Extra Camber (NA)

[Magpie]

Have anybody fitted eccentric bushes or adjustable arms on their NA's to get more camber? There are some posts on the forum but none stating if eccentric bushes were a long term solution or if adjustable arms worked out as well. At the moment I can get no more than -2 camber out of the front (and +3 caster) and would like -2.5 (car is not used that much on the road any more). Car height at the pinch welds is 103mm at the front and 110mm at the rear (with driver weight, 1/2 tank and tyres at 32 psi).

Options I have looked at:
http://www.meganracingperformance.com/1990-2005-mazda-miata-adjustable-camber-rear-upper-control-arms-megan-racing-6674-p-468273.html
http://www.awrracing.com/2009/05/14/new-camber-adjustable-rear-upper-control-arms-for-miata/
http://www.iscracing.net/miatasuspension.html
http://www.superpro.com.au/superpro-parts/SPF1984-80AK
http://justjap.com/store/product.php?productid=20679&cat=&page=1
http://www.epmiata.com/store/Suspension/TMDKCA000.html

[ja9]

I've got the opposite problem, too much negative camber. I have the modification done to the arms and the minimum camber I can get out of them is -4 degrees. Too much for my liking. I was thinking of going with the eccentric bushes to bring it back a little. If you want to save some money on postage I'd be happy to split the cost with you.
Let me know what you decide.

Regards - John

[MattR]

Mark,

For what you want to do with the car I would look at the adjustable arms front and rear. They will give you camber, caster and toe if they are a good quality aftermarket unit, and will save a little weight and look pretty.

You have already gone down the path of handling over ride so rose jointed suspension won't hurt the ride and you can get very precise adjustment from the aftermarket arms. Only problem is the range of adjustment can be a head ƒü¢k if you get the initial setting wrong.

Do your research and find out what people are using in cars similar to yours. If you can get to a PSCRAQ race meeting, have a talk to the guys running the 2B spec cars that have a lot more freedoms than 2F cars, you might be surprised at how wild they have gone or how standard the cars are underneath and there maybe a simple way to get the alignment you want. And also have a look what is being done in other parts of the world, particularly England, as they seem to be the motorsport capitol for good quality gear.

The bits available today have come a long way since I started racing with datsuns where you had to make up longer control arms from 2 sets and adjustable height struts/coilovers were hideously expensive or home made, or you dropped the spring seat down the body to adjust static height and keep a decent spring length.

[manga_blue]

I've had SuperPro offset bushes in for 40,000kms in an NA. Currently running -2.5/-2.0 at about the same ride height as yours with plenty more room to adjust in either direction. They hold up well to mileage and abuse but they do need to be dismantled and re-greased every year or two, which is a fair bit of work. They were also a lot more comfortable and quieter than shagged original bushes.

SuperPros are hard to align because they decided to put the offset centres on the same bushings as the cam adjusting bolts. If everything is nice and free then the whole assembly turns as soon as you loosen the cam bolt and it becomes really hard to adjust precisely with the cams alone. It comes down to personal skill of the operator. Some seem to have no trouble and others just can't cope. Simon at Computerline can set it all in 15 minutes for me, but two other shops (both of them race shops) have abandoned it after 1 1/2 hours. I

If you go for offset bushes then I think it would be better to find a setup with the offset centres on the upper arms, as long as you have wheels with offsets small enough to keep the tyres clear of the suspension components when the upper arm lengths are effectively shortened.

If I was doing all this now I'd be looking for adjustable upper arms and harder plain OEM style bushes like the IL Motorpsort ones.

[Magpie]

Appreciate the feedback. It looks like I will be going adjustable arms at the back and bushes (upper) at the front (as adjustable arms aren't available at the moment). Looking at getting some from the states in the future. I will see how the bushes go.

Also I will be going for -2.5/-2.0 alignment as well. Heights just done today LF 100, RF 100, LR 108, RR 112 (at the pinch welds). I also put 4mm of preload on all the coilovers. I have taken a heap of photos so will make a post soon. All up about 5 hours (excluding scale setup) from disconnecting the sways to letting the 32 psi out of the tyres.