Purpose of rubber intake snorkels

[bigbikerrick]

I was going to do the "sewer pipe ram air intake mod" today while I had things apart, and pulled off the 2 rubber snorkels on the airbox intakes and it seemed they can just be left off for a less restrictive intake,it doesnt seem water will get up the plastic pipes as its quite a distance up, and also there is a drain opening on the bottom of each chamber. what is the purpose of these rubber pieces and has anyone tried running without them? any improvement in performance/mileage, sound etc?

[Skeeve]

I was going to do the "sewer pipe ram air intake mod" today while I had things apart, and pulled off the 2 rubber snorkels on the airbox intakes and it seemed they can just be left off for a less restrictive intake,it doesnt seem water will get up the plastic pipes as its quite a distance up, and also there is a drain opening on the bottom of each chamber. what is the purpose of these rubber pieces and has anyone tried running without them? any improvement in performance/mileage, sound etc?

81677[/snapback]

 

 

The idea is to pull cooler air from in front of the engine, rather than warm air from above it.

[belfastguzzi]

Is a ram air effect really going to be achieved anyway?

 

I cut the back half of the airbox lid off (which gives the less restrictive intake that you are after, by way of destroying MG's carefully designed aerodynamics) but left the front half with the full intake snorkels, for the purpose Skeeve mentions – to assist the passage of cool air to the underseat area and intake system.

[mark.gilmore]

Is a ram air effect really going to be achieved anyway?

 

I cut the back half of the airbox lid off (which gives the less restrictive intake that you are after, by way of destroying MG's carefully designed aerodynamics) but left the front half with the full intake snorkels, for the purpose Skeeve mentions – to assist the passage of cool air to the underseat area and intake system.

81687[/snapback]

 

 

Good thinking Belfast,might do the same to mine.I just took the rubber thingys off the other day,can't tell the diff around town but will go for good ride on Sunday in our local twisties,might even cut the back of that box like you did.

 

Gilly

[biesel]

I think, that they just should prevent more noise emission.

WithOUT the snorkels the engine will get cooler air.

[Guest ratchethack]

I was going to do the "sewer pipe ram air intake mod" today while I had things apart, and pulled off the 2 rubber snorkels on the airbox intakes and it seemed they can just be left off for a less restrictive intake,it doesnt seem water will get up the plastic pipes as its quite a distance up, and also there is a drain opening on the bottom of each chamber. what is the purpose of these rubber pieces and has anyone tried running without them? any improvement in performance/mileage, sound etc?

Rick, FWIW, I've experimented with these things a bit. Here's what I found:

 

1. A standard-issue 1 1/2" black ABS 135-degree "ell" with male one end, female other end, is a "perfect" replacement fit for the stock rubber pieces. The part number on the ones I found is D-2661. They cost less than a dollar at the local plumbing supplier as I recall. As far as I can tell, they don't do a damned thing in any way detectable. You can experiment by putting them on in place of the stock ones and then put the stock rubber pieces on the ends, thereby lengthening the intake tracts, with identical results.

 

2. To justify much more of an expenditure of effort on pre-filter snorkel modifications, you really have to be concerned about extended-range engine performance at WOT - otherwise, what difference could it possibly make? Being an incorrigible Road Geez with no autobahn likely at any point in my entire Nation's future (stupid, just plain stupid ), I'm not so disposed. But for less than a dollar, the above was another thing to think about and fiddle with at next to no cost.

 

3. I concluded that the "slot" shape of the standard-issue intake rubbers very likely not only has a negligible effect on performace (even at WOT), but like intake designs on cars with the same air horn shape, it helps reflect the sound waves of intake "honk" back toward the airbox, helping the bike get by noise emission requirements.

 

4. Their placement in front of the engine would seem to have some performance benefits in terms of ducting cool air - but only when the bike is idling and stationary! This is just me, but I don't lose much sleep worrying about intake charge density at idle... Underway, in buffetted and swirling air, my take is that the location of the end of intake tracts very likely doesn't matter, unless it's in a known spot of lower relative pressure significant enough to affect the air pressure inside the airbox. With the bike underway, they seem to be out of the way of heated engine air and swirling road debris.

 

5. No reason to be concerned about potential water entry in the intake horns. As you mentioned, there are drains in the snorkels. As I recall from having it out, the air box also has drain(s) at the bottom to prevent accumulation of condensed oil vented from the frame/oil condenser.

 

6. IMHO, the idea of creating a super-charging "ram air" effect on the V-11 is futile. Far better to spend your time chasing chimeras elsewhere. On a highly tuned modern race bike, on the other hand, there may be some benefit at speeds over let's say 150 mph - and these benefits would be to possibly very slightly decrease the intake horn vacuum relative to ambient - ONLY AT WOT, and assuming a highly-engineered, highly-tuned intake tract designed in a wind tunnel for racing and optimized specifically for running at WOT, with the intakes placed at or near the leading edge of a highly engineered fairing designed for the purpose of ducting air at high speed. Barring this, trying to "supercharge" a V-11 this way would seem to be simply a fool's errand - but of course, that's just me.

 

AAA, YMMV

[dlaing]

a highly engineered fairing

81710[/snapback]

I am a proponent of ram air and just because someone has not yet been smart enough to

prove

that it has benefits, does not make it a fool's errand.

To prove that it works, you would need a wind tunnel with air flow meters on the intakes.

But just to make it work requires uncommon sense, WBO2 for safety, and some sewer pipe and if you need to prove it to yourself, some high speed runs.

Maximum speed is not the only potential benefit.

If the Air fuel ratio is set up right one might be able to tune it so that they get maybe a 12.5/1 ratio in first gear leaning out to maybe 13.0/1 in sixth gear.

