Whatever you think of the current Nurburgring hoopla/controversy, its undeniable that the Radical SR8LM is an unbelievable car. And while a lot of that is simply its bantamweight nature, another reason is the head-explodingly badass Powertec Engineering RPA Macroblock V8 lump nestled under the bodywork. Heavily based on Suzuki’s GSX-R 1300 Hayabusa engine, it’s a seriously developed and extremely lightweight powerplant that is begging to be shoved into anything it might possibly fit into, and possibly some things it won’t (you will get massive RideLust bonus points if you engineer a Macroblock R/C car, even if it is absurdly nonfunctional). But while the insane Mosler-esque visions we’re having of dual-RPA engined CRXs doing 4-wheel burnouts are almost pornographic in nature, the reality of the engine in its Radical SR8LM application is almost as titillating.
To be clear, this is a Hayabusa-derived motor, but it’s not simply two longblocks sharing a commonly geared crank or some such nonsense. The block itself is custom-milled, relying on the 1300cc engine’s basic dimensions but otherwise bespoke. The heads are directly pulled from Suzuki’s parts bin, however, and adapted to mate up to the dry-sump block. Let’s go through the numbers – it weighs 194 lbs dry and makes up to 450 HP in its Stage 3 2.8L version. That is a naturally aspirated 160 HP per liter, no doubt assisted by the engine’s ability to spin to 10,500 RPM before bouncing off the limiter. At those engine speeds, the damn thing probably sounds like some sort of otherworldly choir of massively oversquare (84mm x 63mm) pistons and rods doing their reciprocal dance of power. And this is all stuffed into what is essentially a LeMans Prototype-class vehicle that is completely street legal, at least in the UK. Are you still with me? Take a cold shower and watch this video of an older 2.6L RPA-based car, the standard Radical SR8, run around Nurburgring (the SR8LM Nurburgring run keeps getting pulled off of Youtube, so this will have to suffice). Then take another cold shower, just for good measure.
[Thanks to Powertec Engineering for the information.]