#TBT: First drive of the then-new 2019 ND2 Mazda Miata

Andy Hollis said:

What matters most to me is whether I can get 7500 in gears 2-4 for consistent lap behavior on the track.  Being able to continue to pull longer in 4th instead of 5th, when the car is really working hard against drag, makes a big difference.  And knowing it will be the same every lap, is also key.

Keith...if you have a 2019 at hand, do us all a favor and run it up through each gear at WOT and see where it hits the limiter, please.

We had the car on the dyno yesterday and I spent a bunch of time playing with it on the street.

I was never able to make it trigger a rev limiter at less than 7500 indicated on the tach in the first four gears. I tried both WOT and light throttle. In fourth, it felt as if the ECU was closing the throttle off as I approached 7500 on the tach - we've seen that on the dyno on other NDs. Basically, it acts as if it has a very soft rev limiter in that case. But more importantly, 100% consistency. It hasn't been on the track - yet - but I may do that tomorrow.

We did find a couple of things that we're talking to Mazda about, I'll go public with them once I have more details.

One other note about the 2019 (and the 2018s) - the car has moved from indirect TPMS to direct. I'm going to yammer on about this - but it is more important to GRM peoples than the average driving public.

Indirect TPMS means the car is not measuring tire pressure directly, but is calculating it. It was a pretty clever system, using speed variation betwen the wheels as measured by the ABS sensors. That's not new, my E39 does it. The downside is that if all of your tires are off by the same amount it can't tell. But the Mazda system also has input from the steering rack. From what I can figure, it's using steering angle to determine corner radius and thus calculating the correct wheel speed difference from one side to the other. If that's off, it'll know that multiple wheels are incorrect. The first time it popped a light after I'd installed tires with a larger OD, I couldn't believe it. You can tell the car that the larger tires are the New Normal and it'll accept that. I love it. It's taking information that's all in the network and using it. Just software, no new sensors, nothing that wears out, no problem with swapping wheels around.

Direct TPMS is like most other cars. A little expensive sensor that's mated to the car and has non-replacable batteries.

If you're swapping tires back and forth, it means you'll have to live with a TPMS warning. Not the end of the world, but it's annoying to see a permanent error light on your brand new car if you've decided to run the bronze wheels instead of the tungsten because they have more tread left...

 But now the conversation has been turned from what the car is like to drive to a bunch of forums and journalists (all over the place) latching on to a sensationalist story without hard data - and dyno runs are not hard data in this case. I feel bad for the Mazda PR guys.

I agree that  it's sort of tragic, but by the same token i don't feel bad for the Mazda PR guys because all they had to do was bury one or two sentences somewhere in the press materials given at launch and this would have been avoided. Someone else referenced the RX8 hp fiasco. They should know better. 

Anywho, thanks for following up with a clearer picture of when it occurs. 

Keith Tanner said:

One other note about the 2019 (and the 2018s) - the car has moved from indirect TPMS to direct. I'm going to yammer on about this - but it is more important to GRM peoples than the average driving public.

Indirect TPMS means the car is not measuring tire pressure directly, but is calculating it. It was a pretty clever system, using speed variation betwen the wheels as measured by the ABS sensors. That's not new, my E39 does it. The downside is that if all of your tires are off by the same amount it can't tell. But the Mazda system also has input from the steering rack. From what I can figure, it's using steering angle to determine corner radius and thus calculating the correct wheel speed difference from one side to the other. If that's off, it'll know that multiple wheels are incorrect. The first time it popped a light after I'd installed tires with a larger OD, I couldn't believe it. You can tell the car that the larger tires are the New Normal and it'll accept that. I love it. It's taking information that's all in the network and using it. Just software, no new sensors, nothing that wears out, no problem with swapping wheels around.

Direct TPMS is like most other cars. A little expensive sensor that's mated to the car and has non-replacable batteries.

If you're swapping tires back and forth, it means you'll have to live with a TPMS warning. Not the end of the world, but it's annoying to see a permanent error light on your brand new car if you've decided to run the bronze wheels instead of the tungsten because they have more tread left...

