August 24, 2010
We knew the second we put the wheels and tires on our super-long-term Miata that it was the right choice. Even if they made the car ride like a Delorean they were worth it for looks alone.
After putting some additional miles on it over the last week or so I don't think they're problematic at all. Sure, the ride is a bit firm, but that's as much the suspension changes as anything. I don't get the sense that they're too big or too heavy for this car and the grip is just nuts. I'm still looking for a good fast turn that will push them to their limits. I think it might take awhile.
Ed Hellwig, Editor, Edmunds.com
August 03, 2010
Finally got around to getting in our Miata project car. It's been in and out of Jay's hands most of its time here, so I figured I would just wait until it had a good chunk of its work done before trying it out.
What surprised me? It's a roomy little sucker. I'm 6'2" and I fit in this Miata just fine. It has a good driving position and the seats are decent given their age. Drives pretty solid too. Good clutch take up and a easy to row gearbox. Yeah, there's not much power, but the engine is willing to rev without threatening to throw a rod.
Jay's suspension mods feel fine to me too. Yeah, it rides pretty firm and all, but there's enough give to make it bearable. Looking forward to getting it on a real road and sampling the stick of the big Hankooks. No doubt they look tough on the new wheels. All in all, a pretty solid ride given what we paid. Can't imagine finding something more enjoyable for the money.
Ed Hellwig, Editor, Edmunds.com @ 178,231 miles
July 26, 2010
Wide rubber has added a lot of precision during hard cornering in Project Miata, our 1994 Mazda Miata, as well as providing some seriously beefed-up looks. I anticipated some additional impact harshness from the shorter, more taut sidewalls, too, and they delivered.
After driving it extensively with the big rolling stock, it has become apparent that chassis stiffness is an area of opportunity.
Being a convertible, the Miata chassis is pretty flimsy -- the real roofs of fixed-head coupes add a whole lot of structural rigidity. And our car's wider tires, being in contact with a larger proportion of the road surface, transmit additional inputs that the suspension cannot damp because the chassis throws in the towel first, quivering and shuddering in response. Then the floppy softtop gets in the act, too, doing some shimmying and shaking of its own.
Making the chassis stiffer would allow the suspension to do its job better, which is goodness on all fronts of the ride and handling equation.
A rollbar is a good start. A rollcage would do wonders for stiffness but is totally impractical for street use. More elaborate underbody bracing wouldn't hurt, but doesn't 'close the box', which is where the real gains are to be had.
Really, the car would be best served by bracing that ties together the two disparate ends of the vehicle. Namely, the front and rear bulkheads. Whenever I drive Project Miata now, I've got door bars on the brain.
Jason Kavanagh, Engineering Editor @ 178,678 miles.
July 13, 2010
Now that the tires have been balanced for real, it's time for us to get the car properly aligned and corner-weighted. But even in its less-than-ideal state, the Miata has amazed me with its grip and nimbleness. I've only briefly driven it on a curvy road yet just from this I can tell it's got mad handling skills. I turned into some corners with what I thought was a fairly aggressive speed and by the end of each one I came out realizing that the Miata had plenty more to go.
In today's world where a 3,300-pound sports car is considered light weight, it's a revelation to be piloting one that weighs just 2,300 pounds and rides on super-wide tires. Plus, it's nice not to feel intimidated in a way you might get when driving a super-sticky (but super expensive) sports car like a new 911 or GT-R. This project car is only going to get better.
Brent Romans, Senior Automotive Editor @ 178,211 miles
July 07, 2010
In last week's post about driving our Mazda Miata on the highway, I mentioned that I thought a tire was out of balance because of a vibration coming through the steering wheel. We had the new tires balanced when we had them mounted, but apparently Miatas are very sensitive to even slightly imbalanced tires. So editor Jay Kavanagh (who's overseeing the Miata project) suggested getting a "road force" balance. A few commenters on that post also suggested the same thing.
So I tracked down a shop (my local Tire Pros) with a road force balancer by using this site. As the description reads for the Hunter GSP9700: "[It] solves wheel vibration and tire pull problems that other balancers and aligners can't fix."
