V7 air induction

[Dinsdale Piranha]

Has anybody out there removed the stock air box altogether and used a pod filter of some sort? I was thinking that quite a bit weight and space-engulfing stuff could be removed, and it could provide more room to work. I did see, on an entirely different brand/model bike where the owner installed a pod filter and used the air box for storage. I've also learned of someone who put an extra fuel tank in the space.
I've been told that the V7 already has a free flowing air induction, so performance gains would be minimal to unlikely.

Ideas, anyone?

 

[Trout]

I like the idea of a storage box or xtra fuel.

 

[Kyle Lamson]

Try the search function, it’s been discussed here at length. I’m not the expert but recall the jist being performance would suffer as the bike prefers pulling from still air.

 

[Godfrey]

When I bought my '89 LeMans V in 1995, the previous owner had removed the, uh, shall we say "a little difficult to service" stock air box and fitted a pair of pods to the mouth of the carburetors. It looked cool and racey, made a good bit of noise, and ran like crap. I spent some time and money, acquired all the OEM airbox pieces. I fitted a K&N filter element rather than the OEM paper element to minimize the need to service it. Once the airbox was fully restored—and even before I started the long detail process of tuning and taming the Dell'Orto 40mm racing carburetors setup so the bike would start, idle, and run smoothly—it ran much MUCH better and was much quieter as well, letting me hear the beautiful exhaust note rather than all the rat-tat-tat of the intake.

 

[Dinsdale Piranha]

As per usual, knowing what to ask is the most important thing. I've just tried a whole raft of search strings involving induction, air box, pod filter, air inlet, air filter et al.

 

[Dinsdale Piranha]

When I bought my '89 LeMans V in 1995, the previous owner had removed the, uh, shall we say "a little difficult to service" stock air box and fitted a pair of pods to the mouth of the carburetors. It looked cool and racey, made a good bit of noise, and ran like crap. I spent some time and money, acquired all the OEM airbox pieces. I fitted a K&N filter element rather than the OEM paper element to minimize the need to service it. Once the airbox was fully restored—and even before I started the long detail process of tuning and taming the Dell'Orto 40mm racing carburetors setup so the bike would start, idle, and run smoothly—it ran much MUCH better and was much quieter as well, letting me hear the beautiful exhaust note rather than all the rat-tat-tat of the intake.

Of course, if the inlet is opened up fueling must be adjusted to suit. If the original inlet is as free flowing as pods then no adjustment to fueling is needed. Most (not all) bikes gain more from freeing up the intake rather than freeing up the exhaust. I have had it on good authority though, that the V7 inlet is already as free as the engine can suck. I'd not heard of the need for some engines to draw their air from a box though. I'll follow that line a little further. What you DON'T want is the induction to be trying to suck enough air out of a particularly low pressure area. Some high performance bike use ram air.

Any'ow, just exploring possibilities.

 

[Godfrey]

Of course, if the inlet is opened up fueling must be adjusted to suit. If the original inlet is as free flowing as pods then no adjustment to fueling is needed. Most (not all) bikes gain more from freeing up the intake rather than freeing up the exhaust. I have had it on good authority though, that the V7 inlet is already as free as the engine can suck. I'd not heard of the need for some engines to draw their air from a box though. I'll follow that line a little further. What you DON'T want is the induction to be trying to suck enough air out of a particularly low pressure area. Some high performance bike use ram air.

Any'ow, just exploring possibilities.

Certainly. The problem is that on bikes like the Guzzis, the LeMans 1000 in particular, there's not really any place to put intake horns of the proper length AND sufficiently large filter pods since the frame and the riders legs are in the way. When setting up the Guzzi engine for racing and land speed record attempts in the 1990s, the right thing to do with those big 40mm carburetors was first to modify the inlet stubs so the pointed more nearly straight back, running a little downhill to the port, and then fit 3" inlet horn on the carburetor that passed it on the outside of the frame tube. I had custom K&N filters made for one bike that the owner wanted to run at Bonneville because of the dust there that had a large oval shape so that with further rears pegs and controls such that his legs could tuck in, but it would have been incredibly inconvenient to ride that way for any distance.

The standard K&Ns that are sold for the LeMans are little conical things that go right on the carburetor mouth. They destroy the tuned length of the intake tract and end up in an area of the bike which when in motion is full of turbulent air. They damp the intake pulses that help cylinder filling. They have insufficient area and volume to allow the standing wave of fuel mist that hovers out the end of a working engine's inlet tract and cause all kinds of mixture problems. Air goes through them at high velocity so they really don't do much filtering other than keeping birds and pebbles out. They just plain suck.

The stock airbox with its rubber elbow connectors to the carburetors give the carburetors the correct tuned intake length and a still air intake plenum to draw from. The long snout of the airbox allows clean air to be drawn from a region where the airflow is non-turbulent and forces the air flowing down into the plenum chamber to slow down so that the filter can actually take the dust out of it. The pulses of the paired intake cause the air pressure in the plenum to be on the plus side of it's cyclic pressure variation when intake is happening. And the whole rig cuts noise by a dozen decibels. Unless you've gone for a very radical engine, there's nothing better.

(Most of the improvement to the LeMans 1000 breathing came from intake work, yes. With those dinner-plate sized valves and the cavernous hole of the 40mm Dell'Ortos, the biggest problem to correct was that Moto Guzzi had made the inlet ports too large for optimum flow: airflow was stalling in the port and not flowing all the way around the valve head. We added material inside the port on the floor to neck it down a little, smoothed the area around the valve guide for better flow, and reshaped the area above the valve to get a better flow all the way around the valve, rather than just at one side of it because of the OEM obstruction at the valve guide. The results were nothing short of astonishing on the dyno, even with a stock cam and stock mufflers, and engine actually idled better and was more tractable too.)

Moto Guzzi has really done an exceptional job of designing the intake air systems on their sport bikes since the 1980s. I wouldn't change a thing there. If you need a pocket to hold some incidentals, get a little pouch with a velcro loop on the back and wrap it around a frame member. I have one of those I use for my bicycle... works great!

 

[roadscum]

I've remove/altered the air box on a few bike the result was more induction noise,poorer throttle response, and less power., not was I was hoping for. Ram air is only effective when you're traveling at speed well beyond the capacity of our bikes. Read this and you may change your mind: https://motorcycleinfo.calsci.com/Airboxes.html

 

[RedHawk47]

I suspect the OP was referring to a current V7, which is fuel injected.
I have read reports that changing the OEM air filter to a K&? on a Stelvio or V7 (I don't remember which, but both are FI) made it run poorly. The "fix" would be a custom fuel map, or go back to the OEM filter.