Let's get nutty.
Project Miata generated surprising stick on stock wheels and stock-sized tires. There are a couple of problems with that approach, though.
First, there's the future -- the stock wheels' snug dimensions severely limit our options for brake clearance, and those skinny tires will be hopelessly overwhelmed once we finally get some power in this thing. Second, the car had all the visual impact of a Vern Troyer roundhouse to the temple.
The addition of 949Racing 6UL wheels changes all of that.
A few years ago, Miata owner Emilio Cervantes observed a dearth of performance-oriented wheel fitments available for his car. He wanted a strong and light 15-inch wheel but was frustrated by the fact that rarely did they stray wider than 7 inches. Rather than gripe about the situation, he took the initiative and made the damn things himself. Thus the 15- by 9-inch 6UL wheel and 949Racing was born.
These low-pressure cast aluminum wheels are manufactured exclusively for 949Racing by a supplier of forged wheels to OEMs. Emilio acknowledges the benefits of forging in producing a stronger and/or lighter wheel. The cost, however, would have been prohibitive. Besides, these 6ULs weigh just 12.8 pounds apiece according to our scale, so we're not complaining. Stock 14-inch wheels are about 12 pounds.
You might be able to see that the tires -- 225/45 Hankook Ventus RS-3s -- are modestly stretched on the 9-inch wheel. The idea of running a slightly wider wheel than usual is to remove sidewall flex in order to enhance transient response and provide more uniform tread loading.
Visualize what happens when you're cornering hard -- the force at the contact patch puts the sidewall in tension. If you have a narrow wheel, the outward-bulging sidewall needs to be contorted quite a bit before cornering forces can build in earnest. The more sidewall deformation required, the longer the delay in the tires' ability to respond to steering inputs.
All else equal, the slight stretch provided by a wider wheel applies a bit of preload to the sidewall, which quickens its ability to react. Less time is spent taking up the slack in the sidewall, so steering response becomes more linear and direct. This strategy of removing sidewall compliance also makes your camber settings more effective. It's like plus-sizing the wheel without actually increasing the wheel diameter.
Like anything else, it's best to use this approach in moderation. At more extreme wheel-to-tire width relationships than we have, there's a higher risk of de-beading the tire if you simultaneously hit a sharp bump during hard cornering. Don't go copying Keiichi Tsuchiya's setup on your street car.
This is just about the widest tire you can fit under a Miata without getting too crazy with the fenders or with wheel offset. With only a flat-roll of the fender lips using a fender roller borrowed from our friend Steve Mitchell of M-Workz fame, we were done. The big tires fit with just a slight rub to our biggie-sized Racing Beat front stabilizer bar when at max steering lock. We can live with that, but to be fair, Emilio recommends his 6ULs in 8-inch width for Miatas that are exclusively street driven and won't be generating more than about 225 whp or so. This should also give you some idea of where we want to go with Project Miata.
Wheel offset is 36 mm compared to the stock 45 mm, which means the centerline of the wheel has moved outboard. This widens the car's track ever so slightly and increases scrub radius. We'll be sure to share impressions on what, if anything, this changes in terms of steering and handling.
To be sure, Project Miata has a truckload of visual attitude now. By looking at it you might even think it has enough power to get out of its own way. All in time.
Jason Kavanagh, Engineering Editor @ 177,072 miles.
Speed Source
15x9-inch 6UL wheels, MSRP $189/ea
949.716.3111
kevm14 says:
01:10 PM, 06/15/10
I recommend an LSx for your power problems.
Seems to add a little over 200lbs, but since you add that weight to the front AND back, it still comes out to 50/50 or 51/49 depending. So it's hard to say the balance is "destroyed."
td53 says:
01:18 PM, 06/15/10
Me likes!
stress83 says:
01:27 PM, 06/15/10
Another vote for a GM LS engine. You could cheaply find a discarded 4.8 or 5.3 truck engine (or 5.7 if you want the aluminum block -- but more $), and with a few hundered dollars for a cam, you've got nearly 400rwhp. I'm sure some friends at www.planetlsx.com would be more than willing to help.
bankerdanny says:
01:28 PM, 06/15/10
OK Kev, I'll bite, what's an LSx?
