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Someone talk me out of this... KZ440B Airbox Mod
- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- tdubya84
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www.kzrider.com/articles/technical-tips/...aking-power-with-air
78 KZ650B
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- 650ed
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tdubya84 wrote: Not sure if this will work for the 440 or not but you may be able to modify the idea to fit your bike.
www.kzrider.com/articles/technical-tips/...aking-power-with-air
I hate to burst a bunch of bubbles, but that article is bogus. The entire premise is wrong - more air does NOT make more power. There is no performance reason to increase airflow on a stock KZ engine. Think of it this way - if the stock air filter passes a sufficient volume of air to support wide open throttle at redline - it sure as hell has no problem passing enough air to support any throttle opening below full throttle at redline. So IF increasing the airflow was going to add power it would only happen at the highest rpm with wide open throttle. Think of a high performance drag bike; then think of the porting, carb mods, etc. that enable that drag bike to use more air &fuel to its advantage; then consider the fact that it only needs to run well at wide open throttle. Since stock bikes cannot efficiently ingest great gobs of air/fuel mixture, and since folks on the street rarely run at redline with wide open throttle, the small theoretical performance gain at that rpm/throttle opening is offset by the impact on performance at other rpm/throttle openings which are used most. Show me dyno sheets showing performance gains in a stock engine by adding pods or modifying the airbox. I don't think you'll find any, but if you do feel free to post them. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- bountyhunter
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Yeah, considering how desperate bike makers are to squeeze out one more HP, you can bet they'd be doing it if there was any "low hanging fruit" to be scooped up by changing the airbox.650ed wrote: Show me dyno sheets showing performance gains in a stock engine by adding pods or modifying the airbox. I don't think you'll find any, but if you do feel free to post them. Ed
1979 KZ-750 Twin
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- ezrider714
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This is a very False assumption regarding induction systems on a 4 stroke engine
Maybe you could provide dyno sheets that show a stock airbox makes the most power on a stock engine
Stock airbox design is a series of compromises including appearance, fit, packaging etc..Performance is not at the top of the list by any means.
Think of it this way if pods did nothing you wouldn't have to rejet..
78 KZ650SR Mine since 79
4-1 Mac Jet Hot coated since mid 80's
Dyna Coils
Saddlebags (I ain't skeered of going nowhere)
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- Proxy
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- 80% Human 20% Nuts/Bolts
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Take it from me cuz I found
If you leave it then somebody else is bound,
To find that treasure, that moment of pleasure,
When yours, it could have been.
1977 KZ650 B1 Being restored to original (Green)
1977 KZ650 B1 Original (Red) Sold
1977 KZ650 B1 Donor Bike for Parts
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- 650ed
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ezrider714 wrote: "So IF increasing the airflow was going to add power it would only happen at the highest rpm with wide open throttle."
This is a very False assumption regarding induction systems on a 4 stroke engine
Maybe you could provide dyno sheets that show a stock airbox makes the most power on a stock engine
Stock airbox design is a series of compromises including appearance, fit, packaging etc..Performance is not at the top of the list by any means.
Think of it this way if pods did nothing you wouldn't have to rejet..
No problem. Read and weep. Ed
kzrider.com/forum/3-carburetor/585949-po...-a-free-lunch#585949
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- kzz1king
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Wayne
74 Z1 1075, 29 smoothbores, owned and ridden since 1976
Home built KZ1000 turbo setup
www.kzrider.com/forum/11-projects/532476...s-budget-turbo-build
www.kzrider.com/forum/11-projects/532489-74-z-makeover
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- 650ed
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kzz1king wrote: I thought larger intake valves, porting, turbos,superchargers, larger carbs were all about getting more air in the motor along with more fuel of course. But more air does not increase performance?
Wayne
Yes, you are correct, those things enable a motor to ingest more air/fuel mixture and done properly that can increase the power a motor can make. However, that is much different than simply exposing a stock motor to more air. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- bountyhunter
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Turbocharging and supercharging are actually about effectively "increasing atmospheric pressure" that the intake system sees. That way when the intake valve opens, it stuffs more air and fuel into the cylinder supplying more to be ignited which can increase power. But you have to keep the ratio of air to fuel correct.kzz1king wrote: I thought larger intake valves, porting, turbos,superchargers, larger carbs were all about getting more air in the motor along with more fuel of course. But more air does not increase performance?
Wayne
Larger valves do not always equal more power, in some cases the opposite. The system flow has to be optimized which is actually pretty complicated.
Larger carbs could usually increase power on the cars we used to soup up back in the 60's, but mainly because the engines were pretty much starved for gas and poorly designed to begin with. Of course, I saw more than a few idiots putting 1050 CFM Holley double pumpers onto a 283 and overcarbureting the hell out of it. You could see the gas spraying out the tailpipe as it ran .... :laugh:
1979 KZ-750 Twin
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- kzz1king
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Wayne
bountyhunter wrote:
Turbocharging and supercharging are actually about effectively "increasing atmospheric pressure" that the intake system sees. That way when the intake valve opens, it stuffs more air and fuel into the cylinder supplying more to be ignited which can increase power. But you have to keep the ratio of air to fuel correct.kzz1king wrote: I thought larger intake valves, porting, turbos,superchargers, larger carbs were all about getting more air in the motor along with more fuel of course. But more air does not increase performance?
Wayne
Larger valves do not always equal more power, in some cases the opposite. The system flow has to be optimized which is actually pretty complicated.
Larger carbs could usually increase power on the cars we used to soup up back in the 60's, but mainly because the engines were pretty much starved for gas and poorly designed to begin with. Of course, I saw more than a few idiots putting 1050 CFM Holley double pumpers onto a 283 and overcarbureting the hell out of it. You could see the gas spraying out the tailpipe as it ran .... :laugh:
74 Z1 1075, 29 smoothbores, owned and ridden since 1976
Home built KZ1000 turbo setup
www.kzrider.com/forum/11-projects/532476...s-budget-turbo-build
www.kzrider.com/forum/11-projects/532489-74-z-makeover
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