I’m going to start off this year’s coverage of Wekfest Japan in a slightly unusual way. We’ll get to the crux of this awesome event in subsequent posts, but I need to share this with you right now.
After two decades covering the Japanese tuning scene, you might understand why I don’t get too surprised these days. It’s not that there aren’t exciting things happening in Japan; it’s just that I’ve seen so much automotive craziness here that it’s almost become normal.
But every now and then something takes me aback. This is one of those times.
As I exited the Port Messe exhibition center to see what I could find in the outside section of the show, an assuming Honda NSX caught my eye.
Glancing into the engine bay as I walked past, I instantly thought someone had adapted a modern Honda plastic engine cover to fit the C-series engine for a little visual enhancement. But then I spotted some shiny piping and purple fasteners. I came to a cartoon-like stop, and turned around for a second look.
That’s when I saw the ‘Earth Dreams VTEC Turbo’ badge and realized what this could be. The owner, who was nearby, confirmed it – a K20C1 all-alloy 2.0L VTEC turbo four-cylinder engine from an FK8 Civic Type R.
This is a big deal, because anyone in their right mind wouldn’t dare mess with an NSX, right? While the C30A and C32B were decent engines, it’s often been said that the NSX’s sweet aluminum chassis deserved more performance than the tranversly-mounted, naturally aspirated V6s could ever muster, especially if Honda really wanted to compete with the European sports and supercars of the time.
Nowadays, NSXs are more expensive than ever, and the number of people modifying them has definitely declined. Most owners prefer to keep things simple and enjoy the balance of the Ayrton Senna-refined package.
But not Nakatogawa-san of S&A Auto Create. He’s the guy behind some of my favorite builds in Japan, a true technical wizard with a real eye for detail. So when a customer approached him with a stock, automatic NSX and a wish to create something special, this is what Nakatogawa-san came up with.
The K20C1 and its 6-speed manual transmission proved to be a very easy swap, as unlike most transplants Nakatogawa-san has tackled in the past, he was replacing a large engine with something far smaller.
The NSX is very much still a work in progress with many small details that still need to be completed and refined, but once it’s complete you can be sure I’ll head over to S&A Auto Create for a proper look. Nakatogawa-san told me that when it’s all done, the engine will be outputting around 450hp.
This swap makes so much sense to me. It keeps things in the family, it’s an all-alloy engine in an aluminum chassis, it’s refined, economical, has VTEC and still revs. Then there’s the turbo boost for a 100-150hp bump over the V6, not to mention the almost 200kg (440lb) weight saving from the motor/transmission assembly swap. Just think what that means for the handling and how it will feel from the driver’s seat…
Personally, I can’t fault this in any way, but I’m interested to hear what you guys think of it. If you had an NSX, would you contemplate this swap?
In the meantime, stay tuned for more Wekfest Japan 2022 coverage.
Dino Dalle Carbonare
From what I could gather, C-series w/ auto was ~700 lbs and a K-series w/ manual trans is ~400 lbs, though I'm not sure if those are both same setup (w or w/o accessories, dry vs wet,ect). thats 300 lbs, and even adding turbo and such in and 200 lbs being direct result of swap isn't far fetched. Add fuel cell, lighter exhaust, lightweight battery, ect and 400 lbs for the project is very believable
That made me stop too. That is massive, especially since the C32B is already all alloy.
This thing is next-level cool. Almost perfection.
Kyle from BoostedBoiz ran the worlds easiest 8 second pass in his K24 powered NSX, I'd say this swap is perfect.
Nice. Assuming it's a reversible engine swap, it should make sense to owners who want more power and are prepared to carefully store all the original parts, to preserve the car's providence.
Should be a norm for autos in cars like the NSX, maybe a new Japanese Law? One can argue about circuit and drag benefits from sequentials/dual clutches/etc but the whole era of the only real NSX actually fits this FK build well. Reminds of a certain few movies like Stealth where the car is the hero and has "a new, revolutionary engine" that turns out to be anti-lag turbos mated to a "jet engine" lol, what did Top Gun did to the small time producers in Hollywood back then. Paint this NSX matte black and get a martial arts master to drive it every night!
I'm not seeing the value of this swap, personally, and it's definitely not a direction I'd go in. By chasing after 'performance' and sacrificing the NSX's biggest strengths to do so, you lose what's special about the NSX, and end up with something that's more akin to modern cars, but less good.
The C-series is a big part of what makes the NSX special - the *noise*, the revs, the throttle response. Take this out and you've just got another old car with all the downsides in terms of infotainment, refinement, safety etc.
If you want a four-pot turbo MR, you could start with an SW20 MR2, or an Alpine A110, or a Lotus Exige, all of which are smaller and lighter due to not being designed around a larger engine. Hell, you could get a new Cayman GTS 2.5T.
And if you want 400hp you could buy a Ferrari 360 for the same money, and keep the multicylinder NA howl.
