Wheel Alignment

[blue_na]

Can anyone recommend where I can get a good wheel alignment around Geelong?

Preferrably someone who has experience with NA mx5's.

Will travel to Melbourne if required.

Cheers, Nathan.

[93_Clubman]

Don't know about Geelong, but PASHN8 recommends Ralph @ Trutrak in North Melbourne (he thinks). PCMX5 is over Geelong way you could try PMing him.

[Matty]

sam (samselectrics) is down in Geelong too, knows a bit about driving, I'm sure he can recommend someone.

[blue_na]

Thanks guys, Sam has told me where I can get one done

Now I need some advice on some specs.

I have read through almost every thread with the word alignment in it
So I have a bit of an idea what an aggressive street setup should be.

These are the specs I am thinking of using:

Rear toe: 1.4mm
Rear camber: -1.1deg

Front camber: -1.1deg
Front caster: Max (4+deg)
Front toe: 0.7mm

I have a completely standard NA6, with 205/45R16's on NB rims.
I want an aggressive street setup with occasional track day.
I realise the camber may be hard to achieve on the standard suspension, so as much negative camber as possible up to this value and then make it even front and rear.

Also, how much toe in do I need on the front to reduce/prevent tramlining?
Is this enough toe in on the rear?
Many have said mx5's should run about 0.5deg more camber on the rear, what are the benefits/disadvantages of doing this?

Any comments, advise, and constructive criticism is welcome.

Thanks, Nathan.

[stevesports]

I would advise a little more camber at the front.

i currently have -1.25 degs front and -1.75 degs rear. I should have gone -1.5 front cuz i'm getting a slight bit of understeer. Kind of irritating.

[Charlie Brown]

You want street aggressive?

For road tyres only.

On the front, max out the castor then dial in the maximum negative camber you can get, be it -0.9, -1.5 or whatever. If you don’t want to tramline put 2 – 2.5mm toe in (total) on the front. If you get serious about track days you will need to go back to 0 to 1mm toe out. This WILL tramline but will improve the turn in.

On the rear for the road match the front camber or go another 0.2 degrees negative. Run 2.5mm to 3.5mm total (1.25 - 1.75mm per side) toe in. NEVER run toe out on the rear unless you like to see where you have come from.
If you are serious about the track 0.5 degrees more camber than the front to start with and then vary it up or down to suit the handling characteristics you want for that track. The higher the toe in on the rear the more stable the car will be in high speed corners (ie Phillip Island) but the slower it will be around the track if “your ball size” is the same. It’s a fine balance and only track experience will allow you reduce the rear toe in to a figure (possibly 2-2.5mm) that you can handle.

A point to note. Not all MX-5’s get the same front negative camber. Some max out less than 1 degree negative while others get around 1.5 negative.

If you are going to run R-spec tyres you need to max out the negative camber. Toyo R888s work best at -4 degrees camber. Sorry but you won’t get within a bulls roar of that in a standard NA.

Also if you want lower track times you will need to go back to the 14” wheels. 16’s on an NA make it SLOW.

[manga_blue]

I'm running -2.5 front and -2.0 rear camber, max castor and about zero toe with street tyres. It's responsive but I wouldn't call it really aggressive. The car tracks perfectly straight and tyre wear is even.

Turn-in is great but tyre wear can get a bit nasty as you move towards more toe-out.

I've had those -1.1 camber settings before - the car felt dead.

[Alex]

What would be the next step from stock if someone wanted to increase the amount of possible camber?

[blue_na]

Thanks for the input so far, I probably should have mentioned this setup will be 99% road use, only the very occasional track day.

As suggested, I think I will go with max castor then max out whatever camber I can get from the stock suspension, though I am unsure about the toe, since I only plan on running road tyres (For now anyway), and don't want tyre wear to be excessive.
I think I will consider 0 toe on the front, but what effect will this have on wear?
Will running 3mm toe-in on the rear cause alot of wear? What kind of value would be a happy medium for rear toe in terms of stability and tyre wear?

Also, you say 16" on an NA are slow, should I swap the 16" NB rims for a set of 15" NB8A rims?
I don't want to go right down to 14's due to choice of rubber and looks.

Cheers, Nathan.

[wun911]

is tram line like you let go of the stearing wheel and it go strait?

when do I start to see un even wear at 3 negative camber??

[stevesports]

tram lining is when the road is uneven and the car follows the direction of any ruts on the road.

re: -3 camber. ahh...maybe after long distances the insides will start to wear out.

[Hellmun]

What would be the next step from stock if someone wanted to increase the amount of possible camber?

Lowering the car is probaly the easiest way to achieve negative camber. Either through springs or an adjustable coil-over set. After that you can put in offset polyeurethane bushes to push it further. My car has both and can hit approximately 4.25 degrees rear and a bit over 2.5 degree's front. That's an NB8B though I will say I havn't really lowered the car that much. That's also with max Caster, 0 toe in front and 0.1mm toe in rear.

[Hellmun]

is tram line like you let go of the stearing wheel and it go strait?

when do I start to see un even wear at 3 negative camber??

I saw it when I had standard suspension maxxed out....Which was about 2.5 degrees on the rear. The 1.25 I got on the front didn't cause it.

[Charlie Brown]

Thanks for the input so far, I probably should have mentioned this setup will be 99% road use, only the very occasional track day.

As suggested, I think I will go with max castor then max out whatever camber I can get from the stock suspension, though I am unsure about the toe, since I only plan on running road tyres (For now anyway), and don't want tyre wear to be excessive.
I think I will consider 0 toe on the front, but what effect will this have on wear?
Will running 3mm toe-in on the rear cause alot of wear? What kind of value would be a happy medium for rear toe in terms of stability and tyre wear?

Cheers, Nathan.

As I said above, 0 toe on the front WILL give you tramlining but no additional wear.

The front won’t track in a straight line but follow all the bumps, cambers, ridges, etc on our fantastically maintained roads. If you’re happy with that in a 99% road car then go 0 otherwise stick in 2mm toe in.

Another thing to remember that under braking the front suspension bushes deform and the alignment goes towards “toe out”. By setting it at 0 it will end up toe out and darting around under brakes.

Having rear toe in is very important on an MX-5. It reduces the change of having the rear let go suddenly under roll oversteer conditions.
2 - 3mm in will not effect your wear and is what is recommended in your owners manual.

Also, you say 16" on an NA are slow, should I swap the 16" NB rims for a set of 15" NB8A rims?
I don't want to go right down to 14's due to choice of rubber and looks.

Cheers, Nathan.

15s would be better.

You know that to improve responsiveness in an engine you lighten the flywheel. By lightening the flywheel the engine doesn’t have to overcome unnecessary mass, so it spins freer and quicker in its charge to the red line. There are some downsides but we’ll forget that here.

Now think of your rims and tyres as flywheels. Increasing the weight of a wheel by 0.5kg really is like adding 2kg to your flywheel. The engine needs to turn that extra mass. It will spin slower, be less responsive, etc.

So by going back to 15s you reduce the additional mass of the 16” rim and tyre that the engine needs to turn. There are additional benefits to the suspension also as the unsprung weight is reduced, handling will improve.

Remember that a lot of the "specs" that the guys are throwing around here are really for MX-5s that are tracked on a regular basis and are set to suit their personal requirements. You’re not doing a lot of trackwork so by sticking with the settings above you will have a MX-5 that’s comfortable to drive on the road yet for more responsive than the standard settings from Mazda. You can do a search to find those standard settings elsewhere on this forumn

[blue_na]

Thanks Charlie, you've been extremely helpful.
Will take the advise, more toe and lighter wheels sounds right for me.