I will be getting an alignment soon after having swapped the strut hats (common way to get -3* camber up front in e36 M3 community) over the winter and am looking for guidance on the front toe setting. My car is not a daily driver and is primarily used for autocross/weekend drives ~1,000 miles/year so achieving maximum tire life is not a great concern. Also, I'm running oem front control arm bushings if that has any influence on your recommendation. My research thus far suggests that zero toe makes the car more eager to turn but, can result in more wandering on uneven roads. I've also seen it mentioned a number of times that the wheels toe out while going down the road and zero static toe results in dynamic toe out, which might not be unnerving on the street. Some suggest going with 1/16 total toe in such that the dynamic toe goes to zero which should give better tire wear, doesn't toe out on the street, and provides more stability on the highway.
Any additional thoughts, consideration, or feedback is greatly appreciated.
Thanks,
John
Zero toe doesn't cause wandering in my experience, it's quite stable...toe-in makes the car feel "hesitant." I'd run zero toe.
How squishy are OEM bushings? Jello bushings would screw with a setup.
Since as you mention tire wear is not an issue I would run what you have set and see how it feels under different driving conditions and types of roads. If for some reason you feel that the car wanders to much or pull to much on a crowned road then you can always add some "toe in". I have always told other cars owners this when I have done performance alignments on their cars. Even for track only cars the toe setting should still be set to how the car feels to the driver. A toe out setting may be faster on track but if the driver is uncomfortable with that setting and doesn't drive the car to its limit then why set it there?
I've played around with suspension setup on my 300TD a bit recently, similar front suspension geometry, I believe. With measurable toe-in the car had a weirdly strong on-center feel, but when I turned the wheel more than a little in one direction or the other, the wheel felt like it was trying to turn more. It was fairly unsettling.
I set the toe basically as close as I could to zero with a tape measure across the tire treads, erring just the smallest bit on toe in. I also bumped out the camber about a 1/2 a degree on each side, to about a degree negative (I did this BEFORE setting toe, as adjusting the camber can muck with your toe settings, be careful of that.). The steering felt much lighter, self-centering was more positive, and handling more neutral. Puppies rained down from the heavens, women flocked around me, men bowed down in front of me, etc.
I set my Miata toe from about 1/8" toe-out when auto crossing to neutral for daily driving. I marked my tie rods and knew how many turns (not even one) changed this. The car was twitchy with toe out and not with toe neutral. Tire wear was an issue with toe out. Turn in was better with toe out.
What's that the kids say, YMMV
GameboyRMH wrote:
Zero toe doesn't cause wandering in my experience, it's quite stable...toe-in makes the car feel "hesitant." I'd run zero toe.
The M3/MZ3 lower control arm bushings are solid rubber and are much better than the vented bushings used in the non-M cars however, they aren't nearly as stiff as polyurethane or delrin. Thanks for the feedback. My questions came from seeing an alarming number of complaints from running zero toe on the street.
You'll just need to experiment. Truth is, there is more at stake than just suspension bushings. Pneumatic trail also changes the way the contact patch actually hits the road. Its kind of a third toe. There is static, dynamic, and how the contact patch deflects on the road surface.
Let's say you set it up with a zero dynamic toe; meaning that the wheel plane is parallel with the direction of travel. Of course to accomplish that, you'll have a tiny bit of static toe-in. The tire will deflect some due to drag; more toe, more deflection. Zero dynamic toe has little or no contact patch deflection. Adding a small amount of static toe-in is there to not only overcome bushing deflection, the tire's contact patch will also attempt to conform by deflecting the tire so that the patch is pointing in the direction of travel.
So, when cornering, that tire deflection changes with weight transfer. The inside tire's contact patch will do more conforming to the wheel's direction and less to the road's direction. Conversely for the outside tire.
For all of these variables (including tire construction, sidewall height, coefficient of friction, road surface, etc) how the contact patch will actually be oriented. My suggestion will sound like a cop-out, but its up to you and your car/tires. Try a few settings. Hard to know. I do know that a zero static on my tall-tire B-body station wagon felt loose and dart-ish, but my Impala with 20s, zero static didn't feel anything other than normal.
I prefer zero toe. Love the responsiveness it provides with most chassis.
My wife can't hardly keep it in a lane. She prefers more sluggish steering response so I set her car up with a skosh of toe in.
Honestly, use a tape measure andfind the toe ssettings you like. Hell, Google it and do your own driveway alignment. When you find the specs you like, pay the man to make sure its right if you feel it's necessary.
I haven't paid for an alignment in years.
I run 1/8 toe out in the front and 1/8 toe in in the rear and I pay for a proper computer alignment done with a tape you can and will end up with all your adjustment on one side.
the toe in on the rear makes the fear want to follow the front
e36 M3 used for track/street alignment #s:
- Front: -3.2 deg camber, zero toe, all the caster my camber plates allow.
- Rear: -2.3 degrees camber, 3/32" toe-in/side.
Good tire wear in consideration that the car used them up w/ track time every season. Neutral, predictable, good turn in and transition, got power down well.
motomoron wrote:
e36 M3 used for track/street alignment #s:
- Front: -3.2 deg camber, zero toe, all the caster my camber plates allow.
- Rear: -2.3 degrees camber, 3/32" toe-in/side.
Good tire wear in consideration that the car used them up w/ track time every season. Neutral, predictable, good turn in and transition, got power down well.
Are you running zero toe with stiffer aftermarket front control arm bushings or are they stock? Does it wander much on the street with zero toe?
Thanks again!
killeen_john wrote:
motomoron wrote:
e36 M3 used for track/street alignment #s:
- Front: -3.2 deg camber, zero toe, all the caster my camber plates allow.
- Rear: -2.3 degrees camber, 3/32" toe-in/side.
Good tire wear in consideration that the car used them up w/ track time every season. Neutral, predictable, good turn in and transition, got power down well.
Are you running zero toe with stiffer aftermarket front control arm bushings or are they stock? Does it wander much on the street with zero toe?
Thanks again!
If defleftion of the FCABs is that much of a concern why not just go ahead and replace them with poly? If you get the ones already pressedinto the lolypops it's like a 1/2 hr job. I think i paid like $80 when I did them on my old e36 a couple years ago. Poly will squeek though.
Plenty of good advice here. For what it's worth, my favorite BMW set-up guru, Chris Sneed, suggests for cars using rubber bushings up front: maxing out the caster if it doesn't kill your camber range too badly, and doing a minimal static toe-in., which will add up to toe-out under track loads.
