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1Back to top Go down   Favorite Intake Setup!? Empty Favorite Intake Setup!? Fri Mar 22, 2024 7:20 pm

Keedo

Keedo
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Hey everyone,

I want to start getting ideas for my 1987 K100 Resto / Cafe build. I am not particularly sure what route I want to go or what I want it to look like, but one thing that has been on my mind for a while is the intake setup. Being a 1987, I am under the impression that I don't have many options. What is the best-looking / appealing intake setup that you've seen or run? 

Thanks!

    

2Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Sat Mar 23, 2024 5:15 am

firstle

firstle
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3Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Sat Mar 23, 2024 9:07 am

jbt

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Keedo wrote: What is the best-looking / appealing intake setup that you've seen or run? 

Thanks!

The OEM one. Others can't run.


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Let us enjoy the transient delight
That fills our fairest day.
    

4Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Wed Mar 27, 2024 7:48 pm

Case1234

Case1234
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What's not being said is that the AFM unit is required to send a signal about the airflow and thus can't be removed.

You will see cone filters attached directly to the AFM, with the airbox removed. Personally I think that looks pretty janky.

My favorite solution is mine of course. Instead of the snorkel I use a small velocity stack esque inlet with it's own mesh screen to keep large debris out.

I don't see much reason to remove the airbox entirely. Unless you are really going to dedicate effort into rewiring and removing the fusebox as well, you will always have plastic boxes under the tank.

https://imgur.com/LjfsGlO

Favorite Intake Setup!? LjfsGlO

    

5Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Wed Mar 27, 2024 9:30 pm

jbt

jbt
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It's pointless to use a velocity stack here. There's a lot of obstacles before the air reaches the intake valve: air filter, flowmeter...any gain of air speed will anyway be instantly lost once the velocity stack ends into the airbox. Dura Bernouilli lex, sed lex.
And there are genuine velocity stacks into the airbox, but directly fitted to the throttle bodies! Well hidden, but there are:

Favorite Intake Setup!? S-l16013

Favorite Intake Setup!? S-l96010

And they even are finely tuned to give the best intake resonance and the best flow possible to the head port.
Removing the airbox will only have negative consequences. The flowmeter is calibrated to work into a quiet environment, with a constant air pressure that the airbox provides.
If you watch the genuine schnorkel, the diameter of it section is increasing from the intake to the airbox: this is to reduce air pressure and turbulences by reducing its speed. It's the very opposite of a velocity stack.
Note that the OEM air filter is absolutely not a restriction to the airflow. There's no difference of power output on a dyno whether there is a filter or not.
And, as always, it's not because you create a big hole for the air to come into an engine that the engine will pump more air. That's because an engine can pump more air (bigger bore, longer intake valve opening) that you have to enlarge the air admission. No confusion between cause and effect!


__________________________________________________
Let us enjoy the transient delight
That fills our fairest day.
    

6Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Wed Mar 27, 2024 11:54 pm

Case1234

Case1234
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I think we can agree there is no functional difference, owing to the large airbox, the restriction of the AFM, the apt plenum and internal velocity stacks. Dura lex, sed lex.

The 90 degree turn at the base of the snorkel into the airbox also owing to it's own inefficiencies and lack of import. Rather it serves it's purpose as an inlet for air colder than what you'd find bottled up in the fairings.


All of this ignoring that the OP asked a question based on appearances.

    

7Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Thu Mar 28, 2024 1:20 am

Keedo

Keedo
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Correct, this is solely for aesthetics. I am not building the bike for performance.

    

8Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Thu Mar 28, 2024 3:06 am

jbt

jbt
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The question is not how to increase or not performance, but how not to reduce it for aesthetics...


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Let us enjoy the transient delight
That fills our fairest day.
    

9Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Sat Mar 30, 2024 2:19 am

Case1234

Case1234
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Keedo wrote:Correct, this is solely for aesthetics. I am not building the bike for performance.
https://pipeburn.com/beastly-brick-bmw-k100-silverback-gorilla-by-two-wheels-empire/

I kind of dig the plenum side of this one. I like seeing the more pronounced individual routing on the intakes.

The airbox side is done better than others I see, but the photos are dark so hard to say what they've done with the AFM. Buried in there somewhere. About as much modification as you could do on the intake bits.


