R1 for Formula Extreme Or Road
Does anyone own or know someone with an R1 that just isn't giving them the rush of adrenaline that journal's, media and dealers all over the world are saying you can expect from a bike which the manufacturer claims over 150 hp (probably measured from the crank) and is backed up with record sales bumping the Fireblade off it's perch which it has virtually owned in the 90’s???
For most of us it is hard to believe that there are people who want more from a bike that already has much more than most of us can handle and stay out of trouble on as a standard bike, and I include myself in this group. But human nature is what it is and I have to admit that as a mechanic I do like the idea of improving a package that is already lethal and unforgiving in the wrong hands.
As with any improvement the sky is the limit provided that you have the available cash flow, as a recent article in Two Wheels on an English performance shop V&M racing show on their R1.
As the rules for Formula Extreme do not allow for that kind of budget, it gives us the opportunity to make improvements ensuring it is competitive at race level but also a good bike for the road that is still sociable, as long as you don't open the throttle too much. The first thing to do is to give it a run on the dyno so we have a base power figure to work from. A really good one has about 135 hp at the rear wheel, this particular bike that we will be working on has 132 hp with 5000 km on the clock
Formula Extreme rules allow you to replace exhaust systems, fit carb kits, replace cams and change cam timing. The cylinder head may be modified but the manufacturer's valves and I think springs must be used. Pistons must remain standard but can be modified, compression can be increased but it must use standard pump fuel. Crankshaft and conrods can be balanced and the standard gearbox can be undercut. On this bike we will only work on the top end leaving the crank, rods and gearbox as they are.
Now that we have dyno tested the bike and recorded the stock output the engine must be removed for easy access to the top end. Off comes the head and a careful inspection is made, looking for any sign of potential problems that could cause engine failure after it has been re-assembled. Plasticine is placed in critical areas around the piston and cylinder head and the head refitted and torqued using the old gasket. Cams are then fitted and timed and the engine turned through one full engine cycle and then it's disassembled again. The plasticine is then carefully removed and measured to check the running clearances of the pistons to valves and pistons to cylinder head. This is the most important part of this job as the wrong measurement will ensure that the bike doesn't make it back to the road, or race track. Once all these figures are taken the head is set up on the flow bench and tested.
Now it's onto the tricky part of grinding and flow testing until a satisfactory result is achieved. At times it's hard to know which is the more tedious, the port grinding and testing or the final clean up which just seems to never end. Though it is worth noting that there is little or sometimes nothing to be gained by cleaning up the ports and at times it is merely cosmetic. Oh the things we do to please! Happy that this is now behind us the seats are cut making sure the smallest possible amount is taken off in the name of compression and the cylinder head machined to achieve the running clearances we are looking for, based on the measurements taken previously.
The head is assembled on the engine, new adjustable and lighter cam sprockets fitted and the cam timing is dialed in. As I pointed out before carb kits are allowed, so in goes the dynojet kit and last but not least the Hindle pipe, which with the New Titanium muffler gives this bike about 10 hp with no loss to the midrange and weighing as little as 3.6 kg’s, a big weight saving of 12 - 15 kg. I challenge anyone to find a lighter stainless steel system anywhere in the world. They are currently working on titanium systems which I am in know doubt will set new standards again.
Back to the dyno and after the final tuning work is complete we have a bike with huge midrange improvements and a healthy top end of around 150 hp. See graph above.
Anyone for bigger valves and pistons?
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