Modifying airbox?

[Space Cadet]

I’ve been told by a couple of Ducati mechanics now to leave the standard Ducati air-filter in as putting an uprated one in can lose low-down power, but have seen a few posts about modifying (cutting extra holes in) the air-box.

Would this give the same result, or would this benefit the standard air-filter?

[dlloyduk]

Just cut the whole top off leave the vertical sides intact-and wear earplugs!

[Bodybag]

Just cut the whole top off leave the vertical sides intact-and wear earplugs!

When you buy a Ducati Performance Airbox, thats exactly what it is. Literally, a standard airbox that someone has taken a knife to, like a lunchbox with the lid off.

[faulkss]

Air Box Lid before i took to it with a saw
http://fnfphotos.com/personal/posts/20080827/01.jpg

After i was finished (K&N was installed a day later)
http://fnfphotos.com/personal/posts/20080827/04.jpg

Just Cut it :D

[Space Cadet]

Thanks guys, looks like a project for the weekend!!, although what’s your opinion on the advice I’ve received to leave the standard air-filter in?

Should I modify the air-box and leave the standard air-filter, or is this effectively giving the same results as fitting an uprated filter.

I ‘only’ have a 620 and don’t want to loose any low-down power.

Thanks again, Mark

[Gilps]

We race a 620 in DD. Ours has the cut off lid and high flow filter. On a dyno we have no loss of power, only gains, although we are running a Power Commander too. Most of the paddock are running the same mod too. I can't see it causing a problem.

[Space Cadet]

Thanks.

Obviously I don’t want to seem argumentative, but what could the Ducati mechanics (two different garages) be referring to when they say not to upgrade the air-filter?

This is my first bike, but I've had lots of experience tuning cars and the right filter in the right application can help, most paper car filters are long-life low-costs options.

I’m all for sticking a better filter in and possibly gaining a few ponys as with modifying the air-box, but I just don’t want to do anything detrimental.

I’ve got a set of low-rise Termis on and the ECU was adjusted at the time by the Ducati dealer, but obviously no power-commander.

Perhaps this is what they’re saying, that unless the ECU is adjusted to take into account the uprated filter that the bike would lose some low down power. Car ECU’s can normal adjust themselves to take into account the better air-flow, perhaps my bike’s isn’t that advanced??

[Headhunter]

Hey fella,

I also have a 620ie with this set-up. Take the bike to Rosso Corse - www.rossocorse.co.uk and get fuelling mapped for c.£70.

Don't understand why they needed to mod ECU for the termi's alone.

[Space Cadet]

Coincidentally one of the mechanics was Ray at Rosso Corse!?

But since writing my last post I have just ordered a Ducati performance filter (with modified air-box lid) set.

I had to order a couple of 25p bolts and the postage would have been £7 so I had a chat with the guy about the airfilter/airbox situation and like you guys he didn’t know of any problems so I ordered one to justify the postage.

Do I still need to get the fuelling mapped?

[adam15]

It should be fine...sound like they are just trying to make some money when servicing your bike, like the air filter if its standard it will need replacing so therefore they get to sell you on lol

[Space Cadet]

I see your point, but the first mechanic was at the garage where I bought the bike from some 150 miles away knowing that I’m not going to likely ever bring the bike back to them.

And I trusted the 2nd mechanic (Ray at Rosso Corse) to give me an honest answer, he was doing some work for me and knew that he would be doing some other work soon, so I don’t think he gave his answer thinking of earning a couple of quid for a new filter in a year’s time when it needs servicing.

Both mechanics knew their stuff and I think they gave me honest answers, both said to leave the filters alone.

This is all immaterial now as like mentioned and based on all your replies I’ve bought a new filter and airbox lid set, cant wait to hear it now!!

[YoungDucS4R]

Both mechanics knew their stuff and I think they gave me honest answers, both said to leave the filters alone.



The subject of airbox design and internal harmonics is a very complex technical and complicated issue, but is widely accepted that it holds great substance.

