Triumphrat

Geoff · 07-05-2006, 08:27 AM

I put one in. I saw a thread which said the result is still more restricted than the N.H. bellmouth, which does look a little bigger.
I wonder if there is any advantage to be had by rounding out the hole in the air-box door, so that the rubber will expand full size instead of being squished into the football shaped hole?
thoughts, comments, poisonous barbs??
Geoff

eagle · 07-05-2006, 09:51 AM

I may be being dim but - why bother fitting a bellmouth at all - just junk the original one. Wouldn't you get more air through the hole? And holes are dead cheap!

monkeyboy · 07-05-2006, 09:52 AM

My sentiments exactly.

Shorty · 07-05-2006, 10:13 AM

Don't know much about flow dynamics, but I always thought that the purpose of a bellmouth is to improve suction flow and to reduce cavitation (at least that's what I've been taught where aircraft jet engines are concerned). How much of a difference it makes in front of the airfilter as opposed to in front of the carb intakes is probably debateable (I would guess in front of the carb intake will make more of a difference in performance).
As far as re-shaping the hole (oval compared to round)...the surface area should be the same as should be the amount of air going through it, the dimensions will be different due to the difference in shape.
Even though I have the polaris bellmouth installed, I don't know if it makes any noticeable performance difference compared to not having it at all. It does clean-up the appearance of the hole (which you can't see under the side cover anyway) but it sure makes the bike intake sound cool in my opinion above around 3500 RPM...I'm talking some serious "Hoover Action".

Shorty

monkeyboy · 07-05-2006, 01:01 PM

Different than no bellmouth at all?

I always thought the best way would be to put some foam around the three sides so it seals the sidecover to the airbox, and leaving the front as a scoop. Maybe even cutting the front off a little to open it up more.

Shorty · 07-05-2006, 01:12 PM

I've been thinking about bell-mouthed air scoops pointing into the airflow also. Been looking around the plant to see if I can adapt some s***** parts to play with (we work on Aircraft Engines) but haven't found anything suitable. Kinda like a velocity stack, but I hear that someone sells them for HD's (Kuryakin I believe) and they say that they don't really work all that good to make a noticeable performance difference.

Shorty

I can't believe they edited s.c.r.a.p

[ This message was edited by: Shorty on 2006-07-05 12:14 ]

monkeyboy · 07-05-2006, 01:35 PM

The content filter has Tourettes.

I understand what you mean. I thought about bending up a small sheet metal one and riveting it on.

The large snorkel is only there to keep the sound down. That's gotta go.

eagle · 07-05-2006, 01:52 PM

Yeah - a snorkel - and no flippers? What were Triumph thinking of? :razz: