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Issue Number 7 February 2000
Inside this Newsletter
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?
Email us for your own fact sheet, including
all the setup specs and dyno curves - only $30.
Please include your credit card details.
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