mx5cartalk.com

Hey guys, found some wheels I really like, 15x8 +20 15x8 +-0... Not worried about running staggered offset wheels, was more worried about the wheels being too wide/far apart from eachother on such a little car.

Will it ruin any handling aspects? Car is nb8a and i think I'd run a stretched 195 or maybe 205

And yes I know she's gonna need some guard work

thanks in advance

send a PM to 16bit

Please post to the correct section next time, ie. MX-5 Wheels, suspension, brakes & tyres.

Staggering the offset WILL change the handling.
Stretching a 195 tyre to an 8" rim WILL (look stupid and) change the handling.
Running different offset to stock WILL change the handling.

Whether it changes it for better or worse is a different matter. It will behave differently to a stock MX5 (which is predictable and nimble).

Stretched tyres are so pathetic. I really hate the look. Please don't.

Boags wrote:Stretched tyres are so pathetic. I really hate the look. Please don't.

it's an odd thing isnt it.

you buy wide wheels to fit wide tyres, therefore: more grip.

why buy a wide wheel, then a skinny tyre, so overall your 8" wheel with a 195 tyre has less grip than a 6" wheel with a 195 tyre.

hks_kansei wrote:

Boags wrote:Stretched tyres are so pathetic. I really hate the look. Please don't.

it's an odd thing isnt it.

you buy wide wheels to fit wide tyres, therefore: more grip.

why buy a wide wheel, then a skinny tyre, so overall your 8" wheel with a 195 tyre has less grip than a 6" wheel with a 195 tyre.

not only that, but you're placing stress on a sidewall it isn't designed to handle

In theory you will have more grip in the rear then the front but it will let go less progressively in the rear. So you will have to listen to the understeer you get from the front as you may find yourself swapping ends un expectedly. I would recommend getting a thicker front sway bar and possibly and strut brace to try and increase the feedback from the front end. This is of course on the edge driving which you should not do on the road.

With 0 offset in the rear i cut the guards (both inner and outer) and used flares. I think you can get the rears under the stock guards with neg camber and maybe a light roll. The front should not be too much of an issue with some good neg camber. You may need to trim the inner guards a little but not too much. This does all depend on the ride height you have. Both for the amount of neg camber you will be able to run and also how much if any trimming you may need to do. That you can experiment with.

I now run effective negative 7 offset front and rear with 15 x 8's wrapped in 205 50 15's. That requires an angle grinder and patience to get it right. I had to make my own inner guards and quite a bit of trimming. I also have neg 3 degrees camber in the rear and neg 2 degrees in the front. My car does handle differently as it did with stock wheels. It has much much more grip and still turns in quite nicely. Though on the limit its a little less forgiving.

As for tyres don't stretch. If you want a reasonably priced 205/50 tyre that is wide enough (not all 205's are the same) the BF Goodrich Sport tyre is apparently a pretty good tyre for the money.

From what I have read the mx5 does prefer a square offset (same front and rear) but the specs you have said don’t seem like they will be too bad. That said I have never dríven an mx5 with odd offsets. If anything it will be a little safer as the front will let go before the rear which is generally nicer on the road.

Clear as mud

ignoring the whole stretched tyre issue for the time being...

hks_kansei wrote:you buy wide wheels to fit wide tyres, therefore: more grip.

why buy a wide wheel, then a skinny tyre, so overall your 8" wheel with a 195 tyre has less grip than a 6" wheel with a 195 tyre.

wider does not necessarily mean more grip, and more grip does not necessarily mean better handling.

Thankyou 16bit for your reply, very informative! Ill also be gettig some bc Coilovers so ill dial some camber in accordingly.

As for the others that seem to think stretched tyres are evil, I'm not only doing it for looks, stretching tyres provides a sharper feel and more stability as there is zero sidewall flex to throw you off. Also the more stretch the less guard work needed!

Im also going to be facing these same problems in the next couple weeks, as I just got myself a staggered set of superlites.

The fronts are 15x7 +15, and the rears are 15x8 +4. I will be running my 195/50's all round, not for looks but to reduce scrubbing. All my guards have been rolled, but I might have to pull the rears a little for it to sit right.

These are the wheels.



This is how the fronts sit so far. 15x7 +15 with 195/50 Advan Neova's



Im going to wait to get a set of coilovers before I run these on road, as I need the car to sit lower.

* shakes head*....

dorifta wrote:stretching tyres provides a sharper feel and more stability as there is zero sidewall flex to throw you off.

That might be so, but at the cost of reduced safety, and increased chance of tyres coming off the rim.... What WILL throw you off as you put it, is tyres coming off the rims if you try to corner hard!

You want less side wall flex? Buy stiffer tyres or put more air into the ones you've got!!

Enjoy explaining to your insurance co why they should cover you for a claim when they see that you've been fitting tyres to too wide a rim

At the risk of sounding like Mr Moorlock The maximum wheel with for a 195 tyre is 7" (Aust Tyre & Rim Association Manual). Fitting to a wider rim makes the fitment illegal in all Aust states (and nullifies your insurance policy) and illegal for any CAMS speed event. Gerard is quite correct, stretching the tyre is detrimental to its construction, and can often lead to the tyre deflating and rolling off the rim. It was done in the 70s with much taller tyres (78 series) that had very stiff sidewalls to start with on things like Ferrari Daytonas (Michelin X 205/70 x 15s etc) because of a lack of available wide tyre sizes, but they were poor handling things by today's standards. Real JDM cars don't run stretched sidewalls IMHO.

*dons flameproof overalls*

NMX516 wrote:

dorifta wrote:stretching tyres provides a sharper feel and more stability as there is zero sidewall flex to throw you off.

That might be so, but at the cost of reduced safety, and increased chance of tyres coming off the rim.... What WILL throw you off as you put it, is tyres coming off the rims if you try to corner hard!

You want less side wall flex? Buy stiffer tyres or put more air into the ones you've got!!

Enjoy explaining to your insurance co why they should cover you for a claim when they see that you've been fitting tyres to too wide a rim

well have you ever dríven a car with stretch? It depends on the design of the wheel.. On my work equips on the 32 (17x9 +18) i ran a 215/45 on front every day and went through many many tyres on rear ranging from 205/40 to 255/45s. The car was used as a drift car but also a daily. No tyre to date has ever "rolled" off a rim or gone flat due to air escaping due to stretch as people fear!

I'm not having a go at anyone I'm purely speaking from experience! Personally I hate running wide/bubble spec tyres, makes the car feel so much slopier. But then again evrreryone has their own preference in ride quality.

If you are going to run stretch, just bump up the pressures a bit more then usual for that extra peice of mind.

green_comet wrote:This is how the fronts sit so far. 15x7 +15 with 195/50 Advan Neova's



Im going to wait to get a set of coilovers before I run these on road, as I need the car to sit lower.

Hot!!!!

At the risk of sounding like Mr Moorlock The maximum wheel with for a 195 tyre is 7" (Aust Tyre & Rim Association Manual). Fitting to a wider rim makes the fitment illegal in all Aust states (and nullifies your insurance policy) and illegal for any CAMS speed event.

Yeah I wouldnt go stressing about running 195's on 8inch wheels, they are not much of a stretch at all. If you dont drive like a complete loon they will be fine. I have seen blokes run 175's on 8 inch wheels, with much heavier cars than an MX5. Now that I would worry about. I know it is illegal but what isnt?, running anything more than a 6.5" wide wheel on a NA is illegal, as standard wheel size on the sticker is 5.5".

If I want to drive fast and handle good ill use my Enkies, but when Im just going around town ill just use the supelites.

Its nowhere near as dangerous as this sh*t...