Combine the benefit of stock air box and individual air filt

[Addy Leung]

Hello! May I share some idea there.
I always have thinking about how to combine the benefit of stock air box & single air filter and the individual 4 air filters to each carbs.
As the stock air box is good for low end( only two 1? holes to restrict less air go into carbs) and individual air filters is good for top end ( more air easy go into the carbs).

Could we install a auto open& close sliding door or moveable cover over the stock cover area of the air box of the stock air box and this new movable cover will have linkage to the throttle wheel of the carbs. So that this cover will be opened and close according to the throttle position. I also think the shape of the cover could be in trapezium, so that the opening area will gradually increase when the throttle open.
Do I think correct? Dose it really help to the performance? Dose it possible to make it?
Hope someone would comment on and share with my little idea? Addy

[vwbeatle1214]

only way it would work is if you found a way to gradually adjust the jetting in your carbs also, all it would do is make it run lean at the top end.

[Addy Leung]

I just also think that:
What about if we set the right main jet at full throttle open of the carbs with the max opened area of the movable cover , then for the middle range, the taper sharp middel part of the Jet needle will do the job to increase the amount of fuel gradually to suit the opening area of the movable cover when we open the throttle accordingly from the bottom to the full throttle.

Is my thinking correct?

[Dink]

Addy my suggestion is to remove the air filter case off the rear of the plenum chamber and install a single large pod in its place..
Dink

[Anonymous]

Dinks suggestion

Addy my suggestion is to remove the air filter case off the rear of the plenum chamber and install a single large pod in its place..
Dink


Addy - I ran a "stock" airbox with a K & N single pod filter - gauze style free flowing.

I cut out the two 1" holes on the bottom of the airbox to a rectangle about 3.6 square inches in AREA.

It was a GS750EZ - TSCC engine.

I got PLENTY of flow with this arrangement and was able to retain midrange power.

You WILL have to consider raising your needles. Since I used a stock 1983 GS1100 INTAKE cam to replace the 750's - and with the cut out airbox, I had to go to a non-stock faster taper needle. I could NOT get the stock needle to come up fast enough, even drilling out the slides for a stage II mod.

I think the setup was more like a stage I with the opened up airbox.

Dink - have you known anyone who did my mod? What were the results?
-Dieter

[crayonjota]

I went one stage further and took the stock box off with a gauze cone filter put in its place.. The bike runs like crap up to 4000rpm and then comes into its own. If I am to do any riding at all in town I swap back the stock arrangement which nets similar results up to 8000rpm with low rpm power too.

Now I am going to play with putting the cone into the stock box and see if I can get the best compromise....
CJ

[Anonymous]

Well...there you go crayonjota....

I am not surprised you do not have lower RPM power.

With my setup, I got 60 rwhp at 5500 and 77 peak rwhp at 8500 rpm.

The bike had driveable torque all the way down to 2500 rpm...

When I first got the bike with stock airbox and a megaphone canister on the kerker header, it wouldn't pull below 3500 rpm.

So - read this and the "epoxy" threads and you will get the rest of the story. (Paul Harvey - Dieter)