Supercharger Performance and Engine Performance Parts

I have adrenaline in my veins. I’ve gone through phases of watching touring cars, Nascar, Drag racing sundays, Formula 1 and lately I’ve been really intrigued by the insanity of MotoGP. Now i’m going to be completely honest here about 2 things:

1- I don’t ride motorcycles, but being an engine builder and performance lover the appeal is intoxicating. The sound of a Yamaha R1 or even an R6 fully open is just to die for.
2- I am partial to Rotrex superchargers and you can probably read that in my writings.

Rotrex chargers are both centrifugal and compact and that to me spells a recipe of success for aftermarket tuning when you’re looking to keep peak torque figures low (so as not to explode your factory connecting rods), keep peak power figures high (to give you the edge in top end racing) and to give you a linear power buildup that works well with most factory short geared transmissions.

Through my interest in MotoGP and through my work at Supercharger Performance, many conversations have sparked between me and my friends who do ride about supercharged bikes and about why America does not have its own superbike…. and even more established companies from other countries (besides Japan and Italy) such as Triumph aren’t in MotoGP either…..

What we finally agreed on was that the stroker nature and the large displacement per cylinder of a 1000cc V-twin was a hindrance to high rpm operation due to the mass of the rotating assembly and the peak piston speed in the cylinder for that combination of bore and stroke, and that with a lower redline of 9000 rpms or so, that a V-twin would never be as competitive as a 4 cylinder bike revving to 20,000 rpms.

In face of these challenges, I am EXTATIC to announce to you, that I have discovered today, that an American manufacturer by the name of Roehr has been finally issued their Certificate of EPA (environmental protection agency) acceptance and conformity. This means that the prototype 1250cc Roehr superbike is now the first street legal American SUPERBIKE!

What’s more interesting, is that the Roehr 1250 builds on a 1.25 Liter Harley V-Rod V-twin with a Rotrex compact supercharger to place the bike within competitive reach of its Japanese and Italian competitors.

What Roehr does it that they take the stock V-rod water pump shaft , replace the factory mechanical driven waterpump with an external electric pump, and use the output shaft to drive the Rotrex Charger. The charger drive system is a cog and toothed belt drive system that prevents belt slip and boost drop at higher rpms or during engine breaking and allows the charger to achieve a conservative un-intercooled 8psi of boost on the V-twin engine. The result of this power package is a conservatively claimed 168 hp and a more realistic figure of 180hp at 9100 rpms with peak torque checking in at 99ft-lbs at 7600 rpms.

Due to the torque nature of the V-twin engine package and it’s cruiser roots, the bike has no problems accelerating in any gear from 3000 rpms upwards and that means that the superbike can make up for it’s lower peak rpm of 9100 rpms by using overall taller gearing and taking advantage of it’s torque bottom end to reach superbike track top speeds from a low rpm package.

No matter how you look at this story, it’s just super-cool: The triumph of an American prototype bike, the engineering of thinking outside of the box, the dedication to work with what you already have available, or the sheer coolness and scarcity factor of owning a supercharged motorcycle.

Here’s a custom Rotrex install on a Hayabusa, using a custom made pulley and pressed in bearing running off of the factory crank. Boost peaks at 0.9 Bar and as you can see in the video the linear buildup of boost (the white needle gauge on the right) with RPM giving great top end and smooth power delivery.

Technorati Tags: MotoGP, Roehr, Rotrex, Superbike, V-Rod, V-twin

Related posts:

1. A snapshot of Lysholm Autorotor Superchargers
2. A snapshot of Vortec performance superchargers
3. A snap shot of Eaton’s superchargers
4. Electric Superchargers – Emperical Proof.
5. Supercharging the Yamaha R1

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