When I was fixing the wiring on Levos' RGS the other day I noticed his was fitted with a trumpet thing on the airboc inlet, Mine is missing, so do these make a difference? Someone suggested cutting 2 40mm holes in the bottom of the airbox to increase flow, would that be better or should I get the trumpet so it's original?
Air inlet trumpet
- Thread starter drikko
- Start date
T
Terry Dymond
Guest
G'day Drikko,
Ran with the trumpet missing for ages, didn't seem to make much difference.
However, just recently, bowing to the collective wisdom and some, I drilled three holes in the bottom of the airbox and blanked off the original inlet.
The holes I drilled are the same diameter as the holes connecting to the carbies. I happened to have some old inlet manifold hoses lying around which I cut down to make some nifty trumpets that now stick out of the bottom of the airbox.
I induction noise is now very 'pleasing' and acceleration has accelerated :
.
Terry
Ran with the trumpet missing for ages, didn't seem to make much difference.
However, just recently, bowing to the collective wisdom and some, I drilled three holes in the bottom of the airbox and blanked off the original inlet.
The holes I drilled are the same diameter as the holes connecting to the carbies. I happened to have some old inlet manifold hoses lying around which I cut down to make some nifty trumpets that now stick out of the bottom of the airbox.
I induction noise is now very 'pleasing' and acceleration has accelerated :
.Terry
After many years struggling to remove/replace the trumpet on my SFC1000 every time I wanted to get at the battery, I eventually realised I should leave the stupid thing off. If I can find it in my boxes of bits I should advertise it on ebay. Must be a collectors item.
40mm holes in the airbox base must be mandatory.
cheers
40mm holes in the airbox base must be mandatory.
cheers
- Location
- Calgary, Alberta, Canada
drikko said:
the intake trumpet is tuned to eliminate all intake noise, and the stock RGS will run fine with it jetted on the mains at about 108 or so.
if you cut/drill 3 holes in the bottom of the air box each roughly the size of the intakes (about 32 mm) or maybe as big as 40 mm, the incoming air will be much less restricted, MUCH noiser, and will require richening the crab jetting as the engine will be flowing more air.
so, it is a trade off, a bunch of increased intake noise for a bit more power and needing to rejet up.
Paul LeClair
Laverdalothar
Hero member
- Location
- Germany
...and only might have an effect if you also drill the silencers end-cap as recommended in the Corsa/SFC parts list...
G
Grant
Guest
Corsa with drilled end caps on silencers and airbox has 118 mains and 65 pilot jets, K1 needles, middle notch.
T
Terry Dymond
Guest
G'day all,
I've been running a stainless free-flowing exhaust system (Staintune) for the last twenty years, with the standard air filter but the inlet trumpet removed. Couple of years ago I replaced the paper air filter with a unifilter foam item and felt that performance seemed to have dropped a bit and consumption seemed to be a bit high (G'day Maurice)
Was a bit alarmed by all the dire warnings about these filters on the forum but as I didn't have much of an option I persevered with it, lubricating it with pre-mix fuel (so that a fine film of oil stays on the filter after the fuel has evaporated).
Bike seems to be running fine now but as I'm a bit of a tuning ignorant, what size jets would you recommend.
Regards
Terry
I've been running a stainless free-flowing exhaust system (Staintune) for the last twenty years, with the standard air filter but the inlet trumpet removed. Couple of years ago I replaced the paper air filter with a unifilter foam item and felt that performance seemed to have dropped a bit and consumption seemed to be a bit high (G'day Maurice)
Was a bit alarmed by all the dire warnings about these filters on the forum but as I didn't have much of an option I persevered with it, lubricating it with pre-mix fuel (so that a fine film of oil stays on the filter after the fuel has evaporated).
Bike seems to be running fine now but as I'm a bit of a tuning ignorant, what size jets would you recommend.
Regards
Terry
redfox
Hero member
On the RGS I think Laverda used no holes in the airbox underneath. No holes in the end cap of muflers either, plus the trumphet.
On the SFC I think Laverda made the 2 40mm holes underneath the airbox, and 4 8mm holes in the end of the muflers, and the #118 mainjet together with the trumpehet.
There was a nice debate about aitflow/intake earlier on with these engines, that also spoke about a tapeted intake tract underneath each of the two holes.
Plus of course, the debate of the paper airfilter/foea filter/open tracts.
As I recall it, the general idea wes, that if you chose to use a foam fillter, clean in very well, and spray it very lightly with filter oil, not too much, or you'll loose power, but I am happy to be corrected in this by the writers of that debate. I think maybe Piet wrote something about the aditional trumphets underneath?
I use the original paper filters, two holes underneath, no trumphet and #118 mainjet on a bigger header/narrow collector/two Jota mufler system. Runs just fine.
And I saved 175 gr. leaving the rubbertrumphet on the shelf.
Cheers,
Jacques.
On the SFC I think Laverda made the 2 40mm holes underneath the airbox, and 4 8mm holes in the end of the muflers, and the #118 mainjet together with the trumpehet.
There was a nice debate about aitflow/intake earlier on with these engines, that also spoke about a tapeted intake tract underneath each of the two holes.
Plus of course, the debate of the paper airfilter/foea filter/open tracts.
As I recall it, the general idea wes, that if you chose to use a foam fillter, clean in very well, and spray it very lightly with filter oil, not too much, or you'll loose power, but I am happy to be corrected in this by the writers of that debate. I think maybe Piet wrote something about the aditional trumphets underneath?
I use the original paper filters, two holes underneath, no trumphet and #118 mainjet on a bigger header/narrow collector/two Jota mufler system. Runs just fine.
And I saved 175 gr. leaving the rubbertrumphet on the shelf.
Cheers,
Jacques.