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Post by 90GTVert on Apr 4, 2015 13:17:19 GMT -5
Wave tuning is used on the intake side as well as the exhuast side. I know they tune air box volumes as well, but have never really read anything with specifics but a bunch of things more or less saying manufacturers keep the info to themselves. They have teams of engineers and rooms full of computers doing computational fluid dynamics to figure this stuff out. I usually assume that most of our scooters feature whatever fits easily instead of something tuned to our engine specs.
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Post by Upgrayedd on Apr 4, 2015 14:10:38 GMT -5
i like that idea! a pod on the airbox inlet Well, it might work but the longer the path and the more turbulence along that path you're actually creating a resistance to the intake. Many new cars use variable intake length manifolds to adjust the torque map this way for better performance. The Ford Taurus SHO for example. yeah a lot of v4 superbikes like the big ducati v4's and such have variable length intakes, somewhere around 7800-8k rpm the computer tells a flap to open in the intake and shortens the intake length via the new inlet, the end result being more power squeezed out at low _and_ high rpms, the best of both worlds if you will. these new superbikes have computer mapped ignition and everything - crazy fast. there's pros and cons to different intake setups for sure.
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Post by Upgrayedd on Apr 4, 2015 14:14:23 GMT -5
Wave tuning is used on the intake side as well as the exhuast side. I know they tune air box volumes as well, but have never really read anything with specifics but a bunch of things more or less saying manufacturers keep the info to themselves. They have teams of engineers and rooms full of computers doing computational fluid dynamics to figure this stuff out. I usually assume that most of our scooters feature whatever fits easily instead of something tuned to our engine specs. yes lots of computer modeling and such i have seen formulas for calculating optimal standing wave/ exhaust diameter & length based on bore,stroke,etc (for 4 strokes) floating around the net, i am not sure if there are intake formulas but likely they're out there to be found as well, i have never looked for them.
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Post by albongo on Apr 4, 2015 15:00:00 GMT -5
I believe I have also experienced this wind surge phenomenon. I look forward to reading about experiments and solutions that may arise in the thread.
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Post by 90GTVert on Apr 4, 2015 21:02:04 GMT -5
yes lots of computer modeling and such i have seen formulas for calculating optimal standing wave/ exhaust diameter & length based on bore,stroke,etc (for 4 strokes) floating around the net, i am not sure if there are intake formulas but likely they're out there to be found as well, i have never looked for them. This one is in Performance Automotive Engine Math by John Baechtel, prob more in others I've got. It's from 60s Chrysler engineers. L = [( K x C ) / N ] ± 3 Where : L = length of the inlet path in inches K = mathematical constant (Chrysler chose 72) C = speed of the pulse (arbitrary according to temperature) N = RPM ± = recommendation to encourage experimentation to find the "sweet spot" Length is from the intake valve to atmospheric pressure.
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Post by humanshield on Apr 4, 2015 22:16:58 GMT -5
Ok, this may not be as technical as Brents posts but......
I was riding in some gusts today (after taking the snorkel back off) and found that if I placed my foot just in front of the intake hole by a few inches, it stopped surging.
I think these scooters may need intake boxes with more hollow chamber inside to buffer the pressure fluctuations. Sort of like a capacitor buffers amperage draw spikes in amplified speaker systems.
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