New Hoosier 245/40/15 R6/A6
 

Looks like the tire everyone has been waiting for has arrived. While not listed everywhere it is available from Hoosier. PN#46521

I was happy to see the tire is 23" tall. I was disappointed to see the tread is only 9" wide.

205/50ZR15= 8.0" tread (measured rim 6.5")
225/45ZR15= 8.6" tread (measured rim 7.5")
245/40ZR15= 9.0" tread (measured rim 8.5")
275/35ZR15= 10.1" tread (measured rim (9.5")

Why is the 20mm change from 205 to 225 .6 inches of tread but the change from 225 to 245 only .4 inches? The 30mm change from 245 to the 275 results in a whooping 1.1" change. Almost double the rate of change from the 225 to 245 (10mm= .2")

What gives?

FWIW the 245 R80/R100 has a 9.4" tread width.

I got a set last week but nobody was in at Hoosier that could tell me all the specs. I have 9's and 10's was going to try mounting them on the 10's.

Bob

I would use the 10's. The specs say up to 9.5" recommended rim. No brainer for 10's there.

There was another thread in the race section where this tire was mentioned last week. What is/was the price?

You need to bring your car to NASA nationals for TT2 Sept 5-8. Take a look at the Mazda contingencies.

Entry List Report

I was going to try and win the Canadian National championship for solo in SSM next weekend then was going to convert back to track duty and do the last NASA TT at Pacific Raceway September 15-16. Then maybe Portland in October. got to turn down the boost I think and get a dyno sheet once I figure out my car weight with all the track stuff bolted back on.

Do it.


In for seeing a daily driven 23 year old Miata kicking some trailered E46 and C6 butt at nationals.

National championship TT cost ~$1000 to enter and Mazda pays $750 to win. 6 regional championship Solo events in Canada cost $45 to enter and Mazda pays $100/$75/$50 each event! They pay $250 to win NT and National Prosolo and they cost $100 to enter. Hoosier pays 2 tires for winning each National tour Solo and 2 tires for regional TT.

Mazdaspeed pays $5,000 for a Runoffs win...

Heck, they pay up to $800 just for you to tow to the Runoffs.

They also pay $800 for a "Majors" race win, which there are usually two per weekend. $1600 a weekend in a cheap to build/race STL car...

Makes Honda's/HPD's contingency look pitiful in comparison ($300 for Majors win, $2500 for winning the Runoffs).

Sorry for thread drift, back to tires

EDIT - Just saw the Mazdaspeed payouts for PT/ST at Nasa Nationals, looks like $4500 for a win. That's pretty good, looks like Emilio and Andrew will be doing just fine for themselves.

Not so good for TT though.

I guess you just got to be like Emilio and win TT and PT the same year

So do we get pics or what?

I saved the day for a friend racing SCCA. Pan captured all of the oil blowing off the rear main seal.

In for big rubber on 10"

:giggle:

havn't mounted them yet. still got the next two weekends playing on the 275's. Tread width appears to be about 20mm wider than my 225/45/15 H20's which means they are way wider than 225 Nittos.

bit of a teaser.

225/45/15 NT-01 mounted on 15X9
245/40/15 R6 un-mounted
275/35/15 A6 mounted on 15X10

https://www.miataturbo.net/attachmen...820_211301-jpg

What kind is the spare tire at the bottom of the picture?


j/k


Nice width increase on the 245s over the 225s.

Ok got them mounted on 10’s. Compare 225 Nitto on 9” and 245 vs. 275 both on 10”. I like what I see. Nothing better for getting the most out of a tires available contact patch width than mounting it on a suitably wide rim. Improved sidewall kinematics as well.

https://www.miataturbo.net/attachmen...821_194621-jpg

https://www.miataturbo.net/attachmen...821_194541-jpg

Money tire
 

Okay, devil's advocate here:

If the 225/45-15 Hoosier R6/A6 costs $247 per tire ($988)
and the 245/40-15 costs $255 (estimated) ($1,020)
and the 275/35-15 costs $288 ($1,152)

and, if someone has already invested in 10" wide 6UL's;

why wouldn't that someone just get the 275's for $132 more?

1. NASA classing favors tires labeled as 245mm or narrower, as mentioned above.

2. 245's are easier to fit under massaged Miata fenders than 275's

For me Im on the ragged edge of the wt/hp to run TT2. ~16 hp gain to run 245 and under and it puts me at a hp level I can achieve with just turning down the boost rather than making the car run bad or adding lots of ballast.

Which is faster assuming ~ 16 hp lost while running fatter I don’t know for sure? I set some pretty fast times on 225 Nitto’s though in the past and the 245’s look like they might have the similar sweet spot for sidewall stretch that so many people have observed including myself when mounted up on the 10’s more so than the 275’s

Ah, thanks, good answers.

I guess I was thinking of my friend ZX-Tex and his LS1 Miata and his quest for grip with a heavy car.

This.

I always knew the 275 really wanted a 10.5 or maybe even 11 but clearance would become even uglier with that width. On paper, the correct size for the 245 is a 10". So yeah, the 245 on 10's should be a marriage made in heaven, just the right amount of sidewall tension.