Clever bit of dress-up on the plenum on this one. But the AFM with a small cone filter fitted and just sort of awkwardly hanging out isn't much of a solution to me. I think it warrants more attention and actual fab if you go that route. Just my opinion of course.
https://pipeburn.com/bmw-k100-ed-turner-motorcycles/

    

10Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Sat Mar 30, 2024 10:01 am

Dai

Dai
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On the first bike the AFM is mounted off the frame rails. Also that 'ram air' setup is more likely to destroy the air flow than make it better, unless the intake length has been tuned (it hasn't. For example, a reverse-head Triumph T140V needs six inches of intake to slow the air down enough for the carbs to use it. Kawasaki tried ram air in the mid-Nineties as a sales gimmick and ended up with over two feet of intake though fairing ducts before the air flow was useable).

On the second bike the AFM is hanging in the breeze as on most K100 customs. The only pic that shows the AFM directly is slightly confusing because there's a cable running in front of it. However, this one is only the second custom I've seen that has successfully dealt with the tank/subframe line.


__________________________________________________
1983 K100 naked upgraded to K100LT spec after spending time as an RS and an RT
1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

11Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 1:05 am

TacKler

TacKler
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jbt wrote:The question is not how to increase or not performance, but how not to reduce it for aesthetics...

A very good point often not realised along with what Dai says.


__________________________________________________
Red 1991 K75S
    

12Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 4:51 am

jbt

jbt
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If it's all about aesthetics, well, don't ask any questions. Do it.
You'll be altering another K to make one more boring clone, so-called racer, with all the fashionista's gimmicks and the full set of uniform gear on it: the saddle (brown, mandatory brown, to respect the original look of vintage seats that all were actually black) too short to be usable ("It's OK, I'll never ride with a passenger anyway"), the too short too large fork with a reduced offset that will smash the tank ("It's OK, I'll never turn at full angle anyway"), an altered angle that will give a terrible agressive look but a very poor road handling ("It's OK, I'm riding carefully anyway"), the missing fenders ("It's OK, I'll never ride in rain anyway") that hardly hide too large off road tyres ("it's OK, I won't really ride off road anyway"), the rear one being fitted on a too large and misaligned rim (It's OK, I'll never post on Instagram any rear view anyway).
And to make sure that everybody notices this so casual unique clone, of course, a shorten but noisy exhaust that will complete the list of alterations of the essential qualities of this bike ("It's OK, I'll ride only out of town, anyway")
Fortunately, the crappy chinese instruments and "simplified" wiring will protect you to be affected by all these alterations. ("It's OK, I won't ever get it running nor ride it anyway").





__________________________________________________
Let us enjoy the transient delight
That fills our fairest day.
    

13Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 6:52 am

Laitch

Laitch
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Favorite Intake Setup!? 4D6qBnTpxAYVqF+dQB1KlNYXLNCbNAAaNHYQLICvNBVgdq15L1WXQuwqIKBuLNKzAgADs=


__________________________________________________
1995 K75 90,000 miles
    

14Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 2:30 pm

Point-Seven-five

Point-Seven-five
Life time member
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jbt wrote:If it's all about aesthetics, well, don't ask any questions. Do it.
You'll be altering another K to make one more boring clone, so-called racer, with all the fashionista's gimmicks and the full set of uniform gear on it: the saddle (brown, mandatory brown, to respect the original look of vintage seats that all were actually black) too short to be usable  ("It's OK, I'll never ride with a passenger anyway"), the too short too large fork with a reduced offset that will smash the tank ("It's OK, I'll never turn at full angle anyway"), an altered angle that will give a terrible agressive look but a very poor road handling ("It's OK, I'm riding carefully anyway"), the missing fenders ("It's OK, I'll never ride in rain anyway") that hardly hide too large off road tyres ("it's OK, I won't really ride off road anyway"), the rear one being fitted on a too large and misaligned rim (It's OK, I'll never post on Instagram any rear view anyway).
And to make sure that everybody notices this so casual unique clone, of course, a shorten but noisy exhaust that will complete the list of alterations of the essential qualities of this bike ("It's OK, I'll ride only out of town, anyway")
Fortunately, the crappy chinese instruments and "simplified" wiring will protect you to be affected by all these alterations. ("It's OK, I won't ever get it running nor ride it anyway").
Priceless!!!

