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-   -   225/45/15 & 245/40/15 Maxxis RC-1 (https://www.miataturbo.net/wheels-tires-78/225-45-15-245-40-15-maxxis-rc-1-a-77840/)

OGRacing 04-15-2015 02:29 PM


Originally Posted by turbofan (Post 1223907)
Right. I mean, I know Emilio has some quick cars, but I don't believe there's a 500hp LS Miata in his stable right now to test which would be faster at that power level.

Do it!

i would order them right now but taxes :( i work for OG racing. too bad i don't own the place.

1999NB 04-15-2015 03:04 PM


Originally Posted by OGRacing (Post 1223891)
i'll ask the question. i got 500hp and it's blowing the tires off any time i get near the power band. i got 15x9. 225 or 245?

A local buddy that I dice around with found the 245 on a 9 to be ~1s faster than the 225 on the same 9 for both Buttonwillow and Laguna Seca at ~130whp. Could be conditions, could be real, but he has run them on 9s for quite awhile before trying the 245. I spent the few hundred bucks to run them on 10s and seems to be fast, so I can't and won't complain although I'm told that 225s on 9s would be faster.

OGRacing 04-27-2015 09:07 AM

https://www.miataturbo.net/attachmen...ine=1422327081

i found this today. This is how a race tire should look. this is a 245 on a 9". i'm not a fan of stretching race tires for road courses. i'll pick a 225 on a 8 every time. it feels like the sidewall is actually doing it's job. allowing for maximum traction. for auto cross i'll run a 225 on a 9". i like the turn in feel it gives.

TheBandit 04-27-2015 09:16 AM

Hey that picture looks awfully familiar.. :)

These will be doing dual duty for road course as well as autox whenever the car gets back together.

aidandj 04-27-2015 10:32 AM

From everything I've read wider is better in both wheels and tires. 245 on a 9 is faster than 225 but 245 on a 10 is faster than 245 on a 9.

tomiboy 04-27-2015 10:53 AM

How are the clearances with a 245 on a 9?

emilio700 04-27-2015 11:01 AM


Originally Posted by OGRacing (Post 1226534)

i found this today. This is how a race tire should look. this is a 245 on a 9". i'm not a fan of stretching race tires for road courses. i'll pick a 225 on a 8 every time. it feels like the sidewall is actually doing it's job. allowing for maximum traction. for auto cross i'll run a 225 on a 9". i like the turn in feel it gives.

Then don't ever do an A/B test with data, you'll be disappointed.

There are a few narrower p1 (prototype 1) 245/40/15 RC-1's floating around with 2014 DOT codes and should not be confused with current production. Maxxis had a bunch left over after the first test and wanted to get rid of them. I bought all 50ish tires and sold them off to team members and selected Club Orange customers. By looking that pic, it's possible its a P1 tire.

This is a production 245 on a 10.

http://www.trackhq.com/forums/attach...015_rc1_1.jpg?

shuiend 05-05-2015 08:26 AM

I have reopened this thread, keep it clean and civil or we will hand out more bannings.

FrankB 05-06-2015 09:58 AM


Originally Posted by emilio700 (Post 1226574)
There are a few narrower p1 (prototype 1) 245/40/15 RC-1's floating around with 2014 DOT codes and should not be confused with current production. Maxxis had a bunch left over after the first test and wanted to get rid of them. I bought all 50ish tires and sold them off to team members and selected Club Orange customers. By looking that pic, it's possible its a P1 tire.

Emilio, we're there also 225's from 2014 that are smaller then the current 225's? Or were only the 245's effected by this?

emilio700 05-06-2015 12:51 PM


Originally Posted by FrankB (Post 1229156)
Emilio, we're there also 225's from 2014 that are smaller then the current 225's? Or were only the 245's effected by this?

No other prototypes ever reached market in any size. The only 245/40/15 P1's were all purchased by 949 Racing and sold to local friends and a few Club Orange customers. Anyone who has some of those P1's knows what they are and also had instructions not to resell them.

There is just about zero chance you or anyone else on the planet has a prototype Maxxis anything without knowing it.

TheBandit 05-07-2015 09:49 PM

For clarity, the above bronze 15x9 with 245 Maxxis was purchased directly from the OEM and as such should not be the prototype release.

ozbrock 05-08-2015 12:13 PM

2 Attachment(s)
For folks wondering about clearance of the 245's on 9's... I was swapping my street wheels back on this morning and noticed that both of the front 245's were rubbing slightly on the inner fender right above the top hat. Those are 15x9 +36 wheels on an NB.

https://www.miataturbo.net/attachmen...ine=1431101632

Turbo Kitten is watching you.
https://www.miataturbo.net/attachmen...ine=1431101632

k24madness 05-09-2015 10:59 AM

I don't want to re-ignite a fire but my own testing support Emilio's findings.