So I guess it's not like my 135 where I can go into the car menu and simply reset it to read new sensors?

I know on the BRZ there is an OBD-II box guys are wiring in that permanently do things like block the TPMS warning light, or always have the car in "Pedal Dance" mode.

AnthonyGS said:

Vigo said:

 But now the conversation has been turned from what the car is like to drive to a bunch of forums and journalists (all over the place) latching on to a sensationalist story without hard data - and dyno runs are not hard data in this case. I feel bad for the Mazda PR guys.

I agree that  it's sort of tragic, but by the same token i don't feel bad for the Mazda PR guys because all they had to do was bury one or two sentences somewhere in the press materials given at launch and this would have been avoided. Someone else referenced the RX8 hp fiasco. They should know better. 

 

Anywho, thanks for following up with a clearer picture of when it occurs. 

You are making the assumption that engineers and advertising execs communicate well.  In my experience as an automotive engineer and as an engineering consultant, engineers do not communicate very well.  They told the ad guys 7,500 rpm which is technically correct, but it’s apparently not a complete answer.  For a low hourly fee, I can help Mazda fix this issue before it becomes rpmaggeddon or rpmgate.

Except that you know that there are many reasons limits are set.  So just raising the global engine limit to 7500rpm may not be the best idea in the world.  Or could be a really bad idea, too.

There are a TON of limits in powertrains, for various reasons.  This group should be aware of why they are there before demanding that they be turned off or bypassed.  There are cost consequences for anyone of those limits being raised.  

z31maniac said:

Keith Tanner said:

One other note about the 2019 (and the 2018s) - the car has moved from indirect TPMS to direct. I'm going to yammer on about this - but it is more important to GRM peoples than the average driving public.

Indirect TPMS means the car is not measuring tire pressure directly, but is calculating it. It was a pretty clever system, using speed variation betwen the wheels as measured by the ABS sensors. That's not new, my E39 does it. The downside is that if all of your tires are off by the same amount it can't tell. But the Mazda system also has input from the steering rack. From what I can figure, it's using steering angle to determine corner radius and thus calculating the correct wheel speed difference from one side to the other. If that's off, it'll know that multiple wheels are incorrect. The first time it popped a light after I'd installed tires with a larger OD, I couldn't believe it. You can tell the car that the larger tires are the New Normal and it'll accept that. I love it. It's taking information that's all in the network and using it. Just software, no new sensors, nothing that wears out, no problem with swapping wheels around.

Direct TPMS is like most other cars. A little expensive sensor that's mated to the car and has non-replacable batteries.

If you're swapping tires back and forth, it means you'll have to live with a TPMS warning. Not the end of the world, but it's annoying to see a permanent error light on your brand new car if you've decided to run the bronze wheels instead of the tungsten because they have more tread left...

 

So I guess it's not like my 135 where I can go into the car menu and simply reset it to read new sensors?

I know on the BRZ there is an OBD-II box guys are wiring in that permanently do things like block the TPMS warning light, or always have the car in "Pedal Dance" mode.

Okay, I checked the procedure. It's like my Dodge, it'll automatically register the new wheel units within 10 minutes of driving over 16 mph. So it's not difficult to do, but it does increase the cost of each set of wheels and tires by $200. It doesn't give you actual pressures or which corner is low, so it brings no actual benefits to the driver over the indirect version. It just costs more. Interestingly, it was not added to all trim levels in 2018, only some.

In reply to Keith Tanner :

Since it couldn't have been bean counters, perhaps it was lawyers...Afraid of liability from the 'dreaded' four-tire-synchronized-leak. LOL

It was obviously lawyers or legislators. The car can already catch a four tire leak - or, more realistically, a change in temperature - with the indirect system so that's not the reason.

More driving impressions.

