R12S - full exhaust system without any special chip

Riv · Riv's Garage

Hello,
I'm about to buy the Akrapovic Racing System for my R12S and I have doubt about the needs or not of a additional control unit like Rapidbike or Powercommander.
I wrote an email to Akrapovic who answered this:

Dear Costumer,

thank you for interesting in our products.

All of our exhaust systems The Bolt-On, Slip-On, Sport Production, Racing, Evolution and

Street Legal lines are designed to function properly using the stock carburetor or electronic

fuel injection set-ups. This means that no changes to the stock set-ups are necessary in

order to use Akrapovic exhaust systems. Also, all of the performance specifications which

we measure and list for each exhaust system model are based on stock set-ups. We

assume full responsibility for the accuracy of these specifications.

Visit our site for more information.

Best regards

Akrapovic R&D team

Now, I have the Akrapovic Ti Slip-On on my R12S and K&N airfilter and everything runs fine even at some rpms delivery is a bit flat ...(however better than stock!)
Can I be quiet sure about the improvement at low-medium rpms declered by Akrapovic?
Anyone has experience?

Thank you all for any answers

signit98 · 07-15-2008, 02:33 PM

I added a Techlusion and it has helped the overall characteristics of the Engine Performance, took care of the flat sport around 5K RPM and fills in nicely on the bottom end... if you just add the exhaust, it will likely run a little on the lean side... I have a full system on my bike, Remus Headers, Akra Exhaust...

2wheelmike · 07-15-2008, 03:46 PM

Ralf,
What air filter are you running? I've heard K&Ns let in too much dirt, but I have no idea whether this is based on any data. I searched the forum for R12 air filter, but didn't really find a discussion of particular brand's pros & cons.
P.S. I did send my money via PayPal for the track day, so thanks!

signit98 · 07-15-2008, 03:52 PM

..got it, Mike... no worries, I actually enjoy doing this and it looks like this time around, I am not going to loose money

I am running stock, AFAIK... I have never even been in there... the K&N's are only an issue if you are riding in environments with a load of dust and such... you just service them more often!

If I don't have a K&N in there now, one will be in there after the 6K miler... I do have one in the GS...

2wheelmike · 07-15-2008, 04:11 PM

Quote:

Originally Posted by signit98

...it looks like this time around, I am not going to loose money

In that case, let me buy you dinner next time to help make it up.

roger albert · 07-15-2008, 04:13 PM

Well, of course that's what they say.
But, unless you're getting one that only looks slicker, or drops weight, or has a deeper tone, but offers the exact same performance, then it is bunk. Look, if you add an exhaust that flows more, then you will need to add fuel to match: Period. All the marketing in the world can't counter chemistry, physics, and common sense. (well, maybe the latter)

Riv · Riv's Garage

Ok....understood....
Thanks for all your (right) suggestions

boxercup · boxercup's Garage

Quote:

Originally Posted by roger albert

Well, of course that's what they say.

Look, if you add an exhaust that flows more, then you will need to add fuel to match: Period.

All the marketing in the world can't counter chemistry, physics, and common sense. (well, maybe the latter)

Greetings Roger,

You are right! Marketing 101.

Especially with a BMC or Pipercross filter. (Which are the only filters I reccommend>higher flow and they do a great job filtering the air)

If you reduce the pumping losses on the intake and exhaust sides you have reingineered the power process. The engine now has different needs.

The engine is an air pump!

More air in-More air out = the need for re-tuning the ECU's timing and injection parameters if you want to reap the benefits of your mods.

zx9rmal · 07-17-2008, 07:19 AM

OK, my $.02, which is about what this is worth.

After installing my full Remus system, there was no question that top end was improved. When I added the foam air filter from BMW of Atlanta, the midrange felt more responsive. It's not seat of the pants. I just dynoed the bike and got 119hp. Even if this particular dyno was a bit optimistic, the numbers would still be better than stock.

Of course, the bike would run better with some fuel management, but I think there is "some" compensating by the stock electronics.

roger albert · 07-17-2008, 08:39 AM

At heavy thottle/load, there is exactly ZERO compensation.
Not a bit, or some, or a little, but NONE.

