Custom Engineering

For the Serious Driver

The Golden Touch

Desperate diseases require desperate remedies. Gerry Speechley has had speed fever for longer than he can remember. His current rocket ship is a turbocharged, nitrous oxide injected 1170 cc CBX geared for a theoretical 190 mph. Naturally, it's pretty useless through the twisty bits, but on the drag strip and the open road... solid gone. No wonder he and his loony mates only come out at night. It's the nature of the beast.

Only someone with a white stick could have missed the Speechley bike gracing the SuperBike stand at last year’s Earls Court extravaganza. But even a blind person, denied the visual feast of this awesome motorcycle, would have registered the sheer menacing presence of this very mean and moody machine.

The bike, a turbocharged CBX fulfils several roles. First off, it serves as a get-to-work bike. Second, with a bolt-on wheelie bar and a Jaguar XJ6 slick taking the place of the Metzeler ME99 rear boot, it’s Gerry’s active service weapon as a participating member of the Feltham Area Racing Team (FART), a drag racing outfit which exclusively runs CBXs. And finally, it acts as a rolling advertisement for the Speechley business, Midas Performance.

It is a tall order doing justice to such a masterpiece in so few words. It’s made even more difficult when just detailing the components ran to nearly two sheets of A4 and read like a shopping list made up entirely from a Who’s Who of the performance world. Anyway, here goes.

The six pot mill runs with 68mm bore Russ Collins pistons. This takes the displacement out to 1170cc on the standard liners, giving a compression ratio of 7:8:1. Power, and there’s lots of it, is fed to the lightened, polished and balanced crank via RC ‘golden rods’. Up at the head, buckets and camshafts are standard whilst the valves and springs have been replaced by RC stainless steel one piece items. Original cam chains have been junked in favour of heavy duty Ontario Moto Tech ones.

Blower is a Rayjay unit. This is mated to an RC Turbo-carb equipped with a race pump which feeds the combustion chamber via an inlet manifold which Gerry had to build himself as RC don’t make one for the CBX. While he was at it, he also fabricated the black chrome exhaust.

Running at 10lbs boost, Gerry, who’s a pretty big bloke, was covering standing quarters in 11.5 sec with a terminal speed of 134mph at the end of last season. Boost is now set to 18psi before the waste gate opens but this has resulted in detonation problems, so Gerry is sorting out a water injector system to cure it.

Once the turbo is running to his satisfaction the plumbing is already installed for nitrous oxide injection. This will be controlled by a solenoid switch to come on when the turbo’s not operating, thereby sort of getting over turbo lag.

Gerry claims the pressure build up in the cylinder head was so great that it was blowing out the spark (ho hum). So the standard coils were replaced with 40,000 volt heavy duty ones. For the same reason, the head gasket is solid copper. Meanwhile, all that extra heat is dissipated by a Serck oil cooler.

The frame is a standard one that has been raked, lowered and shortened but had 5 inches of wheel adjustment in the swing–arm to cope with the conversion to a drag bike. Originally monoshock (like Gerry’s 900 FZ in Superbike March 1981), the bike was switched to twin cheapo springers because they looked better. And by Gerry’s admission, he doesn’t go round corners fast anyway. So they only need to keep the rear wheel from hitting the seat. Extraneous accessories were pared off, leaving the bike nearly 75 pounds lighter and now tips the scales at 450 pounds wet.

Attention to detail has been painstaking, and something you will only appreciate after close scrutiny of the photos. The best of everything has been used with no expense spared: Dymags, Goodridge hoses, JP Dynamics swinging arm… the list is endless and the tab on parts alone came to six grand.

Talking of performance on this machine becomes somewhat esoteric when the needle veers off the calibrated scale. The bike is geared for a top speed of 190 mph. Gerry reckons to have seen 160 mph with his brother on the back running 10 lb. boost. With the nitrous bottle yet to be connected and another 15 pound of boost pressure to pile on when he's got it really sorted, 190 mph cruising should seem like chicken feed.

Turbocharged
Honda CBX

PERFORMANCE

• Maximum Speed: 190mph.
• Standing quarter: 9.59sec @ 156mph

FUEL CONSUMPTION:

• Town - 20-25 mph
  Racing - 1.5 mph

POWERTRAIN

• Air cooled, transverse in-line DOHC, 24V Six.
• Displacement 1170 cc. Bore X Stroke 68 x 54.5 mm.
• Compression Ratio 7.8:1.
• Russ Collins, pistons with RC con-rods.
• RC one-piece stainless steel valves and springs.
• Standard cams and buckets.
• Ontario Moto Tech heavy-duty cam chains.
• Serck oil cooler.
• 40,000 V heavy duty coils, and CDI ignition.
• Forced induction.
• RayJay .25 lag turbo charger.
• RC Turbo-carb with race pump.
• Inlet manifold with water injection and Nitrous oxide injection.
• Midas Performance exhaust system.
• Five-speed undercut transmission,
  RC clutch.
• Chain final drive.

CHASSIS

• Standard CBX frame with the addition of 10° rake to head stock and 5 1/2 inch off seat rails.
• Lowered by 6 inches.
• Helium-assisted balanced front telescopic forks.
• Eagle shocks on rear with JP Dynamics alloy swinging arm.
• Standard brakes with drilled and chromed disc front and rear.
• Goodridge hoses throughout.
• Dymags wheels.
• Front Michelin A48, rear Metzeler ME99.
• Wet weight 450 pounds.
• Owner:Gerry Speechley, Feltham.

Article and photos
by SuperBike Magazine