The next-gen MX-5 Miata thread

[YSSMAN]

I think you're confusing Mazda for Toyota and Honda. Those are two companies that can make a 4-cylinder with soul when they feel like it.

Too bad they gave up the ghost years ago. Between the K20 and the 2ZZ-GE, Honda and Toyota had the game set up perfectly. A damn shame that both have been bastardized, or left for dead. Everyone is going for large displacement NA setups or small displacement turbos. Booooring. I want my zingy, high-RPM nonsense engines that aren't exactly economical...

 

[CodeRedR51]

The NC peaked at 7k, didn't it?

Not sure, but the earlier cars could go that high.

 

[niky]

A few notes:

1. The turbo Cruze is gnash and thrashy because the Cruze engines in general are gnash and thrashy. The Cruze is a great car, but the engine-drivetrain selection just plain sucks. Turbo cars in general are a bit quieter than NA cars... And the Miata's exhaust note is mostly just that...an artifact of the exhaust... Something you can still do with turbo cars... As seen with some modern turbo sportscars.

2. Miata motors have never been very special. The Euro-spec 1.6 would be embarrassing in a Corolla, and the supposedly 140 hp 1.8 was disappointingly not. The NC 2.0 is better, and the post-facelift 2.0 revs to 7.5k.

3. The one possible downside of a 1.4T is throttle response, but seeing as the MX5 already has an e-throttle and that hasn't dulled response, maybe Mazda can do something about turbo response, too. Come to think of it... aside from variable geometry, high compression also improves response with turbos...

 

[eSZee]

Not sure, but the earlier cars could go that high.

I think earlier ones were 6500peak/6700 redline from factory.
NC is 7000 peak and 7200 redline.

 

[mPWRD]

3. The one possible downside of a 1.4T is throttle response, but seeing as the MX5 already has an e-throttle and that hasn't dulled response, maybe Mazda can do something about turbo response, too. Come to think of it... aside from variable geometry, high compression also improves response with turbos...

Variable geometry is still too expensive, heavy and complicated to be used in something like a Miata. They may run a short stroke or direct injection in order to minimize the time it takes to complete one cycle, which would result in reduced turbo lag.

 

[homeforsummer]

I think earlier ones were 6500peak/6700 redline from factory.
NC is 7000 peak and 7200 redline.

I can vouch that the engine seemed happy to rev right into the red. I'm not sure there was much point in doing so, but I don't think I ever hit the limiter.

And as for "specialness" it depends what you're after. The engine in the first-gen was pretty basic and straightforward but brilliant at what it does.

It certainly doesn't produce huge power from stock, like say the B-series in Hondas at the time, but it had great throttle response, was basically bulletproof (was essentially the 323 turbo motor without the turbo, so it was hugely understressed) which means tuning isn't really a worry and it'll take turbochargers or superchargers with little or no modification to the motor.

A good example of the motor's longevity would be the guy in the UK MX5 owners club who has an early model with well over 200,000 miles on the clock and thrashes the car all day long in drift events. It's nothing unusual an engine reaching that sort of mileage, but there aren't many you'd feel confident kicking the hell out of on those sort of numbers.

Subjectively, it also sounds pretty good and suits the character of the car.

I can fully understand wanting an NA engine in the next MX5, and if the SkyActive units produce good power and torque even at small capacity then maybe they'll go that route, but a small turbocharged engine seems most likely for the sort of power and economy they'll want.

 

[niky]

Variable geometry is still too expensive, heavy and complicated to be used in something like a Miata. They may run a short stroke or direct injection in order to minimize the time it takes to complete one cycle, which would result in reduced turbo lag.

Variable geometry turbos are already on cheap diesel compacts and subcompacts in Europe and Asia. For a sports car costing over $25k, they're not going to add that much to the bottom line. Complicated and heavy? A variable geometry turbo gives you the flexibility of a twin-turbo set-up while maintaining the same profile and packaging size as a single turbo unit.

The only downside with one of these is long term durability of the turbo unit itself.

 

[NLxAROSA]

I'd like to add to that I can tell from experience that the behaviour of a VGT in combination with a small engine can be tweaked to almost whatever you want.

