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gpzoduibh
Big Brick Rider
Joined: 10 Aug 2007
Posts: 70
Location: Co. Meath Ireland
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 Posted: Tue Jan 29, 2008 11:47 am Post subject: Ditching the airbox ? |
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Has anyone gotten rid of the airbox and put K+N's or something similar on the throttle bodies with a seperate breather oil seperator ? is the inlet tubes like a tuned length/essential part of the intake tuning ?
Regards
Bill Black
_________________
1995 Grinnall Scorpion III(1990 K100 16v motor)
2010 KTM 450 EXC
Moto Guzzi V50 powered hovercraft !
1989 K100RS (8V) special edition
1974 Yamaha DT360
1972 Sanglas 400 T
1980 Yamaha XS110-Watsonian Palma sidecar
1966 Bridgestone 175 dualtwin
1980 BMW R100RS
1979 Bultaco sherpa T 350
1979 Yamaha DT175MX
1990 Honda XR250R |
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k1100rsr
Mad Brick Rider
Joined: 20 Nov 2004
Posts: 119
Location: Norway, North of Europe
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| Posted: Tue Jan 29, 2008 12:19 pm Post subject: |
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I do not use the airbox any more, but on a normal aspirated engine I would have used the standard long tubes and funnels. If not you may loose some low end torque.
_________________
93 K1100RS TIC-8PSI �hlins rear,WP springs front, 2,62 final drive, K12RS 5" rear wheel
Toy on four wheels, supercharged -97 BMW 540
http://community.webshots.com/user/k1100rsr |
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Euripides
Brick Rider
Joined: 10 Aug 2007
Posts: 45
Location: Central Virginia, USA
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| Posted: Tue Jan 29, 2008 4:40 pm Post subject: Do NOT Tamper with the air intake! |
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| You will most likely alter the power band of the engine and you will not like the results. I suggest to read the two excellent articles in the January 2008 issue of Cycle World Magazine. Also, I do not trust the air filters that you refer. This if from using them! The filter media has a tendency to develop pin holes and allow macroscopic dust particles through. Keep it original, you will be glad you did. The BMW factory engineers spent untold hours designing and flow testing the air intake (and exhauste) systems. Making off-brand parts substitutions will only screw-up the air flow, usually on the mid and low rpm ranges.- Euripides |
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abreeze
Flying Brick Rider
Joined: 17 Jun 2006
Posts: 671
Location: atlanta
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| Posted: Tue Jan 29, 2008 5:14 pm Post subject: |
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in a dyno test done on a k100 a few years back they determined there was no gain in using anafter market filter or removing any portion if the intake system. Now i know this is a 2v model but the 4v model had a 10% increase in power so airflow probably is not an issue.
http://www.ibmwr.org/ktech/dyno/index.shtml |
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duckbubbles
Flying Brick Rider
Joined: 01 Jun 2006
Posts: 361
Location: Austin, Texas, USA
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| Posted: Tue Jan 29, 2008 9:10 pm Post subject: |
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No one has mentioned that you will also be sucking in air heated by the radiator. That lessens charge density and will cost you a little power and efficiency. The stock airbox takes its air from the beside the radiator.
Frank
_________________
85 K100/1100RS, 321,000 miles, 25 years
96 Ducati 900SS/SP, sold it
05 R1200ST, 35,000 miles, 5 years
400,000 BMW miles |
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Flying Duck
PsyKotic Waterfowl
Joined: 27 Jan 2005
Posts: 10102
Location: Bumf***, WA
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| Posted: Tue Jan 29, 2008 9:33 pm Post subject: |
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| duckbubbles wrote: | No one has mentioned that you will also be sucking in air heated by the radiator. That lessens charge density and will cost you a little power and efficiency. The stock airbox takes its air from the beside the radiator.
Frank |
+1
My K75RT would only get up to 117 indicated in hot Nevada weather. Down around 50 degrees it would get up to 125 indicated. The reason: temperature of the intake air.