Does (2) mean they're likely to fit without cutting/flaring the fenders?

I'm currently looking at upgrading from my 225 A6s (for autox, so (1) is irrelevant to me), and had basically resigned myself to having to uglify the car by cutting the fenders and adding plastic flares to fit 275s. If 245s will fit w/o uglification, that's got real value.

--Ian

Conjecture on my part. Folks have coerced 275's on 9's under ravaged but un cut NA fenders. Maybe Bob will post pics. He has flares though.

Speak of the Devil... I just stumbled into this thread. So yeah the 275 A6 grip levels are magical, and i even managed 3 fast laps at NOLA before they overheated. The additional corner exit grip is also very handy.

But, I am definitely interested in the 245 since, as mentioned above, by the NASA rules I can add power back to the car versus a 275 since the correction factor is different for a 245 vs a 275. In my case it amounts to about 13 HP for TT3. I have been wanting this option, and now that it is available, I may have to try it since only testing will tell for sure. It might be a faster setup at the high speed front-straight tracks like TWS and NOLA (140+ mph).

Thanks for the pictures Bob.

This is the other factor. Even with substantial power adders, the Miata is sensitive to tire scrub and aero drag. No precise science in my estimate but I think most full sized road courses will favor the 245/40 up to about 260whp or so. Past that power level there is enough torque to maintain optimum slip angle and actually make use of all the surface area on a 275.

Educate me how I get these in Holland, and how I fit 10s on an NA body?

For me to get the 275's to work with the et25 offset 15X10 6UL’s I needed 5mm spacers to keep the tires from destroying themselves on the shock tower area of the front wheel well and the inboard vertical wall area of the rear wheel well. I don’t know how people are getting these to work with less offset like on the et36 9” wheels with no spacers it just doesn’t seem possible to me unless your suspension setup has crummy bump travel and very little camber. Thus the fender lips are majorly in the way on the outboard edge.

With the 245’s I can take the spacers out and I suspect you can likely get the outboard lip to work without cutting but it would likely take a flat roll and a reasonably doable amount of pulling.

Suspension setup will have an effect. Bump travel and static camber settings. NB’s also have more room by like 5mm.

Ok those worked better than anticipated. 245/40/15 R6 on 10”

NASA Race Weekend set TT2 lap record by a whole lot at Pacific Raceway given that there is not a lot of Nasa history on the track. 1:27.457 is like GT2 car lap record territory however and Im doing it in a street driven Miata. ~13 seconds under spec Miata lap record. I was 4 seconds faster than what I got on 225 Nittos before and was running lower boost to fit in the class while doing it. Sidewall streatch is more optimized than the 275's I think. they are less squirmy feeling and the brake away is more linear. seems like the 275's want 11" rims.

Dynoed at 324.6 hp and weighd 2505 with driver.

I'm sold. :burncash:

You had me at "4 seconds faster" .:wavey:

My closest competition was a 370 hp S2000 running 245 Hoosier A6. It is questionable whether I had area under the curve advantage on power though. I have a mountain of torque in the usable rev range where he makes peak power at redline and 370 hp on the tip of his power curve means he had to be a lot heavier.

What it looks like on shaky video going ~4.5 seconds faster than any Miata based car has gone before at Pacific Raceway. I started doing turn 2 in fifth about 100mph at the apex and had the tires squealing as I was trail breaking it in from 150mph down the straight.

Fastlaps at Pacific Raceway NASA TT2 lap record in Turbo Miata 9/14/2013 - YouTube

Congrats Bob! Thanks for the good data!

+1 Good job Bob. Thanks for the info.

Last couple weekends Set Miata lap record at The Ridge Motorsports Park 1:48.742 at SCCA time trial where the Spec Miata lap record is 1:57.983 . And won NASA TT2 again with a Miata lap record at Portland International Raceway with a time of 1:21.412 where the spec Miata lap record is 1:30.448.

Had some more competition at Portland from a couple fully built BMW M3 Race cars running Yokahama super soft Slicks. One E46 and an E92 As well as the 370hp super charged S2000 also running 245 DOT Hoosiers A6 though. Only had 8 tenths on the tight group behind me all within a tenth of each other after breaking my 6 speed at the beginning of the final session of the weekend and everybody else setting personal all time bests that session.

Car is working pretty good on 245/40/15 R6 mounted on 10” wheels. Also found Pacific Raceway is a track I master better than most.

Warn us with a NSFW tag, jerk.

The purple crack!

I did pretty good this year. won a set on 275's autocrossing SCCA NT's which I used it to get 245's and with those 245's I won two more sets of tires. got another set of 275's and another set of 245's. Thanks to NASA TT in their first season of running Northwest tracks.

WTF!!! I am so far beneath you in driving skill it is not even funny...

I need some serious set up tips and driving lessons from you. Bob, you are my new hero!

Did these fall off of the earth?

u suck sooooooo much....:dealwithit:

Sh*t i really wanted to molest fenders. I guess this works.

Sorry to answer a quite old post, but it seems that there is a Europe distributor for Hoosier's

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I've just asked a quote for a set of 225/45/15 R6 shipped to France...