Critique my allignment settings

[markZ4MC]

Hi,

I have a Z4MC,
- lowered on KW V3s (approx i finger of tire gap)
- Front 19x 8.5et30 255/35 (minor rubbing against rubber splash)
- Rear 10.5et25 285/30 (no rubbing)

Me:
- 1 or 2 track days a year
- will sacrifice track for good tire wear/minimal rubbing

Though some research on the forum, I'm thinking of going with:

Front -2.5 and zero toe
Rear: -1.6 with 1/32 toe in

Thoughts?

[Finnegan]

I'm running the settings you have noted (except a bit more rear toe-in) but it's 5-7 track days/year for me plus some AutoX. IMO you'll see too much wear inside with -2.5.

I'd go -2.0 up front zero toe unless the car were to see more track use, maybe even -1.7 with 1/32 total toe-in to reduce tramlining. (That level of toe-in isn't going to be an issue with the lower negative camber; but with more, yes, zero toe.)

My wife's Z runs -1.8 up front, small amount of toe-in (1/32 total), -1.6 rear, small amount of toe in (1/32/side), with novice level track use (5 days/year) and some AutoX, some spirited driving, and wear has been nice and even over 18K miles.

You may have trouble getting -1.6 rear given lowering. Might be more like -2.0 when said and done (least I can get has been -1.5 on a stock suspension). Only way to address that is with adjustable rear control arms, but those are an install PITA from hell.

Also, planned rear camber is fine, but specs call for more toe-in. I don't recall what it is, don't have time to look it up. IIRC I'm running 1/32 on each side, which IIRC is still "out of spec" but not 1/32 total toe. I'm sure if you search you can find the stock settings. I notice no issues street or track with the rear with "my" settings. YMMD.

[seank]

WHS. I think you have some decent settings. I might raise the front a bit, but that's just me, and it depends on what you call "a finger?"

[The HACK]

You can make the -2.5 camber work if you toe-in. Won't do much for the front tire longevity, but it'll even out and you'll end up swapping a set of 4 tires instead of the two rears first. My old E46 323Ci had similar alignment specs (-2.2 front, 1/16th toe-in front, -1.2 rear with 1/16th toe-in) with zero stagger and front and rear tire wear virtually identical. And this is back when I would do maybe 2-3 DEs a year rather than 12.

[markZ4MC]

Thanks folks,

I would call my track day's Novice as well.

Here's my revised given the feedback:

Front:
Front -2.0 and 1/32 toe in
Rear: -1.6 with 1/32 toe in

I'm a little hesitant to go much less than -2.0 because of the wide tires I'm running. When the Coilovers were installed we maxed out camber.

How does that sound?

[Finnegan]

I'd just measure the tread depth inside and outside and check every 1-2k miles. That way you can adjust if needed and based on data (maybe less, or more).

[Beedub]

The only problems Ive found with the z4 is terrible shoulder wear, a day at the track on 2-1/4 of camber I can see the shoulder still getting more of a beating, I'm having to run -2.5-7ish to eradicate this , also tyre wear is even as those few track days beat the outside tyre enough to wear the tyre even for the times I run the car on the street, I'm doing 6-10 events a years and 2-3 full day track hire where I hire the hole track for me and my friends.

[exdos]

Originally Posted by markZ4MC

I'm a little hesitant to go much less than -2.0 because of the wide tires I'm running. When the Coilovers were installed we maxed out camber.

How does that sound?

If you're using wider tyres, surely there's an argument for reducing camber to ensure that the contact patch is of the full width of the tyre and not just the inner part? If you can reduce lateral bodyroll with stiffer front suspension, you can reduce negative camber by a commensurate amount.

I've found that using a hand-held Infra Red thermometer to measure surface temperatures in 3 places across the width of each tyre (inner, middle and outer) after a spirited drive gives a decent indication of your set up and tyre pressures. If the set up is right, you'll find a temperature gradient across the width of the tyres, where the insides are the warmest and the outsides are the coolest, say, up to 10 degs C difference across the width of the tyre.

In the longer term, tyre tread depth measurements indicates the balance of use by the evenness of tyre wear.