Prairie dual exhaust system ???
#12
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Six,
I'd definitely stay away from the one big, one small idea. You should have different cams for each cylinder, if that's the case. And different jetting. And probably a new crank due to the uneven stresses being thrown at it. Kind of reminds me of that "spy shot" of the fictional Honda MotoGP bike last year--one bank of 3 4-stroke cylinders connected to a bank of 2 2-strokes. Funny, thought-provoking even, but would never work well.
The age-old question remains: how to tune for both low-end torque and high-end power with no compromise? Until solenoid-driven digital valves make it into production I think we're stumped. Sturman Digital Valves
I'd definitely stay away from the one big, one small idea. You should have different cams for each cylinder, if that's the case. And different jetting. And probably a new crank due to the uneven stresses being thrown at it. Kind of reminds me of that "spy shot" of the fictional Honda MotoGP bike last year--one bank of 3 4-stroke cylinders connected to a bank of 2 2-strokes. Funny, thought-provoking even, but would never work well.
The age-old question remains: how to tune for both low-end torque and high-end power with no compromise? Until solenoid-driven digital valves make it into production I think we're stumped. Sturman Digital Valves
#13
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Couldn't find the picture. FST made it. I know they sold the quad to someone that used to post on here. I did find a thread on it tho.
http://forums.atvconnection.com/mess...y&keyword1=800
http://forums.atvconnection.com/mess...y&keyword1=800
#15
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Exhaust pipe diameter, directly effects the power profile of the engine... in general, on a 4 stroke engine, a smaller diameter exhaust pipe, is more conductive to creating higher torque outputs... a larger diameter exaust pipe, is more conductive to creating higher horsepower outputs.
In the first line, torque is in lbs*ft, speed in revs/minute. The third term just converts RPM to revs/s. The fourth term converts revs to radians. The last term is the conversion factor from lbs*ft/s to horsepower. The second equation just multiplies out the constants.) With that being said and knowing horsepower wont be achieved without torque, this is where we should concentrate. Get your torque numbers then try to raise them up the rpm scale. I beleive adjustable back pressure would be a big help to all of us. Those that have the big bores will naturally have more to gain from this without loosing torque since there engines now have a bigger appetite. But just opening up the exhaust without scale or measure is nothing more than guesswork. ( Look good, sound good) YES but not the way to get the best performance. Bigger is not always better (look at indy and formula 1 cars) Having each component work the best with the next componet is what will make the overall difference. this cam with these heads, this exhaust with these pistons. Not just bigger bigger. Im glad to see this heading the right direction. I applaud you newbeatle for bringing this up and hope you keep us posted. PS. Im not by any means saying dont mod your quad (far from it) Im just saying dont do a mod until its needed to compensate for another.
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fordfaithful21
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12-07-2015 05:52 PM
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