I would add "it's OK, I'm just building it to take cool urban wasteland photos of the bike so I can post them on the interweb, and turn on some cool girl with green hair, black eyes and clothes, and a face full of fishing tackle".



Last edited by Point-Seven-five on Mon Apr 01, 2024 4:26 pm; edited 1 time in total


__________________________________________________
Present: 1991 K100RS "Moby Brick Too"
 
Past:
1994 K75RT "Ilsa, She Wolf of the SS"
1988 K100RS SE "Special Ed"
1994 K75S "Cheetos"
1992 K100RS "Moby Brick" R.I.P.
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

15Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 3:41 pm

Two Wheels Better

Two Wheels Better
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"Now get offa my lawn!"
 Favorite Intake Setup!? 1f474


__________________________________________________
"A long ride is the answer to a question you will soon forget!" ~ Anonymous
1977 R75/7-100, '93 K11/K12 Big Block, '93 K1100RS, '95 R100 Mystic, '96 K1100RS, 2 x '98 K1200RS, '06 K1200R & '09 K1300GT
    

16Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 4:44 pm

Laitch

Laitch
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Two Wheels Better wrote:"Now get offa my lawn!"
 Favorite Intake Setup!? 1f474
However, feel free to drop off the Brick's fairings fenders, seat, rear cowl, instrument cluster and related hardware. The gardener will collect them and put them in the shed.


__________________________________________________
1995 K75 90,000 miles
    

17Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 4:53 pm

Two Wheels Better

Two Wheels Better
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Favorite Intake Setup!? 20240410
This gardener has been collecting and storing their cast-offs in his shed (and garage, and attic)...in the hope the trend will end and some will wish to get dressed.


__________________________________________________
"A long ride is the answer to a question you will soon forget!" ~ Anonymous
1977 R75/7-100, '93 K11/K12 Big Block, '93 K1100RS, '95 R100 Mystic, '96 K1100RS, 2 x '98 K1200RS, '06 K1200R & '09 K1300GT
    

18Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 6:39 pm

Keedo

Keedo
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Tough crowd  Shocked

    

19Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 6:55 pm

Dai

Dai
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Favorite Intake Setup!? 44271 Not really, honestly.


__________________________________________________
1983 K100 naked upgraded to K100LT spec after spending time as an RS and an RT
1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

20Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Mon Apr 01, 2024 10:14 pm

Case1234

Case1234
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Keedo wrote:Tough crowd  Shocked

A complete vitriol for anything K100 cafe is a signature K100 forum characteristic.


Feel free to PM me if you have questions. I've been through it all to complete mine. I ride it more than I do my RT.

    

21Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Tue Apr 02, 2024 12:58 am

Dai

Dai
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Life time member
I think the world weariness (rather than vitriol) comes from seeing so many bikes being butchered to be turned into cafe racers and never finished because the builders don't think ahead or think it through before starting. Those that do get finished (usually from a 'professional' shop) almost always ignore the visual problem with using a K100 as a donor and that is the tank/seat line, so the finished product never looks right. There are ways around that problem but in X years of being on this forum I have only seen three bikes that solved it and one of them was built by a forum member from scratch (yes Chris - I'm looking at you). 

The second major problem is that instead of thinking ahead with the fuel tank, there seems to be this sort-of panic that because the fuel pump is inside the tank then you can't use any other fuel tank. Not so - Moto Guzzi use an external fuel pump.

Lastly, the eight-valve engine is the wrong engine to use for such a project because of the AFM. It would be far, far better to start with a sixteen-valve engine because it doesn't have an AFM. Look at this one:

https://www.youtube.com/watch?v=fU6eHCfb9ww

That is a good cafe racer - seat/tank line solved, sixteen-valve engine and a change of fuel tank. We are not anti-cafe racer/anti-custom/K100 purists (both of mine have been hacked about in one way or another); check this thread out too:

https://www.k100-forum.com/t13161-k75-madass

Finally, if we really were anti-cafe racer then there wouldn't be a sparate forum especially for those builds. There's a lot of help in there too.


__________________________________________________
1983 K100 naked upgraded to K100LT spec after spending time as an RS and an RT
1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

22Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Tue Apr 02, 2024 1:26 am

TacKler

TacKler
Life time member
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And further to what Dai says like any forum there are the crusty old pensioners with too much time on their hands who cannot help themselves and just have to criticise those of a younger generation.  Grumpy old men* who always did it better in their day and over the intervening years have lost any sense of humour that they ever had.  

