Snorkel Mods 1290

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abc
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Snorkel Mods 1290

Postby abc » Sat May 21, 2016 11:14 am

When I first got my bike I tried removing the snorkels to see if it made any difference. I put them back in about 3 weeks later because I didnt think it made much difference.
I had another idea at the time but havent had time to do anything about it until now. So here are the details of the latest inlet mods I have done to my bike - I dont ride in the rain :roll:
Its designed to increase the volume and speed of the air and to stop the inlet air being wasted and flowing to the low pressure area below the Rotty filter.
First pics shows the fly screens removed from the entrance to the inlets. The stock set up is very restrictive but works to catch bugs.
Image
The next pic is of the mold I made to lay up a carbon "kicker" to redirect the cold air flow.
Image
Carbon layed up and being pumped down to cure.
Image
This pic shows just how much cold air is being wasted and how the deflector plate now redirects the air up to the filter medium whilst not choking the flow and still allowing the flow to expand.
Image
Plate fits well after lots of exacting mold design.
Image
Top view of fitted deflector plate.
Image
It might be worth mentioning that with the original fly screens removed the bugs can now travel along the snorkels. I am hoping that because they have a greater mass than the air they will move to the bottom of the snorkel and hit the "kicker plate" and therefor be de energised. Hopefully this will stop the filter foam from being eroded away.
I will report back after more testing.
Any modifications you undertake are your sole responsibility, I am not liable for any claims relating to modifications or suggestions posted on this forum. If you undertake any modifications you do so at your own risk.

abc
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Re: Snorkel Mods 1290

Postby abc » Tue May 24, 2016 2:35 am

I have had enough time to test these changes and have to say I am surprised by the results. I was almost not going to say anything about it but for such a simple mod it has proved very worthwhile.
The most difficult part was designing the diverter plate correctly so it forces the larger air volume to the area under the tank. There is still a bit of venting taking place in the low pressure area on the left hand side of the bike just above the Rotty insulation plate but I will fix that by placing another smaller diverter plate vertically to stop these losses.
The bike has responded to more air by being smoother and I believe crisper, so much so that I can feel the difference. I am very surprised by this!
The 1290 seems to respond well to as much airflow as you can give it - yippee
The next thing is to seal around the bottom of the tank so the area under the tank becomes a pressurised air box. This will take a little more time to achieve but it is now on my long list.
Oh yeh I also removed the sound deadening material from the underside of the tank.
More later.
Any modifications you undertake are your sole responsibility, I am not liable for any claims relating to modifications or suggestions posted on this forum. If you undertake any modifications you do so at your own risk.

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skollie
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Re: Snorkel Mods 1290

Postby skollie » Tue Oct 25, 2016 12:36 pm

abc wrote:I have had enough time to test these changes and have to say I am surprised by the results. I was almost not going to say anything about it but for such a simple mod it has proved very worthwhile.
The most difficult part was designing the diverter plate correctly so it forces the larger air volume to the area under the tank. There is still a bit of venting taking place in the low pressure area on the left hand side of the bike just above the Rotty insulation plate but I will fix that by placing another smaller diverter plate vertically to stop these losses.
The bike has responded to more air by being smoother and I believe crisper, so much so that I can feel the difference. I am very surprised by this!
The 1290 seems to respond well to as much airflow as you can give it - yippee
The next thing is to seal around the bottom of the tank so the area under the tank becomes a pressurised air box. This will take a little more time to achieve but it is now on my long list.
Oh yeh I also removed the sound deadening material from the underside of the tank.
More later.



When I bought my Rotty it had a ducting bracket diverter in the pack, which I fitted. Do you think it would be better to remove it, for better airflow?
I cant remove my grillage over my snorkels, as I get caught in the rain every now and then. (I don't go out in the rain, but have been caught, while out).
I am keen to remove deadening material under tank. Was this easy, and any tips?
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jmann
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Re: Snorkel Mods 1290

Postby jmann » Tue Oct 25, 2016 4:16 pm

This is very interesting comrade abc. Without being critical in any way I'd like to examine the reasoning. My memory is that you originally tried making larger vents in the front of the big black airbox and that didn't seem to have much effect (but perhaps it was Kevxtx). Generally, the Rotty replaces the original air box because it opens up everything with a view to sucking in as much air as it can because nothing is restricted. Your thinking is to now try to divert as much air as possible to the top of the velocity stacks by using the original ducts and creating a sealed system, or semi-sealed system, under the tank. Isn't that effectively making a larger air box than the original?