June 28, 2010
When I had our 1994 Mazda MX-5 Miata for the weekend I was already well aware of the fact that 2nd gear needs to be babied. Correction, I forgot at first and then was promptly reminded when I was leaving our garage Friday evening. From then on, I tried oh-so hard to baby it. But still, there were times when the car was not ready to be upshifted and it would emit that nails-on-a-chalkboard grinding noise. Argh!
And for the rest of the weekend, every time I went to upshift to 2nd gear I found myself gritting my teeth in anticipation. So frustrating! Especially considering that usually I love blasting off the line from a stop. But, nooo, had to take my time with this one. That meant I couldn't be faster than the typical sleepy Angeleno driver.
Merging onto the freeway, I usually exploit my fellow drivers' slow reaction times to squirt past them, but couldn't do that here. And ended up being stuck in the wolfpack most of the time. Only cutting and thrusting through small openings and holding 1st gear longer than usual.
Project Miata guy, editor Jay Kavanagh, said that "even though this gearbox can be repaired (bad 2nd gear synchro), we have another one waiting in the wings." Thank gawd, because there's nothing more annoying than driving a car that needs to be driven briskly but...can't.
Caroline Pardilla, Deputy Managing Editor @ 177,717 miles
June 25, 2010
A lot of car people really admire the original Mazda Miata because it's such a simple and well-executed design. But there are also those who'll never get it. I heard one myself last week while I was driving our '94 Miata with the top down: "Look at that. That car is so bleeping blay."
Whatever, dude. I call I can say is you're missing out. He probably assumes it's front-wheel drive, too.
Let's move along. I'll point out Jay's bolt-on mods along the way.
June 17, 2010
I'm happy to say it drives about as good as it looks. Yeah, I happen to like the dents; they make it look like a tough little bastard.
Anyway, apart from the driver's seat bolster, which looks like a popped bratwurst, and that smell, the only complaint I have is the steering wheel, which is too low and prevents me from heel/toe shifting because it presses down on my right leg. Our Miata Meister, Jay, has hinted that a smaller steering wheel has been considered, along with some seat modifications as well.
Shut up and tell you how it drives? Fine.
With the trick new suspension and more aggressive wheel and tire package, I expected a tramlining, bouncy nightmare. But Jay has apparently thought this through because the car's good traits have merely been enhanced. The car gives you great feedback and the damping is more or less spot on. Honestly, the only problem now is not having enough power to overwhelm the cars considerable level of grip.
I was let in on the power plans for this car, and while I don't want to divulge the exact specs or architecture of the new motor, I will tell you it involves pistons.
Kurt Niebuhr, Photo Editor @ 177,078 miles
June 15, 2010
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.
June 08, 2010
After driving so many new cars, it was interesting to get in a 16-year-old car. One can't help but marvel at the way we used to do things back in the day. Remember when cars had cigarette lighters and ashtrays? Anyway, I just snapped some shots of the quaint aspects of our 1994 Mazda MX-5 Miata for your perusal.
The above is a favorite feature of our Project Miata editor, Jay Kavanagh. He said that compared to modern cars that have drive-by-wire, the throttle cable made you feel more connected to the car.
To stroll down memory lane make the jump. I threw in some shots of the 2010 Mazda MX-5 for comparison's sake.
May 27, 2010
Scooting around in our old Miata reminded me just how right Mazda got it from the start. The Miata, especially these earlier models, is so elemental. It's clear that the focus was (and still is) on driving enjoyment. No iPod? No CD player? No problem. I didn't even use the radio as I'd much rather hear the 1.8 wind out than subject my ears to Katy Perry, Adam Lambert or a yammering DJ.
The still peppy engine pulls cleanly across the tach, the talkative steering provides more communication than AT & T, and the flickable gear shifter is so precise and perfectly weighted you'll find yourself blipping and downshifting even when you're just rolling up to a stop sign. But as anyone who's driven a Miata knows, the real fun starts when the road starts to bend. Our car's upgraded suspension and new tires felt fantastic while slicing through my favorite canyon roads.
