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Help me understand what they do....
- SouPortugues
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Perhaps I don't understand the function of such mods other than the obvious, they look cooler!
No really, if it's power, torque, gas mileage, whatever, give me a quick (and relatively jargon free) synopsis. I'm still pretty green to this whole, motor-bicycle thing....
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- clutch
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- I wish I had a tad more patience to do it better!
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The 4 in to 1 exhaust baffles me a bit. The way you get more power out of an engine is to increase both inflow and outflow. How a 4 in to 1 would create better flow than a 4 in to 2 or straight headers is beyond me, unless it creates ideal back-pressure (like a flowmaster exhaust would do for your car or truck).
Anyway, that's what I know about it, and unless anyone has better info than me, I think it is fairly accurate (but would like to learn more as well)
~Clutch
Southern Maryland, USA
1980 KZ250 LTD (traded, but still missed)
1982 KZ750 E3 (Cafe Project) (Dyna-S, Dyna Coils, V&H 4-1, K&N Pods, 6 Sigma Jet Kit, Acewell Computer, Woodcraft Clip-ons, Custom Rewire)
1966 A1 Samurai (Restoration Project)
Wish List:
KZ1000 P (For a "touring" bike)
Z1 (need I...
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- SouPortugues
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- tachrev
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- Rubber Side Goes Down
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I can give you an idea about the pod filters. They give you less restricted air flow allowing more air (and in turn more fuel) into the engine for a better burn. They can increase both power and gas mileage. Using pod filters may require the need to "re-jet" your carbs (use bigger jets to allow more fuel flow) because they will most likely cause a lean mixture if you don't rejet.
The 4 in to 1 exhaust baffles me a bit. The way you get more power out of an engine is to increase both inflow and outflow. How a 4 in to 1 would create better flow than a 4 in to 2 or straight headers is beyond me, unless it creates ideal back-pressure (like a flowmaster exhaust would do for your car or truck).
Anyway, that's what I know about it, and unless anyone has better info than me, I think it is fairly accurate (but would like to learn more as well)
~Clutch
You don't want back pressure, you want scavenging and velocity.
Back pressure just lower the overall efficiency.
A 4 into 1 will scavenge better the 4 open pipes or a 2 into 1 because the previous exhaust pulse will help pull out the next one.
A well designed and sized exhaust can actually put a vacuum on the exhaust valve.
The size and length of the header pipes and collector vs. the size and power of the engine will dictate which RPM you get the optimum scavenging at.
Here is a good article about exhaust system design. It says it's for cars, but the same principles apply.
Popular Hotrodding-Exhaust Science Explained
1977 Kawasaki KZ1000 : Street/Strip
Build Thread
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- l0g1c
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- Hanging on for dear life.
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I don't think pods will give you better gas mileage. More air, more fuel, more power, sure. It defies logic that you could get better fuel economy as well, unless something was off-kilter to begin with.
650ed got the disadvantages spot on. An advantage that I haven't seen posted is that it makes pulling carbs easier, but I'll let you weigh that against the disadvantages.
As far as the exhaust goes, running an unrestricted exhaust will get you some horsepower in the higher RPM's, but it robs the lower RPM's of it.
A 4-1 pipe will run hotter and will benefit from the flow of the other cylinders. I usually hear "scavenge" in terms of a 2-stroker, but I suppose it makes sense in this context as well.
I'm as fallible as the next guy though, so it won't hurt my feelings if someone corrects me. :laugh:
'81 KZ750 LTD
'72 CB350K
Omaha, NE
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- Locozuna
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Unrestricted exhaust poses another problem. It attracts flashing lights. There are towns around here where they are enforcing a noise control legislation. Only stock mufflers are permitted and you will be ticketed. Plus if it is registered and inspected in this state you will have to get it to an official state inspection station who will only OK it if it has original exhaust. BUT, they do not seem to be fully enforcing it. The seem to only be harassing the obnoxiously loud exhausts.
KZ900LTD, KZ750LTD, KZ650, 72'Triumph Trident
"Over the Mountains
Of the Moon,
Down the Valley of the Shadow,
Ride, boldly ride,"
The shade replied
"If you seek for Eldorado!"
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- keith1
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- N0NB
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- Blue handles better
Nate
Nates vintage bike axiom: Riding is the reward for time spent wrenching.
Murphys corollary: Wrenching is the result of time spent riding.
1979 KZ650 (Complete!)
1979 KZ650 SR (Sold!)
1979 KL250 (For sale)
1994 Bayou 400 (four wheel peel )
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- gane
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[img][/img] 1977 KZ1000A1
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- KZQ
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- Walking Behind the Corn May Not Be All That!
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Most folks who opt for pods do so because after struggling to get their carbs out past old stiff boots decide that it just plain easier to dump the airbox and go for pods for the reinstall. My bet is that a great new business would be one that could claim that "We make any new supple intake boots to fit your 30 year old bike."
On the exhaust side:
After market four into one and four into two systems are lighter than stock systems. While they can provide power benefits, most folks install them because stock systems are not available after the stock system either rusts out or gets damaged in a crash.
KZCSI
www.KZ1300.com
Riders:
1968 BSA 441 Shooting Star, 1970 BSA 650 Lightning, 1974 W3, 1976 KZ900, 1979 KZ750 Twin, 1979 KZ750 Twin Trike, 1981 KZ1300, 1982 KZ1100 Spectre, 2000 Valkyrie, 2009 Yamaha Roadliner S. 1983 GL 1100
Projects:
1985 ZN1300
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- timebomb33
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1973 z1 2-1974z1-a,2-1975z1-b dragbikes1015cc+1393cc, 1977kz1000,1978kz1000,1981kz1000j, 1997 zx-11, 2000 z12r,1428turbo nitrous pro-mod and a shit load of parts thats all for now leader sask.,CANADA
I THINK MY POWERBAND BROKE
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