Rizla Suzuki - Tech talk: Part two.

Simon Green, Rizla Suzuki's Team Coordinator, recently held a technical lecture for the students of Kingston University's Motorcycle Engineering Design course, covering all behind-the-scene aspects of top level Superbike racing.

In the second instalment of a series from the lecture, Simon details the work that goes into making a 207bhp British Superbike engine...

Most of the work that goes into turning a road bike into a race bike is to make it go faster, pure and simple. The engine in the 2004 Rizla Suzuki produces around 207-208 BHP at the rear wheel. For a normally aspirated, 1000cc four cylinder engine I think that is something quite special.

There are no super-chargers or turbo-chargers, no nitrous, nothing. The engine has to run on 98 Ron gasoline (equivalent to Super-Unleaded), which is a control fuel from the organisers, we are not allowed to put anything special in the tank, in fact you could put normal unleaded in it and it wouldn't produce much less power. It is all about efficient engine design and very damn good engine management, which mostly comes from experience.

I'm sure you are aware as students the way to make an engine make horse power is to make it more efficient. The person doing our engine development now, probably has nearly 25 years of developing four-stroke engines. Now, you can work out a lot of the things using computers to get the basics right, but in my opinion, there isn't really any substitute for experience in the sense that someone can look down the port of an engine and say whether something will work or not, and that can save a lot of time.

Computer models are very useful to design the original motorcycle but in terms of what we have to do in the time-span we have to do it in and the amount of financial resources available to us within our budget, because we are not talking F1 money here, we have to have a quick and simple solution available to us.

This is one of our strengths at Crescent, the people working for us probably combined have near enough 100 years experience of working in the motorcycle industry, whether it be electronics, hardware, exhaust design etc. Every person that works in the team probably has on average eight or nine years racing experience. If you pool all that together you have an enormous amount of knowledge you can draw on when you have a problem.

Although with the human side of things you are restricted to a selected number of proven routes you can try. If it still doesn't work then for sure you have to speak to someone like Ricardo or Cosworth. If you are familiar with the TT600 Triumph, then you may know that the engine was fundamentally wrong, in terms of racing it was very difficult to make the engine produce enough power because the basic design was not capable of doing so.

The basic design of our new bike, the K5 2005 Suzuki is obviously fundamentally right. Straight out of the crate, a bog-standard big makes 165BHP at the rear wheel, for a 1000cc road bike in standard trimmings that is phenomenal. That gives us a nice head-start, it produces 15BHP more than a standard K4 and as such we hope to expect around 220BHP for next year, which would be a good MotoGP bike.

In terms of what we actually do to the engine, we keep the crank cases, because we have to due to the rules, but even they are fettled. They are sent off to be blue-printed, i.e. we give an engineering company the cases, and the measurements the cases are meant to fit to in the original designs. The company then checks them, and if they are not right, they make them right.

They measure everything, for instance whether the cylinders are parallel and true, that is vertical. If they are not straight and vertical then there will be increased friction and that robs the engine of power. So they make sure the bores are straight, they make sure the tops of the cylinders are flat, they check to see if the journals for the crankshaft are bored straight, and if they are not, they re-do all of this to very, very close tolerances.

The crank-shafts come straight from Suzuki in Japan, then when we get them we send them off again to get them balanced. Although they are very high quality when we get them, if you think of the speeds the engine rotates at, a slight out-of-balance in the shaft will lead to failure before long. We are not allowed to polish or lighten them, they are just balanced and dimensionally accurate, that's all we need to do to them.

The gearbox is strengthened and the ratios brought closer together, so every time you change a gear you drop less RPM, so you are less way down the power band. In order to do this we have a very high first gear, which makes it difficult to get off the line, but once the bike is underway every time you change gear you are back in the power straight away.

The gears are also stronger, because the torque we put through the gearbox is around 25-30% more than on a standard bike. For 2005 Suzuki have addressed this problem by changing the primary ratio. This basically makes the gearbox spins faster, but in doing so puts less torque through it. By doing this they can make the clutch and gears smaller and lighter. This has a number of benefits, not only does it lighten the whole bike, it reduces the mass rotating within the engine, which frees up power.

The clutch itself is removed and replaced with a slipper clutch. When you brake on these race bikes they stop very quickly and it is difficult for the rider to match the speed of the engine to the road. It is no use trying to slip the clutch as the rear wheel just skips, therefore we need a clutch that automatically slips when the bike is decelerating which allows the rear wheel speed to be faster than the engine speed and makes going into a corner a whole lot smoother.

The throttle bodies have to remain the same, but that doesn't mean we can't fettle them as well. The GSX-R1000 has two sets of butterflies, of which we take the second set off but leave the actuating mechanism for reasons that will be discussed later. What this does is allow more airflow into the engine and more airflow means more power basically.

The exhaust is all hand made of course by Yoshimura, and has the two exit holes at the end. Now Yoshimura won't tell us why they do this as it gives the bike another 2 - 2.5 BHP over the singular exit hole, which is a 1% increase. We've even taken one apart but can't fathom why it gives such a benefit. Now a 1% increase may not sound like much but lots of 1% increases add up to a significant amount and that is what we look for.

The other main difference between the race bike and a standard one is the collector box, this is where the four header pipes come out of the engine and collect together under the engine. We use two different arrangements here that gives us slightly different engine characteristics. A four-into-one affair gives us more top end power, whereas a four-into-two-into-one gives us significantly more torque.

So depending on which race circuit we are going to, depends on what exhaust configuration we will use. For instance somewhere like Snetterton, which is two drag strips connected with some fast corners, we will use the four-into-one to get the maximum speed possible, and we can hit somewhere in the region of 195mph. We will use the four-into-two-into one at somewhere like Mondello or Cadwell, where the bike has to be dragged out of some slow speed corners.

Sometimes we will get special stuff from Japan, which we will test on the very good Dyno we have back at Crescent. We may find that one particular system will give us an extra 10BHP, but the engine will blow after half an hour. It is a very fine balance between getting a performance increase and what implication it has in the whole package. We have to evaluate these increases on what they do to drivability, which is very important on a bike, what it does to engine longevity and whether or not it fits within the regulations.