Crackles on overrun

[M12NTE]

Hi all

Bit of a random one this!

Background on the bike is, 2017, Rapidbike, Full Arrow system with long can, K&N filter, Block off plates.

I usually run the bike in 'user' mode, throttle and ddc in SLICK, TC and ABS in RACE.

So in User mode, there are no crackles on overrun at all (i'm talking above 10-11k)

Switched into Race mode today, and above 10-11k, the crackles on overrun are immense followed by a big old Boom at about 9k.

The question is, why are the characteristics different between the two settings?

Cheers Mark

 

[MoranC1]

In race the engine braking is probably different compared to slick so may use the exhaust flaps a bit more? Or more fuel on overrun to reduce engine vaccum

 

[M12NTE]

Yeah maybe.

No valve in the exhaust anymore, however servo motors still attached, so ecu still sending signals

 

[MoranC1]

true enough, was just reading this as i woke up, missed the full sys part.

assume its just downto mapping in the mode then.

 

[M12NTE]

Makes me wonder what engine mode the ecu was in when the rapidbike was mapped :culpability:, or does that not matter?

Depends on whether each mode has the same fuelling maps, but different throttle parameters/characteristics?

 

[alex]

The Rapid bike has configurable engine braking in it...so you can reset it to defaults if you want to test that. But, mine was also pretty strong on the pops and bangs, you could get a real throat clearer at times...

Kinda hilarious {inner child}

 

[MoranC1]

i have a stubby akra on mine, as on the over run at 4k it gives out a few almighty bangs

 

[M12NTE]

Don't get me wrong, it's sounds amazing, and like you say Alex, brings a smile to your face when the big old BOOOOOOM rings out.

Just thought it odd that it only does it like that on the RACE mode.

No bangs at all on overrun high up the rev range on USER.


Weird.

 

[alex]

You've got the block off plates and I would have thought they would have calmed it more tbh.
Who mapped yours? I think they usually map in slick with the DTC off...

 

[M12NTE]

John at Trackelectronics mapped the RB.

Yep, block off plates installed so should be minimal pops and bangs really.

Just add that it doesn't do it in USER. Maybe i'll try SLICK and SPORT mode on the way home, see what happens :culpability:

 

[alex]

Durr yes obvs. Having a brain fail.
Well as you're not on track go into the software and try disabling the Engine Braking (back the map up first). I'd be genuinely interested to know if it changes it. You can load the backup back in after.
If you're not comfortable with computers/changing it then NVM - just a curiosity.

 

[M12NTE]

Thanks Alex, i'll see if i can work it out.

Assume that Slick engine mode has minimal engine braking then, over the other modes?

 

[alex]

Thanks Alex, i'll see if i can work it out.

Assume that Slick engine mode has minimal engine braking then, over the other modes?

Yes. But in USER the engine would be the same if that was set to SLICK also.

 

[M12NTE]

Yes. But in USER the engine would be the same if that was set to SLICK also.

Yep, exactly that in my USER setting - Engine - SLICK, ddc - SLICK, abs - RACE, tc - RACE

 

[alex]

On your roads I'd have the DDC in RAIN

 

[M12NTE]

Tell me about it!

Drove up to Wells at the weekend.....definitely need to take the bike up there next time, cracking roads.

Run down from Wells - Swaffham - Thetford = Lush

 

[Corkgsxr]

Mine had immense crackling with the race. Disappeared completely with the pcv.

Some shock first time tho