Big engine, meet little car

The car's coming along, at least visually.
Those are Advanti Storm S1 wheels, a change from the 6ULs we run on every other ND. The tires are a 245, so we'll do a travel test and may have to do some light tweaking to ensure it can never rub.

The classiest LS3 badge we've ever seen.
This is off the back of a Holden and it's a lot nicer than the ones we usually use. It's a perfect match to the look of the MX5 badge on the other side of the tail.

GRM note: the red/silver ones that we used on Indy get a loving close-up shot in every magazine test. They're about $18/pair on eBay and we have to replace them once a year due to fading. Ah, the glamour.

Another batch of updates!

To keep the hard-working power steering fluid cool, we add this large cooler.
Remember, the car came with electric power steering to start with.

he engine bay is coming along.
It's basically ready for the first start. Let's take a little look around first.

Another view of the bottom of the car.
Hey, it'll be hard to see soon, so let's enjoy it while we can.

We used our Paco Motorsports hub stands to torque the suspension and give the car a rough alignment before the wheels go on.

Another touch taken from the Global Cup Cars.
Relocating this rear brake line is required in that series to prevent abrasion from the wheel or tire. This is especially important with our large rubber and violent acceleration.

Now, let's start the car...

Before we start the car, we have to program it.
First, we log into the MRS gateway and set it up. It takes care of merging the communication between the chassis, the Mazda PCM and the GM PCM. Without it, we can't even engage the starter.
Next, we plug into the GM computer and update the tune in the PCM. Then we unplug the injectors and plugs and crank the car to ensure there's oil pressure. After that, it's time to use the laptop to monitor a full range of parameters and fire the engine for the first time.
It's always a bit shocking the first time one of these burst into life. After the oil pressure cranking, the engine fires the moment you touch the start button.
kaBOOOM whomp whomp whomp whomp.

GRM note: then we fixed the bad wire connection and we could actually use the throttle pedal.

Wheels on, up to temperature, no leaks.
Time for the first test drive. This is not a smoky burnout festival, it's a careful drive to make sure everything's working and following a specific throttle regimen to seat the rings properly. Full throttle testing will come after the car's spent some time on the alignment rack.

GRM note: not that I really have to explain that to this crowd, but it seems that many internet commentators feel a proper test drive involves roasting a set of tires. Not on customer cars, sorry - this isn't reality TV!

Long time lurker, infrequent poster here.

Had to crawl out of the woodwork to say how awesome I think habus are!

Looks like you guys have done a bunch of these. There must be differences in character between NA, NB, NC, and ND habus. Is there a particular generation that takes the conversion particularly well? Is there a particular generation that is more of a pain in the butt than the others to convert?

What year is your favorite habu?

We have done a bunch of these - we've been building them for about a decade and I've got a lot of seat time in each variation. There is a definite difference in character.

The NA is the rawest of the bunch. It's a crazed little gokart that never lets you really forget there's a big engine in there with you due to noise, vibration and heat. Very visceral, and my track car is an NA.

The NB is very similar, but due to the stiffer chassis and a little more engine bay room it takes the conversion more easily. This has been the most common platform for our builds over the years. Specifically the MSM, which drives the MSM enthusiasts nuts. It has the potential for the cleanest, prettiest engine bay and is the easiest for a home build if you're happier with moving metal than electrons.

The NC has more of a GT feel. Better NVH control, room for more tires, more suspension travel and it's a more grown-up interior. It's a heavier car but the weight is put to good use. Good cross country car in particular. There are some at FM who think this is the best platform for the conversion.

The ND combines the best of all. It's an even better GT than the NC because of better NVH control and it retains the light, compact feel of the NA. It has suspension travel for days and can carry decent rubber. It's a thoroughly modern car inside and has a sexy exterior. This is the one that feels like a factory job and my personal favorite. The first time I had it on the track, I was tossing it around just like my own V8 track car immediately. The DIY parts haven't been released yet. It's probably the easiest one to get the engine into, but the most challenging electronically.

Thank you very much for the insight Keith!

With regards to the swap potential of the original engine, the Global MX5 Cup cars actually run a standalone ECU from GEMS. Even they had a hell of a time getting the engines to run well, between the direct injection and all of the CAN stuff. To my knowledge they still have warning lights everywhere (iirc Mazda motorsports will actually sell you a plate to put over the dash to cover them up). Apart from the light weight, I'm not sure what advantage you'd have swapping in a Skyactiv 2.0 over something like a K24...