The level of polish in the controls and calibration is fantasic. Tip-in is very well done and the car seems to be stronger at part throttle than earlier ones - that doesn't show in a dyno. Oddly, I find the car very easy to launch from a start - not a drag launch, just a street launch. I never had a problem before, but the 2019 is really, really good.

The screen that everyone loves to hate until they drive the car has improved sharpness and contrast.

I've driven the ND1 and yes, I still hate that ugly screen jutting out from the dash.  Good to hear it's clearer now...I suppose. 

 Now if they can just do something about that stupid volume control right where my forearm wants to be.....they'd have about a perfect car.  Well, the trunk is too small on the ND too (smaller than even an NA) .....but driving wise, it's pretty spectacular.  

AnthonyGS said:

Vigo said:

 But now the conversation has been turned from what the car is like to drive to a bunch of forums and journalists (all over the place) latching on to a sensationalist story without hard data - and dyno runs are not hard data in this case. I feel bad for the Mazda PR guys.

I agree that  it's sort of tragic, but by the same token i don't feel bad for the Mazda PR guys because all they had to do was bury one or two sentences somewhere in the press materials given at launch and this would have been avoided. Someone else referenced the RX8 hp fiasco. They should know better. 

 

Anywho, thanks for following up with a clearer picture of when it occurs. 

You are making the assumption that engineers and advertising execs communicate well.  In my experience as an automotive engineer and as an engineering consultant, engineers do not communicate very well.  They told the ad guys 7,500 rpm which is technically correct, but it’s apparently not a complete answer.  For a low hourly fee, I can help Mazda fix this issue before it becomes rpmaggeddon or rpmgate.

This makes me think back to the scandal about the HP on the RX-8 and the fact that it would only make the advertised HP when on a rolling road dyno.

Keith Tanner said:

It was obviously lawyers or legislators. The car can already catch a four tire leak - or, more realistically, a change in temperature - with the indirect system so that's not the reason.

Ok, apparently I didn't fully grasp that part of your description...In that case:

Except that you know that there are many reasons limits are set.  So just raising the global engine limit to 7500rpm may not be the best idea in the world.  Or could be a really bad idea, too.

If it only makes the claimed power bump under special sauce circumstances, people will rightly complain. If it makes the stated power gain at basically all times i think it will eventually become a non-issue regardless of under what conditions it hits 7500rpm. 

Vigo said:

Except that you know that there are many reasons limits are set.  So just raising the global engine limit to 7500rpm may not be the best idea in the world.  Or could be a really bad idea, too.

If it only makes the claimed power bump under special sauce circumstances, people will rightly complain. If it makes the stated power gain at basically all times i think it will eventually become a non-issue regardless of under what conditions it hits 7500rpm. 

The power peak is below 7200, so having a gear specific engine speed limit between 7200 and 7500 should not change that..  At least according to the data I've seen (including Kieth's data).

Alfa, I'd love to ride along with you in both the ND1 and the ND2 and hear your comments on the calibration. It's really good. They also played some games with injector staging (3 stage instead of 2) and the combustion chamber swirl that you'd have interesting insights on.

In reply to Keith Tanner :

That would be fun AND interesting.  

Is the engine PF and DI, or just DI?  As the CFD models get better, the more interesting injection strategies you will see- 3, 4, and 5 injections for the most stable and clean start.  All the better for both emissions fuel economy- since you can run the engine at peak efficiency much faster.  And the industry learns more and more what kind of turbulence works better.  IMHO, there will be more engines changes like this one- where power improves (which is more air flow at the top end, which isn't that easy) and still the right turbulence to get the best burn rate for efficiency and cleanliness.  It's one of the reasons I don't see the death of the ICE in the near future as many others do.

Much of this can also be seen in the current Toyota 2.5l that really woke up the industry.  

DI only.

