The NSX has a very special engine: the C30A. It's a naturally-aspirated 3.0 litre, 90deg V6 with dual overhead cams (DOHC) and 24 valves. Equipped with titanium connecting rods - the first production car application of this technology, it should be noted - it delivers an official (though likely understated) 270bhp @ 7,300rpm and 210 lbft (285 Nm) @ 6,500rpm. Its redline starts at about 8250rpm and fuel cut-off occurs nearer 9000rpm. Total science fiction for 1990 production cars! It was also the second production Honda to use the new VTEC system, which itself remains a marvel even today. More of that later. The engine is a gem: smooth but with a characterful V6 bark, linear delivery of torque and power, predictable and usable, modest and polite of manners, and reliable with long service intervals and easy maintenance access. It made a mockery of the archaic technology in the Ferrari 348's engine bay.

"The C30A is a technical tour de force featuring the first-ever production application of titanium conrods and the second-ever application of VTEC..."

And contrary to popular belief, the C30A is not a reworked Accord engine! It is a bespoke design for the NSX. It's also an absolute masterpiece of engineering, so deliberately designed with so many clear engineering choices intended to maximise the purity of the driving experience. More of that in another post, this is about the driving experience of the engine.

The elephant in the room: why "only" 270bhp for a "supercar"?

Much has been written criticising Honda for endowing the NSX with "only" 270bhp, especially in the USA where corners of less than 90deg apparently don't exist for car enthusiasts, but much less has been written on why Honda did this. It wasn't a mistake; it wasn't because Honda couldn't make a more powerful AND reliable engine; it wasn't because the C30A was a warmed up Accord lump. Remember that, at the time, Honda was wiping the floor with the competition in F1 with their turbo V6s and later their naturally aspirated V10s and V12s. They could easily have put a monstrous turbo V6 into the NSX, or even a brutish V10. They chose a relatively modest 3-litre V6 against ostensibly stronger competition from their target benchmarks (Ferrari 328 and then 348).

"Honda chose to give the NSX a relatively modest NA V6 because it was building a driver's car - the NSX has never been about just numbers..."

I won't get deep into the reasons - that can be a topic for another blog post - and rather focus on what Honda was trying to achieve, but suffice to say that Honda certainly had both the capability and the resources to put a 1000bhp atomic bomb into the NSX and chose not to. They built the C30A because they were building a driver's car; a car that enthusiastic mortals could drive fast, safely; a car that mortals could enjoy, access, and exploit; a car where the power and the chassis were mated and matched in harmony. The NSX was never about the numbers, it was about the sensation of driving it. That the Japanese manufacturers had an informal "gentleman's agreement" not to exceed 290bhp outputs (I think that's the number!) is also part of the story, but a small footnote in all reality.

And let's not forget something here: the C30A's specific output (bhp/cc) for a 3-litre 6-cylinder NA engine was only topped by BMW - famous for its incredible 6-cylinder engines - in 2010! The C30A is still a technical masterpiece 35 years later!

The "other failure" of the C30A: it's gutless at low revs

Much has been said and written about how the NSX has very little low-down torque, and only starts pulling at about 3000rpm. Having driven the NSX regularly for 6 years, I can confidently say that those critics are wrong: they are either comparing it to a benchmark with considerably more power or, less charitably, are ignorant. The reality is that the C30A is objectively a powerful, torquey V6. It pulls rewardingly strongly from the bottom to the top of the rev range with a remarkably flat torque curve. Indeed, the VTEC setup on the C30A is unique in the Honda catalogue, because it serves only to extend the power and torque curves rather than change their shape. In every other application of VTEC, its effect is to unleash a flood of additional, almost latent power and torque (and thereby throw the occupants of the car into their seat backs).

"The VTEC implementation in the NSX is unique in the Honda catalogue: it serves to extend the torque and power curves, not change them..."

I have never stalled the engine through careless release of the clutch, the torque at idle easily enough to get the car moving unless you just drop the clutch in first gear with no throttle at all. The torque also builds very quickly from 1000rpm, and you get pushed satisfyingly into the seat when you open the taps. But, obviously, this is not a 1000bhp Saturn V and it was never intended to be such a machine, so the benchmarks do matter. Honda made many deliberate choices to make the NSX a driver's car with finesse, not dumb brute force. For example, despite having the best ICE turbocharging technology on earth - they wiped the floor with their rivals in F1 during the 1980s turbo era - they chose NOT to use turbocharging on the F1 because it corrupted the driving experience in their opinion. They could easily have imbued the NSX with 1200bhp had they wanted to, but they chose a small-ish naturally aspirated V6 instead.

Driving the V6

In all my 6 years of ownership, the engine has never skipped a beat: it fires immediately on cranking it over, and settles quickly into a quiet but purposeful rumble. It's a very aristocratic sounding rumble, a bit like old Aston Martins: you can hear it's there, you can hear that it's got shattering performance potential, but it's not obnoxious at all, not intrusive and always civilised. Many people criticise it for being "too civilised" - they should buy a Dodge Challenger Hellcat and leave the NSX to those who appreciate its finesse, if you ask me.

