NA rims - go with 17's or ...? will tx3 rims fit?

datfreak · Postby **datfreak** » Mon Jun 29, 2015 6:36 pm

I've found some rims/tyres locally-
came off a tx3 with 4x100 so (according to google search )54.1 centre bore and about 35-40 offset.
They have 215/45/17 tyres on them, he isn't sure if they are 17x7 or 17x8.

So some q's -- mainly:
a) could I? ---would they fit the na?

b) and should I? will 17x7 or 17x8 be too heavy and stuff up the na6 balance?
Assume these wheels are standard 5 spoke 'street' alloy wheels and not superlight race wheels.

cheers for your thoughts

hks_kansei · Postby **hks_kansei** » Mon Jun 29, 2015 6:53 pm

PCD and centre bore sound correct for MX5 fitment.

Do you know the offset of the wheels? that makes a big difference to fitting.
I'll assume they're around +40 since that's a pretty common offset for those sized wheels.

The biggest concern would be the tyres, since they work out to be about 8% larger in rolling diameter than the factory NA6 wheel/tyres.

That means at an indicated 100kph the car will actually be travelling about 108kph.
Larger rolling diameter also means you effectively have a taller diff, roughly the equivalent of about a 3.9:1 in this case.

Taller diff (or larger rolling diameter wheels) means slower acceleration etc.

Cus · Postby **Cus** » Mon Jun 29, 2015 7:06 pm

http://www.willtheyfit.com/index.php?wi ... 40#content

Orange rim is the stock daisys.
Green rim is your proposed newness. (roughly, depends on the actual offset)

The Outside Diameter (OD) of the new rubber is too big(*) - if you put new / different rubber on (about a 215/35r17) you'd have about the same OD.

As for the weight, easisest way to find out is to weigh the 17s.
I think from memory my daisies are 13 or 14Kg with rubber, lots more kgs = bad, same or less = gooderer

(*) This is opinion, at stock ride height on rough roads, it'd probably work, if you're lower than stock, it's going to cause trouble (new wheels are about 4cm taller than stock)

datfreak · Postby **datfreak** » Tue Jun 30, 2015 5:44 pm

hks_kansei wrote:snip.

Cus wrote:http://www.willtheyfit.com/index.php?width=185&aspect=60&diameter=14&wheelwidth=5.5&offset=45&width2=215&aspect2=45&diameter2=17&wheelwidth2=7&offset2=40#content

thanks guys for the info. I didn't think of the rolling diameter change..

I was more concerned about the wheel weight and size but the height change will also be a problem.

Think ill wait till a nice set of 15x8 show up

cheers