(FYI: I don't max out my K11s like that since the top speeds are not only more dangerous but also tickets up in those ranges cost much more than they used to.  )
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE |
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Klinker
Flying Brick Rider
Joined: 28 Aug 2006
Posts: 876
Location: SD I-90
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| Posted: Tue Jan 29, 2008 9:45 pm Post subject: |
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| Flying Duck wrote: | | (FYI: I don't max out my K11s like that since the top speeds are not only more dangerous but also tickets up in those ranges cost much more than they used to. ) |
Wise words. I've never tried to max mine out either. Something about an awareness of and aversion to the potential consequences... 
_________________
tlp
1994 K1100RS
Only the Reasonists. They believe in an evidence-based world, something called Rationalism. But it's a tiny group, not so influential.
- Page Griffin |
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Off the grid
Chaotic Good
Joined: 05 Jul 2006
Posts: 3414
Location: At the local taco truck waiting for Jo.
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| Posted: Tue Jan 29, 2008 10:04 pm Post subject: |
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I'm getting old, so when I go above 80 that "Obi-Wan" voice comes on and says, "Hey idiot, slow down".
_________________
Bane of your existence since July 2006
2007 Triumph Tiger ABS. "Sabertooth"
2009 Husqvarna TE610. "The dirty Italian mistress"
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rydor
Flying Brick Rider
Joined: 16 Nov 2006
Posts: 1304
Location: Southern Illinois, U.S.A.
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| Posted: Tue Jan 29, 2008 11:09 pm Post subject: |
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If I had all my fine and court supervision money back from my speed law hijinks, I would have 2 K-bikes in my garage.  Maybe a nice, clean K75S? I've had 2 K75RT's, but never a nice, clean S.
Gotta slow down! |
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Klinker
Flying Brick Rider
Joined: 28 Aug 2006
Posts: 876
Location: SD I-90
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| Posted: Wed Jan 30, 2008 11:01 am Post subject: |
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| Off the grid wrote: | | I'm getting old, so when I go above 80 that "Obi-Wan" voice comes on and says, "Hey idiot, slow down". |
Alec Guinness' voice saying "Hey idiot, slow down. Use the Force, Luke." 
I know - this has nothing to do with airboxes.
_________________
tlp
1994 K1100RS
Only the Reasonists. They believe in an evidence-based world, something called Rationalism. But it's a tiny group, not so influential.
- Page Griffin |
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abreeze
Flying Brick Rider
Joined: 17 Jun 2006
Posts: 671
Location: atlanta
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| Posted: Wed Jan 30, 2008 11:06 am Post subject: |
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| Quote: | | I know - this has nothing to do with airboxes. |
Just blame it on MAX, or did we scare him off too??? |
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k1100rsr
Mad Brick Rider
Joined: 20 Nov 2004
Posts: 119
Location: Norway, North of Europe
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| Posted: Wed Jan 30, 2008 1:41 pm Post subject: |
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| duckbubbles wrote: | No one has mentioned that you will also be sucking in air heated by the radiator. That lessens charge density and will cost you a little power and efficiency. The stock airbox takes its air from the beside the radiator.
Frank |
Maybe not an issue for an Grinnall? I do not know where the radiator are there..
_________________
93 K1100RS TIC-8PSI �hlins rear,WP springs front, 2,62 final drive, K12RS 5" rear wheel
Toy on four wheels, supercharged -97 BMW 540
http://community.webshots.com/user/k1100rsr |
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max
Flying Brick Rider
Joined: 22 Aug 2005
Posts: 309
Location: NZ
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| Posted: Wed Jan 30, 2008 6:24 pm Post subject: |
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| abreeze wrote: | | Quote: | | I know - this has nothing to do with airboxes. |
Just blame it on MAX, or did we scare him off too??? |
Nahhhh... just wait for Jim to come & kick your ass, I'm sure he'll do that?! (yeah, right) |
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abreeze
Flying Brick Rider
Joined: 17 Jun 2006
Posts: 671
Location: atlanta
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| Posted: Wed Jan 30, 2008 6:35 pm Post subject: |
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Hijacked!! another DB Cooper........all we need is a couple hundred thousand $$...
