The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Bill Conquest on April 15, 2011, 01:56:01 AM

Title: mufflers
Post by: Bill Conquest on April 15, 2011, 01:56:01 AM

Anyone have an opinion regarding Mac Whispertone mufflers? I'm looking around for replacements & can't afford the stainless ones..
Thanks bill conquest

Title: Re: mufflers
Post by: airhead27 on May 13, 2011, 08:16:11 PM

i'm  looking for mufflers also. I bought a pair of mac mufflers about 20 years ago for a Kawasaki gpz 750 and they rusted fairly quick; hopefully the quality is better now. I dont know if carbs need to be re-jetted. Has anybody had a set of mac whispertones on their 79-84 r65. Did they last? did the carbs need to be rejetted?

Thanks
Brian

Title: Re: mufflers
Post by: Justin B. on May 16, 2011, 09:04:54 PM

I have them on two and they are great if you want a bit more sound.  If you like the super quiet stockers you may not like 'em...

Title: Re: mufflers
Post by: airhead27 on January 26, 2012, 08:29:06 AM

I ended up buying a pair of sito silencers new, they are top quality not to loud.

Title: Re: mufflers
Post by: MR.E on January 26, 2012, 04:41:22 PM

now then

don't know if this is what you're after but i've got a spare pair of stock mufflers if they'd help!

Title: Re: mufflers
Post by: Barry on January 27, 2012, 03:58:16 AM

I bought a pair of as new Sito silencers off ebay. I suspect the reason they were sold might of been because they were too loud.

Exhaust noise is subjective and each to his own of course. I don't mind a bit more noise than stock when you hit say 4000 RPM but these were grossly louder than the original Zeuna silencers from idle upwards. I couldn't live with the excessive bark when the engine was loaded going up hills and the constant drone even on light throttle so I made and fitted some internal baffles which quietened them down. They are still a fair bit louder than Zeuna's but I can now live with them.

It's a shame some of the after market suppliers couldn't just copy a Zeuna's internals properly to produce a similar sound level and probably more important similar flow and back pressure characteristics. More noise does not by any means automatically equate to more power. The reverse is more likely or a least a shift in max. torque revs. I wonder if after market suppliers ever dyno their products.
  

Title: Re: mufflers
Post by: steve hawkins on January 27, 2012, 04:40:15 AM

I got my shorty pair from Armour Motor Products in the UK.

Although they are marked as road legal, they are certainly much louder.  Which I like.  They only have a very simple perforated spoon baffle at the front, which provides enough back pressure.

I would not modify them to 'improve the air flow' as without the muffler/baffle you get a nice big hole in the mid range that would break the heart of any rider.  Don't ask me how I know : (

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