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Author Topic: Tell me about exhausts  (Read 536 times)

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Offline OomD

Tell me about exhausts
« on: March 14, 2017, 09:34:31 pm »
So I've googled exhausts (specifically for 4-stroke engines) and how they work, how they're tuned, optimised, etc. It's all glorious technical detail, and I'm learning quite a lot.

What I fail to see though, is how a "wrong" exhaust could actually damage the engine. Sure I can see how it will cause the engine to run less optimally, or be less efficient, but to actually cause damage to the engine? What am I missing here?

This question is in part due to BMW's insistence that an "unapproved" exhaust will void the warrantee.

So, what do the boffins say?

Offline rohann

Re: Tell me about exhausts
« Reply #1 on: March 16, 2017, 12:40:55 pm »
All my life with all my bikes I have changed the exhaust to something louder and better but BMW was the first one I came across moaning about warranty.
« Last Edit: March 16, 2017, 12:42:23 pm by rohann »

Offline silvrav

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Re: Tell me about exhausts
« Reply #2 on: March 16, 2017, 01:13:48 pm »
Well I guess their argument is that if the motor does not run optimally the changes are greater for failure (at higher heat or cold spots or or or?)?  :patch:

Offline Omninorm

Re: Tell me about exhausts
« Reply #3 on: March 23, 2017, 07:40:00 am »
All I have learnt is this.
Pay the price for a proper made-for-the-bike exhaust or leave it stock.
« Last Edit: March 23, 2017, 07:41:06 am by Omninorm »
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Offline BlingKing

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Re: Tell me about exhausts
« Reply #4 on: March 23, 2017, 09:02:53 am »
Okaaaaay the BMW okies are going to hate this.
One day in this quaint little town in Sinzig in Shermany ja, I was waiting for a meeting at the Wunderlich offices and I met the okie from the factory in charge of Warranty logistics from BMW AG.
We had the conversation re BMW S.A.'s rules re Warranties and their strange reasoning with anything outside of a BMW OEM part being fitted.
This was obviously in front of a whole bunch of display bikes with a motley assortment of pipes fitted, Laser, Remus, Zard etc.
His answer was very simple - as long as the part fitted had either a TuV or ABE approval certificate (or both) they didn't have any problem with it being on the bike.
He understood BMW S.A's insistence, given that it was in the endeavors to try and fit as many BMW parts as possible to stay current with their back end sales targets that were determined by BMW AG themselves.
One of my bikes went to Northside for a recall (I think it was that brake thing they had) anyway the Technical Manager from BMW saw it there and promptly went back to the office and carte blanche put a big X across the Warranty, on account of all the Wunderlich (and other) extras it had fitted to it.
When I phoned him at BMW S.A. the part he had the biggest problem with was the Wunderlich Performance Controller (or chip as he studiously called it) he maintained that there was no way they could entertain any claim on the motor with that fitted...........well my arguments about the fuelling being in fact better  than standard fell on deaf ears, of course.
Understand I had been through something like 15 GS & GSA's up to that point - majority of which had that same Performance Controller on them. That was at a time where there were several incidences of motors blowing because of the "leaned-out" fuel map that they had to install because of the new Euro IV emission laws. These blew particularly when ridden hard in high temperatures at high altitudes, ask the dealer in Upington how many they had in December 2008!
Anyway, those that know me, know how hard my bikes get ridden, Tri-Track Tours, Track Day Instruction, fast "22's" Red and Black Routes etc etc. Not one of my bikes broke - EVER! I put that down to the superior fuelling provided by the Performance Controller. However, said BMW Technical okie was less than convinced and told me that the judges decision was final and no correspondence shall be entered unto!
Fortunately I had just compiled a comprehensive list of the extras on the bike (all R122 000 of them) and sent this in an e mail to Germany. It was a paltry couple of hours and Northside phoned and said they didn't know whose cage I rattled - but my bike would be ready (recall claim fixed) that afternoon!
So that is the long and long of it.
However know this, that Dealerships are now obliged to make comments on the system if they see any extra on the bike that may make the Warranty questionable.
My policy is very simple -  I fit nothing to my bike that isn't ABE or TuV certified (N.B. ALL Wunderlich, Wilbers, and TFX Suspension that Bling King fits have either one or both approvals) at least you have a fighting chance with Germany should you have any problems!
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Offline silvrav

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Re: Tell me about exhausts
« Reply #5 on: March 23, 2017, 09:30:39 am »
Interesting, thanks blinking

Offline OomD

Re: Tell me about exhausts
« Reply #6 on: March 23, 2017, 10:11:14 am »
Thanks, Blingking. That certainly explains the BMW side of things, and I suppose understably too.

Question still remains though... can an aftermarket pipe actually damage the engine? Let's say the bike is already out of warrantee, what risk is there in fitting an aftermarket pipe other than the BMW approved ones?