Optimal toe for daily/occational trackday
 

Had my car in at the dealership after I lowered it. They are technically within spec, but the toe is as close to 0 as they managed, and as a consequence my car is very nervous at speed and VERY sensitive to any ruts and poor roads.

What do I want to aim for for a nice stable high speed setup? I'd rather sacrifice a little turn-in to benefit motorway stability.

What are the actual specs you ended up with?

0 front toe and about 1/16" rear toe in isn't unstable on the highway, sounds like you might have some toe out?

@atledreier Being sensitive to ruts typically has to do with camber, not toe. Your tire isn't sitting flat on the ground to just go over the grooves. Instead it is cambered in and will be more likely to follow in the grooves.

please post your alignment specs for reeeeal.

I'm -1.1 camber/toe out fr & -1.5 camber/toe in r no glaring issues at highway speed

What are the actual measurements? toe out in front. toe in rear. my car feels great.

Awesome turn in. Zero nervous feeling on bumps or cruising.

What wheels and tires are you using?

Just FYI, I have practically zero toe front/rear but a lot of camber.

My car is "very nervous at speed and VERY sensitive" to imperfections and crowns in the road.

http://www.tirerack.com/tires/tirete....jsp?techid=47

-alex

Measured values after the alignment:

All values are left/right side and degrees

Front:
Caster: 5:48/5:54
Camber: -0.24 / -0.36
Toe: +0.03/+0.03

Rear:
Camber: -1.54/-2.24
Toe: 0.0/0.0

So, it seems the front toe is actually very slightly positive, not sure if this is out or in, it doesn't say. The spec says minimum -0.45 and max +0.45 degrees, again, doesn't really give me anything to determine if it's in or out.
The rear camber stands out as very uneven, but apparently that was the best they could do with no adjustable rear arms.

The car is lowered just shy of an inch, and I run 20mm spacers front and 25mm rear. Stock wheels, 225/45-17 Michelin Pilot Sport 3 front and rear.

You want a bit of toe in at the rear for stability. Probably should get some rear LCAs to fix the camber.

So the front toe isn't causing this?

The stock specs have so much leeway that it can be between undrive-able, to stable, but scrubbing rubber. I tell my alignment tech what to align it to. I ask for 1 degree negative camber on the front, 0.00 degrees toe. As close to even camber on the rear as possible with stock LCA's, and .05 degrees toe-in on each side for a combined .1 degree toe-in on the rear only, no toe-in at all on the front. I get mine aligned after every suspension change.

If you have stock LCA's in the rear there is no camber adjustability, unless you've got some special bolts or something else going on.

add a tiny bit of toe-in in the rear for the car to self-stabilize to a degree street driving. Keep in mind that this also causes the rear to self-stabilize when you're taking hard corners, fighting against rotation, so it's a double edged sword.

Don't you mean "self-stabilize to a"(bit)"street driving"? Since the measurements are in degrees, using the word degree as an adjective as well could be confusing.

Most people talk about toe in terms of fractions of inches, not degrees.

Would these values be applicable to any size wheel/tire size?

For reference, I had an alignment at 6k miles after installing Eibach ProKit springs on stock wheel/tires. At 20k I switched to new wheels (235/45/17 Michelin PSS on XXR 527 17x8.25) and have noticed the car being a bit twitchy at +70mph on the highway.

-1.7 camber front, -2 camber rear
0 toe front and 0 toe rear

My car starts to get unstable and a bit wanders at about 120mph. What speed are you speaking of?

Nerves of steel. :burnrubber:

:)

After multiple top speed runs, 128 mph was the fastest I felt that I could take the car with that setup; too much instability. Before the springs, on stock alignment, the car felt it held true at 131 but was really breathing heavy to keep going. The speed is a differ t subject altogether, the takeaway is that stock alignment specs held true up top and the 0 setting still had quite a bit of headroom; well for the street and for short course. Everyone's milage may vary, just my experience.