De-cat and power commander

[Mick753]

If you change either the intake or the exhaust profile/setup of the bike then it will in pretty much every case require some sort of adjustment on the fuel/air to bring it back to the perfect setting, that is a fact, unless of course the fueling system is adaptive and learns/adjusts itself then there has to be an adjustment of some sort to bring it back to where it was before the changes were made as it isn't going to do it itself.

Regardless of whether an exhaust manufacturer states that an aftermarket fueling module is "needed" that is just them stating that their exhaust "shouldn't" push the fueling out by much and in turn it should run fine.

The length of the exhaust and decatting a system can have a massive effect on the overall running of a bike, my last Aprilia ran like a complete bag of spanners and had dangerous flat spots throughout the rev range when I changed from Akrapovics to Mivv GP cans so much so that it would have needed not just a PCV but also the throttle bodies synchronising again to match them, and yet the manufacturer stated that they should be fine

Also having fitted an SC Project CRT exhaust on my HP4 system, it now grumbles and hesistates a little under 4K rpm and any hint of a blip when trying to change down the gears quickly is met with a hesitation.

Every engine is different but if you want the best out of your engine then any dramatic changes to the exhaust system (decat or going to a stubby from a full length silencer) should ideally be checked on a dyno, especially if the changes cause the bike to run lean, no point in throwing money at a can that pops and bangs because it's not setup right in my opinion

 

[pof]

My thoughts exactly mike

 

[soofsayer]

I would put money on these coping better, that why I asked. I guess some real data is required.

I got BMW to supply and fit my de-cat pipe on the full HP4 system and when I asked about any mapping changes they said the ECU adjusts itself for the difference in the fuelling. The bike has run great since with no issues.

 

[Mick753]

I got BMW to supply and fit my de-cat pipe on the full HP4 system and when I asked about any mapping changes they said the ECU adjusts itself for the difference in the fuelling. The bike has run great since with no issues.

That doesn't make any sense in reality though as that would mean that a PCV, Bazzaz or any other fueling module would be completely redundant if the ECU was already trimming the fueling to the correct ratio.

I have been reading that the HP Race calibration kit has an ECU that "learns" the exhaust profile but is that a standard feature on all S1000RR ECU's as mine certainly hasn't learnt it

 

[Iain-s1000rr]

If you change either the intake or the exhaust profile/setup of the bike then it will in pretty much every case require some sort of adjustment on the fuel/air to bring it back to the perfect setting, that is a fact, unless of course the fueling system is adaptive and learns/adjusts itself then there has to be an adjustment of some sort to bring it back to where it was before the changes were made as it isn't going to do it itself.Regardless of whether an exhaust manufacturer states that an aftermarket fueling module is "needed" that is just them stating that their exhaust "shouldn't" push the fueling out by much and in turn it should run fine.The length of the exhaust and decatting a system can have a massive effect on the overall running of a bike, my last Aprilia ran like a complete bag of spanners and had dangerous flat spots throughout the rev range when I changed from Akrapovics to Mivv GP cans so much so that it would have needed not just a PCV but also the throttle bodies synchronising again to match them, and yet the manufacturer stated that they should be fine Also having fitted an SC Project CRT exhaust on my HP4 system, it now grumbles and hesistates a little under 4K rpm and any hint of a blip when trying to change down the gears quickly is met with a hesitation.Every engine is different but if you want the best out of your engine then any dramatic changes to the exhaust system (decat or going to a stubby from a full length silencer) should ideally be checked on a dyno, especially if the changes cause the bike to run lean, no point in throwing money at a can that pops and bangs because it's not setup right in my opinion

Definitely agree, after thinking about it, the PCV & Dyno route is the best option as it brings peice of mind and clarity that everything is perfect. Even if i did fit the DE-Cat and didnt have a PCV and the fuel system did adjust to suit then in the back of my mind i would still be thinking that ive messed with it and not had it checked over.Thats the slip on i have managed to get hold of is a MIVV, need a de-cat to go with it now and the PCV then will get it all installed and dyno'd

 

[alex]

That doesn't make any sense in reality though as that would mean that a PCV, Bazzaz or any other fueling module would be completely redundant if the ECU was already trimming the fueling to the correct ratio.

I have been reading that the HP Race calibration kit has an ECU that "learns" the exhaust profile but is that a standard feature on all S1000RR ECU's as mine certainly hasn't learnt it

It's all about degrees/margins.
The HP4 has a smaller, less restrictive cat. I also has better software.
I would imagine that the air/fuel ratio change is less on an HP4 than a stocker.

If the BMW is using a good Lambda sensor and manifold pressure sensor it should be able to understand what is going in (AIR) and then be able to adjust the duty cycle of the injectors to suit. The question of needing a Bazzaz/PCV etc is one of how far the changes to the pumping efficiency of the engine go. It will be able to adjust in a set range. Beyond that, some ECU's go into a panic mode and just open the taps, others just carry on as they were. I expect our is the latter.

If you assume the ECU over fuels (for safety) by a margin of 5% anyway, you have wiggle room without changing anything. The ECU will seek to maintain the 5%. But where it can't (lack of available duty cycle on the injectors) you'll be eating into the 5%.

We will never know exactly what BMW have done. The PCV and Bazzaz etc are great tools and provide the ability to really match the fueling to our atmospheric conditions. To unleash area's of the map that are subdued for emissions reasons...but you may not NEED one. It's all about your bike and engine. The best solution will always be a custom map...with a MoTeC

 

[SimonOrsborn]

I think I will get my S1000RR Hilltop-ed in a few months time. I should think it is running lean for sure. I had my gixxer remapped by Steve Jordan a couple of years ago and whilst the before and after dynos were very similar I could instantly feel the improved throttle response and smoothness. The main reason I went for the decat was for the sound. Got a Two Brothers can and that came with a baffle tip that surprisingly quietens it down a lot. I'll probably be needing that for the MOT and track days.

 

[alex]

The MOT doesn't give a hoot what noise or emissions come out of a bike...currently. The trackday noise levels are the thing to be concerned with. So that you can attend the club days!

 

[richy170]

Excuse my ignorance, I know what a PCV does in basic terms, what is the difference from a PCV and an ECU flash at Hilltop. From reading all the threads on here for the last year people can't speak highly enough about Hilltop. Is an ECU flash at Hilltop an alternative to a PCV. If so where are they and anyone know how much it is. I ask as I am looking at buying an Akrapovic titanium header to go with the end can.

 

[bananaman]

From what little I know, reflash is permanent as the ecu is changed internally. Depending on the age of the bike whether it interferes with warranties

 

[alex]

Track Electronics said they wouldn't do BMW ECU cause of reliability issues. I don't know how Hilltop got around that. I don't want to scare munger. I don't know how the process is different between the 2.