After getting the nod to use their gear driven camshaft in World Superbike racing (shown above is the Aprilia’s belt driven camshaft), Aprilia has become a tour de force on the WSBK grid. Aprilia first used the gear driven cams in race environment while at the Miller Motorsports Park round, much to the protest of the other teams.
Aprilia and Max Biaggi have been on a bender since the new camshaft’s implementation, with the Aprilia RSV4 going double-double (no, not that Double-Double) and winning every race since the gear driven camshaft was installed on the race bike.
Not that Biaggi and Aprilia were looking shabby before Miller Motorsports Park, taking a double at Monza and a double at Portimao, but part of the reason that RSV4 Factory has been so dominate since is because the gear driven camshafts are boosting the RSV4′s power by three to five horsepower, virtually throughout the entire rev range. With this added power boost occurring, it’s clear now why the other teams in World Superbike opposed Aprilia using the new camshaft.
However, since the gear driven camshaft is a purchasable part by consumers in the Aprilia Racing catalog, WSBK had no choice but to admit that Aprilia was within the parameters of the rule book. Aprilia even gave the other teams the consideration of not using the camshaft for five races, moving the implementation from Portimao to Miller Motorsports Park.
With this kind of advantage, it’s also clear now why Leon Haslam is urging for Suzuki Japan to throw more resources into its World Superbike program. Likely fearing that the Suzuki GSX-1000R has lost its edge on the RSV4 Factory, Haslam could make up his 37 point deficit more easily should Suzuki find a similar 3-5 horsepower in the Japanese inline-four motor.
With World Superbike racing next at Brno on July 11th, we won’t have to wait long to see if Aprilia can make it three doubles in a row. Should that occur, Suzuki and all the other teams, will have to come up with an answer to the RSV4′s new found power.
That’s strange. The Aprilia should already have a 20hp advantage over the Suzuki.
How does this sport work?! It’s magical. It doesn’t follow any of the laws of nature. No bore/stroke rules. No rev limits. No fuel limitation. No air restrictors for 1000cc bikes. Yet the hp ratings are so close that a cam breathing mod has broken the parity.
Maybe one of these days Paulo will tell us. As a marketer, he’s basically full of truth and light. I’m sure he knows what’s going on at the FIM.
Okay, I just got through to Paulo and he explained the whole thing.
The tires limit the performance of the bikes by limiting the amount of power they put down, unless you add just a little bit. If you add just a little bit of power the tires still work. Also, the tires don’t limit the Ducati b/c the L-twin harnesses the moon’s gravitational pull which allows it to put down more power (no wonder they always win). The Ducati has to be fitted with air restrictors to cancel out the moon’s gravity.
I knew there was a straight forward explanation.
20 bhp more than Suzuki? That’s too high I think, 10 bhp advantage is more like it. Unless comparing with the privateer teams.
Aprilia RSV4 Gear Driven Camshaft Good For 3-5HP – http://aspha.lt/151 #motorcycle
Sorry, but they are making more power because the gear driven camshafts have less resistance, run smoother, no? It has nothing to do with duration/lift/lobe shape etc.? They all can change that as they wish. Not everyone can make gear driven camshafts though …. apples and oranges to me.
Please excuse my militant family member who hijacked my computer. PF is hinting at rev limiting which I happen to agree with though not in such a boisterous fashion. I don’t know whether gear driven cams have less friction or whether they are simply a more accurate drive system with very little flex that improves breathing.
I think the more interesting point is that the 4-cylinder bikes should make very different power output, yet a 3 to 5 hp cam mod has swung the pendulum in Aprilia’s favor. It’s shocking that the BMW and the Suzuki can both race on the same track, let alone that Suzuki routinely finish in front. I suspect something happens during homologation.
Hidden rev limits or not. This is a good article.