My previous car (Opel Corsa OPC 1.6T 192hp/266Nm) had a default map that was peaky, and went up to 6500rpm redline. The default behaviour was that below 1800 rpm there was nothing, at 1800rpm you would get a huge kick in the back, then linear up to about 4000rpm, then another kick. After 6k power dropped. Also, it had a feature called 'overboost' that increases maximum power/torque if you floor the throttle (I thought it was just a limiter to lower the emissions when not flooring it, but that's another discussion ).

After installing a custom mapping, the overboost was gone, power went to 230hp/320Nm, and behaviour was completely linear, almost like a NA engine. The thing just kept pulling faster and faster from around 1500rpm right up until the rev limiter (which was also altered and now at 7k).

I also tried another mapping (fit to match my altered hardware) at 240hp/330Nm which basically had the behaviour of the first map, but more exaggerated, and without the overboost and no rev limit. It was very, very twitchy to drive, because of the peaks in the map at 2k and 4k. Didn't like it as much as the linear map (basically, it was like this when flooring it: nothing, BOOM, nothing, BOOM, nothing).

So that's three different behaviours on the same hardware. There's no doubt in my mind that a small turbo engine can be made to replicate NA feeling almost exactly, as I have already seen it. Though granted, I have never seen any manufacturer deliver it like that as stock (probably because of emission laws etc., which makes them want to have lower power/torque at certain revs because of things like the ECE cycle test).

 

[C-ZETA]

I hope that their 'cleaner' target won't result in them resorting to a diesel engine...although that would make the car so much torquier and faster off the line, so that wouldn't be all bad.

 

[NLxAROSA]

No, but sound wise you'd be missing something I think. And about 2k in revs.

 

[ExigeEvan]

I hope that their 'cleaner' target won't result in them resorting to a diesel engine...although that would make the car so much torquier and faster off the line, so that wouldn't be all bad.

Diesel's produce a greater quantity of non-CO2 emissions that despite expensive and extensive catalyst systems are still next in line for motorist taxes in the UK.

 

[homeforsummer]

Small capacity diesel engines are also ludicrously expensive for manufacturers to produce compared to the return they get and they're beginning to be phased out of smaller cars. I don't think it'd be worth it financially for Mazda to create a turbodiesel MX5

 

[Moot]

Diesel's produce a greater quantity of non-CO2 emissions that despite expensive and extensive catalyst systems are still next in line for motorist taxes in the UK.

It's a big problem, EU is taking legal action against the UK for too much diesel pollution. What has tricked a lot of people including politicians and law makers is the falling of official car makers emissions levels of each new generation diesel car, on paper they look not too bad, but the pollution levels measured in the actual air are not improving. There has been way too much faith in diesel cars.
The UK could escape a very big EU fine by restricting diesel vehicles to be used only every other working day. It would really clean up the air quickly. I'm not sure what other measures could be taken apart from a 100% increase in diesel fuel tax.

 

[ExigeEvan]

It's a big problem, EU is taking legal action against the UK for too much diesel pollution. What has tricked a lot of people including politicians and law makers is the falling of official car makers emissions levels of each new generation diesel car, on paper they look not too bad, but the pollution levels measured in the actual air are not improving. There has been way too much faith in diesel cars.

No one has been tricked at all. Diesel cars only offer significant increases in fuel economy at motorway speeds anyway, where NOx emissions are a far lesser problem. Those who choose to use a diesel mostly in an urban environment have not been tricked, simply ignorant.

Furthermore, the only trick being pulled is the idea CO2 emissions are not directly correlated to fuel consumption. Why are Brits being taxed twice on the same thing?

The UK could escape a very big EU fine by restricting diesel vehicles to be used only every other working day. It would really clean up the air quickly. I'm not sure what other measures could be taken apart from a 100% increase in diesel fuel tax.

And would destroy the haulage and delivery business's over night.

British air pollution isn't all that bad, compared to India/China it's positively sparkling.

 

[fitftw]

there's no way the ND Miata will be 1700lbs, let alone 2,000. My 1996 is under 2100lbs but I had to remove a/c, p/s, passenger seat, spare tire, jack, carpet, etc.

If they make a 1700lb Miata, it will cost more than a Lotus Elise.

 

[Moot]

there's no way the ND Miata will be 1700lbs, let alone 2,000. My 1996 is under 2100lbs but I had to remove a/c, p/s, passenger seat, spare tire, jack, carpet, etc.

