Thanks, RB

Just a interesting note on removing the cat... There is a BMW dealer here in SA that does the same procedure. However, you may get low down torque to suffer if you do this. This is my reasoning...

The cat produces some back pressure in the system, hence a specific diameter tube is specified for the headers. With the removal of the cat, gas is flowing more freely, lower back pressure and the tubing diameter stays the same. This normally results in higher peak output, but lower torque values at the lower/middle rpm range.

I have an Akro system on my bike and it is interesting to note that the header tubing dia is actually smaller than the stock unit's. This system increases middle rpm torque quite a bit.

Another comment that I have heard is that due to our bikes running lean, increasing the gas flow, will lean it out more, resulting in pre-ignition and damage to the piston tops. (There was a recall on some bikes due to running too lean). It will make sense to have a piggy back computer to correct A/F ratio.

A dyno print of a std system compared to a cat-less system compared to a cat-less system with piggy back will be interesting though! :)

Cheers

Here is a picture of cat on my R1200S, showing the honeycomb structure , before I changed the headers , no doubt some time in the past Ron's looked like this too , only cleaner ;)

http://forums.pelicanparts.com/uploa...1221736205.jpg

...low down torque : I know, but I don't care. Most of the time you can find me between the 5000 and 8000 rpm...
...and if 'my system' won't work, I'll probably go back to something with custom made welded tubing, using the rest of the (stock front) headers...

...and this running lean problem ; I have a RapidBike, and had a couple of runs on a dyno once to get A/F ratio right...
...so probably I need another few runs to get the new set up right...

...two charts...




...this first chart : a R1200S with BOS headers, and stock exhaust (no RapidBike)...

http://i145.photobucket.com/albums/r...ensdiagram.jpg



...my chart : with RapidBike and with stock headers & exhaust...

http://i145.photobucket.com/albums/r...indstand-1.jpg


...you can cleary see, those BOS headers (without the cat) give better performance around 5000 RPM in comparison with my chart, but less torque around 3000 RPM...

That's not a trade-off I'd make on my bike. Stealth Pipes are my choice. I don't want them to know I'm there until I'm not.

...that's the reason why I bought a (relatively cheap) second set of pipes, and didn't fool around with the original set...

...and empty... :)

http://i145.photobucket.com/albums/r...8Image0010.jpg



...BTW ; these headers are made by LAFRANCONI... (http://www.lafranconisilenziatori.com/eng/index.htm)

...famous in the old days for their Ducati & Guzzi exhausts...

Surrounded by the guts of a cat converter.........

http://www.blueskyok.com/SNL3/conten...e/DSCN7267.jpg

Brock

So cat converter innards can cause rapid cell duplication and splitting?

ZB52080... RIP 11-17-2007 snif sniff....

Look at the state of those shoes, tsk tsk.

...slippers my friend ; slippers... :)


...RT & slippers go very well together... :D



http://www.mantjetexel.nl/drupal/fil...s/IMG_9761.jpg

+1 yep I've heard of this method (not on R1200S but on a car cat) without the need for a dremel.

...as said ; the R12S is a metal cat, not a ceramic one...

Hmmm

PS: all in all > was the whole thing worthy?


http://forums.pelicanparts.com/uploa...1221841574.jpg

...don't know yet ; first I have to find me a TIG-welder, who can weld me the few bits and pieces (outer shell) nicely back together again...

...MIG welding isn't a problem for me, but TIG is a different lingo...

RoLoo:

Since my time on this site your one of my favorite people, also I really like the way you have your 12S set up! However, for about $500 to $700 U.S. dollars one can get a Remus, Lazer, or HPE header/cat removal system, which was designed/tested to get max. H.P. performance/get rid of the 5K flat spot, without any fuss or muss. Anyway, I appreciate the time, energy and meticulous approach you put into this project (you really do some nice work!) but to me it’s overkill, and in the end it would be interesting to know much this actually cost?

Mike K.
gray/silver 12S
Dana Point, CA.

a) He bought the exhaust off of a wreck, or otherwise used, for not very much.

2) None of the aftermarket headers work with the belly pan.

He's mentioned both of these points already in this thread, as far as I know.

...thanx !...

...of course I would like having the HPE pipes, or something else, but I also like the belly pan I have, and aftermarket headers in combination with the belly pan is a serious no go...

...and these stock replacement headers were only some 140 bucks (100 Euros)...
...ad a bit of welding, and maybe some time on a dyno...

...so, worth a try (I thought)... :)