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Basically a copy of the old school chopper airboxes.

Should work better then pods.
 

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Unsure what you mean.

basically closing up the box to better replicate the stock airbox and creating a stable atmopshere within. the way this breadbox air filter is now, don't all the holes create uneven air flow into the carburetors?
 

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basically closing up the box to better replicate the stock airbox and creating a stable atmopshere within. the way this breadbox air filter is now, don't all the holes create uneven air flow into the carburetors?
I think you would need to do a little math on the volumetric flow of each carb, and then see what size plenum they would need with a corresponding sized opening for it to be really worthwhile. The nice thing about that box having mesh along its entire circumference is that it should keep the air pressure relatively equal between bellmouths, have little to no restriction, as well as "dead" air so there is minimal disruption of the air flowing through the stacks.

Then you have to deal with details like how much space should there be between the bellmouth of the stack and the front of the airbox. That has a huge effect to airflow as well...

On a side note, I don't get how these guys sell their individual stacks with the mesh filter on the inside. Way to reverse the effect a velocity stack is supposed to create in the first place! Talk about selling hipster bullshit.
 

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Fit K&N pods or a stock airbox.

The steal dragging ones look far too small in volume to work very well. They only built them for looks, period.

If old chopper airboxes worked better than pods fossil superbike racers would be using them on race tracks now. They ain't.

Danger, is my business."
 

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The first generation SOHC CB750 carbs are just as fussy when it comes to velocity stacks. Whether or not this setup would work very well is partly dependant upon how well those velocity stacks replicate the stock ones. If they are much different, then (as already mentioned) you would be better off swapping the stock stacks into this air box assuming they will fit and there is sufficient clearance between the mouth of the stack and the back of the air box. It might look better, but you are most likely better off sticking with the stock box.
 

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Discussion Starter #11
I am completely satisfied with my 750's performance with the stock airbox.
Had someone else ask me about this and wanted to get some opinions.
 

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I scored a set of Cir-Cycle velocity stacks from a salvage yard and am perfectly happy with them. If and when I put a good built motor (and not a low mileage salvage yard motor) in the frame I will chase the last few HP with jetting changes. But then I have an early 1972 model, which still had the no smog law rich jetting (120 mains). Plugs look golden brown now that I have good coils, a new Dyna, and the float levels set properly.

I really have no idea why you can't buy these today. Likely because not many guys are spinning aluminum, compared to the number of small CNC machines out there.

CB750 Redo (16).jpg
 
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