FatDuc - can't get it just right... - Ducati.ms

Activator · Jun 19th, 2009, 3:40 pm

Hey-

Well, I've read all the FatDuc posts over and over and I understand how it works, and it DEFINITELY works, but I just can't get it "perfect".

I'm working with a bone stock '08 non-S Hyper. I started at 13.5, which seemed to be the "default" setting from the posts I've read. That most definitely smoothed out the sub-4,000 rpm surging, as well as fully eliminating the popping on decel. Great, but the bike now felt "lifeless" and, while I was not having any idle surging or "sticking", the throttle didn't seem to "drop" as fast during normal shifting, so it was giving a little "rev", like blipping the throttle, between shifts... not pleasant.

So... I dropped the FatDuc to about 14 (leaner), which is roughly 9 O'clock on the dial. This brought the bike back to life, but now it was surging at low speed, and the popping on decel was back.

Today I "split the difference", and set the dial at roughly 10:30 O'clock, which is probably something like 13.7 or 13.8. This seems to be better... very little surging and only mild popping on decel, with plenty of power and no throttle stickiness... but it's still not 100%.

IS there such thing as 100%? Note that I've ridden 20-30 miles after each adjustment.

heffergm · Jun 19th, 2009, 6:23 pm

Short answer: no, there's no perfect setting. It's a stopgap solution to a problem that needs more sophistication (i.e. the DP ECU) to really deal with. The FatDuc just takes a stab at it and offers an $80 alternative.

FWIW, my results are pretty much the same as yours (bone stock): at 13.5, it's a bit too fat. No surging or popping, but the throttle response off load (like when blipping during shifts) suffers. Altough I haven't had any rev-hanging like you mention.

Leaner, around 13.9/1 or so, and it's still surging/popping a good bit. Split the difference and you get to a bit of a middle ground, which as you mention isn't really perfect.

After about 1000 miles of fiddling now and again, I've basically decided on about 13.7/1 or so, meaning just a hair counterclockwise from straight up (13.5/1).

Activator · Jun 19th, 2009, 9:36 pm

Sounds like I'm in the sweet spot. I'm going to try a hair richer - 11 O'clock/13.7-13.6 - and see if that's better , but I think I'm probably in the zone now.

Activator · Jun 28th, 2009, 9:24 am

So, after trying a dozen TINY tweaks to the FatDuc, I've settled (happily) at around "9:45" on the dial - approximately 13.95:1 in FatDuc speak.

At that setting I have virtually no surging under 4k rpm, no idle sticking, strong and clean acceleration, and just a bit of popping on decel - which I have to admit I actually LIKE!

One weird thing is that, when slowing in, say, 3rd gear, and the tach moves through the 4k range, I can actually FEEL a little surge/buck right at 4k, and then it immediately smoothes out.

Very happy now. The FatDuc in combination with the G2 Throttle Tamer has brought the Hyper's throttle response from "really good" to "perfection".

Suigeneris · Jun 28th, 2009, 1:14 pm

Hey guys, along the same subject, I just got the fatduc and the cat eliminator. If I install the cat eliminator, doesn't that loose the o2 sensor and thus the fatduc too?

**CDONA** · Jun 29th, 2009, 2:24 pm

Is there a bung for the O2 sensor on your cat eliminator? I have heard there is one on the LV version, Yes?

33996 · Jun 29th, 2009, 4:10 pm

Quote:

Originally Posted by CDONA

Is there a bung for the O2 sensor on your cat eliminator? I have heard there is one on the LV version, Yes?

Mine just showed up today, and YES it does have on and a plug should you choose not to use it.