The previous engine wasn't exactly a dinosaur, but they did manage to improve it all the way around with both old-school stuff (cams, porting) and some reprogramming. Some guy named "Tom Suddard" (like that's a real name) uploaded a Mazda PDF full of pretty pictures that's a good read. The combustion chamber flow CFD looks like what I remember you saying about the Toyota engine.

https://www.dropbox.com/s/7c6tczlh6mvwjc2/19MY%20MX-5%20SLP%20PRESO%20-%20FINAL.pdf?dl=0

In reply to Keith Tanner :

That is an interesting document.  Their triple injection isn't what I was thinking about- most everyone does it to get the catalyst lit off really quickly.  What their press release is doing addresses an area that DI engines have had a different problem with- pre-ignition- so bad that you can quickly grenade a motor.  And everything thing I've seen about it suggests that it's very much related to particulates.  Doing triple injection at high load, low speed should reduce that.

And some of the smoothness you feel is that even combustion.  Instead of wavering on the edge of knock, perhaps pulling spark out here and there, and having some questionable combustion, the triple injection should allow better spark, and much smoother torque delivery.  Pretty cool.

So, how do I rip that low tech engine out and drop in an F20C for some more power and a real 8000 rpm redline? Can I buy the chassis without an engine? 

No, but you can try driving one and see if it makes sense to install 20 year old low tech in a modern car and make it slower. The ND is faster and  ( if memory serves) makes more power at the wheels than the old Honda. If you think the F20C is high tech you’re waaaaay behind the times.

After this thread died out, we did more testing on redlines and tach displays and got hard info from Mazda on when it uses which limiter and honestly, I’ve forgotten the details because it doesn’t matter. What is interesting is that the spread between the ND1 and the ND2 Global Cup Cars at COTA this weekend was a bit more than 2 seconds!

In reply to Keith Tanner :

Looks like 200 whp, listed as 240 crank, out of a 2.0 liter 19 years ago. What's with Mazda's 160 to 170 whp in 2019?

S2000 Dyno

I've got dyno charts somewhere that we did in our own shop. The difference wasn't all that big between the two. But what's up with it? The S2000 engine is so dirty it couldn't be legally sold in 2019 to start. And it was in a car that was a lot more expensive than a Miata.

Also, don't just look at the peak number. Look at the area under the curve. The Miata's ahead of the S2000 below the VTEC change at 6000 rpm. Above that, the Honda is slightly ahead until the Miata runs out of redline. That peak power number is all due to rpm and nothing else. You're also quoting a dyno run from the F22, which has more torque (!) than the F20. Here's an F20 dyno that we did back in 2000 or so. Don't mind the turbo Miata on the same chart.

So in any situation where the S2000 engine can't be on cam, the Miata engine will be faster. When it does get on cam, you'll have a slight advantage and it will make cool noises.  Is that worth all the effort of trying to integrate the electronics of the Honda engine with the Mazda platform? I don't think so. If you're going to all that work, do something that's really going to make a big difference.

If Mazda had sacrificed the bottom end of the ND1 engine in order to get the high rpm improvements of the ND2, it would be more like the proposed S2000 swap. The cool thing about it is that they managed not to sacrifice it, basically keeping the engines the same below 6000 and seeing nice gains up above.

FYI, one thing we found is that the ND2 engine responds really well to breathing mods. A simple midpipe and muffler swap got us a nice big change across the board. It was a bit surprising how much. That's without any reflashing or emissions-related modifications.

It's not like the S2000's horsepower spec is a lie, but if the Miata was more like the S2000 it would be discontinued too. Street cars have to sell on their strengths as street cars, and as a street car an S2000 feels slower than it actually is.  I'd rather have a car that overdelivers on 180hp worth of expectations than underdelivers on 240hp worth, although if you're looking for that from a Mazda you could always try an RX8. 

Keith Tanner said:

What is interesting is that the spread between the ND1 and the ND2 Global Cup Cars at COTA this weekend was a bit more than 2 seconds!

These are the same except for the motors, right? Do I remember that they were going to offer a motor upgrade for the ND1 cars?

Honestly, the reports from COTA were the first time I’d heard they were running two classes - but the Conversion document does indicate that the only difference of any note is the engine. The motor upgrade is “take out motor and wiring, install 2019 parts”.