On a related note, props to GM for releasing the E-ROD packages, which is similarly modern and complex in what it's doing but user-friendly enough for the average joe to install.

Great job on the swap and thanks for documenting. I'm a Mechanical engineer but got my masters in mechatronics, so this sort of integrated work fascinates me. Hit me up if you guys are hiring...

And it's loose on the streets.
This is the point where we fine-tune the suspension, get the car aligned, have the "crank learn" procedure done at the GM dealership, break everything in and generally debug the car. Every one of these has their own personality, and this one is a fast and smooth cruiser instead of the slightly nuts FM shop car.

The main reason for that is the cam choice. This has the production car cam while our own car has the "check THIS out" ASA cam. The production cam - known in-house as the 430 due to the power rating - has perfect manners. A smooth idle, no driveability quirks anywhere and is a total sweetheart. It's very easy to live with and if someone told you it was a new factory engineered car, you'd believe them. Combined with the EROD engine management package it's also very easy to get through an emissions test.

The ASA cam is rated at 525 hp, but we know it's really only worth about 50 hp over the 430. It has a very different personality, with a rump rump rump idle and a wicked edge to the throttle response. It's the racy choice, the one that wears its nature on its sleeve and is down to party anytime, anywhere.

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And that's pretty much it for the build diary. I'm not sure if we'll be putting the car on the dyno or not, but it should make just over 400 wheel hp. We'll continue to drive and debug it before handing it over to the customer.

Anything else you want to see while I have it here? Assume that it's a freshly completed custom build that belongs to a customer, so burnouts and fastest lap videos will have to be with another car.

I think it's perfect, signature FM understated exterior, fun car. Thanks for the build, some really really nice parts and work in there. 

Crank learn procedure?

A calibration procedure for the EROD. Interestingly it's not mentioned for the non-EROD crates and it doesn't make a noticeable difference in how the car drives - but the car comes with a coupon for it that you redeem at the dealer, and it's always fun pulling into the service bay. GM techs dig these cars.

How long from the time the customer orders until the car is done?

In reply to Keith Tanner :

Have there ever been any GM or Mazda dealers not want to touch one of your swapped cars?

Stampie said:

How long from the time the customer orders until the car is done?

There are two aspects to that. One is the backlog - we can't start immediately. It varies.

The second is the actual build time. If we can go start to finish without interruptions like the Summer Camp or incorrect axles  or the need to get the tech involved to do some R&D, I think we could do an ND in four weeks. Possibly less. Every one of those interruptions happened on this build, of course.  NAs and NBs take longer, I think our record is six weeks. 

Pete Gossett said:

In reply to Keith Tanner :

Have there ever been any GM or Mazda dealers not want to touch one of your swapped cars?

Ironically, it's easier to get one of these serviced than it is a turbo four cylinder. Once the tech gets over the shock of the carrying case, all the parts are really familiar. I don't know how many Mazda dealers have been asked to work on one, but I can tell you that GM dealers in general don't bat an eye. The Mazda dealer in Denver specifically invited us to bring one out to their grand opening of a new building last weekend.

For example, I once had a steering pump failure in our R&D car that took out the rack as well. Naturally I was in Mojave. The Chevy dealer in Lancaster, CA had all the parts on the shelf and was happy to align the car when I brought it back in after swapping in the new parts. I don't know if they would have done the steering rack change, I didn't ask.

I lied when I said there would be no more updates. I've thought of a couple that are coming. Remind me if I don't put them up by Friday.

With all of the electronics hurdles you guys had to jump over do you think this sort of swap will ever be DIY-able again?

Of course it will. We'll make the crucial components available. People will complain they're too expensive but people always complain that anything electronic that costs more than one resistor is too expensive

Heck, it's DIY-able now if you have the patience and the skills. That's the thing - it's a different skillset than simply cutting and welding and watching YouTube videos on how to strip down a junkyard wiring harness. There are guys working on DIY CAN integrations, but most of them are trying to use componentry that isn't powerful enough like the CANBus Triple. The MRS parts we're using have amazing capabilities but you have to invest in the development software. It's a bit like tuning an ECU in that regard. You can toss in an aftermarket unit that's inexpensive and stripped down and will do a lot of what you want, but isn't a replacement for the capabilities of a full OE unit. Or you can buy a tuning interface and the software and start poking around - but in our analogy, our ECU hasn't been cracked yet so you have to reverse engineer it. Definitely DIY-able, but not if you only know how to tune carburetors.