ExBox, airbox and Fatduc

[motorad]

I did some searching and some reading but didn't come up with any definitive answers.  I have a 695 with Exbox and a fatduc.  Is the FatDuc capable of compensating for an open airbox?  If so what should I set it at?  Max?

Thanks in advance.

[He Man]

QD says the exbox works with stock ecu, so with an open airbox the fatduc should work.  just follow fat duc tuning instructions

[WhiteStripe]

I am by no means an expert, BUT having played around a lot with my FatDuc (including a few hundred miles with just an udder), i woudl say you will def not want it maxed, not even close.

The richest i have ever had it is at about 3:00 with jsut an udder and then arrows no dbs.  Putting he dbs in was able to lean out a bit more with no surging etc.

I do not have an open airbox, but i do not think that will make you want to go full rich.  I would personally start at 2:00 and then tweak richer from there.  As HeMan said, follow the FatDuc instructions.  YMMV.

Have fun.

[Moronic]

I may be mistaken but my impression is the FatDuc won't compensate for anything the stock ECU won't compensate for on its own.

Think about it: the FatDuc works by tricking the ECU into thinking the mixture is leaner than it really is. So the ECU adds a bit more fuel to get it right, and your bike runs richer and better.

BUT ... the enrichment is all coming from the ECU - that is, the FatDuc does not increase the ECU's capacity to add fuel.

So ... if opening the airbox causes the engine to run leaner, the stock ECU will detect that lean state with its 02 sensor and will enrich the mixture until the stock fuel ratio returns. That is assuming the ECU has the capacity to add enough fuel. However, IF IT DOES NOT, then adding the FatDuc won't help.

Of course if the ECU can add enough fuel to cope with an open airbox, then you should be able to tune the mixture with the FatDuc just like you can with the closed airbox.

Which should explain where to set the FatDuc - should be the same place in each case.

My 2c. 

[Moronic]

The FatDuc is really only effective in the closed loop map where the ECU isn't making all of the decisions unaided.

Fixed  .

If you open the airbox & it's running fine in the open loop but lousy in the closed loop the FatDuc will definitely help.  Wether it's enough or not I don't know but mine is def on the lean side of the FatDuc with a lot of adjustment left ('07 S4RS with Zard's).  Also I believe the ECU has the capacity to add enough fuel - it's just a matter of convincing it to do so.

Jury seems to be out on this, but I have a feeling you may be right.

A tune for the open loop will def be required.

And that is a very good point.