Good to hear from you MAX!! |
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Flying Duck
PsyKotic Waterfowl
Joined: 27 Jan 2005
Posts: 10102
Location: Bumf***, WA
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| Posted: Wed Jan 30, 2008 6:47 pm Post subject: |
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I ditched my air box once.
In fact, I "ditched" the whole frickin' bike. :
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE |
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6899
Mad Brick Rider
Joined: 11 Oct 2006
Posts: 103
Location: Indianapolis, IN
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| Posted: Wed Jan 30, 2008 10:08 pm Post subject: |
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Hey, we got a guy who has a Grinnel in our club. If you want, I'll send you his email. 
In the meantime, I examined this COOL mini car. The radiator is in front just like a car and has piping to the motor in back. The airbox is just behind the seat, ie its in the stock setup just like a normal K. If I recall, the only change is that intake tube to the airbox was rerouted somehow. 
If it was me, I'd look into a larger Scoop for the intake to increase air inflow but try to get a cold intake.
Good Luck.
_________________
1996 K1100LT, 73K (bought at 61K on 2006)
1977 R100/7, bought new, rode 97K in 29 yrs before parting out
1970 R50/5, bought used, rode 40K & sold
BMWMOA #6899 since 1976
Indy BMW Club since 1975 |
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BobZ(IL)
Rider in the Sky
Joined: 20 May 2007
Posts: 651
Location: Bourbonnais, IL
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| Posted: Wed Jan 30, 2008 11:04 pm Post subject: |
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Ugh, the ditch job's not pretty. Dare I ask what happened?
_________________
'93 K1100LT
'78 R100S
'05 R1200GS
BMWMOA, CRBMWOA, ABC, K11OG #997
Live well, do good work, enjoy the ride. |
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Flying Duck
PsyKotic Waterfowl
Joined: 27 Jan 2005
Posts: 10102
Location: Bumf***, WA
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| Posted: Wed Jan 30, 2008 11:36 pm Post subject: |
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| BobZ(IL) wrote: | | Ugh, the ditch job's not pretty. Dare I ask what happened? |
Was "exploring" in November of 04 up near Port Angeles, WA. Rode up a backroad. noticed one turn on the way up that looked particularly nasty. Said to myself, "Self, you'd better take it easy coming back down this turn." It was wet, mossy (yes, we get so much rain around here that certain roads actually have MOSS grow on them. ) On top of that, it also had wet ground up cedar bark on the pavement - another very slick material.
I prepared for the turn on the way back down the hill and and slowed WAY down. Right before entering the turn, I gently applied both brakes. The rear started to slide out so I let off the brakes to let the bike right itself, and then I just plain ran out of turn.
If I'd known then what I know now, I would've looked through the turn and just trusted the bike. I suspect part of it was target fixation on the ditch as well. It was a SLICK road so I odn't know if I would've made it - who knows?
I didn't get hurt aside from a slight bruise on the hip and the leathers I was wearing got a few scrapes. My ego had a large dent however.
In the end, it worked put for the best. I parted out the K75RT and it was almost enough to pay for my 14k 93 K1100LT. Which is like a K75RT on steroids.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE |
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BobZ(IL)
Rider in the Sky
Joined: 20 May 2007
Posts: 651
Location: Bourbonnais, IL
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| Posted: Thu Jan 31, 2008 9:02 pm Post subject: |
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Yeah I'm an ex-Oregonian and would move back in a flash if the rain would stop.
_________________
'93 K1100LT
'78 R100S
'05 R1200GS
BMWMOA, CRBMWOA, ABC, K11OG #997
Live well, do good work, enjoy the ride. |
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