Airbox Mods

[Borderer]

I see some reference to airbox mods on Das Mototech site, and below on the griso section, Does anyone have any information on opening up the airbox on the 1200 sport which i would guess is different to the griso having a circular filter not the flat like on the V11 centauro etc.
It looks to me that the airbox is very restricted with only two small openings at the back under the nose of the seat

 

[blackcat]

I have been thinking about pulling the cover off the airbox to see what happens. I'll let you what happens.

 

[cliffyg]

Hi Blackcat,
I recently had the lid off my airbox and noticed how small the circular opening is against the width of the airfilter!.It reminded me of my Aprilia Tuono i had ( and the breva airbox is Aprilia too!) one of the mods to de-restrict the uk market Tuono was to enlarge the inlet to the filter.
I've done this on the Breva and along with re-routing the engine breather to a seperate catch bottle and plugging the airbox connection.
I now have a bike that certainly revs and pulls better than before and also i have had no signs of the dreaded 'pinking' that quite often affected the engine (that sound like soemone s put loose nuts n bolts in the cylinders:dry: .
And overall i'm well chuffed :silly: ..:dry:

Cheers
Cliff.

 

[john zibell]

Cliff,

Do you have pictures/dimensions for the enlarged opening in the airbox?

 

[cliffyg]

Hi John,
I have no measurements at this time but i cut the intake hole to match the internal diameter of the filter,i couldn't cut perfectly round i recall as there is small portion of the moulding that is offset but i can't remember offhand what it was :dry: err temp sensor maybe!!.
I work away so at the moment i can't offer any more info!
I've just been to online pdf manual and it is the temp sensor !! john zibell wrote:

Cliff,

Do you have pictures/dimensions for the enlarged opening in the airbox?

 

[Roblatt]

cliffyg,

Sounds interesting about the pinking fix. Is yours the B11? If so, did you need to have it re tuned after the air box mod or is it ok as is?

thanks in advance

Robert

 

[cliffyg]

No retuning,and she's running sweet as B) .Yes its a B11

Roblatt wrote:

cliffyg,

Sounds interesting about the pinking fix. Is yours the B11? If so, did you need to have it re tuned after the air box mod or is it ok as is?

thanks in advance

Robert

 

[Roblatt]

thanks muchly

 

[FOT]

1200 sport -08 (2v) light mod from Finland.

Orginal airbox off.
V 11 trumpets.
Pipercross C 1151 dual trumpet sock.
Rapid bike.
Mistral.
http://picasaweb.google.fi/00FOT00/2010_01_25#


Dyno
http://picasaweb.google.fi/00FOT00/2010_01_13#


Jukka

1200 sport -08 http://picasaweb.google.fi/00FOT00/2010_01_21#
750 Breva -06
1000 Le Mans -88
RIP.
1000 Le Mans/race -88
1000 Le Mans/race -87
.
.
.

 

[GrahamNZ]

Getting the engine breather out of the airbox and into an alternative catch-can does wonders for a Buell and I'm confident a Guzzi would benefit similarly. Well done Cliffy.

Graham

 

[Roblatt]

cliffyg wrote:
"I've done this on the Breva and along with re-routing the engine breather to a seperate catch bottle and plugging the airbox connection."


I've been scrolling through a workshop manual for the B11, and I noticed it had a 'oil recovery tank' next to the air box. Why not redirect the oil breather pipe there instead of a separate catch bottle? Or does the catch bottle you installed have venting system so that there is no pressure build up?

Pardon me if this is a silly novice question.

