We have a 2008 SC59 race bike and I'm wondering which velocity stacks would be the best ones for race use? Currently we're running with 2014 - 16 stock ones. If you could recommend me something better.
Hi Kake I replied to your comment on my for sale and for the Venturi system ones but I'll mention here too for anyone else... I race a car with a SC59 cbr1000rr engine and they are mostly standard, stacks are one of the things we can change. Most people run the Venturi system ones. They give a nice bump in peak horsepower but also carry that gain on much better after peak to the limiter which is obviously useful for gearing the motor to empty it out in 6th gear. I am also developing my own stacks that I'm 3D printing, I suspect they will have a bit less top end but a bit more mid range, given the extra weight I'm lugging around I need the grunt, for a bike I think the short ones are probably best.
Another thought/piece of advice, be wary of the ten Kate/mwr flush fit style ones that are mega short. You will make maybe 1 hp peak more than the Venturi system ones but way less everywhere else. They are best for tuned engines that have a raised limit and only live above 11k
This did make me look into the benefits of the stacks and looking at the youtube dyno vid it was very interesting there is not a lot to be gained from standard, should have put a link but but should not be hard to find Viewer 3d Printed Velocity Stacks - Trumpets - Intake runners - Dyno Tested
Seen all his videos before, they are very good... There's literally no such thing as standard though with his setup his base setup is one that he already tuned himself. Comparing apples and oranges. If you look at the videos where he tests different sizes and lengths they make a huge difference. There is a significant difference in peak performance between standard sc59 stacks and aftermarket ones, but some are too peaky for my liking. The standard ones are not only long but choke down the intake side diameter of the throttle body. I should know Ive spent plenty of time analysing / measuring and making my own stacks and I've ran various ones on my cbr1000rr engined car that gets a hell of a lot of abuse.
I would add that my comments are based upon the OP racing his bike. For a road bike I'd stick with standard to be honest. For racing, the bump in peak power and the fact the curve drops up a lot less after peak toward the limiter is a significant advantage.
