Best way to get more -ve camber on front

  1. My model of MX-5 is: NC
  2. I’m based near: Hampshire
  3. I’m looking for technical help or recommendations on: Best way to get move -ve camber on front

Just to be clear - I need more -ve camber than can be achieved through rotating the eccentric camber bolts.

I can see there are 3 ways of doing this. These are my thoughts.

Adjustable upper arms

Pros:

  • Shouldn’t lose their position
  • Easy to fit

Cons:

  • Heavy
  • Expensive
  • Not compatible with stock brake hose fittings

Various brands of offset bushings for the upper arm inner bushes

Pros:

  • Cheapest

Cons:

  • Prone to rotating?
  • Hard to get the pair aligned, potentially causing binding?

Superpro lower arm Inner Rear offset bushes These are for castor!

Are my thoughts correct? What do other people do to get more -ve camber at the front?
What bush hardness to people choose for predominantly track use?

I thought there were eccentric bolts on most of the suspension pivots to allow changes to the suspension geometry, camber being one of changes allowed. The adjustment allows changes for most road and track geometry requirements. Paul Roddison Motor Sports (“Rodders” on the forum), would be able to advise.

I thought there were eccentric bolts on most of the suspension pivots

There are, but they only have a limited range of adjustment. There’s not enough adjustment on the front to get enough -ve camber for serious track use

Another option would be adjustable top mounts, but I don’t think I’ve seen them used on an MX5

Edit: Not an option on the MX5 because it doesn’t have MacPherson struts!

Because there is no top mount of the type you are thinking of.

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Just how much -camber are you wanting?

What tyres are you using??

What springs/dampers do you have?

I did a dozen track days last year in my ND, and by the end of the year, IIRC, I ended up with about -3.75 per side on the front (I’ve not got the exact figures in front of me), which was working well for me in the dry. I’m expecting to want something similar in the NC. I’m about to fit some dampers and springs to the NC and thought I’d do the wishbones at the same time.

I’ve been running stock-size 17" A052s on the ND, and now have several part warn ones which will go onto the stock 17" NC wheels. When they’re dead, I’ll probably switch to something cheaper in a 16" size. I probably won’t go wider on the rubber - I prefer a car that is under-tyred

Dampers and springs about to go on are Meister Club Race 10 / 6.

I won’t touch the anti-roll bars until I see how it feels

As much as I like the ND, it’s worth too much to play with on track. I’ll be putting it back to stock and selling it once I’ve got the NC ready

I can’t even conceive needing -3.75 degrees at the front…if it is to prevent understeer I would say there is something not right at the rear end.
I’ve been involved in Motorsport my whole life both competing and building cars, admittedly not MX5’s, but that seems strange to me. Have you a lot of castor stopping it from turning in?
I would like to see what people suggest here…best wishes…I wasn’t having a dig just curious!

If you are running stock wheels & a treaded tyre anymore than -2.5 you will struggle to stop it as you will have a very small contact patch for braking……
I would also think you will not get the best for cornering also.
I think you need to do some seriously testing and data logging
Tyre contact temps etc

Paul

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Just checked the figures now I’m home: 3½°, or 3°30’, so just slightly less extreme!

I’ve certainly not noticed any detrimental effect under braking wet or dry, but I see what you’re saying about size of contact patch and I don’t have any data to back up what I think I’m feeling.

For tyre wear, it’s a huge improvement - I was wearing the outside edges far too fast. This is a big consideration when the tyres are expensive.

Yokahama state that optimum camber for the A052 set up for race is 3.5 – 4.0 degrees negative, although that will obviously depend on the car. They don’t state if that’s total, or per side, but I suspect they mean per side.

It was chatting to a couple of ND guys at the Nurburgring that got me experimenting with more camber. They’re both running -4° front camber on AR-1s, although that’s not to say they’re right in what they’re doing!

In my experience you might want that level with a slick, but you risk overheating and blistering the inner edge of a treaded tyre with extreme camber. Of course if it is just standard power, them you mitigate that somewhat.
Tyres will wear on the outer edge as that is where the load goes in cornering. Putting extreme camber to even out wear again puts more load into the inner edge which negates the principal of asymmetric tyres as you are not getting the load transfer to the outer edge.

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