Robert

 

[cliffyg]

Hi Roblatt,
I re-directed the breather hose from the recovery tank to a seperate bottle which has a vent so the engine is breathing ok.
If i had a big enough tee piece i would have ditched the recovery tank and had the cylinder breather pipes going direct to the new bottle!.
I hope thats clear to you

 

[Roblatt]

Yep

thanks for that

I have a new winter project
I also spoke to my car mechanic (he has several bikes) and he said this simple task should be enough to stop pinging because the engine will be getting clean air. So I will do this first and then if it doesn't work I'll do the air box opening too.

cheers

Robert

 

[Borderer]

Well I decided to go for it..
Looking at the air inlet snorkels they seem to have a smaller intake area than the Throttle bodies and judging by the amount of deadening/damping material they are designed for noise reduction rather than performance.
Firstly I pulled off the rubber snorkel which opens up the airbox quite a bit but the top of the filter housing still masks about 1/3 of the inlet.
So out with the Dremmel. I scribed round the profile of the Oil catch tank and down to the slightly curved top of the filter cover and cut the "towerpeice off" I reckoned that it would be easier to reattach one big peice than to do it in stages.
It wont be going back on!!!!
There is a definate improvement in performance, it is both torquier and smoother the only downside is an increase in intake noise, not bad up to half throttle but above that a beautiful roar:cheer:
it will cruise at 90 to 100 with no more noise than standard and the engine seems much smoother at 4 to 6000 rpm
I am getting a much better fuel consumption, but as I packed the temp sender at the same time so cant be sure how much better
Bike is a 1200 sport with Staintune silencer BMC air filter and the latest map

 

[Roblatt]

Borderer,

how is the torque compared to before? I've heard that sometimes by increasing "air in", you can reduce the thrust of air going out and therefor reducing torque.


Robert

 

[Borderer]

Dont see why. But anyway torque is increased,enough for example to be using 6th gear on twisty roads where I would have been using 5th

 

[erix2]

Hi All,

While I was doing the mod on the breather I had a look at improving the air intake bearing in mind the need for MG to quiet the intake "roar" to meet the latest regs.

I took off the rubber snorkel and as its not venturi shaped and is lined with foam i think it is safe to assume it is just a silencer.
So off it came, its made of soft rubber so not damaged. This easy fix opens up the airbox inlet considerably.

Inside the filter top is the round black inlet pipe which goes half way down the height of the element. Seems like another noise damper so I cut 1/2 inch off the bottom.

If you see in the pic, there is a semi-circular recess in the cover which is asking to be cut out.....maybe next time the tanks off...:lol:

The result (together with the breather mod) appears to be a stronger, smoother pull from around 3500rpm upwards all the way plus a lovely roar from the airbox !
Its also nice to hear a "hard" edge to the exhaust note as the revs rise when you give it some stick.....
Hell, I might start leaving my earplugs out....:laugh: ......well maybe one of them...:unsure:

Hope this helps.....



Eric B)

 

[londonrob]

Hey Eric, I tried your mod too!
Snorkel off, 1/2 inch off the filter inlet pipe, and fitted a new breather hose which sits temporarily inside an old milk carton stuffed by the battery.
Tank on, and a quick trip up the M11 for a test run to Stansted.
Definitely more acceleration, lovely intake roar when you cane it, but what impressed me the most was that at 6 grand in top gear i used to be doing 100mph
Now at the same revs i'm just nudging the 105 mark.
The motor is definitely more lively, and high speed cruising is a breeze

 

[erix2]

Great stuff Rob...

Its a good mod, you`ll be chasing the planes taking off from Stansted now....:laugh:

I dont know about going faster for the same revs/gear though.....but I get yer drift m8.

I`d like to let mine breathe better at the other end next but cant find a can cheap enough for the Norge.....I cant see £300/350 value in any of the few I`ve seen yet......any ideas ?

Eric B)

 

[guzzibob]

londonrob wrote:

but what impressed me the most was that at 6 grand in top gear i used to be doing 100mph
Now at the same revs i'm just nudging the 105 mark.

Ummm, unless you can explain to me how altering the airbox intake somehow changes the otherwise fixed gearbox/powertrain gear ratios, seems to me this is impossible. Placebo effect on the riders mind/powers of observation, perhaps? Not saying there might not be a positive effect to the alteration, but the above suggested result just defies the laws of physics.