MX5 Wheels

Author
Discussion

wedge girl

Original Poster:

4,688 posts

240 months

Sunday 17th October 2004
quotequote all
Thinking of changing from 185x70 14" to 15" or 16" with a lower profile tyre.

Any ideas how this will change the handling.

>>> Edited by wedge girl on Sunday 17th October 14:48

flat_steve

1,533 posts

248 months

Sunday 17th October 2004
quotequote all
Bigger wheels will raise the ride height and the centre of gravity as well as slightly increasing the unsprung weight, but as the MX-5 is so well-balanced anyway it shouldn't adversely affect the handling. 15's will be a good trade-off. 16's and bigger will make the car look like an off-roader without a set of lowering springs. TBH as it's such a small car 15's look big enough imo

douglasr

1,092 posts

273 months

Sunday 17th October 2004
quotequote all
Make sure you keep the rolling circumference of the wheel/tyre the same, otherwise the sppedo wont be accurate and the gearing changes.
Its explained here:
www.performancetyresdirect.co.uk/faqs.htm

Use the converter here:

www.performancetyresdirect.co.uk/converter/converter.html

tuttle

3,427 posts

238 months

Sunday 17th October 2004
quotequote all
Flat Steve made a good point about springs,larger wheels will need lowering springs.Not only does this give your car a nice'sporty' profile,will also help to stiffen body roll/handling too.If you leave the springs you may find car seems to be 'sitting' on top of your new wheels.

RobDickinson

31,343 posts

255 months

Monday 18th October 2004
quotequote all
If you use something like :

www.miata.net/garage/tirecalc.html

You can keep the circumfrence/diameter roughly the same - so shouldnt affect ride height or COG at all - and you did say lower profile tyres.

Benefits will be :
Less tyre wall slip, so more responsive cornering. Oh and looks.

But against that we have:
Poorer overall ride quality.
Heavier wheels.
More expensive tyres.
Change in tyre pressure I guess, and you may have to?

cptsideways

13,551 posts

253 months

Monday 18th October 2004
quotequote all
195/55/15s will do the job nicely, make SURE you find the ACTUAL wheel weights, heavy wheels effect the handling & scuttle shake more on an MX5 than most cars. Buy the lightest you can.

15's will be more than plenty, only go for 16's if you can get light ones.

Tyre calc here

miniman

25,013 posts

263 months

Tuesday 19th October 2004
quotequote all
Mine is on 15s with Toyo Proxy tyres. It is also lowered (I believe, with Eibach springs etc. according to my mechanic mate who has had the wheels off a few times). Be careful if you go down the lowering route. The clearance on mine is BAD and renders any kind of speedbump a virtually impossible obstacle.

wedge girl

Original Poster:

4,688 posts

240 months

Tuesday 19th October 2004
quotequote all
Miniman, have you fitted polybushes to yours?

miniman

25,013 posts

263 months

Tuesday 19th October 2004
quotequote all
wedge girl said:
Miniman, have you fitted polybushes to yours?

Couldn't tell you that! I haven't personally but it seems to have had quite a few suspension mods in the past. I had no idea other than a suspicion that it looked a little lower than standard but I put that down to bigger wheels. I had some problems with the brake pads moving about and clunking so my mechanic mate has had the wheels off and mentioned the uprated springs etc. I'll ask him about the bushes.

It certainly handles great. I did a track day at Castle Combe last month and it certainly sticks to the track - couldn't get the back end out despite significant efforts! However, wet roundabouts are a different matter altogether.

Budget-permitting, I will look at either a turbo or supercharger conversion at some point for a little extra

NickG

1 posts

235 months

Sunday 31st October 2004
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Here is a picture of my 5 with Oz Racing Superleggeras 195/45 x 16, nice light wheels. You will get 17s on however I went for 16s as I want to lower the car.

tuttle

3,427 posts

238 months

Sunday 31st October 2004
quotequote all
They look a really good suit for your car NickG-will fill the arches nicely when you've dropped the springs!

benjc

677 posts

249 months

Thursday 4th November 2004
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As said before, wheel weight is very important on an MX5. But remember that offset is important too. Mk1 cars had an offset of 45 as standard and Mk2 cars 40. Its best to be as close to those figues as possibe to avoid tramlining and bumpsteer and all other kinds of nastys.

Oz superlags 15" matt:

andy mac

73,668 posts

256 months

Friday 5th November 2004
quotequote all
flat_steve said:
Bigger wheels will raise the ride height and the centre of gravity as well as slightly increasing the unsprung weight, but as the MX-5 is so well-balanced anyway it shouldn't adversely affect the handling. 15's will be a good trade-off. 16's and bigger will make the car look like an off-roader without a set of lowering springs. TBH as it's such a small car 15's look big enough imo

Why will it make ride height bigger, and the centre of gravity higher?