Triumph Tiger 800 - Tuning - Air-box
If you want to contact me about anything on this site please email me -
In my opinion the standard air filter should flow enough air to keep
up with the flow through the throttle bodies so I am not planning to
upgrade the air filter anytime soon.
This is the view of the standard Air Intake on my 2015 Tiger 800, circled in
blue is the location of the one and only mounting screw.  The Air Intake is
easy to remove and a bit fiddly to replace.
View with the Air Intake removed, circled in Red is the large diameter
intake pipe, circled in yellow is part of a thin rubber skirt that stretches
across the top of the frame possibly to direct air, keep water out or to
maybe to keep noise in.
Photo of the Air Intake from an early Tiger 800,
note the narrow moulding and the small cross
Photo of the Air Intake from my Tiger 800 XCx 2015.  
No I have not been cutting away the moulding, this is
stock Triumph, clearly  effort has been made in
improve air flow into the Air-box.  The inside diameter
of the air intake is 47mm which is larger than the
single intake on my stock Tiger 1050.  However the
800 intake faces rearward, on the 1050 the intake
faced forward.
As I write this in October 2015 no one seems to have attempted an Air-box mod on a Tiger 800 2015.   It was easy to tweak my Tiger 955i and Tiger 1050
with Air-box mods to gain modest but tangible improvements in performance. ( I did not make changes to my Explorer, it  had more than enough power as
standard).  I do not want to spoil the road manners of the standard 800 motor.  On investigation It seems that Triumph have got there before me because
the air intake on the 2015 model is less restrictive.  Like all manufacturers Triumph are forced to restrict airflow into the Air-box in order to eliminate
induction noise.  So I am thinking will my Tiger 800 run better with the Air Intake moulding removed?  Also see Tuning Summary page.
Air-box - My Conclusion
When I put my Tiger 800 XCx on the Dyno we proved that the Arrow Tune +
the Leo Vince Evo2 silencer improved power delivery, especially at the
bottom end.  On my final run removing the plastic Air Intake improved low
end power slightly and gave the best fuelling.

I therefore decided to make a number of runs on the road with and without
the Air Intake in place and measure the results using the Torque App on my
Galaxy Note 4 phone.  I repeatedly tried Top Gear Roll-Ons from 2,500 revs
to measure 40-60, 60-80 and 80-100 times.  Without the air intake there was
more induction noise, this additional noise was obvious in the Dyno room but
less so on the road.

On the road the best results occurred when the Air Intake was in
.  This surprised me, there is little difference but the initial pickup 3 -
4,000 revs and 4 - 5000 revs was better with the plastic Air Intake in place.   I
assume that Triumph have spent a lot of time in a wind tunnel and the Air
Intake is designed to trap and redirect air as it flows through the Tiger's
bodywork.  I thought removing the Intake would help, it does in static air on
the Dyno but not when riding on the road.  Overall this is not a bad thing
because I can leave it in place and I do not have to tell my insurance
company or risk invalidating my warranty.
In my youth I spent many hours gas flowing all sorts of engines.  The Air
Intake moulding has many rough edges and the area below the intake hole is
particularly bad so I spent time smoothing these out with a rotary file to
improve air flow.  
Shame really, I was hoping that removing the Air Intake would result in a
marked improvement. I am sure that fitting a larger, shorter bellmouth close
to the Air-box would really help top end but I am not going to bother, too
much hassle to get it set up correctly.  If I want to go really fast I can ride my