it. Caster is good.  

Strange, yes, it appears you are right on BMW's.
That is opposite of many other cars. Then again, from what I have seen on  BMW suspensions, that is about par for the course.

[AL GReeNeRy]

to make it simple...

FWD cars usually have slight toe out on the front wheels because under acceleration, the wheels tend to toe in.  so while in motion, the wheels are close to 0.

RWD cars usually have slight toe in on the front wheels because under acceleration, the front wheels are stationary and the rear is pushing the car.  this causes the front wheels to toe out.  again, while in motion the front wheels will be close to 0.

rear is ALMOST always 0 or slight toe in on any setup.  as ecpreston stated, toe out in the rear will cause high speed instability as well as yaw.  

of course when it comes to auto-x, drifting or any sort of racing setup, the rules are much different...

also, when turning in any car, the front wheels tend to toe out slightly due to the geometry of the suspension setup.  it also has a lot to do with the oversteer/understeer and differential theories.

*** oh yea and i agree on the m3 CABs... more positive caster is always a good thing - they wouldnt put them on an m3 if it wasnt! ***

[Zoso]

I'm just finishing my first set of tires after I installed E30 M3 CABs.  I have H&R sports and Bilstein sports.  I saw no significant tire wear problems with this setup.  I did rotate the tires throughout their life.

The one negative about the M3 CABs is that it gives me a little problem with larger tires.  I have some studded snow tires mounted on the bottlecaps.  Because the front tires are more forward than before, the larger than stock snow tires can rub a bit if I jack the wheel all the way.

The car does feel a bit more squirrely on the highway though.

[AL GReeNeRy]

The car does feel a bit more squirrely on the highway though.

squirrely being good? what brand/size non-snow tires did you get?