Sixteen years old, 128 horsepower and 176,000 miles. And still a helluva lot of fun.
John DiPietro, Automotive Editor @ 176,290 miles.
May 19, 2010
Project Miata's new suspension has given it some serious stick. The kicker? It achieves this on stock-sized tires, which are measly 185/60s on stock 14-inch wheels. Let's hear it for light weight cars, folks.
Hit the jump for the track test results.
When we performed baseline testing on Project Miata, it produced 0.89 g on the skidpad, ran through the slalom cones at 64.3 mph and braked from 60 mph in 129 feet. That was on the bone stock suspension and good summer tires.
Once we installed the Fat Cat Motorsports coilovers and Racing Beat front bar (along with 949Racing end links), we had the alignment checked and corrected as needed. It actually hadn't changed much despite the new, lower ride height of 4.75 inches front and 5 inches rear (as measured at the pinch welds).
Then we were off to the test track to confirm what our posteriors were telling us -- that this is a whole new old Miata.
We didn't bother testing acceleration this time. Just handling and braking. Keep in mind that only the suspension was changed and not the tires -- it's rolling on the same 185/60R14 Dunlop Direzzas as before. As per our usual testing protocol, the fuel tank was full and the spare and jack were in place.
Braking 60 - 0 (ft): 117
Slalom (mph): 71.3
Skid Pad Lateral Acceleration (g): 0.95
Impossible to be consistent. Very difficult to threshold brake without locking right rear tire. Strange -- perhaps due to off-camber surface & stiff suspension?
Skidpad - Very neutral balance going counter-clockwise runs but far less neutral turning clockwise - just solid understeer. Still, an incredible number on stock-width rubber.
Slalom - Very stable here - better than the current model MX-5. Lithe, communicative, predictable and fun. Easy to place and easy to drive. Doesn't even mind mid-corner bumps - rare for a Miata.
Jason Kavanagh, Engineering Editor @ 176,112 miles.
May 17, 2010
What's going on here? I removed the seats from Project Miata over the weekend to gain some headroom.
No, here the cabin is drying after I made another attempt at removing the smell that Jacquot mentioned the other day. Out came the seats (easy, five bolts each) and at the suggestion of a commenter, I carefully poured detergent-y water in and went to work with a brush, then shop-vac'ed it up.
It's better. Not 100% gone, but better.
While I was in there, I started daydreaming about having a driver's seat that's not blown to pieces like the stock one. More thoughts after the jump.
Having actual lateral support would be great. Same with a lower seating position. We'll want something that can accept a five- or six-point harness, too, for track work. And sliders are a must, since so many people drive it. Bonus: a single-piece shell seat will be much lighter (not to mention safer) than the floppy stock seat.
May 12, 2010
Ditching Project Miata's stock suspension wasn't a tough decision. The tepid roll stiffness and tired dampers meant that when driven over bumps of any significance, the car was constantly bouncing off the bump stops. And although you could sense the underlying Miata goodess, it was covered in a thick layer of suck.
The colorful bits you see above -- Fat Cat Motorsports coilovers, a Racing Beat tubular stabilizer bar and 949 Racing endlinks -- represent a first step in eradicating the suck.
Hit the jump to see what they're all about.
Now, it isn't unusual for stock cars to employ the bump stops as supplement spring rate to the coil springs, but we're talking 1994. Bump stop technology had some way to go. An NA Miata's bump stops were made of hard rubber. Not quite hockey puck material, but getting there.
Together with the scarce bump travel of a stock Miata's suspension, the effective spring rate goes from very soft to holy crap in a hurry. This nonlinearity in spring rate makes for a car that is bump-sensitive, a situation that has obvious ride and handling implications particularly when the dampers are worn.
Fat Cat Motorsports Coilovers
Fat Cat Motorsports (FCM) coilovers address the Miata's inherent issue of limited travel from a number of angles.
May 11, 2010
One difficulty with modifying suspensions is that, on the surface of things, doing it right looks deceptively similar to the way an ape would approach it. There's some amount of additional spring rate and maybe some thicker stabilizer bars, and some stiff dampers for good measure. Ook ook.
