Honda Motorworks

Toyota races a Camry in NASCAR, the Mini staged a comeback via Germany, and Ford delivered a V-8 with overhead cams. The automotive world has thrown us some real curveballs in recent years. But could anything be more shocking to a sport compact car enthusiast than a torquey, turbocharged engine from Honda?

Sure, Honda had great success in the '80s racing Formula 1 cars with 1,000-plus-hp turbocharged engines. Around the same time, it also sold a turbo passenger car in Japan, the Honda City Turbo, and even a turbocharged motorcycle over here. But this is the first time the company's ever made turbo technology available for American-market cars.

Surprising or not, the K23A1 engine found in the all-new Acura RDX is the New Testament of the great Honda story, and it's bound to make more than a few preachers of the high-rpm, low-torque book eat their pointy hats. The very company that has been the cornerstone of the rev-happy philosophy has taken a page out of the turbo Bible.

A Rare Expert
We know from experience that the best way to get the inside scoop on a new product usually involves copious amounts of alcohol and Spanish Inquisition-style interrogations. We set out to do just that over dinner with Nobu Takahashi, Chief Engineer of Honda's Engineering Research Department ER2 - the big cheese in charge of designing the K23A1.

We were shocked to find that Takahashi-san is not some shy, dry, abacus-wielding dork but a feisty fun-loving woman. When was the last time you pictured the chief engineer of a massive Japanese company being (a) female and (b) feisty? What do we mean? Well, within minutes into our meeting she let it slip that the only reason she didn't wear her "I Love Beer" T-shirt to dinner is because Honda PR objected.

Throughout the lively conversation that ensued, we learned the intricate technical details of the RDX turbo engine - including how it's different, and, most importantly, whether it will fit into the engine bay of your Honda or Acura. Here are the basics:

Engine volume is exactly 2,300cc, and it's the torquiest thing Honda has ever plopped into a U.S. production vehicle, generating 260 lb-ft of torque at 4,500 rpm (4 lb-ft more than the previous title holders, the J35A91 of Honda's Ridgeline and the J35A3 of the Acura RL, both of which hammer out 256 lb-ft). It barely sips gas, thanks to the help of a state-of-the-art turbocharger and i-VTEC and VTC technology. And thanks to substantial beefing up in the bottom end, the K23 looks like it's built to take a beating.

Fine, But Will It Fit Into My Honda?Takahashi-san looked at me like I was crazy when I asked the question, as though I hadn't even been listening during the last hour of our conversation when she stressed the massive amount of research and development that went into designing the RDX-specific engine. I'm sure she thought I was joking; but just to add emphasis she shook her finger and said in English: "NO."

But the fact that it's a K-series means it's at least architecturally similar to the engines found in the RSX, the TSX, and of course, the Civic Si, among others. It's a mixed blessing that the K-series has been modified fairly substantially to accommodate the increased burden of turbocharging. The block is quite a bit beefier, but, at the same time, it's a little bigger - big enough that the bellhousing connects to a variant of the larger RL transmission rather than that of an existing K-series.

But before you go fabricating a bellhousing adapter plate to make the swap happen, you should know that the RL transmission is no lightweight for a reason. Should you succeed in mounting up the K23A1 to a Civic or TSX transmission, Takahashi insists that these transmissions are too weak to handle the extra torque of the turbocharged 2.3. But what does she know, right? People are twisting hundreds of pounds of torque through K-series trannies already. We'll settle somewhere in the middle of that debate and say that it's probably time to call the cryo-treater.

"Engine Mounto Very, Very Different"The engine mounts are substantially different than those found in a TSX, RSX, or Civic engine bay. Rather than a conventional dog-bone mount, the K23A1 incorporates an additional reinforced piece to cope with the increased torque of the turbocharged engine. Differing engine mount locations and styles have failed to stop tuners like HASport in the past, and our bet is that they won't be dissuaded this time, either.