air flow

I have torn my 82 maxim 650 almost to the frame. I am wondering if retro fitting a forward style air filter would help with the airflow.

 

well, first off i am no expert in bikes- i used to build hot rods in a custom paint/restoration shop. that being said, I would say YES. a less restricting forward oriented air box/filter set up would be just that-less restrictive. BUT heres where it gets sticky! the bike was setup to run best in THE STOCK postition. If you feel the need, by all means start fabricating, but dont forget that you MUST modify the carbs/jets/pilots/etc to accept your modified intake. good luck man, ps: how do you plan to do this? side scoops?---they would warm the air from the hOt upper--- tube wrapped to the back, then scoops?---dont make your intake tubes longer than they need to be...

i have toyed with this idead in the past, as i modify every other vehicle i own to produce more power and efficiency. (intake being the first, then cams so on so on....) where it is stock, it gets enough air, guarded from heat and weather etc. without doing major modifications and tweaking to the intake (carb) system, it may be tough. your motor needs the correct amount of air/fuel/combustion to run right. its euphoric as it is stock, with modifications you will need to find the correct 'euphoria'.

sorry to post a book. just trying to save you the hassle, and warn you of the potential mods that would pursue. GOOD LUCK and PLEASE post if you do find a good platform and setup for this sort of modfication, i will be the first to congratulate you

 

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I was actually going to make a bracket for a cone shape forward facing filter. A pretty common kind for those big cruisers. I have an idea for the bracket...now all I need is a filter.

 

Why not take the head off, turn it 180 degrees, put it back on, then remount the carbs so they're facing into the wind. You could even put huge bell-shaped air horns on them. That way the air would be rammed down their throats the faster you went. you'd have to rework the exhaust, but...

(No, I'm not serious, but made you think about whether it would be possible for a second or two, didn't it? )

 

gamaru, you had me pulling out hair till the end there.... lol.

bane, that would work,just dont mount it too close to the head, and make sure the cone(s) is (are) hidden from the elements, dont forget to adjust the rest of the intake (carb) !!!

 

If you had "ram air" you would have to "dump" any pressure because at about 1/3 PSI you get no fuel in the carbs, or you have to bleed some pressure into the tank, which causes a continuous vapor leak at the cap.

Theoretically, of course, I didn't try it.
Edited here--I tried it! I ran a hose out the window of my truck into a water filled tube and got only 2 inches at 80 MPH which would be 8 inches at 160 MPH--not enough pressure to stop fuel flow---IMO.

 

After talking to a custom builder in town he seems to think that maybe a very slight scoop on my existing box would be all the coaxing my engine would need. I think I will try that first. I'll let you know where I land. Thanks fellas for the input. Here goes nothing! Well maybe something?

 

The Cubic Feet per Minute necessary to run the bike at its optimum output is factored-in and regulated by the Inside Diameter of the Rubber Intake Port on the Airbox.

The instant you disrupt the Stock Intake Air Quotient ... you have other compensations to make.

Although there are some people who modify and redirect the Air flow into the Intakes ... it is not done without needing to modify Jetting and Exhaust.

In the very long run ... you can get the Bike to run GREAT by doing some intensive tuning and race prepping of the Carbs.
Upsetting the Intake CFM with a larger port, scoop, pods or nothing regulating Intake Air can be a very frustrating adventure.

 

....and after you go through all of this, you will spend even more time going back to stock, because tuning these carbs for performance upgrades is a royal pain. :mrgreen:

There's just not a whole lot you can do to an XJ motor to make it go faster without machining the heads, valves, etc... IMHO the performance gain you get from less restrictive intake/exhaust is marginal, and rarely worth the $$$.