Cat removal Y-pipe. Costs, benefits?

RavensAteMyEyes · Post by **RavensAteMyEyes** » Fri Dec 06, 2013 3:44 pm

Hi all.

I recently bought a lovely stock R1100S (2001, 19k on the clock) and I'm now pretty used to it.

I love it, I do.

The only thing that is leaving me a bit nonplussed is the exhaust note. I have both the stock OEM one and, I believe, the Lazer pipes (the latter of which are fitted).

It doesn't sound overly fruity.

So, would removing the cat with the Y-pipe be of any benefit to this, or other, causes?

Thanks muchly,

R.

Boxered · Post by **Boxered** » Fri Dec 06, 2013 3:47 pm

Ohh yes, aside from the weight saving, it will breathe a lot easier and you'll notice a distinct improvement in the noise department

Steve

RavensAteMyEyes · Post by **RavensAteMyEyes** » Fri Dec 06, 2013 4:32 pm

Beautiful!

So, who makes a good Y-pipe? It has the O2 sensor in the cat, so I'm assuming I want to keep that?

Bikerhoss · Post by **Bikerhoss** » Fri Dec 06, 2013 6:07 pm

Hens teeth 2nd hand, Try one of these
www.boxertrix.com/phpBB2/viewtopic.php?t=15009

Mister C (Marsh) · Post by **Mister C (Marsh)** » Fri Dec 06, 2013 7:10 pm

This any good...

http://www.ebay.co.uk/itm/BMW-R1100-S-1 ... 1e80d47152

Regards Marsh

RavensAteMyEyes · Post by **RavensAteMyEyes** » Sat Dec 07, 2013 12:46 pm

Ooh cool.

First thing I have to do is fit the aftermarket end cans!

By god the OEM exhaust is a pain to get to. I've got the pannier racks off, the rear cowlings and the light cluster... and still can't quite work out how to get to the exhaust mounting bolts!

Any tips??

SP250 · Post by **SP250** » Sat Dec 07, 2013 3:30 pm

Marsh

Can't see where the Lambda sensor goes?

Mister C (Marsh) · Post by **Mister C (Marsh)** » Sat Dec 07, 2013 7:07 pm

Dunna know John, don't some folk disconnect this? I have to admit I haven't a clue what it does.

Marsh

Blackal · Post by **Blackal** » Sat Dec 07, 2013 8:38 pm

Is that full REMUS exhaust on Ebay still for sale (E-bay links)?

A bit more money, but if funds allow - perhaps the better option?

Al

Tapio · Post by **Tapio** » Sat Dec 07, 2013 10:23 pm

Mister C (Marsh) wrote:Dunna know John, don't some folk disconnect this? I have to admit I haven't a clue what it does.

Marsh

The lambda sensor?
It sends feedback to the Bosch motronic system, and fine-tunes the Air/Fuel ratio.

SP250 · Post by **SP250** » Sun Dec 08, 2013 8:57 am

Lambda sensor, as Tapio says, is pretty damn important for the ECU to control the engine mixture. Best if you keep it.

slparry · Post by **slparry** » Sun Dec 08, 2013 9:29 am

On the other hand, my BCR has its Lambda disconnected from before I owned it, and it seems to go well enough and get reasonable MPG

SP250 · Post by **SP250** » Sun Dec 08, 2013 10:35 am

I can only assume that it is important and needed.
If it wasn't then the accountants who run companies these days would save the money and not include it in the build process.

slparry · Post by **slparry** » Sun Dec 08, 2013 11:17 am

SP250 wrote:I can only assume that it is important and needed.
If it wasn't then the accountants who run companies these days would save the money and not include it in the build process.

It is, my understanding is it's mainly at low revs to allow for cleaner running. But once you have a sports pipe (I have a remus) and a K&N it's an advantage to have the mixture enrichened.

I asked the question a couple of years ago when I discovered it was disconnected and got told if it was running well to leave well alone. I got one off ebay "just in case" but haven't got around to trying it out.

SP250 · Post by **SP250** » Sun Dec 08, 2013 11:35 am

Steve

You may find that if you go up an Alpine pass that the mixture just gets too rich and the ECU can't compensate due to the low air pressure. But as all seems ok without it and up to the Ponderosa then ok.