Relevant:
viewtopic.php?f=29&t=23840
http://www.ktmsmt.com/viewtopic.php?t=6511

abc
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Re: Snorkel Mods 1290

Postby abc » Tue Oct 25, 2016 10:07 pm

skollie - this is news to me, i have never seen anyone with another diverting plate downstream of the inlet ducts. Post pics maybe. OR maybe you are talking about the Rotty plate that is designed to reduce heatsoak and is placed above the front cylinder head???
I think kevxtx has a post on his forum about removing the sound deadening materials from under the tank - keep in mind that it will increase the resonance and therefor the induction noise. best go there to save me writing about the how to.
jmann - you sometimes do my head in :? :D
Yes it will eventually be a larger air box with the Rotty guts inside it, I still have to build the sealing flanges that will seal around the bottom of the tank and the bottom of the rotty base plate. This will eliminate any hot air that makes its way to the filter through heat soak.
My idea is that by removing the mesh from the front of the snorkels you immediately allow more cold airflow to the filter area. A simple area restriction calculation will determine this. Then I noticed that a lot of that increased cold air was being wasted and flowing to the area below the filter and effectively bleeding out the side, especially on the left side - as we all know air will always take the path of least resistance blah blah blah...............This bleeding was not that obvious when using the standard snorkels with the mesh screens fitted but once the mesh was removed it was obvious.
So i designed the diverter so it didnt choke the flow at the exit of the snorkels and kicked the flow up towards the filter and away from the lower venting areas, therefor not wasting all the extra air now being swept over the filter. I could have been a smart ass and placed pressure transducers in selected spots to effectively map the flow field and quantify the bleed rates etc but that is just not necessary because the airflow bleed in pretty obvious.
Once the bottom of the tank is sealed (making the bottom of the tank the new top of the air box)it will be a much larger area that will be fed with only cold air and in theory should improve performance.
If it doesnt work (and I think it will) I can easily remove everything and do the next thing on my list to make it go harder - it keeps me busy on those rainy days!
Any modifications you undertake are your sole responsibility, I am not liable for any claims relating to modifications or suggestions posted on this forum. If you undertake any modifications you do so at your own risk.

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jmann
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Re: Snorkel Mods 1290

Postby jmann » Wed Oct 26, 2016 1:04 am

Comrade abc: Profuse apologies for doing your head in. As you should know, I am but full of admiration for your ideas and work. If I could be just one tenth of the craftsman ...

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anexp
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Re: Snorkel Mods 1290

Postby anexp » Thu Oct 27, 2016 1:52 pm

Hello abc.

I had something similar to what you are describing on my 02 Aprilia Falco. The kit was made by Evolutione, although it did not consist of a trick CF diverter plate :wink: . It was just a billet and unit that replaced the top of the airbox with the rubber seal that pressure fit to the underside of the tank.

http://www.apriliaforum.com/forums/show ... ity-stacks

And because of your post, I have learned about Helmholtz.... So thanks for sparking my gray matter!
https://en.wikipedia.org/wiki/Airbox
https://en.wikipedia.org/wiki/Helmholtz_resonance

+1 on jmann's comment on craftmanship! Keep up the good work - I look forward to future updates!
Last edited by anexp on Sun Oct 30, 2016 9:57 pm, edited 1 time in total.
2015 KTM 1290 Super Dookie

DribbleDuke
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Re: Snorkel Mods 1290

Postby DribbleDuke » Thu Oct 27, 2016 4:20 pm

Too much turbulence. I doubt it creates much if any positive effect.
It did create more tinker time on a rainy day and in that it was beneficial.
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abc
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Re: Snorkel Mods 1290

Postby abc » Fri Oct 28, 2016 6:59 am

Theres disturbed airflow everywhere, even the flow being consumed at the entrance of the ducts would be a mess to map. There are issues with flow being restricted by the mesh and disturbances everywhere in the stock design and its interface with the rotty design. its better to have this cold airflow diverted over the filter medium than have it wasted and vented to the major area below the rotty baseplate and just stand by and allow the filter to suck heat soaked air - its as simple as that…..
Any modifications you undertake are your sole responsibility, I am not liable for any claims relating to modifications or suggestions posted on this forum. If you undertake any modifications you do so at your own risk.