I too was a non believer. Then I saw the light.

245's on 10's played a BIG role in the 1:41.6 at Sonoma last year!

Savington 05-09-2015 11:17 AM


Originally Posted by ozbrock (Post 1229819)
For folks wondering about clearance of the 245's on 9's... I was swapping my street wheels back on this morning and noticed that both of the front 245's were rubbing slightly on the inner fender right above the top hat. Those are 15x9 +36 wheels on an NB.

This isn't inherent to 245s. 225s and even a wide 205/50 (Hoosier) will produce those same marks with adequate camber. IOW, if you don't see those marks on your shock tower, you drive like a pansy :party:

wannafbody 05-13-2015 10:22 PM

Throwing gas on the fire...

After reading this thread I did some research on Tire Rack. Something I think some people have missed is that section width of a tire IS NOT equal to the tread width of the tire. Just looking at the specs on Tire rack, most 205/50/15 tires have a smaller tread width than section width.

205/50/15 Toyo RA1-8.4 inch section width/8 inch tread width
205/50/15 Potenza RE-71R-8.4 inch section width/7 inch tread width
205/50/15 Dunlop Z2-8.4 inch section width/7.5 inch tread width

Point is that saying that a 205 50 15 on an 8 inch wheel is always best is only part of the story.

emilio700 05-13-2015 11:15 PM


Originally Posted by wannafbody (Post 1231244)
Throwing gas on the fire...

After reading this thread I did some research on Tire Rack. Something I think some people have missed is that section width of a tire IS NOT equal to the tread width of the tire. Just looking at the specs on Tire rack, most 205/50/15 tires have a smaller tread width than section width.

205/50/15 Toyo RA1-8.4 inch section width/8 inch tread width
205/50/15 Potenza RE-71R-8.4 inch section width/7 inch tread width
205/50/15 Dunlop Z2-8.4 inch section width/7.5 inch tread width

Point is that saying that a 205 50 15 on an 8 inch wheel is always best is only part of the story.

A bit late to the party. No two models of tires have either the exact same tread and casing widths for a stated size. Our recommendations refer to tread width, not casing width. Hoosier DOT tires are heavily cantilevered, skewing the casing width measurement anyway.

The only 205's that might not be fastest on 8's (other than Hoosiers) are low performance street tires that are much narrower than 205mm tread. For those types of tires, no one cares about max g anyways. We're sort of assuming <240tw, DOT R compound or full slicks with a stated "205" tread. In which case theses 205's will be significantly wider than say, an 400AB Nankang Highway Grand Master Supreme XT, and thus, fastest on 8's.

turbofan 05-13-2015 11:29 PM

In addition, using those examples above, all 3 have an 8.4" section width. It seems to me that the section width is what will determine how it behaves on a particular wheel width more than the tread width.

I would wager that each of the tires listed would perform better on an 8 than on a 7" wheel.

emilio700 05-13-2015 11:41 PM


Originally Posted by turbofan (Post 1231256)
In addition, using those examples above, all 3 have an 8.4" section width. It seems to me that the section width is what will determine how it behaves on a particular wheel width more than the tread width.

I would wager that each of the tires listed would perform better on an 8 than on a 7" wheel.

You would think. Always being curious about this, I tend to measure every tires that passes through our shop. There isn't a direct correlation of casing to tread width. Casings designs vary. In any case, tread width is constant. Actual area that eventually touches the pavement varies little even over wide range of wheel widths. It might be pinched when parked but when driven hard, the tire will roll to about the same spot regardless. Casing width varies depending on measuring wheel, thus it's difficult to communicate the concept. If I tell folks XX wheel for XX casing, they don't know what the measuring wheel is and it would vary for each size tire. So instead I've taken to using the tread width as a starting point because one can state a simple, unambiguous formula. Wheel equal or slightly wider than tread. I have never encountered a combo from 185/60/14's to 335/35/18's that didn't works best at that ratio.

tomiboy 05-14-2015 08:04 AM


Originally Posted by ozbrock (Post 1229819)
For folks wondering about clearance of the 245's on 9's... I was swapping my street wheels back on this morning and noticed that both of the front 245's were rubbing slightly on the inner fender right above the top hat. Those are 15x9 +36 wheels on an NB.

https://www.miataturbo.net/attachmen...ine=1431101632

Turbo Kitten is watching you.
https://www.miataturbo.net/attachmen...ine=1431101632

Are those 6ULs? Do you have brake ducts? If so will the 245s clear the ducting? What about sway bar clearance?

ozbrock 05-30-2015 12:31 AM


Originally Posted by tomiboy (Post 1231294)
Are those 6ULs? Do you have brake ducts? If so will the 245s clear the ducting? What about sway bar clearance?

They are the TRM c3m wheels. No brake ducts (yet), and I haven't seen any signs of rubbing on my stock MSM front sway bar.


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