Drilled Air Box ?

[Gerry]

A friend of mine had a nice Ducati (got a big BMW now) and he mentioned that on his Ducati he drilled holes in the airbox & fitted a K&N filter.

The theory is that the increased inlet air flow helped (together with a free flowing exhaust) but his main point was the nice noise it made as the air was sucked in.

Is any of this known or done by us Org'ers ?

Cheers
G

[lee67]

loads of diff bike forum's mention the same..alot of the tl lads did this too,(i never did)..my advice leave well alone, cos it will need setting up to run right imho

[LEXINGTONONE]

if you look at the JHS site they do a conversion kit that does away with the top of the air box and the filter element is then secured with just a band that holds the element down, I achieved the same on my SV by cutting the top of the air box, only thing is mine is a pointy so not sure if it will work on a curvy or not, this along with the filter and power commander (dynojet kit on a curvy) seems to make a big improvement and the noise is good too,

[Spanner Man]

Good afternoon all.

Who knows more about your motorcycles induction system, Suzuki, or Black & Decker?:D

Quite a few people indulge in the B&D school of airbox tuning, & apart from the noise, it does nothing for performance, & in some cases it ends up ruining the engine due to lean running. Leave well alone methinks!


Cheers.

[Gerry]

Good afternoon all.
Who knows more about your motorcycles induction system, Suzuki, or Black & Decker?:D

Quite a few people indulge in the B&D school of airbox tuning, & apart from the noise, it does nothing for performance, & in some cases it ends up ruining the engine due to lean running. Leave well alone methinks!
Cheers.

I see what you mean, but if you lived by that rule we would all have stock (quiet) cans :(

Sometimes manufacturers don't get all they can from a vehicle for many reasons (environmental, fuel economy etc etc).

Not rushing for a saw, but am interested...

Cheers
G

[Dave20046]

I've done this to a bike, it'll only work with carbs (I believe) however a couple of more knowledgeable members had a good laugh at me for doing it!
My idea was to accompany the straight through exhaust (more going out) and bigger jets (more petrol coming in) I'd need more air.

[fastdruid]

Well, if done correctly it *might* work, problem is that an airbox done properly *gains* power, you just need to fill it quickly enough.

If you look at for example the NC30 race bikes they drill the carb mounting plate and run without an airbox.

It would be very easy to c*ck things up and make things worse than stock or get a very small increase at one point in curve at the expense of a big drop elsewhere.

If you have a spare airbox and access to a dyno I'd give it a play, otherwise just get a performance filter (eg BMC or similar).

Druid

[Alpinestarhero]

I'm not sure of this. Isnt an airbox supposed to maintain some pressure, in order to aid "force feeding" the engine? Or is this only on "ram-air" type systems?

adding lots of holes could just aid turbulant air flow, potentially decreasing power

Be intersting to see a scientific study. Peronslly, I imagine you'll just hear a whole load more noise

[The Guru]

Duno about the Curvey, but on the pointy I swapped the 'Snorkel' air intake with that from an SV1000.

See the size difference..
http://forums.sv650.org/picture.php?albumid=207&pictureid=3718

That way you dont have to make holes all over the airfilter box and it can be returned to standard in 5min.

[fastdruid]

I'm not sure of this. Isnt an airbox supposed to maintain some pressure, in order to aid "force feeding" the engine? Or is this only on "ram-air" type systems?


No, the idea is to
a) Have a reservoir of calm fresh air
b) Take advantage of resonant effects to gain power.

In the case of ram air systems then it also runs at positive pressure at high speeds but the idea remains the same.


adding lots of holes could just aid turbulant air flow?


Not always a bad thing. Adding turbulence at the right point increases power. :-)

Airflow is odd though, sometimes less is more.

Druid

[Mr_Chin]

If it's just noise you're after, then just de-snorkle your air box and hear the horendous induction noise it makes. That way, you can simply put the snorkle back on once you're fully disgusted. I've tried the de-snorkling mod, and IMO it was gobsh!te. Just my opinion though, many may beg to differ. Chin

[Holdup]

Duno about the Curvey, but on the pointy I swapped the 'Snorkel' air intake with that from an SV1000.

I just removed mine and added a K&N filter at a later date, i noticed a difference in accelration immediately after removing the snorkel (but none extra with the K&N), paired with some tank risers (which i havent got) will aslo add a bonus

[Spikenipple]

I just removed mine and added a K&N filter at a later date, i noticed a difference in accelration immediately after removing the snorkel (but none extra with the K&N), paired with some tank risers (which i havent got) will aslo add a bonus

Placebo effect....

[Dave20046]

I just removed mine and added a K&N filter at a later date, i noticed a difference in accelration immediately after removing the snorkel (but none extra with the K&N), paired with some tank risers (which i havent got) will aslo add a bonus
Apparently tank risers are a can of worms fuelling wise, have you got a full race system?

Induction sounds supposedly unbearable with tank risers in, couple people have told me that. It's got to be really,really loud to make such a nice noise unbearable.

[xXBADGERXx]

I de-snorkeled and added tank raisers , the noise drowned out my can , was a waste of 30 minutes of my time and the raisers were sold on here for £5 a few hours later . No advantage whatsoever apart from sounding different to the rider .

[Holdup]

Apparently tank risers are a can of worms fuelling wise, have you got a full race system?

Induction sounds supposedly unbearable with tank risers in, couple people have told me that. It's got to be really,really loud to make such a nice noise unbearable.

Nah just an end can

I havent got tank risers and dont want them because i can see my filter getting wet(ter)

I dont think the induction noise is that bad, i barely notice it now

P.S. im a little tired so my post may not make sense...

[Dave20046]

P.S. im a little tired so my post may not make sense...
indeed

I was saying the induc noise is supposed to be bad with tank risers, not a problem when desnorkled.