Pulling off from rest, the engine provides a very rewarding shove - not a kick or a punch - and only starts shouting once above 4000rpm. Anything below 4000rpm, the engine is wonderfully smooth, tractable and fluid. It's so easy to manipulate the power and torque at low revs and road speeds, endowing the NSX with childishly easy city-driving manners. It's really a pussycat to drive, you might not even notice the difference between the NSX and a Jazz, it's that easy and civilised. And it's really no mean feat - nor a coincidence - that the NSX can behave with such docility in the city. You also don't "need" anything above 4000rpm for most road-legal driving - the gear ratios are long and the engine so tractable, you can do 60mph in 4th and 2800rpm without ever labouring the engine.

"It's almost freaky, and I enjoy wondering what other drivers think as they wonder, "When is he going to change gear??" No need, the engine still has 2000rpm to go before I even start thinking of changing up"

When you start to push on, the engine acknowledges your intent with a flourish: its exhaust and induction notes become more purposeful and loud, more urgent, and the engine seems to respond with greater urgency: its response to throttle inputs somehow seems faster, even though objectively nothing has changed (I don't think there's any change in engine management anyway). And it's intoxicating to watch the tacho needle keep turning around the dial far beyond where other cars' needles have hit their end stop. The engine just keeps going, noise and revs increasing faster and faster without the engine ever feeling like it's running out of breath. The only indication that you're gone beyond the rev range's troposphere is when the rev limiter intervenes and the engine starts coughing. Nothing sinister or scary, just a modest "ahem" from the engine management system to say, "Sir has reached the limit now, would Sir please change gear?" It's almost freaky, and I enjoy wondering what other drivers think as they wonder, "When is he going to change gear??" No need, the engine still has 2000rpm to go before I even start thinking of changing up! 

The Engine's Sweet and Not-So-Sweet Spots

The engine really comes into its own when you're navigating fast, flowing bends and you can keep the revs above 3000rpm. The long throttle travel - like the steering - combines with the engine's power delivery characteristics to afford the driver supremely precise control to meter out the torque. You can deliver just the right amount of torque at any moment to both balance the car on the rear axle and to power out of corners smoothly without upsetting the balance. I really got to appreciate this characteristic while driving on the famous "Sea to Sky Highway" between Vancouver BC and Whistler BC, an almost endless ribbon of the most glorious twisting, flowing mountain highways - my favourite trip being with Stuart when he and Lisa visited and travelled with us in a rented Mustang GT.

But like the steering, appreciating and exploiting this characteristic of the NSX requires the driver to pay attention to it. You don't need to pay attention to it to stay alive, as you would in a contemporary Ferrari, because the NSX is such a better car than that - but you need to pay attention to revel in the car's finesse.

"The NSX hates slow corners requiring hard acceleration on exit, its transmission confounding the engine to produce an objectively frustrating driving experience..."

Where the car and engine don't shine is in slow corners requiring hard acceleration on exit, think the hairpin at Suzuka as an example or any slow 90deg corner. The engine is up to the job, no question, but the NSX's long gearing and long final drive (shortened in the NA2 and the NSX-R) confound the engine and make for an objectively frustrating experience.

 

You just don't get the punch that the E60 M5 can unleash unless you can somehow get the car into 1st gear without locking the rear axle up (I think Senna used 1st at the hairpin in his famous lap of Suzuka in the NSX-R, in his white socks and loafers). The E60 M5 absolutely mashes you into your seatback and the traction control desperately tries - and invariably fails - to contain the torrent of torque from the V10. The V10's brutal grunting roar turns quickly into an intoxicating F1-esque howl at the same time as the NSX's V6 is still labouring against the gearbox to haul the car out of the corner - the NSX is left for dead by the M5 in such corners.

Closing thoughts...

I think the C30A is a gem of an engine and it suits the car - and the intended driving experience that Honda sought - perfectly. Pay attention to it, and you'll quickly realise just how well designed the engine is and how well incorporated it is into the chassis. It becomes obvious how many hundreds of hours were spent fine-tuning the engine to the chassis and the chassis to the engine for the car's intended purpose. The expertise of the test drivers shines through brightly, and you realise you're standing on the shoulders of giants when you drive the NSX.

"When you massively increase the power output of the C30A you undermine the NSX's raison d'etre - you just cannot improve the NSX by increasing its engine output for the sake of it..."

In this context, I find it unfathomable why so many people - mostly Americans - feel the need to modify the engine and extract ever more ludicrous levels of power through turbo- and supercharging the C30A. It ruins the NSX in my opinion. If you want "that" kind of car, get a Supra Mk IV! When you modify the engine so much, you corrode the finesse of the NSX and undermine its raison d'etre. I am a purist, it's true, but I am also an engineer and I just don't believe that you improve the NSX by (massively) increasing its power output just for the sake of more power. Yes you can do it, and yes it will survive, but that doesn't mean that you should do it.