An aluminum driveshaft connects to a RX-8 rear differential. FD RX-7 ring and pinion guts were placed inside. Those parts were REM treated. What does REM do? It creates a super micro-polished surface which has two main benefits: reduces friction and increases fatigue life. Two good things for a race car. Some stuff you can see are the: 3” exhaust with a Vibrant muffler, RX-8 rear uprights and RX-8 wheel bearings, RX-8 rear “high-power” axles, SPL links for the rear suspension arms, SPL end links, Racing Beat rear sway bar, hacked rear wheel wells to make space for 275 wide Hoosiers, cut-out rear trunk floor (more space for go fast stuff, less weight), AST 2-ways Jensen valved himself, and probably a few other small things I’m missing. What can you not see? The stock fuel tank was cut in half and welded up because it’s a time attack car and it didn’t need a stock sized tank. A Holley Hydromat is attached to a 400 LPH lift pump which supplies a surge tank with twin Bosch 044 pumps plumbed with -6AN lines. No lack of fuel here. Oh yeah, there’s a red tow strap hanging down there. In the name of quick maintenance, the Aeromotive fuel pressure regulator is plumbed with a dry break fitting so that the fuel tank can be drained easily.
The stock rear differential mount didn’t last long with the turbo power, so this tank of a mount ties into the differential cover to keep everything very solidly mounted.
Here is another nicely fabricated brace helping to keep the rear differential properly located.
The fiberglass and aluminum honeycomb splitter extends pretty far to also act as a flat underbody panel to reduce drag. Hidden behind that panel surprisingly is the stock OEM wet sump oil system. The NC HAMR does lack the extreme aero of the other Unlimited class cars which kills the cornering speed. So the stock wet sump is good enough for the mild aero and Hoosiers. The front knuckles are from the updated 2010+ and the lower control arms are located by SpeedSource bushings. A Tri-Point front sway bar pairs with the AST suspension to control the front end. More raiding of the Mazda parts-bin for that OEM+ upgrade are RX-8 front wheel bearings.
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Fun minor point that is easy to overlook – ABS module visible in some of the underhood shots is another parts bin raid. There’s a type of RX-8 ABS module that works without ECU interface and doesn’t have ice mode – it was also done in Pirelli World Challenge NC MX-5s too.
Really do like this build; I feel like people underestimate the NC
With NA & NB’s price being where they are and where they’re headed, and NC just being an objectively faster car, I think people won’t be sleeping on them for much longer.
Thanks for posting this! I saw this car also and had been hoping someone would do an article!!! great build.
slight correction, Goodwin doesn’t make hardtop, he prolly just bought it from Goodwin, but its most likely a DG Motorsports hardtop
I love it, even if I don’t like the look of the NC, this is such a no-nonsense build, lots of easy to source factory parts, lots of ease of maintenance thought put into it.
I have no clue about the MZR swap though, unless he had one laying around or was intimately familiar with that engine. I know it’s related to the duratec/ecoboost so it’s probably a good platform.
A full cage linked up to the front strut towers and a diffuser are probably the only things I would add. Maybe move the radiator to the back if it helps the corner weighting.
MZR/Duratec (same family) is the same family that came in the NC, so it’s relatively trivial to swap – akin to putting a K24 in place of a K20. If I recall correctly, this build evolved from using the OEM transmission. IMO they’re pretty under-rated – they don’t have the evolution of the K series Hondas but they have a lot more potential than people think.
Ah, if it bolts in without much fab it makes sense. Still, when you are putting down 700hp “how hard is it to find X part when it breaks” becomes important.
I’m still shopping scrapyard BPs for my NA mostly because they drop in and the aftermarket is great not because they are better engines.
Aftermarket isn’t as big, but the 2.3 and 2.5L variants were used in everything – there’s millions in junkyards, the production numbers were huge and relatively recent. And the aftermarket does have the necessary stuff covered – cams, rods, pistons and stuff.
700hp means a built engine, but you can do a 400hp stock 2.5 and thats an easy and cheap replacement that can be had for under $500 with low miles.
Great build! Isn’t that mazdaspeed crank one of those without a keyway? Did they machine keyways for all components?
you can use the crank out of the 2.3 ecoboost which is keyway’d.
No OEM Duratec/MZR offers a keyed crank. Many companies offer relatively inexpensive keying services and can also remove the balance shaft drive gear if equipped.
The 2.3L ecoboost crank is great bang for the buck as it’s forged and allows more revs than a 2.5L crank- 94mm strove vs 100mm. They go for $375 new from Ford.
HGT Precision now have a proper bellhouse for the MZR/Duratec engines for their Sequential Gearboxes doing away with the need for adaptor plates.
These cars are underrated. I built a 2012 NC with Ohlins coilovers and a GT3071R turbo for the street. Very lively! With maybe 300 WHP it ran 60-100 MPH in 5.5 seconds.