Reformed Squid · 07-17-2008, 09:48 AM

I guess I'll stick my neck out here to get my head taken off. Before I put the full Akra system on my bike, by friends SuperDuke would pull out 3 bike lengths and stay there. After the exhaust install he's half a bike length behind me and cannot pass me. I definitely want to get an RB or a Power Commander if one ever comes out to even further optimize the gains, but to say you get nothing but sound without one has not been my experience. This buddy is the most hyper-competitive person that I know and I can assure you that this test is conclusive as every weekend we have to do a retest because he's made some change. Just my worthless .02.

Gerry

roger albert · 07-17-2008, 12:18 PM

No one is saying you can't get a bit more performance from uncorking the motor.
Only that the mixture wont' be right, and thus that you won't get much, and, that you're invariably running leaner, and thus hotter, and are making life on your motor much harder.

Anecdotes about pulling X lengths on bike Y are horribly inaccurate ways of evaluating any performance. WAY too many variables to be of any use. If it makes you feel good, cool, but don't fool yourself.

Rapid Dog · 07-17-2008, 01:18 PM

double dat Rog!

zx9rmal · 07-17-2008, 01:44 PM

Roger, you certainly are more knowledgeable about boxer motors than I, for sure. If there is no adjustment by the ECU/sensors, then I assume that if ya get a bit more power with a pipe, there must be a bit of richness in the A/F at the top.

Reformed Squid · 07-17-2008, 02:16 PM

Definitely understand that opening up the exhaust will lean things out even more. Since there's no word on when or if a Power Commander will be out, I have a question about the Rapid Bike. Do you throw the bike on a dyno and tune it just like you would with a Power Commander?

Gerry

roger albert · 07-17-2008, 02:25 PM

> I assume that if ya get a bit more power with a pipe, there must be a bit of richness in the A/F at the top.

Mal:
In some cases yes, but not much, if any. The real mechanism is that the extra power due to more airflow increases a bit more than the power drop-off due to poor mixture. It's a 3-steps-forward / 2-steps back scenario. Of course, the motor will run hotter, be more subject to knock and a bunch of other issues etc, but there can be a net power increase (even if an ill considered one) even if the mixture wasn't already biased rich.
hth

RS:
Other guys know the rapidbike better than me, but yes, you'd want to tune it with a dyno.

phoenixtexoma · 07-17-2008, 02:30 PM

To Bob Foster & others who've asked about a related subject. After 3k miles on the Collins injectors, you literally can't tell the plugs apart. Very light tan, no carbon, even with the Techlusion yellow and red pots set to max (green at zero). Performance issues aside, the bike is dramatically smoother, almost zero vibration in the 4k to 5k rpm range. Not doing an advert, just feel the money was well spent.

Also, Roger mentioned hydrogen embrittlement a while back after I had some fasteners chrome plated. It's indeed a serious issue and also interesting topic. In my case, it turned out that the plating (done by a friend at an aircraft shop here) was flash-chromed only, heat-treated immediately and x-rayed in a batch with some other parts. Apparently, the hydrogen can cause minute initial cracks that will potentially cause an unpredictable, catastrophic failure. Especially not good in aircraft.

phoenixtexoma · 07-17-2008, 04:13 PM

Here's a pic of one of the plugs.

signit98 · 07-17-2008, 04:42 PM

Quote:

Originally Posted by Reformed Squid

Since there's no word on when or if a Power Commander will be out, I have a question about the Rapid Bike. Do you throw the bike on a dyno and tune it just like you would with a Power Commander?

Gerry

Gerry... there is a Power Commander out for the 12GS... I wonder if it could be tuned for the 12S... I can't see why not. With a bit of Dyno Work, I am sure you can dial it in pretty nicely!

Reformed Squid · 07-17-2008, 08:37 PM

Quote:

Originally Posted by signit98

Gerry... there is a Power Commander out for the 12GS... I wonder if it could be tuned for the 12S... I can't see why not. With a bit of Dyno Work, I am sure you can dial it in pretty nicely!

I saw that and they also now have it for the R1200R. When I called them the other week to inquire if there'd be any issues putting it on the 12S, they gave me the company line of we haven't tested it so you're on your own. I agree that everything should be fine, but with my luck the end result usually involves fire. I guess I need to take one for the team and just buy one and see what happens.

Gerry