3rd gen Alignment specs from Pettit Racing

[Herblenny]

http://www.rotarycarclub.com/attachment.php?attachmentid=478&stc=1&d=1205432293

[IR Performance]

I ran those for a while. Tire wear was slightly accelerated but car handled awesome.

[SPICcnmFD]

I think they are probably a good comprimise for steet and track driving, but I've got -2 degreees all around and I need more in the front for the track. The rear could use less probably -1.5 or -1.

[Herblenny]

This is what I got..

Decide to go more towards street..

FRONT
Camber: -0.3
Caster: 6.6
Toe: 0.03in

REAR
Camber: -1.2
Toe: 0.05in

Car rides OK with the Delrin Bushings, H&R, Koni Yellows, RB front sway, RB sway brace...

[Chadwick]

This is what I got..

Decide to go more towards street..

FRONT
Camber: -0.3
Caster: 6.6
Toe: 0.03in

REAR
Camber: -1.2
Toe: 0.05in

Car rides OK with the Delrin Bushings, H&R, Koni Yellows, RB front sway, RB sway brace...

Phil, I would not run any tow on the street, toe is what wears out tires. With the small amount you’re running, it will make no real difference in handling anyway. Pettit's track settings are very conservative; I run -2.5 all the way around for camber, and around 3 caster. Too much caster will actually increase tire lift in corners. For Toe I run 0 front and .16" in on the rear. My setting are for track, not street use.

[albertomg]

For street and open track use, I run specs pretty close to those of the 16" wheels even though I'm running 17" wheels with 255/40/17. Running Konis with H&R springs.

Camber -1.5 front; - 1.2 rear
This wound up being more aggressive than I wanted but has been OK thus far. Someone on the other forum had apparently tested the Pettit settings with a pyrometer on track and said they worked well and provided proper tire temps. FYI - Having more rear camber than front camber increases understeer. The camber Phil listed above just about matches the specs on my Mini Cooper which is setup for lots of understeer from the factory. :)

Toe .06 degrees of toe in front and 0 in rear
For many cars driven on the street a little bit of "toe in" up front helps keep the steering from being darty when driving on the highway and trying to hold a straight line. I had mine at 0 front toe when I first got the car and didn't like it on street. It kept wanting to pull side to side driving down the highway. IIRC, more "toe in" in the rear helps the rear of the car rotate. Autox guys tend to use a decent amount of toe in in the rear.

Caster is now about 6 degrees
I experimented a bit with caster. When I got the car it had almost 7 degrees of caster. The steering had always felt heavier on this FD compared to my last one and after a year or so, I learned it was b/c I was running so much caster. While at the alignment shop, I was talking to the alignment guy and we decided to experiment with caster settings and we brought it down to 6 degrees. It made a world of difference. The steering feels much better and quicker. Now I understand why Rynberg always used to say "the FD doesn't need more than 6 degrees of caster". :)

Hope that is useful to someone.

[Chadwick]

IIRC, more "toe in" in the rear helps the rear of the car rotate. Autox guys tend to use a decent amount of toe in in the rear.



More toe in in the rear helps the car power out of the corners better (keeps the back end planted), toe out would help it to rotate.

Dan

[Herblenny]

Hey Dan,

Even if its only 0.03inch?? Its so minor:)

Also, what is Stock alignment from Mazda??

[Chadwick]

Hey Dan,

Even if its only 0.03inch?? Its so minor:)

Also, what is Stock alignment from Mazda??

Not really enough to worry about, and like albertomg says, 0 toe will make the car track to the road conditions.

Dan

[Chadwick]

total toe-in 0.04 +- 0.16
Camber angle 0 deg
Caster angle 6 deg 40'

REAR:

total toe-in 0.08 +- 0.16
Camber angle -1 deg
Thrust angle 0deg +- 0.8 deg

[FD3S2005]

what do you go to a place that does alignments and say i want this toe and this caster and yada yada?

[Chadwick]

what do you go to a place that does alignments and say i want this toe and this caster and yada yada?

I do my own alignments and most shops will dial in what ever you want.

Dan

[dhays]

Good thread. I'm really a noob, both with the FD and particularly with suspension and alignment. My FD is a weekend car with some auto-cross. I have yet to have the alignment checked since I bought it almost 4 months ago. It drives and handles better than I do at this point, but what settings would you folks recommend for my situation?

I have 18x8.5 wheels with 235/40/18 tires. As far as I know, the suspension is completely stock. I was thinking just using Pettit's short track specs as a compromise. Any ideas or suggestions?

[Chadwick]

Good thread. I'm really a noob, both with the FD and particularly with suspension and alignment. My FD is a weekend car with some auto-cross. I have yet to have the alignment checked since I bought it almost 4 months ago. It drives and handles better than I do at this point, but what settings would you folks recommend for my situation?

I have 18x8.5 wheels with 235/40/18 tires. As far as I know, the suspension is completely stock. I was thinking just using Pettit's short track specs as a compromise. Any ideas or suggestions?

Short track settings would be pretty good for you, but I would make the front and rear camber equal.

Dan

[albertomg]

I guess it would depend on how competitive you are at autox. Too much negative camber on the street isn't always a good thing.

[dhays]

I guess it would depend on how competitive you are at autox. Too much negative camber on the street isn't always a good thing.

I'm not competitive at all. The recommended front camber settings for 18" wheels for short track is only -1.0 or only .2 more negative camber than the "street" recommendation. Rear is only -.2 instead of 0.

Would you think that would be too much for the street?

Dan, why equal and if so, what would you set it at?

[SPICcnmFD]

^That shouldn't be to much at all. I would make the toe zero in the front, and at the most just a in in the rear. Toe will wear you tires faster than camber, as your basically pushing the tires sideways down the road.

[albertomg]

I didn't realize you were running 18s. I should have read your post better. That should probably work well but I've never driven on 18s on the FD.

I personally follow the school of thought that says use as much camber as you Do use for the majority of the time.

In regular street driving even my -1.5 degrees of camber is more than I need. On track it is good. For autox it is enough for my current skill level. If I were a more competitive driver such as Chadwick, that would be a different story. Even with only -1.5 the car likes to follow ruts and road irregularities. My time is spent about 60% street 30% track and 10% autox. On my next alignment, I'll probably drop down to -1.2 up front depending on what my tires look like after my next track event.

You play with that balance of good street mannered car that tracks straight when you start going to more race inspired alignment settings. OEM dials in just a bit of toe in up front to help in that straight line stability. I absolutely hated zero toe up front as the car was more darty than I'd like. It sounds good on paper and works well on track but I didn't like it on street. Even just .06 of a degree will help that and won't hurt tire wear in any noticeable way.

Another thing I noticed when experimenting with alignment last year is that I enjoyed having a little less negative camber in the rear than I was running in the front. More negative camber in the rear (all else being equal) will make the car understeer a bit more. Perhaps Dan can shed some light on his recommendation also.