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Dukem
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Re: Snorkel Mods 1290

Postby Dukem » Fri Oct 28, 2016 8:39 am

Great work abc, it gives me a couple ideas to do with my intake. cheers

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skollie
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Re: Snorkel Mods 1290

Postby skollie » Fri Oct 28, 2016 3:20 pm

abc wrote:skollie - this is news to me, i have never seen anyone with another diverting plate downstream of the inlet ducts. Post pics maybe. OR maybe you are talking about the Rotty plate that is designed to reduce heatsoak and is placed above the front cylinder head???
I think kevxtx has a post on his forum about removing the sound deadening materials from under the tank - keep in mind that it will increase the resonance and therefor the induction noise. best go there to save me writing about the how to.
jmann - you sometimes do my head in :? :D
Yes it will eventually be a larger air box with the Rotty guts inside it, I still have to build the sealing flanges that will seal around the bottom of the tank and the bottom of the rotty base plate. This will eliminate any hot air that makes its way to the filter through heat soak.
My idea is that by removing the mesh from the front of the snorkels you immediately allow more cold airflow to the filter area. A simple area restriction calculation will determine this. Then I noticed that a lot of that increased cold air was being wasted and flowing to the area below the filter and effectively bleeding out the side, especially on the left side - as we all know air will always take the path of least resistance blah blah blah...............This bleeding was not that obvious when using the standard snorkels with the mesh screens fitted but once the mesh was removed it was obvious.
So i designed the diverter so it didnt choke the flow at the exit of the snorkels and kicked the flow up towards the filter and away from the lower venting areas, therefor not wasting all the extra air now being swept over the filter. I could have been a smart ass and placed pressure transducers in selected spots to effectively map the flow field and quantify the bleed rates etc but that is just not necessary because the airflow bleed in pretty obvious.
Once the bottom of the tank is sealed (making the bottom of the tank the new top of the air box)it will be a much larger area that will be fed with only cold air and in theory should improve performance.
If it doesnt work (and I think it will) I can easily remove everything and do the next thing on my list to make it go harder - it keeps me busy on those rainy days!



I do not know how to put an attachment here, but this divertor plate came with my Rotty kit. I called Chris at Rottweiler performance yesterday, and he said the new kits dont have snorkel holding plate or divertor plate anymore. I will remove mine over winter break.
YOU KNOW IT MAKES SENSE

DribbleDuke
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Re: Snorkel Mods 1290

Postby DribbleDuke » Fri Oct 28, 2016 3:48 pm

abc wrote:Theres disturbed airflow everywhere, even the flow being consumed at the entrance of the ducts would be a mess to map. There are issues with flow being restricted by the mesh and disturbances everywhere in the stock design and its interface with the rotty design. its better to have this cold airflow diverted over the filter medium than have it wasted and vented to the major area below the rotty baseplate and just stand by and allow the filter to suck heat soaked air - its as simple as that…..

I see it that you are diverting air but what I see is that you are diverting it directly into the path of unrestricted airflow. Effectively pressurizing the upper area and creating a damping affect rather than a redistribution effect. The ramp is too steep
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abc
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Re: Snorkel Mods 1290

Postby abc » Sat Oct 29, 2016 3:16 am

the majority of that "unrestricted flow" is just pissing out below the filter baseplate and is wasted and useless, its better to use it in some way. Take a look at the side view of the assembly, as the kicker extends outwards its face moves further away from the inlet exits, this also spreads the flow upwards and over the sides of the filter - this effectively reduces the kicker influence as it progresses away for the centreline. Unfortunately the main constraint in the diverter plate design is in its packaging and the requirement to not choke the flow. Lower the ramp angle and you waste more available air. everything becomes a compromise the more it is constrained, thats also why there is a gap in the front edge to allow warmer air to be scavenged and contribute to the activity and help push the cold air flow higher.
If I had more time I would design a complete system and not try and work with existing interface and its restrictions.
Can you throw something into CAD at 1:1 and post it so I can see a better alternative, keeping in mind the restriction on space.
Any help is welcomed.
In the longterm all this won't matter because I would like to supercharge my bike and piss the rotty inlet and throttle bodies off. I would put the charger up top above the starter motor and push the new inlets up through the tank and just run big S&S throttle bodies. Of course driving the charger is the biggest issue along with the necessary frame and engine case mods - but I need a fair bit of time to achieve this and enough money to buy a smashed 1290 - all good things come to those that wait…….
Any modifications you undertake are your sole responsibility, I am not liable for any claims relating to modifications or suggestions posted on this forum. If you undertake any modifications you do so at your own risk.


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