748R Airbox

[Old Baldy]

Anyone with experience running no airbox at all, with some tuning?

[foggy123]

Originally Posted by Old Baldy

Anyone with experience running no airbox at all, with some tuning?

Monsters do it all the time.

My 1080 4v motor uses pod filters and rides just fine. Can't say whether it would be better with a bigger airbox because on the monster/st bikes there is no room.

[DucatiStu]

You'll really only see the benefits of a bigger airbox at higher speeds. An engine will aspirate quite happily even when the bike isn't moving, however the idea behind an airbox is to generate a positive pressure to drive more air into the engine, especially when the bike moves and air is drawn into the system. The 748/916/996/749/999 and even the newer 848/1098 all have ram air induction and sealed airboxes in order to enhance this effect.
With a larger airbox the volume of air held inside it is greater, however this will mean that the pressure will not rise at the same rate as with a smaller airbox. Thus the airbox size on roadbikes can be the limiting factor and it is with this reason that race bikes have larger units fitted.
The essential message is that you need to be moving at great speeds in order to generate enough positive pressure (above 1 bar) in order to get the benefits from larger airboxes and this is why it is not always the most pressing upgrade to be made by most Ducati owners. Of greater benefit will be fitting tuned throttle bodies... larger bore or those with changed lengths

[foggy123]

BTW-
748r airbox is 2 pieces. Bottom is in the frame, top is what you see from the outside of the frame.

Bottom bolts to heads (2 bolts each head) then to rubber gasket boots send the fuel to the valves.

[TomTom]

OB, if you can wait until christmas or so I'll do a proper test, with and without box.

[DucMarauder]

Nice.....

First try opening up the EVR box so the inlets will accept the larger corse air runners. Then the breathing won't be restricted.....at the upper end of the dyno chart. A larger box should require a increase of airflow right?
The OEM tubes are your point of restriction. With your dyno chart you just have proved just how well the oem runners flow or the limit of the head flow.

Second with an increase in volume I would expect to see an increase in lower to midrange performance if the bike was tuned for this area of the powerband. The box would and has work better with a bigger bore and longer stroke motors that flowed more air and had the potential to make larger torque numbers. That's why this box performed so well on the 996 over the oem box considering it used the same air runners. On a 916 or one with larger valves?

The main benifit of the EVR box was bottom end performance drive on a stock bike, open it up and it got better if used properly.

Want upper rpm go with the 97 corse airbox. The factory got that one right.

I'm sure there is someone who had been on a corse team of long ago who might be a bit amused at this thread.

Like Brook Henery told me a long time ago," One can port an engine to a complete stop!" It's the same for building a motor....everything has a place and a use.

[sideways]

Originally Posted by TomTom

OB, if you can wait until christmas or so I'll do a proper test, with and without box.

That would be cool

[Old Baldy]

Originally Posted by TomTom

OB, if you can wait until christmas or so I'll do a proper test, with and without box.

Tom, at the rate I'm going now, I could wait for 3 YEARS!!!

Seriously though, that would be cool. My problem right now is...wondering about fitting bored 996 TBs to a Testastretta motor (with pod filters, no airbox) I'm sure as hell not going to be able to do pods on the showers.

[CrimsonCloak]

Is that setup far from what Ducati did with the S4RS in terms of throttle bodies? Might get some preliminary ideas from some of the Monster guys with velocity stacks and pods.