The suggestion is that hacking and drilling the airbox is in fact destroying the inbuilt resonant properties which cause a positive internal pressure at certain frequencies, which can be "tuned" to certain engine revs.

On other forums this has been a very emotive subject!
A good point of reference on it is:

http://www.thunderproducts.com/AirboxesDynotech.htm

The author Kevin Cameron is a well respected, long time racer, mechanic, and writer for Cycle World Magazine.
It is the likes of this that your Ducati mechanics may be referring to.

YD.

[banditloon]

This is all immaterial now as like mentioned and based on all your replies I’ve bought a new filter and airbox lid set, cant wait to hear it now!!

I hope you have ordered some earplugs too ;)

[Space Cadet]

Thanks, very informative!!

I’ve ‘dealt’ with this problem with tuning cars in the past; usually up to a very high bhp level the standard air-boxes work far better than induction kits, the panel filters in the standard air-boxes can be uprated to allow better air-flow needed say for forced-induction engines.

Anyway, I’m hoping that by going for the Ducati performance filter and airbox lid specific to my bike that Ducati will have developed it to work with my engine/airbox and produce gains rather than messing things up and possibly seeing losses.

Coincidentally I spoke with yet another Ducati mechanic at lunch on another subject and I quickly asked him about the filter/airbox scenario and he said they are worthwhile to do and that it should work fine but ideally to get the fuelling checked to take into account the filter.

[Headhunter]

Ray definitely knows his stuff - likewise with Marcus.

I doubt very much you'll see any losses. Just in the ear dep't.

[mikej]

Does this mean i can cut the airbox lid off mine and not have to worry about getting a PCIII or anything?

I have race cans which haven't had any sort of effect on the fuelling, but i was always led to believe if i did the airbox mod i would need to get it set up on a dyno?

[dlloyduk]

I run mine most of the time with DP filter and open airbox and shortened termi,s with no ill effects, plugs always look ok so I can only assume it would run a little rich when standard.

Use my standard airbox on longer journeys for a little peace and quiet.

Only ill effects are a tendancy to keep the throttle open further and for longer, Monster induction roar sounds better than Termi's!

[desmo]

I have just fitted a DP air filter & open air box top & I have had no problems.

[Nickj]

Stock fuelling is usually on the conservative side and frequently richer than it needs to be, adds a bit more safety margin .. more fuel = cooler running and slightly less power. So a bit leaner will put out a bit more power and be within the tolerances for the standard fueling.

I found a cut box and my arrows gave me a real buzz, plus a tendancy to go for max noise, then a headache..

Must be old age :(

[Nickj]

Just looked at that article... errrr what's new about it?? Anyone with a background in 2 strokes ought to understand the same effects in expansion pipes happen in airboxes, it's always been about tuned resonanance.
We woz doin it to LCs 26 years ago with different length inlet tracts.

[Space Cadet]

Fitted the Ducati performance air-filter/air-box lid set last night, only took literally 2 minutes.

Haven’t been out for a ride yet, but started her up and all I can say is “ITS LOUD!!”, sounds absolutely fantastic!!, can’t believe it could have made so much difference.

[Space Cadet]

Stock fuelling is usually on the conservative side and frequently richer than it needs to be, adds a bit more safety margin .. more fuel = cooler running and slightly less power. So a bit leaner will put out a bit more power and be within the tolerances for the standard fueling.

I found a cut box and my arrows gave me a real buzz, plus a tendancy to go for max noise, then a headache..

Must be old age :(

I took my bike (with the performance filter/air-box fitted) to a local Ducati garage on Saturday and the mechanic took it for a test-ride and said it rode perfectly, apparently had a little flat-spot around 3k but much better than he’d seen on many standard bikes.

He said that it was running a little rich, even with the cans and filter so this ties up with what you were saying.

Plus the cans/filter would have actually helps make it a little leaner, so it much have been over rich from standard.

The only thing to do now he said was to fit a Power-commander and have it set-up on a rolling-road, but he said that it wouldn’t get much better than it was.