However, things become much clearer when you go back to the basics. Those basics aren't spring rates or the diameter of the bars, either -- those things are actually the outputs of the suspension modification process, not the inputs. What we're actually interested in when we talk about the fundamentals of revamping suspensions is ride frequency and roll couple.
Come join me on the other side of the jump where we'll skim the surface of this suspension nerdery a bit and apply it to Project Miata.
In a way, the stiffness of your car's coil springs are only as high as the suspension geometry allows them to be. You'll notice that Dan Edmunds points out the suspension's motion ratio in his suspension walkarounds. It's important, and here's why.
A strut-type suspension has a high motion ratio since it locates the spring very close to the wheel, so the coil spring "acts" stiffer. The double-wishbone setup locates the spring further inboard, giving it relatively low motion ratio because the wheel acts like a longer prybar, effectively making the spring softer. More mechanical advantage, in other words.
Take two cars that are identical except that one has a double wishbone suspension and the other has a strut-type setup. Same weight, spring rates, everything. If you were to drive each car over a speedbump, the strut car would ride much more firmly than the other (forget about dampers for a moment). This is because of the suspensions' differing motion ratios and the resulting effect on ride frequency.
Back to our bouncing cars -- the frequency at which each car bounces is its ride (or bounce) frequency, and it's one of the first things you should decide when modifying your suspension.
The higher the ride frequency, the firmer the ride. Plain-jane modern street cars will be in the 1.0-1.5 Hz range for comfort. Modern stock high performance cars generally hover closer to the 2.0 Hz range. The rear ride frequency is typically about 15-20% higher than the front to keep the rear end's activity in sync with the front -- after all, the rear encounters each bump after the front does.
May 03, 2010
What's that? Shut the heck up and start spinning some wrenches on Project Miata? Right, then.
Here, our longterm Miata is under the knife at MD Automotive in Westminster, CA, where the owner was kind enough to let us use his lift, tools and sage advice. Lots to talk about in the coming days. In the meantime, you should be able to spot what we're up to here.
Jason Kavanagh, Engineering Editor @ 175,310 miles.
April 26, 2010
You've seen the dyno and track numbers for our 1994 Mazda MX-5 Miata, so you know it's slow and, um, slow. But even in its current tired, wornout state, this car makes me happy whenever I drive it. (And basically, I've been driving the car whenever JayKav isn't busy with it.)
This is the first time I've driven a first-generation MX-5. And though I'd hoped that first drive would come in a newer car, the fundamental goodness of the original Miata is evident in our project car. The engine doesn't do much in the acceleration department, but it sounds good, grunting obediently as you full-throttle it down the road.
Changing gears takes a deliberate, unhurried hand and smooth footwork (yes, especially going into 2nd), just as it did in our Ferrari 308 GTSi, but done right, it's still very satisfying. Even heel-and-toe downshifts are fun, though with the unadjustable steering wheel restricting movement of my leg, I really do have to get the throttle with my heel (rather than a lazy blip with the side of my foot). I guess I'd like it if I could tilt the steering wheel up a bit, but aside from that, at 5-foot-10, I fit perfectly in the car.
Steering response isn't exactly crisp, but there's a directness here that our 2006 MX-5 never had. Worn suspension bits keep the car from changing directions with much immediacy, but there's still a trustworthiness to the way the car behaves. Right now, a lot of it has to do with the nice new Dunlop Direzza Sport Z1 tires, I'm sure. But every time I drive this car, I get the feeling that with some new stuff to hold it up, it would really be great. And I'm now giving serious thought to buying my own Miata project car.
Erin Riches, Senior Editor @ 175,090 miles
April 22, 2010
This one's for you, td53. We put Project Miata -- in stock, pre-molested state -- through its paces at the test track to establish its baseline performance. You've seen its baseline dyno performance already, I trust.
Hit the jump for its test track numbers. It turns out 1994 was a long time ago.