Finally if you just have an auto NSX you love, well a certain Project NSX shows how to make the best of it.
The value of an older car is in its intangible charms - ripping out the biggest such charm in search of cold performance numbers makes little sense.
personally I have to agree with Mr. Westmacott
I think this is very subjective in what you think makes an NSX so special. For many, it's the well balanced chassis or look and though the engine sounded beautiful, their power was a letdown. It's well known that the NA C30 engines were not rockets in stock form and aren't easy or cheap to upgrade or get parts for. For people in that category, a lighter and more nimble chassis via engine swap is a win-win.
Though it would have a different feel with a small turbo K series, they're still very fast revving and responsive engines. That's why people love to swap them in various chassis. Amir Bentatou in the states has even put one in an NSX already.
I agree that this isn't for everyone, but it very much depends on how you view the car. Is the engine the soul that needs a lift, or is it the chassis and it needs a new heart to reach its potential.
Amir's street-class k20 nsx also ran a full second faster than a limited-class 720s at COTA, the chassis makes a car more than the transmission in my opinion.
Amir's a little bitch though lol.
I have been reflecting on this idea in the past two weeks. I believe it comes down to owners wanting to experience the car as they remember it, not as it actually is.
In a world where seemingly every car has at least 300hp a 280hp car weighing over 1350kg will not seem as magical as it did in period. I believe that this drives owners to modify.
Personally, I don't care what you do with their cars so long as it brings joy. I simply ask that everyone share their treasures so that the rest of the community may have joy too.
A 200kg mass save is huge!!! That must have had a significant impact on the CoG. Did Nakatogawa-san elaborate on any potential changes needed to the chassis to take this into account?
Thanks for the cool story Dino!
Yes it's a lot of weight (15% or so) to drop, however the C of G of the NSX is probably around the engine bay anyway, so taking weight out there likely leaves the overall balance the same, just a bit lighter.
I'm surprised this swap isn't more of a thing, as it makes so much sense
As it was an Auto, it was already a crime in my eyes.
Quite an interesting take really it reminds me of Boosted Boiz's NSX with the K24 swap
Personally I wouldn't have swapped out the engine as there's nothing wrong with the C-Series V6 but it's still pretty neat something different
If deciding things by numbers then yes the swap makes sense. A power bump and weight reduction is always nice. However, although pretty mediocre by todays standards the c30 is a lovely engine with a fantastic intake noise. I’m not sure I’ve honestly heard a better one. I’m not sure why people value power adders in combustion cars anymore, if you want a fast car just get an EV. If you want to get the engagement to the driver focus on the subtleties that only a fine tuned sports car can deliver: steering feel, shift feel, brake pedal feel, beautiful noises from the engine. For that I think going to a 4 cylinder feels like a step backwards.
440 lb weight drop?!? Huge change to driving dynamics! I am a fan!
I mean... it's different, but I'd rather just have a stock NSX for what it's worth. This would work for people with a lot of cash on hand, but it's kinda like LS swapping a ferrari. Cool, yes, but is the application right? Well that's for the owner to decide, but I wouldn't have it.
Well, it was only a matter of time till someone swapped the K20C1 in the NSX. Might as well since the guys at Tegiwa and RS Future have shown the way with the K20/K24 Honda powerplants.
Polarizing build. Some will like it (like me) and some obviously won't . It's not like someone took a 50+ million dollar Ferrari GTO and added K power, or made a McLaren F1 GTR electric. The swap can be reversed, the car is more fun for the owner, and the next caretaker will be free to revert her back to her original drivetrain. Thank you for covering this car, Dino. Looking forward to a more in-depth write up when you have time.
"the Ayrton Senna-refined package" - barf
The deification of Senna with relation to the NSX is a trope that can go away anytime.
I did alot of work on a +800whp NSX(with the C32). The stock engine leaves ALOT to be desired imo. The 440 weight reduction seems like alot but I don't think everyone realizes just how heavy the C32 is with it's iron alternator bracket or massive castings. The K20 increases the torque and looses alot of weight so it gets alot of thumbs up from me. Sure the sound is more of a lateral move but is it really worth 3-400lbs?
At the end of the day this looks like a very clean swap and I can only assume the owner is super happy with the outcome so this is great.
HART(Honda of America's in house, volunteer racing team), built a new NSX with this same engine to go amateur racing with and it ruled as well.
Next CRV diesel hybrid transplant producing 880hp mated to Bolinger dogbox. Lifted 2". Nsx safari Hokkaido Ed.
I did expect a K series swap...just not that one haha Pretty mad
Pretty fascinating how many people in the comment section do not understand fundamental vehicle physics.
Weight > everything.
Yes, a win-win all around for a street car, perfect! For a track toy I would prefer a N/A K-series, but this is a swap I can certainly agree with. However, are you sure about the 440lb difference between the auto C-series and the manual K-series?