Richard Sims has a long history...
Richard Sims has a long history of building serious horsepower machines that have graced the pages of Sport Rider many times.
For those who may be serious long-time readers of SR
, the name Richard Sims surely rings a bell. Sims' handiwork has been featured numerous times over the years in this magazine, from some of the original UFO shootouts back in the '90s, to the middleweight UFO shootout we did back in April '01 ("600s Gone Wild"), to his custom-designed/fabricated supercharged Kawasaki ZRX1200 ("Blown Away", Feb '05). Sims has one of those engineering minds that loves to figure out an elegant solution to a problem-and luckily for us, one of his favorite problems to solve is how to generate more power and get that power to the ground in order to go quicker and faster than ever before.
This particular project began about eight months ago when Sims decided he wanted to build a bike of his own. "Every other bike I've built was owned by someone else," said the garrulous bike builder, "so this time I wanted to build something that I could keep, and ride on the street." After a seven-year stint working for Muzzys Performance in Oregon, Sims moved back down to Sacramento to start his own Sims Motorsports speed shop. "I got tired of seeing all these 'blinged out' 'Busas running around that were all show and no go," relates Sims, "and Hayabusa owners spend a lot more money than the other bike owners at my shop, so I knew a 'Busa was going to be the starting point for my own bike."
Sims has been in the motorcycle industry for many years, so he's forged many business relationships in the performance market. That experience and his engineering knowledge allowed him and his son Ryan to build one of the wildest-and yet nicely crafted-Suzuki Hayabusas we've ever thrown a leg over.
Inside The Beast
An example of just how stout the Suzuki's bottom end was engineered is that a large majority of heavily modified 'Busas still keep the stock crank and rods, and Sims' bike is no different. "That crank is strong enough to handle nearly anything," said Sims. "Only if you're going for crazy horsepower do you need to go with aftermarket rods, and even then it's more for insurance than anything else. The stock rods in the second gen 'Busa are well built; the rod bolts are big and strong, and they can handle the stress of big horsepower." The bearings and crankcases are just as stout, although when the engine is seriously modified for major power, the case halves can actually "shuffle" against one another from the forces of the rotating crankshaft. This is where APE's heavy duty case and cylinder studs come in-their beefier construction keeps the cases and cylinder/cylinder head assembly together and sealed tight.
Ultra-light carbon fiber BST...
Ultra-light carbon fiber BST wheels shod with Avon VP2 Sport tires put the power to the ground. Brock's Performance titanium full exhaust not only has good clearance for cornering, but lowering as well. Vortex sprockets and EK chain transfer power to the rear wheel.
Huge 86mm CP forged pistons (stock bore is 81mm!) reside in a Muzzys Performance billet big block cylinder assembly. Interestingly, in order to fit such oversize bores while maintaining enough material between them, the Muzzys cylinder block (machined from a solid block of aluminum) actually has the bores offset to the outside in relation to the rod journals; the outer bores (cylinders 1 and 4) are offset 1.5mm, and the inner bores (cylinders 2 & 3) are offset 1mm. The pistons' wrist pin boss underneath has been machined for clearance, and even though the loads are uneven due to the piston offset, the APE tool steel wrist pins are so strong-they are used in countless drag bikes pushing 700 horsepower, with no record of a broken wrist pin ever-that Sims is confident there won't be any issues. There's a lot of work involved, though; because the cylinders are now offset in relation to the combustion chambers, the valve pockets in each piston head need to be modified (Sims feels that the cylinder walls aren't close enough to the valves to cause any shrouding or other flow issues). Total displacement of the engine is 1510cc.
Instead of the old-style, time-consuming method of hand-porting the cylinder head, Sims turned to Competition CNC in Oakville, Connecticut, to modify his cylinder head ports using a five-axis CNC machine (a method seeing increasing use in production with the OEMs). Because the porting is done by a machine, every facet of porting along every square millimeter of the port wall can be precisely and consistently controlled (and modified, using three-dimensional CAD programs). A three-layer Cometic gasket maintains a positive seal between the head and cylinders; Sims kept compression ratio down to a conservative 13.5:1, "because I knew we'd be doing top speed runs, and I wanted to ensure there were no detonation issues, especially when you start using nitrous." Custom-spec Megacycle camshafts using APE adjustable cam sprockets push on Kibblewhite stainless steel valves of stock diameter, with APE valve springs and titanium retainers ensuring that everything stays together at high rpm.
The stock Hayabusa fuel injectors are used ("They've got more than enough capacity to handle the engine's needs without nitrous," said Sims), and the airbox and ram-air intake system are all stock as well. Spent gases are handled by an exquisite Brock's Performance CT Series titanium 4-into-2-into-1-into-2 Dual Full System that is not only designed for maximum ground clearance for cornering, but also lowering for dragracing.