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Re: Track guys - Tyre size query
Posted: Tue Mar 13, 2007 3:12 pm
by Mr_Q
old'n'slow wrote:... the 225s obviously have a larger contact area with the road and would hang on (and look) better.
They'll give a
wider contact patch, not necessarily a
larger one.

Are they both the same type of tyre (i.e. same manufacturer, rubber, etc.)?
Which track do you mainly run at? Would the acceleration or better top speed be more worthwhile?
Posted: Tue Mar 13, 2007 5:16 pm
by bruce
Oh god, who gives a crap! I think we are really splitting hairs here (tenths of a second).
Just fit the tyres, get out there and try to improve each time.
Posted: Tue Mar 13, 2007 6:05 pm
by Mr_Q
My vote's for the 205s. Other than that - what Bruce said: just drive them hard and see how they go. Tyres are consumables anyway so try the 225s next time (if you think you need to).
Posted: Tue Mar 13, 2007 10:48 pm
by Boags
Aren't 205s a tad on the small side for an 8\" wide rim?
It'll look dori dori, that's for sure.
Boags
Re:
Posted: Wed Mar 14, 2007 5:35 pm
by irwin83r
Boags'MX5 wrote:Aren't 205s a tad on the small side for an 8" wide rim?
It'll look dori dori, that's for sure.
Boags
205's are a bit narrow for 8" but it has a fair amount of side wall to bend in.. not like the tempe specials
205 will have better turn in than the 225 maybe.. better acceleration due to total rolling Diameter but it wouldnt be bucket loads different
the 225s will look better

and i'd say are more suited to a 8" wide rim.
id go the 225s but im in no position to be taken too seriously

im a newb
if in doubt... which is cheaper

and which is made where?? see if one is a dodgy korean make..
the kumho's apparently warm up fairly fast and have some decent water grooves.. no idea on the bridgestones..

havent heard much about them
Posted: Wed Mar 14, 2007 6:35 pm
by kula
i run 195s on an 8 inch wide rim and its fine,
that said, some tyres might not like it as much.
Posted: Wed Mar 14, 2007 7:47 pm
by Mr_Q
205mm is 8 inches - so you'd think it'd be a good fit.

Posted: Wed Mar 14, 2007 11:32 pm
by Boags
Fair enough! Thanks guys.
Boags
Posted: Thu Mar 15, 2007 11:02 am
by Ted
A 225/50 is a very tall tyre, esp for an MX5. That is about the size I would expect on a Saloon car, in fact I think that is their control tyre size. Its seriously got to be at least 30mm taller than a 205/45.
Unless its a fairly high power car, I don't know too many MX5s that can turn a 225/50 well. On the plus side, you could run a 4.4 diff and still have moonshot gearing.
Posted: Thu Mar 15, 2007 11:55 am
by manga_blue
I can't help thinking that 225/50x16 is a pretty large tyre. It's going to be pretty tall and it just looks it's big and heavy - OK for a full size sedan but not for a small car. I'd expect it to generate handling and ride that's big and heavy as well.
205/45x16 is the recommended size for that rim in a MX5.
Posted: Fri Mar 16, 2007 8:29 am
by kula
there are quite a few cars in japan runnin that size but 15.
including this:
http://www.hundred-one.com/demo1.htmwhich is the fastest around tsukuba.
PANASPORTS特注品F 15X8J R 15X8.5J
A048 F:225/50-15 R:225/50-15
Posted: Fri Mar 16, 2007 3:38 pm
by Benny
A 225 will perform worse than a 205 on an MX-5.
The 225's are just over-tyring the car and have too much grip.
In R spec tyres, even 205's are a bit too much for a NA MX-5, but are OK with SP's and the like.
Go for the 205's.
Posted: Sat Mar 17, 2007 1:55 am
by deez
On a related note, thoughts on tire pressure on the track? For a 205/50/15

Re:
Posted: Sat Mar 17, 2007 10:23 am
by Boags
deez wrote:On a related note, thoughts on tire pressure on the track? For a 205/50/15

I run my semislicks at around 26 hot. Does that help?
What type of tyre? Different tyres have different characteristics at different pressures.
Boags
Re:
Posted: Sat Mar 17, 2007 10:28 am
by StanTheMan
Boags'MX5 wrote:deez wrote:On a related note, thoughts on tire pressure on the track? For a 205/50/15

I run my semislicks at around 26 hot. Does that help?
What type of tyre? Different tyres have different characteristics at different pressures.
Boags
Yea it all depends on what tyre it is. I run my Azenis at 32 in the dry. 28 psi in the wet.
Being a pit slave, I've been istructed to put 19psi into some DO1's when cold. But tyhese are serious race cars.