Daytona 200: while waiting for the race, let’s talk about bolts…

Daytona 200 is a race apart. Its format of course but also its technical regulations.

To start, we can simplify by saying that these motorcycles have performances located between a Superstock and a Supersport.

The engine preparation is very close to what exists in the French championship and the essential difference is greater freedom in the choice of fuel.

The TOBC team remains discreet about the preparation of its engines even if it remains regulatory, undoubtedly it is more out of habit than out of necessity but we respect their attitude especially since it is that of almost all the teams.

However, This team told us to use VP MR12 gasoline. We wanted to know a little more, here is what we learned.

We often talk about a very high octane level to define a competition fuel but this is a somewhat simplistic vision and also a little outdated. We compare this high octane rate to the possibility of significantly increasing the compression rate, generating good efficiency. Of course, this remains true but it is partial.

A competition gasoline must also allow a high combustion speed, the higher this speed, the greater the energy delivered by the fuel. What determines this energy is the density of the fuel. A competition species is “light”, that is to say its density is low. For comparison, the average density of a commercial gasoline is 0,755 and that of a commercially available competition gasoline sometimes goes up to 0,675 for non-marketed ultra high tech fuels. For another point of comparison, diesel is at 0,850.

This density is very important data because one of the key points of an engine's performance is the air/fuel ratio which is measured by considering the mass of the fuel and air (grams) and not their volume (liters). ) which can vary depending on temperature and pressure conditions.

Finally, we will seek in a competition fuel to obtain the highest possible cooling value, that is to say its capacity to limit the rise in temperature of the air/fuel mixture. Specialists call this characteristic of a fuel vapor pressure.

Cédric Tangre's motorcycle prepared by the TOBC team therefore uses VP MR12 gasoline which is the most efficient fuel marketed by VP for four-stroke engines for long distance races (versus Dragster). VP is one of the leading American suppliers of competition fuel.

The question that comes to everyone's mind is obvious, which is "How much more power?" », the answer is less simple because it depends on the characteristics of the engine and the injection/ignition settings. Nevertheless we can locate this increase in power compared to gasoline delivered to the pump between 2 and 6%.

This gasoline has a pungent odor and makes exhaust muffler tips very white.

As we won't know more about the engine, we focused on its peripherals and the cycle part.

Let's start with the engine peripherals.

The exhaust used is a complete M4 brand titanium system which is very common in the USA, especially for Suzukis.

Injection and ignition are entrusted to a Yoshimura EM Pro ECU assembly (the competition ECU most used on Suzuki GSXRs) coupled to a Power Commander V from Dynojet. This association may seem surprising to a European because we often ride one OR the other. In fact the reason for this “doublet” is entirely pragmatic: the maps are made on the bench with the EM pro and the Power Commander “from zero” because the EM Pro is more efficient in this exercise then we adjust on the circuits, especially depending on the weather conditions, these adjustments with the Power Commander because Dynojet is present in the paddocks with a torque and power measuring bench and an engineer made available to the teams' technical teams.

The regulations stipulate that the tank must remain original without changing its shape in any way either below or above and that rapid filling valves are authorized. To reconcile these two points, we cannot install two rapid filling valves as we do in endurance, which is why the TOBC team only installed one of these valves in place of the original cap. This makes filling a little slower than WITH two valves but this assembly complies with the regulations. Some other machines have an advantage on this point because it is possible to mount two valves without changing the shape of the original tank.

Let's come to the cycle part.

We find the classic Öhlins fork cartridges and shock absorbers, this is no surprise and it is also due to the presence of Öhlins support on the circuits.

More surprising is the fitting of a Pit Bull brand rotary steering damper because although this rotary type is widely used off-road it is less so at speed, especially in Europe. Cédric is not complaining about it, so it works well on this very bumpy circuit in the infield.

The semi-rapid wheel mountings meet the specific regulations of this race and the TOBC team took advantage of this as evidenced by its victory on this machine in 2015.

For the front, the mudguard is mounted very flexible which allows the fork legs to be pivoted to be able to remove and then mount the front wheel without removing the calipers. It is, all in all, very classic for those accustomed to endurance races which allow this flexible mounting of the mudguard. What is more surprising is the use of a bicycle wheel quick release axle as a screw holding the wheel axle in the fork base. Additionally, where there are two original screws, there is only one of this system. This had been done in the past in endurance in 24-hour races and then banned. It's surprising but proven and saves a few seconds.

For the rear, TOBC has chosen to ensure that the caliper remains in place when changing wheels and to position this caliper under the swinging arm and not above it as originally to facilitate the introduction of the disc into stirrup.

Finally, the wheel spacers are made captive to the wheels.

We conclude from all this that the preparation of the Suzuki GXR TOBC is unsurprising in its principles while being very "American" on certain points and surprising on others such as the use of a bicycle wheel axle as a fork leg tightening.