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Turbo GSXR1100


By Paul Peczon


From LA Bike, Feb 1993

Just what do you do when you've got this old turbocharged intercooled and fully streetable 89 GSX1100R that's getting long of tooth? I mean, sure, maybe you'd ride around all the time in the desert at ballistic speeds, but the question is; What do you have in the works for next time? Most people don't really need a bike much faster than a stock GSX1100R, but if you're reading this then you clearly know the difference between need and want.

Henry Louie over at South Bay Del Amo was so pleased with this particular bike that he decided to work with Bob Behn at RB Racing to develop a second generation GSX1100R. The original bike got both Henry Louie and his partner J.W. into the 200 mile per hour club at Bonneville. Henry was flat tracking Velocettes, Nortons and Harleys, way, way back in the olden days, and the the crew at Del Amo thought that they needed a phase II deployment. Everyone knows Del Amo Motorcycles supports racing and really care about high performance motorcycling.

Not many motorcycle mechanics would ever try to build a fuel injection system with a pile of aluminum billet and a stack of AC-Delco fuel injection parts. This is varsity level hot rodding. For starters, it involves building a computerized fuel delivery control system. We're talking about messing with microprocessor chips and building your own fuel injector flow testing instruments. Serious, yes, but then Bob Behn was turbocharging Harleys back in the late seventies, and this is all about building ultrabikes.

Bob has always felt that "carburetors, no matter how sophisticated, are riddled with compromises." He doesn't like tradeoffs. This particular tradeoff took three years of development and over 6000 lines of computer code to fix. The computer age has hit motorcycling, and the beauty of it is that the most complicated part fits into a little hermetically sealed, anodized aluminum black box about half the size of a Tom Clancy paperback.

It has a triple sealed boot on one end that attaches to a neat wire harness that monitor and control everything on a motorcycle that makes it go fast. This little harness and all the goodies that attach to 23 of the pins are all of the highest caliber. Top of the line AC-Delco sensors, high pressure Bosch fuel injectors and fuel rails. Aerospace quality, boys and girls.

The electronic control unit is fully digital. There are no wonky little screws to adjust and you can't open the enclosure. But if you're really ambitious, the other end of the box has a standard 9 pin IBM connector so you can recalibrate the system yourself with a PC (or a new Mac) and the optional software. You racers can use this jack to log all of the engine's performance data. Or you can hook it up to a modem and RB Racing can recalibrate it over the phone.

The Phase II GSX1100R hit 208 miles per hour on its first run last October at Bonneville, before it was fully calibrated. It has hit 218 on a one way run, and does the quarter mile in 9.3 seconds @ 163 mph on stock tires without a wheelie bar. It has been calibrated since, but right now it's being taken out in the streets for a few thousand miles to see if anything shakes loose around town.

The original bike already had adjustable boost control, water injection, air-to air intercooling, a glycerin filled boost gauge, and bunch of da kine stuff. Both bikes have largely stock engine internals and suspension. The oiling system was replaced with a system that bolts into the pan cartridge style. Most of the package fits under the bodywork, but enough sticks out that other bikers know that something is up. The new bike has all this hardware, but doesn't have carburetor doodads like a choke or little brass jets to worry about.

One problem the original bike had in the streets was that it was a little hairy when the turbo kicked in when the bike was leaned over in a curve. A two hundred horsepower kick in a corner could easily kick even the best rider sideways and the paint job would get ruined. So the new bike has a big lean angle boost control knob which controls exactly when the boost comes on in a corner, if at all. It also senses wheelie angle, and will cut down boost when the front wheel gets as high as you set it for. 260 rear wheel horsepower will easily spin it upside down otherwise, something I for one hate to worry about.

It also has a new blow-by valve that keeps the turbo from going into shock when the throttle is snapped shut at high speed, like a secondary waste gate. A nice thing to have at El Mirage, where you have 3/10 of a mile of alkaline bed to stop on after the radar trap before you literally hit the fence.

But the thing that makes this bike much sweeter than the original one is the microprocessor controlled fuel injection. It's a closed loop system, like the kind modern passenger cars get. The ECU keeps the fuel to air ratio constant under all conditions, by monitoring every pressure, temperature, and voltage on the bike, with the kicker being a Bosch Lambda oxygen sensor in the exhaust. It has a backup system which will operate even if one of the sensors gets knocked out. This is far and away the most sophisticated and user friendly system available for a bike anywhere. The system adapts instantly to any modifications to the engine, or changes in air pressure or temperature. The system will adapt to any fuel with a few keystrokes, be it pump gas or high octane racing firewater.

The whole point of developing the fuel injection system was to make it practical for street use. It cold starts instantly, and is very manageable in normal traffic. It's tranquility around town and the lean angle sensor eased my mind around town, but once we hit the highway, this bike rocked my world, big and bad. When the turbo started building boost, my shoulders started being pulled out of their sockets, and when the boost started getting somewhere, the front tire left the ground. I shouldn't admit in print that I'm one of those guys who likes to go out to secret desert highways and run literbikes flat out, but lets just say I have exceeded the speed limit in my day. This bad dog reached speeds I have never been able to hit before in seconds, and I was far from reaching full throttle. And when I returned to surface streets, it behaved like a sweet little kitty. My perspective on life, I must confess, has changed.

Bob says "Building this bike wasn't all about making money, it's something I wanted to build." However, the bike is a prototype of something RB Racing will be releasing on the market this year, so if you really want to know about getting one, you should call them up and get the catalog. The basic fuel injection and turbo kit costs about $6500. The catalog also lists and describes custom manifolds, exhaust, various turbo kits, race equipment, nitrous kits, full service engine work, heavy duty brakes, etc. It is well written and very instructional. If you want to visit the bike and pay homage, it's usually at South Bay Del Amo, because lately Henry rides it to work every day, even though he's got about thirty other bikes.


RB Racing is still very much in business and have a kick ass website now. At first glance you'll note they are pushing their hottest selling products, Harley exhausts But dig deeper and you'll find the turbo kits on the products page. check it out at RBRacing-rsr.com Their current sportbike turbo kits are Triumph Daytona, ZX-11, and hey maybe they'll still spin up a turbo GSXR for you. They have indicated interest in the Hayabusa....

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