What are the actual downsides of removal? Is water more likely to enter the airbox? Is the air not as cold when sucked in without a snorkel?

 

I don't know 100% about air temp but.....
I've owned and ridden LOTS of bikes with correctly jetted carbs and no air box and or snorkel.

I've never had an engine washout with heavy rain and I've driven in some serious thunderstorm downpours with bikes that have anywhere from 2 to 4 cylinders using separate pods on them.
I can't say there will never be a case where leaving the snorkel on is a better fit because I don't go off road in swamps and jungles with a street bike but... so far, I don't think it really matters much.
I'm pretty convinced that the whole idea of the snorkel is more for sound control...curb drive-by, DOT requirements. etc.

 

No downside

 

Hmmm...

i'd be interested in hearing more about this: is there really no downside to taking the snorkel off? I have to admit I wonder.

 

removing the snorkel, gutting the air box baffles + putting on a bellmouth were common air cooled mods, even relocated my IAT sensor per Dr Forchetto!!!

 

Member Xtoff did some light experimenting by running without the snorkel for a short while with encouraging results:

http://www.triumphrat.net/water-cooled-twins-talk/752362-street-twin-airbox.html

The Free Spirits air filter kit bypasses the airbox, leaving it in place and the Australian importer claims +8 bhp at the rear wheel:

https://www.freespiritsparts.com/en...er-high-flow-kit-for-triumph-thruxton-1200-bonneville-t120-water-repellent.html

Australian importer:

http://triumphperformanceparts.com....cleaner-high-flow-kit-for-triumph-thruxton-1200-bonneville-t120-water-repellent

 

Snorkels are usually oriented with the opening down. This is to help separate heavier particulates from the air flow before it ever gets to the filter. Think less sand in the filter. It's their entire purpose. The T120's snorkel is very large, as is the filter. Neither of these pose any restriction to air flow. There's no reason to remove the snorkel, or to bypass or remove the filter. You're unlikely to get any noticeable increase in HP. As far as a usable increase goes, if you turn off TTC and goose a T120, the front and the rear wheels will try to swap ends, so there's already more power than can be used. So, what's the point of this little exercise, other than dicking with something that's working, only to be able to post about it?

 

So, what's the point of this little exercise...

Fair question. Answers: some people enjoy experimentation, general tinkering, looking for performance modifications, and learning something new.

... other than dicking with something that's working, only to be able to post about it?

Oh, you weren't actually asking a question.

Most objective reviews note a marked difference in intake sound (louder, throatier) and as @Xtoff mentions in his thread about ST airbox removal, he noticed a performance improvement.

Other than that weird looking cone intake from FreeSpirits (essentially an airbox bypass) there is no drop in performance air filter available for the water cooled twins yet. Several existing K&N filters are close to the same dimensions, but not quite, and they need to be the right size so that the gasket seals correctly and actual filtration takes place.

I'm interested in testing out some higher performance filters for a bit more power and improved intake growl. If anyone has any insight or knows of a new product definitely let me know.

Edit: I see DNA makes a drop in filter replacement:

https://www.e-dnafilters.com/produc...mph/DNA-1248/TRM-STTW/Triumph-Street-Twin-900-(2016)-DNA-Air-Filter-P-TR9N16-01

 

I saw this also : http://www.rg-racing.com/browsebike/Triumph/Street_Twin/2016/BMC-FM916-20/

 

most gains are at higher rpm + added fuel is necessary as to not get lean, more air + more fuel-at the proper ratio makes more power!! a cleanable reusable filter is a plus as well!

 

Adding a few more photos of a Street Twin snorkel removal. You can see the snorkel shape, and the inside of the airbox, which is baffled.

 

Adding a few more photos of a Street Twin snorkel removal. You can see the snorkel shape, and the inside of the airbox, which is baffled.

View attachment 462258

View attachment 462250

I haven't pulled the side covers off the T120 so visualizing the intake setup has been difficult until now. It looks like there is one snorkel under the left side cover and air is pulled from around the sides of the cover. I can't say what removing the snorkel or putting individual forward facing filters on each throttle body ($600 for 2 filters and 2 tubes????) would do in terms of lessening the restriction but for comparison, consider the Rocket. Here, the definition of snorkel is different. The air path is into a duct opening towards the back of the seat, through the seat duct, through a downward facing "snorkel" which fits over the airbox, through a single filter, and through a tube that comes out under the tank. This is fitted to a large plastic plenum that opens to three sections that fit over the three throttle bodies. The intake air temperature sensor fits into this plenum. This is the definition of restrictive. Changing the single filter in the airbox to a high flow Triumph or K&N filter did nothing. Ripping the plenum off and placing a K&N filter directly over each throttle body made a big difference in conjunction with a performance exhaust and a proper tune.

 

On my T120 I will install: FreeSpirits X-Pipe + V&H no Baffles (off-road) + FreeSpirits Aircleaner.
Will I need to remap?

 

I did it cause I could. And, it Does sound better upon accelerating. If you don't want to Dicker, then don't. Don't judge me cause I do.