jefe2000 says:
01:41 PM, 06/15/10
I know that I don't know much about offsets, fender rolling, and other wheel topics. At some point, I'm thinking about getting upsized wheels for my WRX (18" instead of the stock 17"). Where can I go to learn enough about these wheels topics so I don't get myself into trouble when purchasing new wheels?
lmbvette says:
01:42 PM, 06/15/10
@bankerdanny
LSx is a term that means any GM LX based engine (LS1, LS2, LS3, LS7, LS9, LSA, etc).
lmbvette says:
01:43 PM, 06/15/10
Edit...I meant "any LS" .....we need an edit button!
smilespeed3 says:
01:46 PM, 06/15/10
Nice choice of wheels - I wouldn't swing the 6ULs, so I ended up getting the same tires on a set of 15x9s from Tire Rack. Little heftier but it will have to do.
It sounds like you guys are going all out on miata parts :).
daddiod says:
02:01 PM, 06/15/10
How has this affected the vibrations at 65-70 mph?
Miata's are very sensitive in that area and a bigger/heavier set-up could lead to some nasty vibrations!! I am trying to cure mine with limited success so far....
On another note, can I have the old wheel/tires? Those Dunlops were practically brand new!
fuhteng says:
02:11 PM, 06/15/10
Those are nice looking. Good work guys.
Do the flames on the tires make the car faster? How many hp do they add?
nealibob says:
02:35 PM, 06/15/10
@jefe2000: I would check out the Tire Rack. They show you a list of products that fit on your vehicle, which makes the process relatively foolproof. There are probably other companies/sites that offer this same capability, but I have not seen one yet. I have purchased 3 sets of tires and two sets of wheels from them and I have been happy with everything.
sgude says:
04:09 PM, 06/15/10
I'm thinking it's going to be a 5.0 Ford motor the IL guys and gals are going to stuff in the Miata.
mrhuangsta says:
05:05 PM, 06/15/10
hm.....would 225/45 be a little overkill versus the stock 185?
Also, i wouldn't like a LSx setup on the car. Even if it doesn't kill the balance, i dont think that's where Project Miata is aiming for. I think keeping it lightweight, great handling, and ~200 hp is where its headed for.
clarkma5 says:
05:08 PM, 06/15/10
I hope you guys don't do a V8, everyone does a V8, it's boring. I love the KL V6 (from the 626) swap in these things, only a few people have done it but it goes in reasonably smoothly with an RX-7 Turbo transmission. It makes me wish Mazda had made a Miata V6 at some point...
stephen987 says:
05:23 PM, 06/15/10
How about swapping in a Renesis instead?
subytrojan says:
05:58 PM, 06/15/10
jefe2000: Start here: http://forums.nasioc.com/forums/forumdisplay.php?f=88 You're welcome. :o)
stress83 says:
05:59 PM, 06/15/10
@mrhuangsta:
I agree that a LSx swap is probably not where they are headed, but could one imagine transplanting the long term Z06's LS6 into this little thing?!
949racing says:
07:09 PM, 06/15/10
@smilespeed3
12lbs heavier per set according to our scale.
949racing says:
07:10 PM, 06/15/10
@jefe2000
We actually generated the fitment info that TR uses for the 15x9 wheel. We no longer publish our extensive Miata FAQ but if someone has a question, just give us a call or email. We'll help you find the solution that best fits your needs.
BTW, I've seen the engine that's going into this project car. Sitting next to my race engine in the same shop it was. Some serious oomph on deck :)
speed6er says:
07:14 PM, 06/15/10
Love the tread pattern on the Hankooks. I'm curious to hear what you guys think about them. I have the previous version RS-2s on my speed6. You'll have to let us know if the performance is what you expected versus some of the more expensive (and familiar) high-performance tires. I got such a screaming deal on the RS-2s ($80/tire for 235/40-18) that I couldn't pass it up.
mrjost55 says:
09:28 PM, 06/15/10
This car is finally wallpaper worthy, kudos to 949 :)
hybris says:
09:33 PM, 06/15/10
Why do people think a little rubbing is ok?
Especially in a car that will spend most of its life in the city where turning at full bore is more likely to happen.
slickersdrip says:
09:35 PM, 06/15/10
@stephen987,
I'd love to see them put in a Renesis. I bought an RX-8 three weeks ago to replace my SRT-4 and already I'm dying for more torque. Like to see them put in the 13B and turbocharge it--keep it in the Mazda family but do what I'm planning on doing with it (looking at GReddy turbochargers and aiming for >400rwhp).