I wouldn't have thought anything more than desnorkleing and possibly the airfilter would be worth it without a race system.

[madness]

Remember that the airbox is only the start of a long path for the air as it passes through the engine. What's point in having a super flowing airbox if flow is then restricted by inlet port size, valve diameter and shape, exhaust port size or exhaust.

[fastdruid]

I love the sound of mine.

BMC air filter (which has no snorkle)
http://www.fastdruid.co.uk/albums/SV650/thumbs/640x480DSC05294.JPG
and tank raisers.

The exhaust is still louder though :-)

Druid

[Dave20046]

I love the sound of mine.

BMC air filter (which has no snorkle)
http://www.fastdruid.co.uk/albums/SV650/thumbs/640x480DSC05294.JPG
and tank raisers.

The exhaust is still louder though :-)

Druid
Can't often hear mine over the snort :(

What other mods have you got? Much noteable change in performance?

[fastdruid]

Can't often hear mine over the snort :(

What other mods have you got? Much noteable change in performance?

I posted the full spec some time ago but to sum up

700cc (JHS, unknown amount of work[1][2])
BMC air filter
Akrapovic headers
Scorpion silencer
Geared down
*lots* of weight lost
USD frontend.

Just shy of 80BHP@rw.

It pulls like a train and tops out on park@cadwell.

Druid

[1] I bought the engine complete of someone going mini-twin racing who wanted a standard 650, came complete with a receipt for 1800quid for the engine work.
[2] The dyno guy said he thinks it has high compression pistons at the very least.

[bengrrr]

Don't forget guys 'n' girls any modification of your air box, filter will effect your insurance. Modification or performance enhancement needs to be declared, even a number plater change. Insurers are hot on finding a reason not to pay out! don't give them one!
That even goes for K&N filters, if you put them in you should let them know. Shouldn't effect your premium but if you don't declare you could find yourself in a spot of bother.

[dizzyblonde]

I have to run Suzy with a de snorkeled air filter and a Art race can, as it was dyno'd and re-jetted for it at Holeshot racing many years ago. TBH can't really see much performance enhancing going on.
However run her with a standard air filter and she runs like a bag of poo..did that once as an experiment, never again.

[jambo]

Curvy and pointy air boxes are very different designs.

But let's hold this thought for a sec. On the curvy if you drill holes in the air box you allow air to bypass the air filter. So your sandy gritty air is allowed past that lovely fine mesh, straight into the engine. That doesn't sound like a winning idea to me. On the curvy, a free-flowing air filter such as the BMC Race / BMC Race RS is as good as you want to go. Because the air intake at at the top of the air box, there may be a benefit in fitting tank raisers.

On the pointy I believe the air filter sits inside the air box seperating it into 2 halves (it's been a while since I've seen one open) so you probably could drill holes in some places without bypassing the air filter. I doubt this would help your power at all, but at least there's a potential for doing it without getting grit in the engine. As the air intake is at the front of the air box, not the top, tank raisers do nothing, but the SV1000 snorkel may help when combined with a free flowing air filter and a check for fuelling.

Jambo

[LEXINGTONONE]

Just to add to my previous comment, the standard airbox is probably fine for flow on a standard bike, perhaps a BMC filter might help a little if you also put a dynojet kit in to get the fuelling right, my bike is not standard and that is why there was a need to get more air going into the engine, this meant that the standard airbox/filter combination would not flow enough, on the pointy SV the filter is still doing it's job even with top of airbox removed, as for the noise well with a good exhaust system on the bike the noise seems to balance up just right with a combination of exhaust throb and induction roar.

[xXBADGERXx]

You could also remove the lining off the bottom of the tank if you want more air into the Curvy airbox , I`ve heard of that being done . Probably just as pointless as the rest of it to be honest .

[Dave20046]

I posted the full spec some time ago but to sum up

700cc (JHS, unknown amount of work[1][2])
BMC air filter
Akrapovic headers
Scorpion silencer
Geared down
*lots* of weight lost
USD frontend.

Just shy of 80BHP@rw.

It pulls like a train and tops out on park@cadwell.

Druid

[1] I bought the engine complete of someone going mini-twin racing who wanted a standard 650, came complete with a receipt for 1800quid for the engine work.
[2] The dyno guy said he thinks it has high compression pistons at the very least.
Sounds good!

[fastdruid]

You could also remove the lining off the bottom of the tank if you want more air into the Curvy airbox , I`ve heard of that being done . Probably just as pointless as the rest of it to be honest .

Yep, done that too. Noticed absolutely no difference but does remove the risk of it coming loose and blocking the airbox. Probably makes it a tadge louder too.

Druid

[xXBADGERXx]

Yep, done that too. Noticed absolutely no difference but does remove the risk of it coming loose and blocking the airbox. Probably makes it a tadge louder too.

Druid

Somebody on here had that problem a year or so ago didn`t they . The bike kept dying on them and it turned out to be a flappy loose bit of that lining , quick splash of contact adhesive and problem was sorted .

[fastdruid]

Somebody on here had that problem a year or so ago didn`t they . The bike kept dying on them and it turned out to be a flappy loose bit of that lining , quick splash of contact adhesive and problem was sorted .

The example I was thinking of was rather more than a year ago. :-)

But then I've been here since the old forum. ;-)

Druid

[xXBADGERXx]

Well the reason why he had such a problem with it was that no-one could help and somebody actually remembered the old story about it , probably the one you are reffering to . We had tried every other solution until somebody did a link and I was thinking "Bloody hell ......... yeah , that`d do it" . The guy came back an hour later after glueing it and was made up :)

Actually it might not have even been a guy , could have been a damsel in distress ?