Definition of BD Box Acel/Dcel

[Kestrel2126]

Could someone give me the definition of the Acel, and Dcel Parameters (AF, DR, SN and DF, DR, SN) in the BD Fuel control box, and how you are using them to tune. I'm running a Pro RMK with a '11-'12 model BD Fuel box (not the brand new one), with 3D Mapping. I've just upgraded from the standard 2860, to the Tial, as well as done an RKT head/Piston's combo. After the first break in ride today, I noticed a pretty significant stumble when I would get into the throttle, drop it completely, and then try to get back into it under load, or after it had dropped below engagement RPM's . I did expect to be rich, with the numbers from last year, but I am Just wondering if I should be adjusting those other two screens, or just the lower RPM screens and the "Extra" screen. Any help is appreciated.
THanks

 

[Kestrel2126]

Any help out there?

 

[WesG]

No help on the fuel box but...

Let me know how the new turbo compares to your old turbo if you don't mind.

Wes

 

[fastgas]

Could someone give me the definition of the Acel, and Dcel Parameters (AF, DR, SN and DF, DR, SN) in the BD Fuel control box, and how you are using them to tune. I'm running a Pro RMK with a '11-'12 model BD Fuel box (not the brand new one), with 3D Mapping. I've just upgraded from the standard 2860, to the Tial, as well as done an RKT head/Piston's combo. After the first break in ride today, I noticed a pretty significant stumble when I would get into the throttle, drop it completely, and then try to get back into it under load, or after it had dropped below engagement RPM's . I did expect to be rich, with the numbers from last year, but I am Just wondering if I should be adjusting those other two screens, or just the lower RPM screens and the "Extra" screen. Any help is appreciated.
THanks

AF = Accel Fuel (fuel amount added/removed during acceleration, every time when throttle is increased)
DF = Decel Fuel (fuel amount added/removed during deceleration, every time when throttle decreased)
DR = Duration (number of engine cycles fuel is added or subtracted)
SN = Sensitivity (smaller numbers make it more sensitive, 0=on all the time!)
Be careful making changes to ACEL/DCEL if you like to get "busy" on the throttle since it could disrupt the normal fueling too much.

Xtra settings are fuel adjustments that work independently of boost and are designed to shut off after boost reaches 2-4psi. This fueling is determined by the rpm LO/HI settings (fuel is only added between LO to HI) and when boost is below PSI (4.5 numbers per psi, so 9 = 2psi).

This year's program with integrated EBC has more adjustments and better blending (and tunes much better/easier) so you might want to check it out.

Edit: Some versions (later programs) have two ACEL fuel adjustments (AL/AH) that allow acceleration to be tuned in two stages. AL (Acel Low) works before boost reaches a set value and AH (Acel High) works when boost is above a set value. This value is determined by the Supertuner D setting: 4.5 numbers per 1psi, also on some versions if D=even number, it turns off the ADA feature so try to keep it on an odd number. (call if you need info on supertuner mode/settings - don't mess with A,B,C,D,E,CR,OS settings unless told to do so since they can really change how the box operates). Also earlier kits (early 2011) had 1 aux injector and later kits had 2 - the program settings and numbers are different. Placement of the boost sensor (should be in airbox, early Dragon kits were in throttle bodies) can also have a big effect on operation.