20 valve trumpets: silver vs black

**oldcorollas** · 27-02-2009, 07:36 PM

part of the extra noise might be from the sound waves directly hitting the large flat side of the airbox, as opposed to being turned more to face the front of the airbox...

i am wondering how much effect there is from reflecting those waves toward the bellmouths.. seems like quite a bit... so ther emight be more scope for altering airbox shape/size as well as the trumpets... lots to play with

**gixer** · 27-02-2009, 07:38 PM

Yeah lot's to play with and soooo interesting. I will be leaving all that stock, I want the underbonnet to look stock if I get pulled over by the cops! Stealth mods

**gixer** · 27-02-2009, 07:39 PM

It would be nice to fuck with a variable trumpet length, would be trick as fuck and could get some good gains, maybe I should strt looking in the bike wrecking yards for the intake off an R6/R1, they have the 'two' staged ram tube length, could easily be hidden inside stock airbox(especially BT)

**oldcorollas** · 27-02-2009, 07:46 PM

funnily enough, thats what many production cars do.... not trumpets per se, but altering the length of the intake tract..
i had a pic of interesting beemer one, will look.. is constantly variable

**gixer** · 27-02-2009, 07:57 PM

Yeah I've been aware of variable intake tract length as you have pictured above, but usually complex to make for a diy'er. on ITB's changing ramtube length is very easy for a simpleton such as myself ;-)

I might keep my eye out for an R6/R1 set and have a play, might see if I can hit Yamaha up for a free set :-)

**kassma** · 28-02-2009, 12:42 AM

So for all round performance, what length VS would be recommended? I'm looking at the I.Mec ones you have, as well as the T3 VS, which are 70-75mm in length... Couldn't find any more performance figures for the T3s tho...

But have come across this one... where they were running 150mm VS and it gave them additional 14Hp, which is about 10Kw. http://www.efihardware.com/download/...alve-ram-tubes ... None-the-less... 150mm VS won't fit in the airbox.

Hence, my contemplation on which to get... although I have to admit... I'm keen on the IMec units.

MIKE.