Muffler off; Mileage up

[Beemeridian]

11

[Ves]

Simple... put the muffler back on for the same amount of time you've had it off... do the same ride... and see if mileage goes back down... take the muffler off... see if it goes back up... if all that confirms you're findings than you know it's real... otherwise it's just a coincidence...

I've had my muffler off for over a year... my mileage is about the same... it doesn't overheat... doesn't run weird... just sounds louder and deeper... sounds good through the earplugs... don't think I'd do that if I rode without earplugs.. Well, I'd still probably do it cause weight savings is a good thing...

[Dr. Strangelove]

Do you have your Cat Code Plug (CCP) in or out?

hey, Bob,

Don't even know what that is, nor where it is.

John

[Dr. Strangelove]

Simple... put the muffler back on

Yeah, Ves, I know, but my remaining testosterone levels suggest the can stays off, while my diminishing energy levels demand it.

Yesterday I filled again--the light started going on just under 170 this time and my mileage was 45, with half and half city near-hooligan and the other half steady 70. This was the lowest it has been since the muffler came off.

John

[Beemeridian]

11

[Dr. Strangelove]

The spot where it looks like there is a bulb stored in blue mesh has a plug with a yellow relay(?) in it--for my ABS???

The spot where the CCP lays is empty. What is it and what does it do?

[Beemeridian]

11

[Sunbeemer]

Since you asked...

The CCP is a plug with a shunt wire inside that shorts two terminals to program the Motronic computer to use a specific fuel map for operation in different countries. The CCP modules make different connections for different countries and are different colors (US is yellow). It is a simple way to program the bike's computer to control the fuel/air mixtures to keep the emissions within each nation's environmentally regulated emissions standards.

For instance, our US bikes are programmed to let an Oxygen sensor control the air/fuel mixture to reduce emissions while maintaining the efficiency of the catalytic converter, as well as operate a vapor recovery system solenoid that keeps unburned vapor from being emitted to the atmosphere. If you pull the CCP out, the bike will run richer (and possibly better), but after some time, so I've been led to understand, this will plug the catalytic converter with unburned carbon deposits that could ultimately reduce performance by causing excessive exhaust back-pressure.

Speaking of which, perhaps your old can was plugged up causing more back-pressure and removing it is letting your engine breathe as it should? Just a thought as to possibly why your mileage went up so dramatically after removing it.

[Dr. Strangelove]

Thanks,
I bought the bike used and a previous owner must've removed it.

I do notice the exhaust has a bit of a rich smell to it, more when the muffler was on.

[DJ Downunder]

Thanks,
I bought the bike used and a previous owner must've removed it.

I do notice the exhaust has a bit of a rich smell to it, more when the muffler was on.

Many BMW dealers remove them when you have a service done without even telling you..It often fixes surging issues.

DJ

[iowabeakster]

Doc,

Your bike probably came without one. That means it is Euro mode... or was it Yankee mode... I can't remember.

http://www.r1150r.org/board/viewtopic.p ... &hilit=CCP

[KHaynes]

Perhaps with the extra noise you are lighter on the throttle resulting in a fuel saving. 17% is a huge reduction. Perhaps it's a real saving because the can is off.
Whatever the cause, I wouldn't be complaining.
I much prefer the sound of an R a la DJ. I have heard his bike and much prefer the sound to the OEM setup.

[Airman]

Dr. Strangelove,

Do you have your Cat Code Plug (CCP) in or out?

If I can get a little more mpg, I may take that muffler off again.

I am running without the CCP, and have been doing that for years.

I'm interested in that too. I have been running without it for quite a while, believing it helps the surging a bit. My mileage actually went down a bit. My current setup is a Remus y-pipe and the stock muffler. I am going back to the CAT only with one of those chrome DJ tips on it. My daily round trip is about 40 miles so a little milage gain would not hurt my feeling any. In the different configuations I do not recall a mileage increase. I have never got more then about 38 mpg with my mixed town and freeway riding.

[fj_pastor]

I removed the can and run only with the tip.
I also use 98 octane fuel.

Results:
- Deeper sound, more torque at lower rpm but ........

No power drop at 4.000 rpm

The bike now runs incredibly smooth from 2.000 rpm to 7.000 rpm

It is a single spark model

I cannot be more happy.

(PS. I also tried the Chitown recipe for the Pirelly Scorpions Sincs and the handling is magnificent !!!! )

Best regards to all

[Dr. Strangelove]

latest tank, Light came on steady at 172; filled at 179+ and it took 3.62 of 89; mpg 49.44+

This was mostly cruise controlled 70mph per Zumo, prob 2/3--but against some 25 mph winds for most of that; and 1/3 hooligan jack rabbit starts, up to 4th/5th gear city.

JOhn

[Beemeridian]

11

[Airman]

Doc,

Not wanting to be left behind in the race for higher mileage, today I re-installed the CAT, put on a 6" high milage pipe extension, and out the CCP back in. After the usual pulling of the #5 fuse and clacking the throttle 5 times I'm ready for huge mileage increases.
I'll let you know.

Airman

[rdsmith3]

Doc,

Not wanting to be left behind in the race for higher mileage, today I re-installed the CAT, put on a 6" high milage pipe extension, and out the CCP back in. After the usual pulling of the #5 fuse and clacking the throttle 5 times I'm ready for huge mileage increases.
I'll let you know.

Airman

I pulled the muffler on Saturday but I am not going to put the CCP back in. I want to vary one thing at a time to see about mileage.

Alas, I was not able to ride today.

[Airman]

Doc,

Not wanting to be left behind in the race for higher mileage, today I re-installed the CAT, put on a 6" high milage pipe extension, and out the CCP back in. After the usual pulling of the #5 fuse and clacking the throttle 5 times I'm ready for huge mileage increases.
I'll let you know.

Airman

I pulled the muffler on Saturday but I am not going to put the CCP back in. I want to vary one thing at a time to see about mileage.

Alas, I was not able to ride today.

I have not had a chance to ride far yet. I'll fill the tank today to start the baseline. I have gotten 38 mpg for a long time, but I have a few miles on him now abd haven't had the CAT on for a while. I didn't notice any surging from the re-installation of the CCP. Probably when I do the 24k service here shortly I will notice better performance in all areas.

[def38]

haha so taking off my muffler should not hurt the bike?

the bmw dealer said its gonna make it run lean and hot

Your BMW dealer is correct. Modifying air flow through the boxer by removing the muffler, removing the CAT (illegal), employing after market air filters means the engine now receives more air for a given throttle setting. But are you adding more fuel along with this increase in air?

No, you are not because the TPS is still in the same position and air flow has increased and you have now upset the stoichiometry so carefully adjusted by BMW at the factory. Your engine is now going to run hotter combustion chamber temperatures, exhaust valves and guides are going to run hotter and you may end up doing engine damage (read holes in pistons).

In order to change the fuel/air mix back to the correct ratio, you'll now need a Power commander or some other fuel map device to provide the new fuel delivery rate. Then, your mileage will suffer because you have upset the factory stoichiometry........quit screwing around with mufflers, CAT removal and other hot rodding crap...there is no economical way to extract meaningful added HP from the boxer engine without changing valve timing, turbo charging or other costly engine modifications. You want more noise?....put playing cards in your spokes or buy a Harley. Want more performance?.....loose 15 lbs.........want better handling?.....take an advanced rider course or buy some instructor/track time.