If I was to guess, we're looking at an LSx swap.
smilespeed3 says:
06:41 AM, 06/16/10
@949Racing - I meant couldn't swing them, not wouldn't (and the nickle wheels were OOS). Love the 6ULs/Sexuals, and you guys are a great shop.
Any other hints you can swing about powertrain? ;)
@hybris - on an NB (99+ miata) these don't rub at all, on an NA, maybe they are slightly rolling the fenders.
5lmiata says:
06:42 AM, 06/16/10
I've had the 15x8 6UL's on my 95 Monster Miata for a couple of summers now and they are fantastic wheels! They make a huge difference to the look of the car, and with my 300hp 5.0L V8 under the hood I needed the extra wheel width to put the power to the ground. I was running 15x6 Konig Heliums before the 6UL's and could only fit a 205 width tire. Lots for the stock 4cyl, but not enough tire for boosted or V8 powered cars.
I'm looking forward to what your next steps are with this car. I used Martin's V8 swap kit (www.monstermiata.com) and did the swap 5 years ago. Drive the car every day during the summer months and its been a blast! A link to my car here: http://www.cardomain.com/ride/3248177
tjoines says:
07:21 AM, 06/16/10
@jefe2000
Thanks nealibob for the comment. Tire Rack develops our applications based on our won experience and testing. Our mechanical engineer has an advanced measuring device that we use to scan the brakes, suspension and wheel wells of vehicles and then loads it into our CAD/CAM system. The CAD/CAM systems have engineering drawings of our wheels which allows us to determine exact fitment of the wheels we offer. Proper fit is much more complicated than simply width and offset.
We have a tech article that explains some of the areas that should be considered when selecting the correct wheel. http://www.tirerack.com/wheels/tech/techpage.jsp?techid=95
We can help you pick an application that is a direct bolt on or aggressive fitments and can offer information on what modifications are needed to make the application work for almost any vehicle on the market. Our reps can assist you on the phone or you can see all the applications, with size, offset, recommended tire size, and even specific fitment notes if any modifications are needed on our website when you search by vehicle.
chaforjohn says:
07:55 AM, 06/16/10
@949Racing, if the motor is @ 949, then i'm going to try and guess that it's a 99+ 1.8 w/ some sort of EMS and upgraded internals.... Based on a suggestion you made to me when I came in looking for some clutch parts (you were out of stock) about a month ago.
jefe2000 says:
09:32 AM, 06/16/10
Thanks everyone for the great info!
rx777 says:
11:23 AM, 06/16/10
i vote a 20B rotary engine (because it's a mazda)
or
f22c engine out of an s2000 (screaming high redline, fit's miata's personality)
sportyaccordy says:
01:18 PM, 06/16/10
This project car makes me happy. You guys should attack other old cars to build up... and go a little eccentric with the choices (old Honda Accords, etc). You'd be surprised at what a little tweaking can do to an unassuming grocery getter....
I think the LSX would be cool, but is also overkill to a degree. I'm sure there are turbo kits out there that can bring power up to a more reasonable 200-250WHP or so. I am staying tuned.
kevm14 says:
01:29 PM, 06/16/10
The thing is you could use a bone stock LS1 from a 99 Camaro. You can even put mufflers on it. It will sound pretty unassuming but still pack 270-285rwhp. And you'll probably get over 30mpg on the highway with it, even though this is the last car to take on a road trip.
old_volvo says:
07:38 AM, 06/17/10
this is awesome.
949racing says:
08:53 PM, 07/ 2/10
@ tjoines:
You are no doubt quoting a standard corporate line but you are actually in error. I don't blame you though. You are a salesman hidden deep within TR and don't actually eat, sleep and breathe Miatas like I do. Take look at the information printed on the receipt TR ships with their C3M. Perhaps you do not recognize it but I certainly do, I wrote it. If your advanced R&D techniques preclude any fitment issues then why did the wheel hit the brakes on the 02-05 Factory Sport Brakes on the Miata? I was nice enough to bring that issue to TR's attention before anyone was hurt. You're welcome:)
The borrowed fitment info you provide indicates they fit just fine. That is of course because it's was borrowed from a wheel that actually does fit the OEM Sport Brakes.
Did you know that proper fit is much more complicated than simply width and offset?