Cutting hole in Airbox

[Lex]

I've been reading this thread with much interest since I know big twins need to breath deeply and the V11 air box looks very small compared to other big twins. In fact, I got so excited I made an air filter holder yesterday. First ride indicates a very nice noise (directed at the rider, not my neighbors) and a nice improvement in the seat-of-the-pants dyno. I'm also hoping I will get the same leaning of the mixture Rich commented on, my bike is on the rich side based on the plugs and poor fuel mileage. It also seems to be a bit smoother. This should get me by until I can get to Todd's House of Furniture and Fast Guzzis to get my PCIII dyno tuned, all good.

 

My question is based on the picture on the FBF page. My plan was to make my air filter holder and upgrade to a professional model later if I was happy with the results. I figured I'd buy a nice holder and aftermarket filter when my current filter is due for replacement. I followed the link Al provided, saw the price, $80 isn't bad considering, and all seemed good. Then I looked at the picture and got worried. The filter holder in the picture on the FBF has two bolts in the rear, my air box has one bolt. Any words form the folks who know more about this issue? I don't recall this coming up from past threads on air box modification.

 

TIA for any advice,

 

Lex

[dlaing]

RacerX/Todd,

 

I've sent you an email, but I'm not convinced you will see it.

 

My son has a personal computer in his room. I take it that I remove the power commander off the bike and into his room where I connect the commander to the computer via its cord, follow a link to the correct map and download the correct map. Is this how it is done? Can you send me here a link to the right map? I'm buying my K&Ns today (SU 1780), and will put everything back together tomorrow.

 

Thanks,

 

~Cap'n

You will need the 9volt battery power commander battery adaper.

It is pretty inexpensive and they are very fast at sending out orders.

Usually they process the order same day,

They also sell an adapter for Palms®.

[al_roethlisberger]

I'm surprised by comments advising not to cut holes in air box - I've had a number of holes drilled and should the day come when i want to return to standard, I shall simply glue some plastic over them - Job done - where's the problem, no one can see it.

 

My bike acheived 85.7 bhp on the dyno with above, PCIII and free flowing pipes - not bad me thinks!

 

Paul

uk

 

 

Paul,

 

It's not that cutting holes is ineffective(although other prior to your feedback, I haven't good or ill either way...) ...however since there are several methods and aftermarket kits to allow the air-box lid to be removed "cleanly" and expose the stock air-filter even more fully to the atmosphere, while preserving the OEM part, cutting holes seems like a less desireable option.

 

However, to your point, yes, cutting some holes is a simple operation and "free"

 

al

[al_roethlisberger]

Lex,

 

FBF sells several kits for Ducs, etc... so the photo may be for another bike If I recall correctly, the kit they sell for the V11 has a single bolt location/kit front and aft to fit the stock airbox just fine.

 

All V11 Sport/LeMans air-boxes seem to be pretty consistent so far, unlike many other things Guzzi

 

al

[Gio]

I recently cut the snorkel arms off my air-box and also drilled the stock lid with 27 x 1/4" holes. I run a PC and K&N filter. There is a definite improvement in response and the associated sound is quite acceptable (enjoyable).

 

I installed new plugs and will monitor fuel consumption to see if this improves.

 

Gio

[Motomonster]

Then I looked at the picture and got worried. The filter holder in the picture on the FBF has two bolts in the rear, my air box has one bolt.

I just installed the kit on my Stone. Don't worry, they have you covered. They have bolts included for your bike; you can use only two of the fasteners, they slide to where you need them.

 

The performance is very noticable, especially when you reprogram your powercommander. If you are thinking about getting one, stop everything and do it now.

 

Enjoy,

 

Motomonster

[Gio]

By way of an update on the air-box mods, the new plugs are turning a nice chocolate/tan colour indicating that all is ok with the mixture....

 

BUT - I have experienced the dreaded "vapour-lock" twice in the last few days under considerably cooler conditions (~15c) than previously - I'll pick this up under the vapour-lock thread (listed under FAQ) but my first thought was that without the airbox snorkel arms, hot air from the engine can now fill the air-box quite easily (which is where the temp sensor is located..)

 

(Having said that, a liberal dose of cold water over the fuel lines/pump followed by a blast of compressed air from the nearest gas station got me going again ie classic heat-related symptoms)

 

Gio

[Janusz]

I think that, colour of spark plugs notwithstanding, the most important factor still is the considerable leaning out of your mixture after airboxtomy.

 

That makes all your engine so much hotter that pinging/vapour lock becomes an immediate issue. Playing with your PC helps a lot. I was able to cure all symptoms totally and the engine runs better then ever.

[Gio]

Hi Janusz,

 

I agree that the partial "airboxtomy" (excellent term btw) must have leaned out the mixture further and thus the engine would be running hotter as a result (with hind-sight it would have been interresting to measure), but I detect no symptoms of an overly lean condition.

 

I have been away from the forum for the last few months, but would be very interested to learn what changes you made to the PC map which cured the problem.

 

Gio