Author Topic: Open header  (Read 7509 times)

Offline tycham

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Open header
« on: October 31, 2017, 07:33:18 PM »
Does anyone have experience with just open up swept headers?  I have seen a couple of photos and I like the look, just wondering how it is on noise and performance
  • Graeagle, CA
  • 1990 K75S, 1982 K75RT

Offline The Mighty Gryphon

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Re: Open header
« Reply #1 on: October 31, 2017, 09:41:25 PM »
Noise?  What do you think??? 

Performance.  BMW and most manufacturers spend a fair amount of money and time on exhaust systems.  On the one hand, the EPA imposes strict regulations on OEM exhaust systems.  On the other, manufacturers are engaged in a contest in the market place to produce the fastest most powerful machines in their class. 

They have large, experienced engineering teams operating in expensive test facilities working on getting the most performance possible from their machines.  I seriously doubt that someone working in his back yard going to an open system will positively affect performance without spending a lot of time tuning the engine to operate with it.  More likely, he will do some expensive damage, probably in the form of burnt exhaust valves or holed pistons.

 
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline tycham

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Re: Open header
« Reply #2 on: October 31, 2017, 10:08:05 PM »
Not meaning to be disrespectful but the question is has anyone done it. I see several cafe/bobber ans was wondering. As far as the performance, I would be more concerned about burnt valves, etc. If I wasn't high performance then I am working on the wrong platform. I have several Beemers to do that with  and a Suzuki Hayabusa.


So, anyone with experience?
  • Graeagle, CA
  • 1990 K75S, 1982 K75RT

Offline Laitch

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Re: Open header
« Reply #3 on: October 31, 2017, 11:25:16 PM »
Not meaning to be disrespectful but the question is has anyone done it.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
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Offline tycham

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Re: Open header
« Reply #4 on: November 01, 2017, 12:06:32 AM »
That is what I am talking about. I wonder if is idling badly because of the pipes or something else



  • Graeagle, CA
  • 1990 K75S, 1982 K75RT

Offline Laitch

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Re: Open header
« Reply #5 on: November 01, 2017, 12:39:02 AM »
That is what I am talking about. I wonder if is idling badly because of the pipes or something else
It might not be idling attractively but it isn't necessarily idling "badly".
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline Andrew2

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Re: Open header
« Reply #6 on: November 01, 2017, 01:16:23 AM »
  With out back pressure it would not be good for your motor in the long run. Certainly looks and sounds good though.
  • Wollongong, Australia
  • 1987 K100RS
It is no measure of one's health to be well adjusted to a profoundly sick society

Offline Filmcamera

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Re: Open header
« Reply #7 on: November 01, 2017, 08:44:07 AM »
If you run a turbo on the bike having open pipes would much less effect on the engine and also the noise would be reduced by the turbo as well
  • San Jose, Costa Rica
  • 1991 K100RS 16v ABS1, 2018 Triumph Street Triple RS 765
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Offline jay1622

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Re: Open header
« Reply #8 on: November 02, 2017, 09:34:09 AM »
That is what I am talking about. I wonder if is idling badly because of the pipes or something else


I'd certainly say something else. This is a cold-start of my K75 when I was testing the gearbox; I hadn't installed a single piece of the exhaust yet. Hope this serves to answer this question...


  • Charlotte
  • Previous: 1986 K75S, 1977 R75/7, 1999 R1200C, 2003 R1150GS, 2001 F650GS, 2005 R1200RT... Current: 2005 R1200RT and my Brick, a 1988 K75S

Offline tycham

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Re: Open header
« Reply #9 on: November 02, 2017, 10:26:36 AM »
I noticed the same thing on the R1100's I have do gearbox work on. Not too loud and they were in the reverberating garage. I think I am going to try it. It is easily reversed.
  • Graeagle, CA
  • 1990 K75S, 1982 K75RT

Offline propav8r

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Re: Open header
« Reply #10 on: November 06, 2017, 12:33:34 PM »
A guy here in town has a K100 with an open exhaust. I heard him going down the highway from my house last night (the highway is about a mile away.)

Doesn't sound bad as far as open header motors go, but why? You're not going to appreciably gain anything from an open exhaust on an otherwise stock bike.
  • Franklin, NC
  • 1985 K100RS, 1978 GL1000, 1972 Kawasaki H2 750

Offline tycham

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Re: Open header
« Reply #11 on: November 06, 2017, 01:58:56 PM »
Looks. I am building a bobber with no holds barred. Rear set, etc
  • Graeagle, CA
  • 1990 K75S, 1982 K75RT

Offline Arktasian

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Re: Open header
« Reply #12 on: November 09, 2017, 09:22:45 AM »
"Loud Pipes Save Lives" won't exactly apply. Expect a reduction in performance as the scavenging effects of an engineered exhaust system will be nullified. A turbo with an open header will and does enhance performance while providing that thrill. The loud droning of N.A. open ports may seem fun at first but numbing towards any reasonably long rides, even with ear plugs and helmet muffling.
I have a dual exhaust circuit on my turbo'd R100Rt, where a right side toe shift lever allows "Open Header" turbo outlet on the down position, or "Quiet Muffler pathway" on the up position. The open side has a nice sound quality and is plently loud (all the better to hear the turbo do its thing) but after having that set up for about 3 or 4 years now I find I tend to dwell on the quiet side most of the time. I click her open when rolling on hard during significant passing sessions, then close again when on cruise.
I'd hang onto all the bits - you'll probably be wanting to reinstall. 
  • Abbotsford

Offline tycham

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Re: Open header
« Reply #13 on: November 09, 2017, 09:28:16 AM »
Let me more about a turbo for the K100

  • Graeagle, CA
  • 1990 K75S, 1982 K75RT

Offline Arktasian

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Re: Open header
« Reply #14 on: November 09, 2017, 11:34:00 AM »
There are several posts over on the "Custom" folder, either guys adding their own system or bikes that had the Luftmeister kit added years ago (actually built by RB Racing). This is not casual stuff, for the feint of heart or pocket book as a rule.
* bmwk100_turbo02.jpg (79.2 kB . 752x500 - viewed 703 times)
Not sure but you may be able to still purchase a kit for your bike (at some cost$$$). The RB web site isn't really clear on this and I only note K1200 in the price list for K's.
  • Abbotsford

Offline tycham

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  • Posts: 11
Re: Open header
« Reply #15 on: November 09, 2017, 11:56:55 AM »
I am going to talk to them. They are pricey but maybe for my LT
  • Graeagle, CA
  • 1990 K75S, 1982 K75RT

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