If they make a 1700lb Miata, it will cost more than a Lotus Elise.

Why would it cost more? Mazda could charge less by sheer worldwide volume of production. It wouldn't cheap but it wouldn't be "more" than an Elise.

 

[eSZee]

I would hope not. You can buy 2 NCs for the price of an else.

 

[Tornado]

It's a big problem, EU is taking legal action against the UK for too much diesel pollution.

I dunno why, but I find that hilarious.

 

[fitftw]

It doesn't matter what you can buy for the price of an Elise. 1,700lbs is supercar territory. Lotus is a supercar. Supercars cost a premium. The current NC weighs 2,480. How on earth can they even remove 780lbs and still keep a/c and p/s and a passenger seat? They can't. My guess is 2,200lbs and that's being conservative. Most likely 2,300-2,400.

 

[mPWRD]

Complicated and heavy? A variable geometry turbo gives you the flexibility of a twin-turbo set-up while maintaining the same profile and packaging size as a single turbo unit.

Those VGTs are for fuel efficiency. For performance, you need much finer control. Granted, you save weight versus a twin-turbo, but with all the hydraulics, lines, reservoirs (necessary for both hydraulic and electrohydraulic systems), you're still adding significant weight to a "lighter and cleaner" car.

 

[Moot]

Autocar are saying 1.5 petrol turbo engine. 800kgs target but very unlikely to succeed.
to reduce curb weight the car manual will be provided on a USB stick. The speakers will be made of neodymium-magnet instead of ceramic-magnet.
Unknown whether 80kg hard roof will feature.
Bonnet has had to be made pyrotechnic die to pedestrian impact.

The later is a bit of weight saving new owners can do by removing the explosive system for the bonnet, watch those fingers mind.

 

[Dan_]

Yep, and this is the article.

Autocar’s product planning source doubts that the highly ambitious 800kg target will be met. However, progress is described as “not bad”.

Don't know if that comes from a reliable source but seems logical. 800Kg just looks plainly impossible, specially when the article states that steel will be used for most of the structure. However, that pretty much depends on how far they go with all the downsizing.

 

[niky]

Those VGTs are for fuel efficiency. For performance, you need much finer control. Granted, you save weight versus a twin-turbo, but with all the hydraulics, lines, reservoirs (necessary for both hydraulic and electrohydraulic systems), you're still adding significant weight to a "lighter and cleaner" car.

You already need oil lines to the turbo... the extra hydraulics don't weigh that much besides what's already there. Getting a 1.5 to about 150-170 hp isn't much different from current implementations. Current VGTs already have fine control... the real trick will be to tune power around the changeover point to prevent unwanted surges or spikes in power output.

-

800kg, I'll believe it when I see it. I'm betting 950kg is probably a good catch-weight.

 

[Crispy]

This Pyrotechnic idea is dumb. Because if getting hit by the car wasn't bad enough, getting launched in the air by a pop up bonnet released by a firecracker just makes things a whole lot better.

 

[Moot]

Surely Mazda will make a NA 1.5 version too if they get the low weight they are looking for? The lack of turbo and ancillaries would help with that also. Would make a nice entry model. With weight being same or less than original MX5 and power bettering or matching it with about 110bhp. You end up with all the charms of the original but with 2012 crash protection, emissions, economy and the lowest list price.

 

[ExigeEvan]

I don't think a NA is likely. Perhaps a detuned version of the turbo, it's considerably cheaper to implement for the manufacturer than a whole different engine (Small turbo engines are distinctly different to NA).

 

[fitftw]

there's no way it will be as light as an NA. It would have to be made of carbon. I'll believe it when I see it.

 

[Moot]

I think for weight purposes also it will have 15" lightweight alloy wheels, which would be fine for a car this light with upto 160bhp or so.

 

[homeforsummer]

there's no way it will be as light as an NA. It would have to be made of carbon. I'll believe it when I see it.

So the march of over 20 years of materials and engineering technology isn't enough to make you believe it could be lighter than the NA? Really?

 

[Tornado]

So the march of over 20 years of materials and engineering technology isn't enough to make you believe it could be lighter than the NA? Really?

The march of over 20 years of legislated safety and emissions equipment makes me believe that it couldn't be lighter than the NA.