airbox mod

[stef]

jus in case this hasnt been posted yet,
here are two pics of my modified airbox, and the K&N.
http://www.chez.com/sdavid/photos/moto/airboxbefore.jpg
http://www.chez.com/sdavid/photos/moto/airboxafter.jpg
I left a bit of plastic, so that i have some more to drill out when i move to stage 2 jets.
(it seems that you will have to copy the URL in the address bar to get the link to work..crap webhoster !)

[A Yerbury]

hmm page not opening justa tiscali message?

[stef]

you get an error if you just click the link. you have to copy the URL in the address bar.

[Jamcoly]

you should have kept the raised lip at the back and opened up the front of the lid.

[Paranoid Dave]

http://www.chez.com/sdavid/photos/moto/airboxafter.jpg


I always wondered about the positioning. When I first saw my airbox lid and lifted the filter out I realised the air passes over the lid then has to travel back to the front of the box as the air passes through the inlets which are the other end of the airbox to the trumpets on the lid. Surely this means the air is travelling in an S formation to get into the engine? I would have thought taking the trumpets off would make it worse as without them the air will just pass straight over the box? I asked my service man about it and he said not to bother with airbox mods, I guess he meant in relation to anything not involving stage 1 or 2. Imagine what would happen if you moved the trumpets towards the front of the airbox?

[stef]

I only have the stage 1 jets and some loud cans, so i guess only a bit of the lid had to go.
i'll move to stage 2 in a couple of months, the rest of the lid will be drilled in a similar fashion. once the whole top is drilled, it wont matter if its too much at the back or too much at the front !

[Paranoid Dave]

Can I sak why you don't just take the lid off and run without one?? Suerly that beats drilling the hell out of plastic all afternoon ;)

[stef]

i tried it, but the filter will not stay properly on the box. i cannot leave any gaps on the sides, where air could just get in without passing through the filter. so the sides need to be pressed down by the lid.
I had a test run with insulating tape around the filter and no lid.
works well, but not reliable.

[A Yerbury]

I have a cut open and a drilled one, over time the cut one splays as the catches pull down on it, so now I have a roll bar airbox....

[Spike]

Dave if you moved the trumpets to the front of the box and had them face forward it would be a bit like any sports bike a kind of ram air system. Used to turn the heads around on the old bonnies that was fun with the bell mouths foward only problem is you have to clean the gauze of insects and crap every now and then :cool:

[A Yerbury]

then attach hoses and run thru front..ta da mzxr600.

[gary tompkins]

I've heard that even just removing the trumpets from the standard lid, may leave a bit of a hole in the midrange power and generally F**k up the jetting. Not sure if cutting out the top of the lid has the same effect, but would have thought any power gain (even with re-jetting) would be small on a 600.

I stuck a stage 2 dynojet kit, K&N and race cans on my 600 and only saw about an extra 3bhp at the back wheel, but it did improve the bikes mid range pick up and gave better MPG.

A dyno run would prove this one way or the other, and is something I want to do next year. I plan to match high Sil's already fitted with a Power Commander + K&N filter (no mods to lid) on the 900ie. DRC just did this to his M1000ie and got an impressive 100bhp at the back wheel!

In the end there's no substitute for cc's in the quest for more bhp :D

[A Yerbury]

a little bhp on a low bhp bike is a large percentage (maths innit) as you say its the low to mid where you feel it, and where its needed, and it works.
AY

[stef]

i agree. the bike runs better with the K&N, open box and race cans. it's definitely not as lumpy at the bottom end.

[MotoNik]

Forgive me if I sound patronising, and it's entirely possible I might be wrong in what I say, but surely there's going to be no difference between cutting different size holes, removing airbox snorkels etc. Ultimately there's one thing which determines how much air gets in to your engine, and that's the air filter.

The lid has two purposes - to keep induction noise down (for vehicle type approval) and to limit the amount of crap getting in and clogging your filter.

I've cut the top out of my airbox lid. It now sounds lovely, and will flow as much oxygen as the filter will allow it to.

If I remember I'll try and post a picture so you can see how I've done mine.

As an aside, someone mentioned just taping the filter in place (no lid to clamp it down). I believe Fast By Feracci or someone like that (in the US) do a filter clamping "ring" - which you could make yourself with a bit of aluminium...

cheers,

Nik

[A Yerbury]

hang on, if no lid is an improvement, then vis a vis a heavily drilled one will also be. logic innit. I had some b4 after dyno print outs somwhere.............

[MotoNik]

Indeed, a heavily drilled one would do the job just as nicely. :) I was more making the point about removing the snorkels and whether or not it has an effect on the performance. It probably does (very slightly), as it removes some restriction, but ultimately the filter can only flow so much air, and the only way to open up the full expanse of filter is to chop the lid, or heavily drill it.

BTW From experience this can cause problems with carb icing on a 600 (this could also be the case on other models). My M600 had undergone airbox lid surgery by a previous owner, and on one particularly cold ride up the M1 I found the revs remaining constant as I peeled off down a slip-road. Disconcerting until I released what it was. As soon as I slowed a bit the engine warmth thawed it out and it was ok again.

Never experienced any problems with rain getting in to the filter though, on the M600 or my 900ss. I think the trick is to leave at least 2" of airbox lid at the front, and that gives enough of a lip to prevent ingress of water. On that basis I probably wouldn't want to bother with a filter clamping ring which does away with the lid altogether. Unless you live somewhere a lot drier and warmer than the UK of course!