 

I removed the snorkel and grommet on my Street Twin and the induction noise is noticeably louder under acceleration. It's noticeable enough even my wife noticed it without me saying anything.

 

Well noise is the only reason it's fitted in the first place, so it's definitely going to be louder. It only exists to reduce intake volume, like a muffler for the intake.
I took mine of the Thruxton as soon as I got it, mainly because I like hearing the intake roar.

 

Anyone noticed that on the inside of the side cover is a piece of plastic that sticks out - looks like it would partially cover / protect the snorkel opening, maybe it's a rain-guard. Wonder what effect it has.


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I love this assumption that 'ram air' would somehow improve the performance of the bike, but additional air requires additional fuelling, and unless you've maxed out the internal movement of air your engine is not going to be suffering from insufficient air intake, particularly when your bike red-lines at 7K rpm!
The snorkel is there to reduce noise. It reduces power, so it's blatantly not a source of 'ram air', and I'm extremely sceptical that the FreeSpirits Aircleaner does anything more than get in the way of your knees and give you a bit of 'brag factor'.
I've essentially opened the airbox on mine, and it gave a tiny extra air ratio, but no measurable power gain.

If you really want ram-air, fit a supercharger. You'll also need to reduce compression, but check out some of Scotty's dyno results, where he tops out at about 190bhp, and makes more at 2000rpm than my bike makes at peak!
Alternatively, go buy a ZX14.

 

I love this assumption that 'ram air' would somehow improve the performance of the bike, but additional air requires additional fuelling, and unless you've maxed out the internal movement of air your engine is not going to be suffering from insufficient air intake, particularly when your bike red-lines at 7K rpm!
The snorkel is there to reduce noise. It reduces power, so it's blatantly not a source of 'ram air', and I'm extremely sceptical that the FreeSpirits Aircleaner does anything more than get in the way of your knees and give you a bit of 'brag factor'.
I've essentially opened the airbox on mine, and it gave a tiny extra air ratio, but no measurable power gain.

Your reactions and expertise are always appreciated, but you're not the only one modifying these bikes and others have already done similar to what I was describing:

www.triumphrat.net/water-cooled-twins-talk/810441-street-twin-flat-track-hooligan.html

While I agree that these engines are not air starved, increasing the static and or dynamic pressure of the incoming charge is part of the equation to making more power. Fueling can be changed via aftermarket accessories like the PowerCommander.

I just like to tinker and have realistic expectations, but I've already netted power gains from my relatively simple existing mods. Hope you don't mind people like me sharing ideas and having a bit of fun with our customizations.

 

After reading this thread, I went out today on my Street Scrambler and not only removed the snorkel, but then completely gutted the lower half of the box. as in where the snorkel came out of is now a rather large hole so i can guarantee that it can breathe as good as it possibly can and I get cool induction noise. This combined with the fact that I decatted it, there is a major marked difference in acceleration. The little 900 screams now. It still needs a bit more power, but it's a lot less gutless now. I'm happy with what I've done to it so far.

Thankfully it's fuel injected so now rejetting needed and it compensates for the changes.

 

What so no filter?


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I did the same on the Thruxton after I'd taken some dyno runs, but on the Thruxton you don't get much additional benefit beyond that of the snorkel being removed, even with a DNA filter.
What was clear from the testing was that the engine is certainly not struggling to get air in, as apart from the initial gains there's nothing much else to gain on the intake side with the factory heads.

Now that "Flat Track Hooligan" bike is interesting. What they don't mention on there is exactly what it is that Triumph did that they can't tell us about, but I know that Triumph UK have not-for-market race heads available for the 1200 engine, so it makes sense they would also have them for the 900. I'd say this is where they found their hidden gains. The heads probably have increase compression and different cam profiles/timings, and would definitely come with a different ECU tune.

One thing's for sure, short of fitting a supercharger like Scotty did, nothing we've seen yet has exceeded the performance gains from a simple de-cat and de-snorkel. These engines are simply don't have much in the way of factory restriction, which is a little disappointing :/

 

it's an airbox mod. I don't think I've ever NOT modified the air box on anything i've ever owned if there wasn't a readily available affordable cold air intake, and like every one I've modded, it's not obvious that it's even modified unless you're looking for it.

Not at all in any way caring about needing or wanting a stock box. if the whole thing were more easily removed from the bike I would have seriously gone to town on it and even cut down the fins inside and removed the bellmouth on the "above the filter" side, but I know it's there to smooth incoming air turbulence.

K&N filter has been ordered.

 

A&J Cycles also sells pod filters for the 1200's that are only $60 for the pair

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Just wondering if anyone has tried putting the bike on a Dyno with and without the side cover. It seams to me (the average guy on the street and by no means an expert) that if the snorkel is restricting airflow then the side cover would as well. If my theory is correct, a side cover with a mesh covered hole would be an advantage along with the snorkel removal.

Just a thought.

 

We did this today. With the snorkel in place just by removing the cover the bike gained 3hp. But my bike is a 22 model which has the mesh covered holes, has an xpipe, dna filter and Dnk tune so I don’t know if the same will apply to stock bikes.