Which Aftermarket Muffler?

[prwatts]

Hi, which muffler is best to replace the OEM one, give better breathing and a nice (but not naughty) growl? And save some weight.
Peter

[marc]

If you want better breathing you'll probably have to replace the cat with a Y-pipe. Just about any aftermarket is lighter than stock. If you want really light just remove the can. The sound coming from the cat is reported to be not all that loud. It's easy enough to try. A few folks have made a short pipe that sticks on the cat output.

[prwatts]

Thanks - if you remove the CAT does the ECU adjust to it or do you get a warning on the dash? I already have a Light Globe Failure warning constantly on because the previous owner fitted HID headlights so the Canbus thinks a light globe has failed.

[marc]

You will not get a warning on the dash. If the replacement replacement pipe has an O2 sensors then engine management should be happy.

But be warned. Several folks have complained of the system running lean.... more lean than stock which is pretty lean. So then they go and add something like a power commander so they can richen things up.

I'm glad that I'm happy with stock.

[prwatts]

This is what the Wunderlicht Web Site says:

Wunderlich Sport Exhaust Header System
If you truly want to save weight and achieve an optimum performance curve, you can go far with the header system:
• Performance gain nearly over the entire rpm range and much higher peak performance (a performance enhancement of up to 14 HP and 10 Nm can be achieved with a free-flowing sport
exhaust system plus the PerformanceController)
• Low weight as it has no catalytic converter or balance pipe.
• Strong sound (approx. 5 dB(A) more).
• Optimised pipe routing.
• With provision to bolt the oxygen sensor in (no modifications of vehicle).
• Easy to install.
• Extremely strong system from satin-finish V4A stainless steel.
• Matched to original and Wunderlich silencers, but other aftermarket silencers fit as well.

Remove the catalytic converter?
No problem at all! We only ever sell collectors with built-in oxygen sensor connection.
As far as the sensor is concerned, it does not matter whether a catalytic convertor is present or not. The main thing is that the sensor is able to measure something and transfer this information to the Motronic. The unit can therefore be exchanged without any problems/hazards. The lack of a cat. is often crucial for increased performance and the use of lower quality petrol.

[Schtum]

If you're going to fit aftermarket headers sans cat' to an >'07 bike, you'd do well to have it run on the dyno to check air/fuel rations, at the very least. In fact do it with '07 bikes as well. OEM fuelling is progressively lean.

I fitted Remus headers and can onto my '04 bike and transferred them to my '07 when I got that. It was noticeable just how much hotter the exhaust gases on the '07 were. Speaking to my local dyno guy he told tales of mapping a Power Commander on an '07 bike, with a full system, which was dangerously lean.

So far, I've only fitted the Remus can to my '09 bike as I believe that they're even leaner out of the factory. If I do fit the headers, it'll demand a trip to the dyno and fitting the <'08 PCIII onto the bike which according to Dynojet will fit fine but which has a different basemap; confirming the information that the later bikes are even leaner.

[prwatts]

Many thanks,
Did the Remus Headers and Can work ok on the 04 GS?
peter