MX-5 Wheel Alignment Specs..

[MrRevhead]

My current is -3.5° F & -3.0° R camber, Zero toe and 2.3° caster, however I am running R specs and very little road use. The car has an issue with caster at the moment

In the past I have use -2.0°/-1.5° F/R camber, Zero toe and 3° caster with no issues.

What ride heights are you running?
Will the wheel alignment place allow you to sit in the car when they are doing the alignment? This will change the amount of toe they set.
How old are the alignment bolts as they do stretch?

Thanks Magpie, those specs do seem more agressive/track orientated. I am more after spirited, daily driving specs.

12" (300mm) hub to fender ride height (approx 110mm ground to pinch welds)

I assume the bolts are stock.

[Magpie]

The second one is no too agressive, however my current one is

[manga_blue]

max caster

front camber -.5 deg
rear camber -1.4 deg

.2 deg toe in front .3 deg toe in rear

It'll drive like cold porridge with that.

Magpie is on the money for a street car with -2.0/-1.5 camber, zero toe and as much castor as you can reasonably get.

[Magpie]

For minimum tire wear and power loss, the wheels on a given axle of a car should point directly ahead when the car is running in a straight line. Excessive toe-in or toe-out causes the tires to scrub, since they are always turned relative to the direction of travel. Too much toe-in causes accelerated wear at the outboard edges of the tires, while too much toe-out causes wear at the inboard edges.

The toe setting on a particular car becomes a tradeoff between the straight-line stability afforded by toe-in and the quick steering response promoted by toe-out. Nobody wants their street car to constantly wander over tar strips-the never-ending steering corrections required would drive anyone batty. But racers are willing to sacrifice a bit of stability on the straightaway for a sharper turn-in to the corners. So street cars are generally set up with toe-in, while race cars are often set up with toe-out.

Not my words

In addition toe in/out adds friction/drag to the car and will impact on acceleration and speed. Again not really a street issue but if you are looking at getting the best acceleration for spirited driving consider Zero toe.

My Words

[MrRevhead]

Yes, I am also prioritising tyre wear as I have acquired a new set of KU31's

I just thought F 2 degree R 1.5 degree camber was a little excessive given previous reponses/posts and from what I have read.

But if you guys have had good results with those on the street, I am willing to give it a try and tweak further on if it doesn't suit my driving style.

[Magpie]

Also Zero toe

[MrRevhead]

To summarise, street spec with spirited driving, recommended settings:

FRONT:

Caster: Max (3+ degrees)
Camber: 2 Degrees
Toe: 0 Degrees

REAR:

Camber: 1.5 Degrees
Toe: 0 Degrees

?

[manga_blue]

That's about it but you may find your suspension doesn't let you get as much as -2.0 at the front. If that's the case then drop the rear camber down so it's still 0.5 less than the front.

[MrRevhead]

Thanks Manga for the input

[Roadrunner]

To summarise, street spec with spirited driving, recommended settings:

FRONT:

Caster: Max (3+ degrees)
Camber: 2 Degrees
Toe: 0 Degrees

REAR:

Camber: 1.5 Degrees
Toe: 0 Degrees

?

I got a wheel alignment done yesterday to these same specs (though 4deg caster from memory).
Difference is quite noticeable.
Going through my favourite freeway offramp S-bend, there's zero understeer where I use to get a little and the whole car just felt stable.
Will be interested to see how it goes over the next few weeks and at the next track day.
Will keep an eye on tyre wear.
The wheels sit a noticeable way in from the guards now too

[chefie]

What a difference a alignment makes

I recently installed BC Br series and had a full race alignment done by a race alignment guru in Brisbane, the first day out was Lakeside and my first in 4 months at this track. the car felt skittish and after an oh f^% moment sideways at 160Ks at the left after the bridge I slid on the outside track grass to a dead stop to touch the wall with my finger, show my respect and drive away, I worked through the remainder of the day a bit tepid.

once home and a revue of the tyre wear I was at 60% contact wear on the fronts and 65-70% contact wear on the rears, below are the settings tyres specs and pressures for the day.

all feedback welcome as i may have gone too aggressive on the camber settings and unbalanced a light car,

Front

camber Left -2.20 Caster +6.5
Camber Right -1.5 Caster +6.0
Toe 2.0 mm toe in

Rear
Camber Left -3.5
Camber left - 3.8

overall setting sq on car and Drivers side 5 mm short at axle to axle

Running Yokahama ado8Rs at 30Psi cold and 33-34 hot fresh rubber in January three track days

[Magpie]

In general more negative camber in the front than the rear.

Whilst the amount of toe in will give you high speed stability it will impact turn in. You could run toe out front and toe in rear.

Try 3.5 neg front, 3.0 neg rear and zero toes. Maybe toe out front. Be aware toe will impact tire wear! Look at your tyre temps and adjust the alignment/pressures accordingly.

Who did the alignment in Brisbane?

[M1474]

I'm guessing you might already be maximum camber front? Reduce the rear camber to 2/3 or 3/4 whatever you can get on the front and remove most or all of the toe.

[chefie]

In general more negative camber in the front than the rear.

Whilst the amount of toe in will give you high speed stability it will impact turn in. You could run toe out front and toe in rear.

Try 3.5 neg front, 3.0 neg rear and zero toes. Maybe toe out front. Be aware toe will impact tire wear! Look at your tyre temps and adjust the alignment/pressures accordingly.

Who did the alignment in Brisbane?

Thanks Magpie

The a full day at the last sprints at LS has shown noticeable inner tyre wear due to the toe in, the front left also had a camber bolt, ill give accurate a try next week and drop the rear camber back a bit, best I can get out of the front is -2.00 camber at the sacrifice of bit of caster

in saying that the car felt balance and previous under steer was gone although the ado8r have stiff side walls and I have them running at 26psi cold

[StanTheMan]

so in sumary,
get 0.5 deg less in the rear than the front if -2.0 is not attainable for spirited street driving.


is there any recommendations on where to get it done in Sydney? Since Stu is no longer about.