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Discussion Starter #1
What are people typically running for rear camber for auto-x? My car is a 2007MS3, I'm running 18"X8" RX8 wheels and 245/40 Hoosiers.

The front alignment is easy, as much negative camber as I can get, but I'm unsure of how much to run on the rears (never had a car where that was adjustable before). Currently the car has -2 degrees, but I'm playing with increasing that, both for performance and to move the tire further away from the fender lip (car is lowered).

Suggestions?
 

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The car currently has -2 degrees front or rear?

On fwd cars, I don't like to run a lot of negative camber in the rear. Somewhere in the -0.5 to -1.5 range is usually okay, but it also depends on the front camber settings.
 

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Discussion Starter #3
I'm talking specifically for the rear. The mazdaspeed recommended setting for the rear (with the coil-over kit) is -2. I can't recall what the front is at the moment.

Hoosier calls for a recommended minimum of -2.5 degrees, however I need to understand what that will do to the handling of car before setting it to that amount.
 

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It's really not a simple answer. It depends on so many different factors. Normally tires are more "happy" with a few degrees of negative camber; "happy" tires = more grip. With that said there is a limit, continuously increasing camber does not continually increase grip.

Now that is considering the rear tires by themselves. When you put them with the entire suspension system, especially considering we have fwd vehicles, it gets much mroe complex. With fwd, we can never experience power on oversteer, the gas pedal on a fwd always increases rear wheel grip up to the maximum grip potential, never going past that limit. So the only opportunity to have rotation is entry-oversteer, lift off oversteer, however you want to word it. There are many different ways of achieving this. Decreasing rear wheel grip in general increases oversteer, as does increasing front wheel grip. This can be achieved with sway bars, springs, damping, camber, toe, tire width, the list goes on.

So, can you share more information on your setup?
 

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Like Justin said, -1 or less is best for the rear. There is no need for more and will make the car tend to push (understeer). The idea with front drive is to maximize front grip, not rear grip.
 

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Discussion Starter #8
Hoosier tire info sheet, bottom of page #2.
https://www.hoosiertire.com/pdfs/tctR6_A6.pdf

Setup:
Mazdaspeed/KW3 coilovers
18"X8" RX8 Wheels w 245/40-18 Hoosier A6
JBR Rear Bar (new this year)
Whiteline front suspension bushing (stock alignement type - new this year).

Ran it last year a few times with just the coil overs on 18"X7.5" wheels using 215/45 V710s.

Alignment was to the recommended mazdaspeed specs, but with front toe set to zero.

It was OK, but undertired and had push in fast corners, even with the rear shocks sat at full compression stiffness and the fronts turned down.

My plan for alignment this year is as much as neg camber I can get in the front with zero toe and 2.5 neg camber in the rear with the mazdaspeed toe settings.

I ran on old FSP Scirocco for years, but the rears didn't adjust easily (had to use shims).

Planing on running a full local season this year and hopefully beating a couple of local turbo Hondas (close last year). I may run a Match Tour event later in the year, but expect to get killed by the fully prepped cars if I do.
 

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Hoosier tire info sheet, bottom of page #2.
https://www.hoosiertire.com/pdfs/tctR6_A6.pdf
HOOSIER: "For optimum performance the Hoosier P-Metric radial tires require about 3 degrees of camber. There will be a trade off in maximum performance to maximize wear.
Generally, 1/2 degrees less than optimum will result in the best compromise for wear and speed. Less than 2.5 degrees can result in excessive wear on the shoulder junction."
The section in bold is pretty important. You have to choose whether you want better performance or better wear. Hoosier is making VERY generalized recommendations. A 1,600 pound FSP Scirocco built for autox is going to require a much different set up than a 3,600 pound Mustang built for road-racing. They also don't specify front or rear in their camber recommendations.

That said, you could certainly try -2.5 degrees in the rear. However, my experience in various fwd autox cars, has been that -.5 to -1.5 works very well.
 

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I run about 1.6 rear FWIW
 

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nope. They looked hard to install and I won't have time to align it this month. So in April I'll slap them in with the stiffer springs :)
 

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Do you guys think I should tinker with alignment adjustments for mine or just continue running stock settings. I still have not figured out what my hatch is capable of on entry speeds but I am pretty sure I am very aware of what it can do when I come in slower than what it can do then accelerating to what it will handle before under steer kicks me in the ass
 

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Brake into the turn, give it more gas as you unwind the wheel past/at the apex. If you are getting understeer mid turn under throttle then you are giving it too much gas too early.

Work on finding those braking points. Pick a turn on the course and keep on braking harder and harder later and later to find where it can go. Goal is to make it muscle memory so when you experience that corner again in another course you know what you can do.

The other more experienced guys can comment further.
 

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Dialed in a bit more camber in the back for the local event this weekend. Moving up from around -.5 per wheel to -1.5 in an attempt get the back end to hook up and net a little more stability in 35-45 degree weather.
 

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are you having issues with the car rotating? running less rear camber could help with that. too much and the rear will grip better, thus amplifying understeer issues.

For the MS3 I would recommend running 0 toe all around, max camber and caster you can get up front (set camber first). and in the rear run maybe 1-1.5 camber. id also run a big honkin rear bar too. and if you still have plow issues maybe consider a tire stagger. one M3 owner runs 255's in front and 235's in rear and it works pretty well.
 
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