[Capo]

Just looked at that article... errrr what's new about it?? Anyone with a background in 2 strokes ought to understand the same effects in expansion pipes happen in airboxes, it's always been about tuned resonanance.
We woz doin it to LCs 26 years ago with different length inlet tracts.

That article probably dates from 30 years ago.

[Gilps]

I took my bike (with the performance filter/air-box fitted) to a local Ducati garage on Saturday and the mechanic took it for a test-ride and said it rode perfectly, apparently had a little flat-spot around 3k but much better than he’d seen on many standard bikes.

He said that it was running a little rich, even with the cans and filter so this ties up with what you were saying.

Plus the cans/filter would have actually helps make it a little leaner, so it much have been over rich from standard.

The only thing to do now he said was to fit a Power-commander and have it set-up on a rolling-road, but he said that it wouldn’t get much better than it was.

I'm surprised the dealer didn't try to adjust the fuel/air mixture using the mathesis. A Power Commander will certainly help but may be overkill if your stock ECU will actually allow the mixture to be adjusted correctly. It may not, in which case the PC would be the right way to go, but at least give the mathesis a try first to save a few pennies.

[BluprintZ]

So, Ducati's run a touch rich do they?
That would account for my not having had to use the choke very much, for starting first thing in the morning.
The bike lives outside, so as the weather get colder, i assume it will need to be used more.
I haven't had the spark plugs out since they were replaced in April, when i bought it, although the bike runs fine so i assume they are ok.
The airbox mods are interesting, more air = weaker mixture, so it's just a case of carb adjustment to compensate for the gain in air intake?
Bottom line is, most internal combustion engine are fairly similar, not exactly rocket science i'm sure most of you will agree.
Seeing as my `97 900 is a carb model, i don't have the dubious pleasure of having to take into account ECU'S, Power Commanders, etc, if i want to modify the airbox, or indeed remove it altogether and replace it with K&N's, or whatever.
I'll probably do that over winter, then pop it along to my friendly Dyno man and get it set-up, i'm also considering a two-into-one exhaust system, although i haven't yet decided what can i'll use.

[Rancid Badger]

I've been looking at doing an airbox mod to my S4RS, but rather than chop the lid about I was thinking of replacing it with K&N "Pod" filters.

Has anyone done this?

Does anyone know which ones I would need?

[Space Cadet]

The air box is the shape and volume it is for a reason, I personally would leave the air-box as it is and replace the filter and then chop the lid, or just buy a Ducati Performance filter/lid set as I did so you will have the originals as spare. If you wanted to save a few quid you could just cut the lid out yourself as they are the same part-number.

[skank]

I've been looking at doing an airbox mod to my S4RS, but rather than chop the lid about I was thinking of replacing it with K&N "Pod" filters.

Has anyone done this?

Does anyone know which ones I would need?

There has been reams of text on forums about running pods. the K&N's you need are RU-1750 (at least, thats what i run on my carbed 900)

AKAIK, no one has proved pods are any better than a cut box and flat filter, but open to correction on that. the TPO Beast kit comes with ram stacks which would help but its expensive.

[mediumdave]

I've got a '94 M900 - just had my airbox top cut off, K&N filter (make sure you get the right one - I was told there are two types for the old M900), new exhaust cans by Carbon Can Company (baffles out of course), the carbs needed a mild dynojet kit as the motor wasn't getting enough juice with the new set up - was set up properly on the Dyno and now runs flippin loverly, no flat spots, ticks over beautifully and sounds like thunder when given the berries.

Work was done by Moore Speed Racing in Poole who did a very neat airbox chop, and a superb job in the fitting and set up and got me a very good price on the cans (plus they did try to save me dosh by having a go at setting the carbs in the first instance without a jet kit but found I did need one), can't recommend them highly enough...

cheers

dave

[Bodybag]

I've been looking at doing an airbox mod to my S4RS, but rather than chop the lid about I was thinking of replacing it with K&N "Pod" filters.

Has anyone done this?

Does anyone know which ones I would need?

Markus did this to his S2R if that helps?