Camber Caster and Toe

[Mad Hatter]

Hi, I have two Time Attack events coming up and I was going to try to get -2.0 Camber before the weekend. What caster and Toe would you suggest? We have only have small tight tracks here in Chile with my max speed currently at 180km/h.

Running square with 275/35-19 Dirreza ZII. Can I reduce my oversteer with Toe out? Its not much of a problem really, The rotation on late braking is great, but power coming out of the corner has to be with care. I guess no alignment settings will help that?

 

[2012YellowBoss]

I understand more caster is best, the race shop set mine to 5.5. Zero toe works well on these cars and is what most people run. I tried the toe out one time, forget the amount but it was a lot and I did not like the feel. The race team set mine to -.065 that is barely out. I like the way the car turns with it set close to zero toe.

 

[wherermykeys]

I've been told by a few people who are much faster than me in their Mustangs that factory caster angles are usually the best and zero toe. Why only 2.0 degrees of camber though? I'd run at least 2.5 degrees on the track. My street/track car has been at 2.5 all year. Will be going with 3.0 in the spring when I switch to R compounds.

 

[PeteInCT]

The issue is how much you can squeeze out of the car. I have MM camber plates, gird p springs and 302S front lca's. Most I can squeeze is -2 degrees.

 

[JScheier]

The others have pretty much covered the alignment settings. I usually run -3.0* or more in the front with OEM caster and just a touch of toe-out. A little toe-out in the front will assist with turn-in on corner entry. A more toe-in setting will provide more straight-line stability. 0* toe is a very neutral setting and works well.

As for any of these addressing over steer, that's most likely not going to happen.

To reduce over steer, you'll either want to increase front spring rate or reduce rear rear rate. This can be done with springs, sway bars or a combination of both. It can also be achieved by returning to the staggered wheel setup the car came with.

In my case, I run 18x10s with 305's on all four corners. I (originally) went with a larger front adjustable sway bar (Strano) and an adjustable rear sway bar. I found that the front, on OEM springs, worked well on medium/ stiff (one side in full stiff, one side in medium) with the rear on full soft (basically OEM stiffness). I've since moved up to specific rate springs and I believe both front and rear bars are on the medium setting.

Hope this helps.

 

[wherermykeys]

The issue is how much you can squeeze out of the car. I have MM camber plates, gird p springs and 302S front lca's. Most I can squeeze is -2 degrees.

Ah OK. I think I squeezed a bit more out of mine when installing my AST dampers. The bottom spindle mount hole is slotted so I tilted the top of the spindle all the way in before I tightened the bolts. I'm at 2.5 and still have lots of room on my plates.

 

[boro92]

FWIW, one can run camber bolts in conjunction with camber plates if the travel for the plates are limited.
I've been able to get -2.1 on a stock ride height Boss with just Eibach bolts. Running 0 toe.

Even on the factory P zero rubber, -2.1 is not enough if your circuit is a tighter one. The outer parts of the tire still get worn the most. A sign of:
1) Not enough camber
2) Too much understeer

This is despite trail braking where ever possible and getting rotation on entry. If you are experienced on the track and push the car hard, I suspect you'll want more than -3 on street tires (again, on a tighter course). As others have stated though, this all depends on

1) How hard you push the car
2) How you want the car to handle

FWIW I have written about this very topic on my blog. Addressing the "oversteer" equasion is not necessarily as simple as stiffening the front/softening the rear:
http://dreamingin302ci.blogspot.ca/2013/11/suspension-tuning-primer-2-look-at-big.html

And a topic on addressing what handling traits you want to cure and when. Sometimes, it's not always setup. Driver inputs is a big part of the equasion:
http://dreamingin302ci.blogspot.ca/2013/11/suspension-tuning-primer-1-figure-out.html

 

[Mad Hatter]

Great help guys! much appreciated. Will do my reading tonight and head of for alignment tomorrow.

 

[Mad Hatter]

In the end I did the following, OEM caster, zero toe, and -1.9 camber. Went right to the stopper of the MM camber plate and could get -1.9 left and 2.1 right so left them both on -1.9. Thanks for all the help!

Have two time attacks this month, feel like a kid with a early Christmas.

 

[boro92]

Would be great to hear your thoughts after that alignment!
Those look like very street friendly numbers, but will definitely enhance the on track experience. Have fun!

 

[Mad Hatter]

Had a great time at the track, got 3rd place overall out of 60 cars so very pleased with my Boss!!! The camber change added front end grip and rotating the tail out was just a matter of lifting the throttle, rear end never got out of hand and tire wear was very good despite 90 degree heat. I think I must have a little toe still as the car felt stable with no wondering on the straight away.

I have a set of P springs on the way, I guess dropping the front 1/2 inch will give me a little more negative camber?

 

[2012YellowBoss]

Had a great time at the track, got 3rd place overall out of 60 cars so very pleased with my Boss!!! The camber change added front end grip and rotating the tail out was just a matter of lifting the throttle, rear end never got out of hand and tire wear was very good despite 90 degree heat. I think I must have a little toe still as the car felt stable with no wondering on the straight away.

I have a set of P springs on the way, I guess dropping the front 1/2 inch will give me a little more negative camber?

It should but not sure by how much.

One little number I have that can help at the track is that turning the rods on the tie rods one flat equals .046 change in toe. So if it is known you have -0.02 toe out and turn the left rod one flat (pull the wrench toward the front of the car) and right side one flat (push the wrench toward the back of the car. You would have -0.066 toe out.

 

[Mad Hatter]

Thanks! will give it a try