Upon purchase, this car was rolling on bald off-brand Chinese tires, so we threw on a set of summer tires and gave it a decent alignment (F: -1.3-deg camber, 0.10" toe out, 4-deg caster; R: -1.6-deg camber, 0.12" toe in). Also, its pads were worn nearly down to the backing plates so we swapped them out for Stoptech 309 street pads.
Other than those changes, it's stock. We brimmed the tank as per our usual protocol, and let 'er rip. Okay, rip isn't the right word. We let 'er meander in a deliberate fashion.
Vehicle: 1994 Mazda MX-5 Miata
Driver: Josh Jacquot
Drive Type: Rear-wheel drive
Transmission Type: 5-speed manual
Engine Type: DOHC inline-4
Displacement (cc/cu-in): 1839/112
Redline (rpm): 7,000
Horsepower (hp @ rpm): 128 @ 6,500 (when new)
Torque (lb-ft @ rpm): 110 @ 5,500 (ditto)
Brake Type (front): Ventilated disc, single-piston sliding caliper
Brake Type (rear): Solid disc, single-piston sliding caliper
Steering System: Rack-and-pinion
Suspension Type (front): Double wishbone; stabilizer bar; coil springs; adjustable camber, caster and toe
Suspension Type (rear): Double wishbone; stabilizer bar; coil springs; adjustable camber and toe
Tire Size (front/rear): 185/60R14 82H
Tire Brand: Dunlop
Tire Model: Direzza Sport Z1
Tire Type: Summer Performance
Wheel Size: 14x6 inches (front and rear)
Wheel Material (front/rear): aluminum alloy
As Tested Curb Weight (lb): 2,327 pounds (53.1 / 46.9 % F/R)
0 - 30 (sec): 3.4
0 - 45 (sec): 6.5
0 - 60 (sec): 10.9
0 - 75 (sec): 16.6
1/4 Mile (sec @ mph): 17.6 @ 77.2
0 - 60 with 1-ft Rollout (sec): 10.6
30 - 0 (ft): 31
60 - 0 (ft): 129
Braking Rating: Could be better
Slalom (mph): 64.3
Skid Pad Lateral Acceleration (g): 0.89
Handling Rating: Needs work
Db @ Idle: 51.7
Db @ Full Throttle: 83.8
Db @ 70 mph Cruise: 76.0
Clutch doesn't want to be slipped, and second gear refuses to be rushed. Doing so results in a nasty grind. Feels tired. Smells bad, too.
Difficult to judge perfect amount of pedal pressure on initial application. Lock them up once and recovery will cost you 10 feet in stopping distance.
Skidpad - Slow reacting thanks to everything but its tires being worn out, but still respectably well balanced. Fun, even.
Slalom - Goodness! Plenty of "windup" in the Miata's body during rapid transitions make it somewhat difficult to control. Doesn't like any unevenness in mid-corner. Still, there's some fundamental goodness here - even in a worn-out Miata.
Jason Kavanagh, Engineering Editor @ 174,866 miles.
April 19, 2010
As I was wrapping up Project Miata's baseline dyno test session, the dyno owner -- Mark DiBella -- hollered from across the shop.
Mark: "Hey, so how'd it go? Let me guess. 98 horsepower, right?
Dang, he's good. Hit the jump for the dyno chart.
March 09, 2010
Last night I drove our new project car for the first time. How was it? Well, let me just say we have a lot of work to do, starting with the stench that still permeates the interior.
Incredibly, however, even with no working suspension parts, or actual braking ability, our 1994 Mazda Miata is fun to bang around town in. The engine pulls to its redline without any funny noises, the transmission shifts well if you take your time and the steering wheel changes the car's direction even if it is in my crotch (I never did fit well in first gen Miatas. The driver's seat is just too high and the steering wheel too low.)
Other goodness is the air conditioning, which froze me out, the clutch, which seems fresh, and the oil pressure, which is as it should be.
Should be a fun year with this thing. In the meantime, I hear our Corvette Z06 is fixed. Full update on that tomorrow. Cross your fingers.
Scott Oldham, Edmunds.com Editor in Chief