Straight Pipe

[lymanwhite]

Here are two quotes from previous post:
I started this discussion about running rich vs lean was because of the issue I am experiancing, it isn't a major issue, its just an indication of a "slightly" richer mixture with the VL pipe vs stock, or maybe a change to what it "SHOULD" be
jettech01

Under acceleration beyond some load limit, it is not running closed loop and is blindly dumping in fuel. If you have more air than before, then you can ONLY trend lean. No way around that.
roger albert

The interesting tread can be found at: http://forums.pelicanparts.com/showthread.php?t=411544&highlight=r1200s+exhaust

Please see 2nd post.

[lymanwhite]

I am wondering ( at the risk of flames from the no loud pipe guys ), how the stock 2007 R1200S would perform with just the tail pipe and muffler removed, just after the catalytic unit. It should run leaner, unless as jettech suggests less exhaust restriction (all else stock) creates a richer A/F mixture.
If he is right about less restriction at the exhaust improving A/F ratios, then it could also improve cooling.
Any serious thoughts appreciated.

[gigantic]

whwhwhwhwhwhwhwh...what?!?!?!

[JonyRR]

'how the stock 2007 R1200S would perform with just the tail pipe and muffler removed'

why don't you do the 'speriment for us yokels.

Be sure to dyno the before-and-after so there's empirical, not just anecdotal evidence.
Use an EGT, an EGA, A/F meter and sparkplug thermocouple.
let us know how long it lives without a muffler and cat.

[roger albert]

There's nothing new to say. If your more "open" pipe is really flowing more air (at some rpm/throttle-position combination, then it will be leaner than it was at that operating point.
It CAN"T be anything else.

[ckcarr]

Loud bikes feel faster.

[chewie]

I took my remus silencer off incl pipe, just after cat...sounded crap - no bassline, didn't ride it like that coz I had no indicators or number plate, there's a guy on Adv rider that has been running his GS like that for yonnies, so...

[BMathison]

Originally Posted by ckcarr

Loud bikes feel faster.

And just think of all the lives you would be saving!!

[peter f]

Originally Posted by lymanwhite

I am wondering ( at the risk of flames from the no loud pipe guys ), how the stock 2007 R1200S would perform with just the tail pipe and muffler removed, just after the catalytic unit. It should run leaner, unless as jettech suggests less exhaust restriction (all else stock) creates a richer A/F mixture.
If he is right about less restriction at the exhaust improving A/F ratios, then it could also improve cooling.
Any serious thoughts appreciated.

As Roger said > more freedom = leaner mixtures (and hotter boxers).

I'm doing some "tests" here at 41o C (hot Athens). Tests are not completed but appears that the only way to cool down the boxer (traffic = 2-3 bars below max oil temp) is to use one of my 2 maps in RB3 - how rich is the mixture VS the "stock"? have no idea. Note Castrol 15W-50 semi synthetic, 100RON fuel, non stock filter, NKG Iridium spark plugs.

Consumption : 7.4-8.2 Liters/100 Km (town), 6.6-7.7 Liters/100 km (canyons).

BTW : Stock end-can = ugly/bulky/ugly

[lymanwhite]

Nothing to fear boys, but change...
Amazing how protective and positive of their sentiments folks are!
But you see that in all walks of life, why should it be different here?
Yes, in adv forum there are several guys riding w/o tail pipes or mufflers.
One said no problems in 70 K miles on 1150.
Factory tech opined that w/ 3 ft of header, a cross over pipe, baffles in the catalytic, that there should be plenty of back pressure for the valves.
Not to mention the closed loop idea that the ECU would sense open exhaust and pour more fuel as one guy (jettech01) tried to post ( he even flow benched ), and was met with the same zealous, hidebound thinking might I say.
I find that the 'sewing machine' group want quiet bikes, and believe they 'know' more than they actually do about the technical aspects.
Well, its a big world, look to the future. It's coming quick!
For insurance though, I did change out all fluids for Amsoil 100 % syn ( 1 bar cooler)!

[lymanwhite]

Here is a good thread on the technical aspects of ECU mapping. Note the advice from Peter Parts, Atlanta BMW, and Deans BMW.
http://forums.pelicanparts.com/showthread.php?t=411544

[klennop]

Originally Posted by BMathison

And just think of all the lives you would be saving!!

I ALMOST spit my drink out!!!! That is funny!!!

[RBMann]

Originally Posted by lymanwhite

One said no problems in 70 K miles on 1150.

For insurance though, I did change out all fluids for Amsoil 100 % syn ( 1 bar cooler)!

One is a good data point, but what does it really indicate?

Also, using dino or syn, how many bars do you go to when you ride? Which model?

Good luck, RB