mx5cartalk.com

I need to replace the rotors all round on my NC.
Does anyone recommend a set of 2 piece front and rear rotors that work with the oem calipers?

how come you want to go 2 piece?

I’m not that fussed, just seeing what’s out there. I had a look on the usual suspects web sites and also on Wilwoods but couldn’t find anything mirroring the oem size rotors for sensible money. GWR offer a “cheap” option which comes in around $2000 delivered with duty paid - holy crap!

I do like the idea of unsprung and rotational weight saving. Saving 1kg off rotors made a massive difference when I was racing Clubmans but maybe less so on an MX5.
I actually don’t think there’s any thermal issues with the oem kit, it seems more than up to the job with good pads and fluid and now I’ve fitted braided lines and flushed the fluid twice I have decent pedal feel, travel and consistency.

I am starting to think about getting some weight out of the SE front brakes, and maybe improving performance at the same time (dual duty car). Degree of difficulty = road car . We have annual inspections for rego, and that means engineering the mod. I suspect the biggest issue here will be dust seals on the callipers - all off-the-shelf kits have none.

I am in the process of discussing with V8R their Stoptech kit, the callipers can be had with dust seals but I need to confirm fitment, availability and cost.

The weight savings in going to alloy hats and alloy callipers is massive, I weighed the old and new when I put the Wilwoods on the NB8B racecar but can't remember the figures. Some of this gain can be lost if you go to a big (25mm) rotor, but if you need that size rotor the weight is unavoidable (really high power cars), and would probably (I think) still be under the weight of the stock setup - those NB8B callipers are very heavy and I am guessing that NC callipers would be no lighter and maybe heavier. With a mid range rotor (18-20mm) you should easily notice the effects of the lighter front end.

The advise I was given on the NC brake set up was to stick to the stock (smooth) rotors.
The slotted rotors tend to increase the wear rate on the brakes and with little performance gain.

The braking performance of the NC in stock format is good for a NA engine.
By sticking with the stock rotors I was advised that I should get 12 months from pads and rotors.
So far, so good.