Soft cut on 06 hayabusa?

[tcbusa]

Just wondering how the gen 1 2006 hayabusa limits the engine rpms? Got the motor apart the other day to find detonation on 1 and 4. while cylinders 2 and 3 looked brand new. ive heard somewhere the busa limits rpm by cutting fuel in cylinders 1 and 4 at redline? is this true? which would cause detonation. and how to remedy the problem?.. needs to be cutting spark instead of fuel in my mind

 

[turbobusa2000]

You need to flash your ecu to make the change.

 

[Commuta_Busa]

it's standard practice to toss the soft limiter on turbo and nitrous bikes. It's not a bad idea for NA engines as well.

 

[megawatt]

When doing the reflash it is changed to a hard cut (all cylinders not two) and it stops the spark, not the fuel.

 

[BigRod1300]

When doing the reflash it is changed to a hard cut (all cylinders not two) and it stops the spark, not the fuel.

YEP....Hard cut! Like said

 

[tcbusa]

yep thats what i thought. il post some pics of what happened. took out a chunk of piston 4 and 1 while 2 and 3 look brand new

 

[Professor]

It does soft cut the fuel on two cylinders, but I don't remember which ones. I remember Petrik posting the info when he first started exploring the ECU code. It cuts about 1/2 the injector pulses on the two cylinders. As stated, the ECU code can be modified to raise (or eliminate) the soft limit RPM (and Hard limiter).

 

[cdhoroho]

it cuts 1,4

be sure to check the other 2 pistons for lifted ring landings
cause 2,3 usually aren't very far behind 1,4
(just check as a precaution)

 

[busa2001]

Thats correct the pulses is reduce on 1,4 at red line, remove the softcut, you might also want to unify the fuel and ignition maps, i find it makes tuning much easier..