Full Akrapovic with no power commander according to BMW!

[nwills]

Spoke for a good 20 min. today with the head Motorrad tech at my BMW dealer about full exhausts and power commanders/remaps.

Here's what he had to say....

According to him the ECU on the S1K is totally adaptive. The idea of over-riding the ECU with a map from a power commander is a bad idea (in his opinion).

He said that when you go with a full system the bike will learn it and remap itself in a way that is absolutely optimal.

He also claims that the idea of the bike running lean is absolute bull$hit considering how "adaptive" and real time the ECU will remap.

BMW sells Akrapovic exhausts as part of their catalog and fully support their products. On the other hand any modifications to the electronics such as a power commander piggy backing on the ECU is a great way to potentially cause warranty issues if a problem came up. Hence the reason BMW does not offer any power commander options of any sort nor do they in any way support it.

As a BMW corporate option they offer full Akrapovic systems without any type of power commander and there's a reason for that....

Not sure what to make of that but it seems like a valid argument!?

What do you guys think?

[demon]

As far as Im aware, the akrapovic exhausts are sold for the bikes standard set settings. All their catalogue figures are shown for this, and without a PC.
Nigel will be along shortly to inform you of the ECU setup.

[Poodie]

I bought a full Shorty SS Akra Evo. I planned on putting on the exhaust, driving for a few weeks then putting on the PCV so I can comment on how much better it was. As it probably is more smooth, I haven't gotten a PCV yet... Runs great. No dyno yet

[2_stroke_bloke]

I doubt the stock ECU has the range of ignition retardation and advance, AFR adjustability that a PC would. It might, but I highly doubt it.

[1ntheoc]

Originally Posted by 2_stroke_bloke

I doubt the stock ECU has the range of ignition retardation and advance, AFR adjustability that a PC would. It might, but I highly doubt it.

I agree, it probably doesn't, but it probably does have enough to make up for a free flowing exhaust...

A power commander (or any piggyback) will allow you to make more power, exhaust or not. It's going to allow you to optimize air/fuel and timing.

The OEM ECU has the ability to learn and make changes, however, these changes are in an effort to conform to the OEM fuel/timing map which is not optimal for power. Keep in mind, when a manufacturer creates a map, they have no idea what fuel you'll be using, what ambient temps you'll be in, what the altitude will be, what humidity will be, how much load will be on the bike, etc, etc. So, their target map is very "safe".

[1ntheoc]

Originally Posted by nwills

Spoke for a good 20 min. today with the head Motorrad tech at my BMW dealer about full exhausts and power commanders/remaps.

Here's what he had to say....

According to him the ECU on the S1K is totally adaptive. The idea of over-riding the ECU with a map from a power commander is a bad idea (in his opinion).

He said that when you go with a full system the bike will learn it and remap itself in a way that is absolutely optimal.

He also claims that the idea of the bike running lean is absolute bull$hit considering how "adaptive" and real time the ECU will remap.

BMW sells Akrapovic exhausts as part of their catalog and fully support their products. On the other hand any modifications to the electronics such as a power commander piggy backing on the ECU is a great way to potentially cause warranty issues if a problem came up. Hence the reason BMW does not offer any power commander options of any sort nor do they in any way support it.

As a BMW corporate option they offer full Akrapovic systems without any type of power commander and there's a reason for that....

Not sure what to make of that but it seems like a valid argument!?

What do you guys think?

The tech is 100% correct. This doesn't mean that a bike won't benefit from a power commander (exhaust or not); it most certainly will... but it's not needed.

[mikef4uk]

i also have the full Akra/long can, I took my PCV off for the BMW service and yes the bike ran fine, it was noticable that I had to twist the throttle more to get the same acceleration as with the PCV and I found the throttle stop a lot easier.

The bike however runs much better with the PCV fitted: in fact it's ballistic

I also run the autotune, I have narrowed the tuning band to +/- 5% now that the map is complete, one thing that is noticeable is depending on the ambient temperature the autotune trims can vary between these limits, sometimes they are all very close to +5% and other times -5%, that's nearly a 10% swing in fuelling

[verrucktaxe]

not that mileage is my primary concern (i drive a V8, not a hybrid), but it is a concern if riding through west Texas in the middle of the night like a few weeks ago. the PC kicks the mixture from the below-stoich ratio to a richer ratio if i recall correctly, so how does that affect the mileage from what you guys are seeing? i got 46 mpg if i was just cruising at 90 on the way to CO. just curious.

[Nigel]

Nothing wrong with what he said, it will remap and get back to the stock ACU's target air fuel. But that is not good enough as the target is a compromise air fuel target. The only way to fix this (and get more drive and power) is with a HP race calibration kit (which BMW supply duh!) and of a PC or similar devise. That why you inmprove the power and torque as well as the direveabilty with the PC.

P.S. My bike picked up 9hp with a PC. And that is more or less what everyone is getting here at altitude.

N.

[NotAgain]

I installed the Akra Evo full Ti system, and my bike ran like S*** until the PCV went in, was way to lean, not at all pleasurable to ride, almost unrideable, just my 2 cents.
Fran