Nik

[A Yerbury]

Great minds nik, my previous open (prev owner) was just the rim, which splayed over time so that when the tank went down it would knock one of the (useless) clips off. got a new standard one, drilled away but lo whats this!!?? the new design is tapered at the front corners too narrow for kandN, chopped that but back to square one with front of filter exposed to english weather! one carved up video box and some zip ties later all is well!

[nambduke]

I've just bought a 1000ie late last summer and thats fitted with the high flow airbox filter. Basically it replaces the whole of the top box assembly as it has its own clips to hold it in. Might be another option for yourself and get rid of the 'modified' airbox?

Mines also fitted with high level Titanium cans and an ecu upgrade......sounds terrific.

[A Yerbury]

except that ducati charge money for what is effectively a standard box cut back to a rim job -ahem- yup u get the filter too but the chap already has the kn which is the same type of thing. the ducati kit is 50 plus vat I believe.

[Pedro]

Running without Trumpets?

I tried running my 900 with the trumpets removed from the airbox last weekend to try to get the plugs a better colour as it seems to be running a little rich. The theory being more air can flow etc.

Removing the trumpets only gives about 4 times the area for airflow and a whooping big hole in the mid range!! Wouldn't pull full throttle properly so the trumpets went back on!

Souded nice though......

[palooka]

If anyone has ever read Ian Fallon's excellent book on performance tuning for desmoquattro engines, he covers the subject of airbox mods quite well. Theory goes that the power gains associated with an airbox are not so much related to how open it is but more to it's "resonance" (Helmholtz resonation for the boffins out there). The volume of the airbox seems to be the important factor as it can act like a 2 stoke's expansion chamber (but obviously on the inlet side of the engine).
Fallon quotes Brooke Henry from Vee-Two here in Autralia and Chris Spalding from Sigma performance in the UK as saying that increasing the airbox size and making effective use of resonance is the way to go for good performance gains through the rev range.
That's not to say that a few judicial cuts and dices to the top of the airbox won't liberate a few ponies here and there!

Cheers

[A Yerbury]

that would explain why the pod style KN s would/could be restrictive?

[palooka]

Correct. Good point there.
Apparently there are some aftermarket filters out there that take up a bit of airbox volume and they have detrimental effects to performance. They supposedly do a better job at filtering but I think the standard Ducati filters are pretty good. I've never noticed any dirt or crud on the airbox.
Chris Spalding actually recommends spraying a bit of chain lube into the inlet tubes :rolleyes: but this is something probably more suited to a 916-996-998 type duke.

Having said that, I love the intake roar from my K&N filter :D

[manc skank]

read somewhere at some point when considering pods (aven't we all? :D )
that to get any gains from pods over standard opened airbox you would need to fit ram pipes over the carb mouths before fitting the pods.

will dig some more....

[manc skank]

a gain of 1.7HP using the DP airfilter kit according to Moto-One on a M800. without tuning or swapping the ECU.

http://www.moto-one.com.au/performance/800monster.html

more here

http://www.moto-one.com.au/performance/750ssie.html


moto-one is a trove of tuning info if you have to time to read. :cool:

[Flip]

O.K. my two penneth worth on the subject is...

The Monster range on the whole has a very restricted size airbox due to the amount of room there is under the fuel tank, therefore modifying or getting rid of the airbox lid completely can only be a good thing as it gives an airbox as large as is needed so long as the filter can pass enough air and the fueling can cope (the valves are included in this equation also don't forget).

It has taken taken some imagination and design to overcome this in the later Ducati models such as the 749/999 and Multistrada (they are HUUAGE!) have a look at Sigma Performance for more details to see what we with Monsters are up against: http://www.sigmaperformance.com/torquemonster.html

My old '97 900 now currently fires up with a stage two dyno-jet kit, fully open air box and free breathing FBF pipes (although the pipes probably make the least difference in all honesty but sound lovely to me although my neighbours may disagree).

Yerbs, I again spoke to those that know at PDQ (Emma & Jonathon) regarding pod filters and they basically said if it is for power gain then I may be out of luck as without 'a lot' of messing about with jetting etc (a stage two kit would be a good starting point) I might not see any but if it was for more asthetic reasons (albeit somewhat weather permitting) then to go for it and they are in stock for £28.94 a piece.

Ped if you want to have a little more of a play around (open airbox is DEFINITELY the way to go with proper jetting) I may have some dyno-jet jets in my garage along with a hacksaw for the airbox lid should your Dremmel be blunt after cutting carbon clutch covers.

[Matt Black]

Like Flip I also have an M900 and fitting the K&N was such a b*st*rd that the airbox lid and sides were removed. All I can see is filter. Looks fab. Dynojet stage 2 added at the same time and the bike had loads more stonk and the induction noise alone made it worth doing the mod.

A friend with a 900SS has also butchered the air box on his (very) similar engine.

[A Yerbury]

I am sure the airbox lids have changed size or something? the new ones dont fit between the frame and the lid of the k and n. thankfully I an an h'expert at cutting things up.

[DesmoDog]

Hmmm, I'm sure the previous owner had the bike K&N'd, yet the trumpets are there for all to see. I shall open her up tonight and take a look.

[A Yerbury]

the k n filter says k and n. this top tip brought to you by.........

[sjr999r]

Ive got a 900m,when i brought it,i had a stage 1 kit inside,(still has).the guy brought it off.kept going on about it.blah,blah,blah,i just wanted to see service history!!!! He had cut a 3 holes out infront of where the OE trumpets go,fair enough. He said,'Sounds really great, nice growl,good top end'
But what he didnt tell me,that there was no mid range,so i taped up the hole with gaffer tape, but put the trumpets back on,**** loads more midrange,but i will have to take the stage 1 off,as its black smoke out the back,a bit rich me thinks :o ..........do'h
sjr999r