This would help highway touring fuel mileage while keeping the engine cool in the city.

For those pursuing peak HP, I don't think it will work great in all gears because the air pressure compensation is not accurate enough...but power is not everything.

The changes would likely be subtle and only have an effect of one HP or one MPG, but to me that would be worth it.

[bigbikerrick]

Rick, FWIW, I've experimented with these things a bit.  Here's what I found:

 

1.  A standard-issue 1 1/2" black ABS 135-degree "ell" with male one end, female other end, is a "perfect" replacement fit for the stock rubber pieces.  The part number on the ones I found is D-2661.  They cost less than a dollar at the local plumbing supplier as I recall.  As far as I can tell, they don't do a damned thing in any way detectable.  You can experiment by putting them on in place of the stock ones and then put the stock rubber pieces on the ends, thereby lengthening the intake tracts, with identical results. <_>

 

2.  To justify much more of an expenditure of effort on pre-filter snorkel modifications, you really have to be concerned about extended-range engine performance at WOT - otherwise, what difference could it possibly make?   Being an incorrigible Road Geez with no autobahn likely at any point in my entire Nation's future (stupid, just plain stupid ), I'm not so disposed.  But for less than a dollar, the above was another thing to think about and fiddle with at next to no cost.  

 

3.  I concluded that the "slot" shape of the standard-issue intake rubbers very likely not only has a negligible effect on performace (even at WOT), but like intake designs on cars with the same air horn shape, it helps reflect the sound waves of intake "honk" back toward the airbox, helping the bike get by noise emission requirements.

 

4.  Their placement in front of the engine would seem to have some performance benefits in terms of ducting cool air - but only when the bike is idling and stationary!  This is just me, but I don't lose much sleep worrying about intake charge density at idle... <_ underway in buffetted and swirling air my take is that the location of end intake tracts very likely doesn matter unless it a known spot lower relative pressure significant enough to affect inside airbox. src="%7B___base_url___%7D/uploads/emoticons/default_knownothing.gif" alt=":huh2:">  With the bike underway, they seem to be out of the way of heated engine air and swirling road debris.

 

5.  No reason to be concerned about potential water entry in the intake horns.  As you mentioned, there are drains in the snorkels.  As I recall from having it out, the air box also has drain(s) at the bottom to prevent accumulation of condensed oil vented from the frame/oil condenser.

 

6.  IMHO, the idea of creating a super-charging "ram air" effect on the V-11 is futile.  Far better to spend your time chasing chimeras elsewhere.  On a highly tuned modern race bike, on the other hand, there may be some benefit at speeds over let's say 150 mph - and these benefits would be to possibly very slightly decrease the intake horn vacuum relative to ambient - ONLY AT WOT, and assuming a highly-engineered, highly-tuned intake tract designed in a wind tunnel for racing and optimized specifically for running at WOT, with the intakes placed at or near the leading edge of a highly engineered fairing designed for the purpose of ducting air at high speed.  Barring this, trying to "supercharge" a V-11 this way would seem to be simply a fool's errand - but of course, that's just me.

 

AAA, YMMV

81710[/snapback]

Thanks RH, I knew you would come around with an intellingent, common sense response, I must agree with your hypothesis. alothough sometimes we all have fun and entertainment with "fools errands" HeHe, as the saying goes.... "theres no fool like an old fool"

[Daniel Kalal]

An open Guzzi induction system can be fairly loud. To pass the EPA noise emission test (which involves accelerating past a set of microphones at a fairly high throttle setting--I just looked it up) it would be better to separate all sources of noise as much as possible so the mics don't pick up both induction and exhaust at the same time from the same direction.

[Guest ratchethack]

...a highly-engineered, highly-tuned intake tract designed in a wind tunnel for racing and optimized specifically for running at WOT, with the intakes placed at or near the leading edge of a highly engineered fairing designed for the purpose of ducting air at high speed....trying to "supercharge" ....this way would seem to be simply a fool's errand - but of course, that's just me.

Well Gosh, Golly and Gee Whiz! I reckon I might've been all wrong on this one after all...

 

Ya just gotta LOVE the idea of that incredibly powerful "ram-air" supercharging effect through two giant fairing intakes - in combination with leading-link forks - on a vintage BayerischeMotorenWerkeZwillingsWaffen sled...

[Skeeve]

Ya just gotta LOVE the idea of that incredibly powerful "ram-air" supercharging effect through two giant fairing intakes - in combination with leading-link forks - on a vintage BayerischeMotorenWerkeZwillingsWaffen sled...

81931[/snapback]

 

Yah, those Beemer owners don't respect anything w/o those dumb kidney-shaped grills, not even a Bimmer...

[luhbo]

I had the snorkels removed once. It will give you more annoying noise and less air, means less power.

You can proove it. If someone has an O2 probe installed he will see that without the snorkels ARF is richer.

 

Hubert

[dlaing]

Ya just gotta LOVE the idea of that incredibly powerful "ram-air" supercharging effect through two giant fairing intakes - in combination with leading-link forks - on a vintage BayerischeMotorenWerkeZwillingsWaffen sled...

81931[/snapback]

I love it!

They just need to upgrade to a decent pair of shocks.

If I was sensible, I'd get a bike like that!

[dlaing]

I had the snorkels removed once. It will give you more annoying noise and less air, means less power.

You can proove it. If someone has an O2 probe installed he will see that without the snorkels ARF is richer.

 

Hubert

81983[/snapback]

Did you test it with an O2 probe?

Was this just the rubber snorkles removed and the plastic snorkles still in place?

Or was this lidless or just the plastic snorkles trimmed?

[belfastguzzi]

Surely Raceco would not have removed the airbox lid if it meant that the result was less air and less power?