We are fortunate on this forum as it is well moderated and any attempts at character assassination are shut down.  There are other forums out there which are aggressive and unwelcoming and this one definitely is not.












*  I'm working on it.


__________________________________________________
Red 1991 K75S
    

23Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Tue Apr 02, 2024 6:27 am

jbt

jbt
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Life time member
Dai wrote:  

Finally, if we really were anti-cafe racer then there wouldn't be a sparate forum especially for those builds. There's a lot of help in there too.

I'm not an anti-cafe racer. At all. I've been building BMW cafe racers some since 1995, when Internet, Instagram or Aliexpress did not exist. In those days, making a racer was really meaning to make it.
I built this one from a R75/5 20 years ago, and rode it a lot on road, hill climbing and for mountain roads japanese pilots taming.
Favorite Intake Setup!? Racer211

I just don't like copycats using a inadequate basis to aproximately tinker a bike by shopping trendy parts without considering ergonomics, harmony or efficiency in their "work".
Make sparks, stack parts, park crap.

But I sincerely admire those who create their own racer, making it from scratch and paying attention to the consistency of the design and concept.


__________________________________________________
Let us enjoy the transient delight
That fills our fairest day.
    

24Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Tue Apr 02, 2024 10:16 am

caveman

caveman
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I like seeing someone do a nice job on a cafe. I hate seeing someone hack a good 75. But for me motorcycles are to have fun with so if it puts a smile on your face, that's cool.

Note: Chris, It will not bother me if you do as many 75s as you can.

    

25Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Fri Apr 05, 2024 8:15 pm

Two Wheels Better

Two Wheels Better
Moderator
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The ultimate solution for those who wish to appear to have a clean intake system whilst retaining the full function of the airbox. Available in handy three or four packs for the café-d out engine of your choice.
 Favorite Intake Setup!? Rmr-bm10
Sort of clips on like a bow tie for your convenience. I reckon it'd make a swell addition to any K bike out for the day on the Distinguished Gentleman's Ride.
Favorite Intake Setup!? Rmr-bm11


__________________________________________________
"A long ride is the answer to a question you will soon forget!" ~ Anonymous
1977 R75/7-100, '93 K11/K12 Big Block, '93 K1100RS, '95 R100 Mystic, '96 K1100RS, 2 x '98 K1200RS, '06 K1200R & '09 K1300GT
    

26Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Sat Apr 06, 2024 6:59 am

jbt

jbt
Life time member
Life time member
Don't forget to drill holes in the airbox of the same diameter of these velocity stacks to align them or they will have no effect at all...


__________________________________________________
Let us enjoy the transient delight
That fills our fairest day.
    

27Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Sat Apr 06, 2024 7:09 am

Two Wheels Better

Two Wheels Better
Moderator
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Favorite Intake Setup!? Rmr-bm12
A closer look. 
Laughing


__________________________________________________
"A long ride is the answer to a question you will soon forget!" ~ Anonymous
1977 R75/7-100, '93 K11/K12 Big Block, '93 K1100RS, '95 R100 Mystic, '96 K1100RS, 2 x '98 K1200RS, '06 K1200R & '09 K1300GT
    

28Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Sat Apr 06, 2024 7:34 am

jbt

jbt
Life time member
Life time member
About these velocity stacks, I changed the ones installed on my R75/5 racer, made from...old cup trophies, for new shiny aluminium aftermarket ones. Because I got them for 10€ only.
Test ride yesterday: the engine has lost a lot of power at high RPM... The only difference is that the new ones are 1 cm shorter. That's enough to ruin the resonance previously set up to enhance the performance at high RPM.


__________________________________________________
Let us enjoy the transient delight
That fills our fairest day.
    

29Back to top Go down   Favorite Intake Setup!? Empty Re: Favorite Intake Setup!? Sat Apr 06, 2024 7:39 am

Two Wheels Better

Two Wheels Better
Moderator
Moderator
Of course, those K bike velocity stacks are a complete, and to my mind, an embarrassing joke; a mere add-on accessory for looks.


As for velocity stacks on carburetors, they work much better on slide carbies than they do on CV carbies.


Constant velocity (CV) carbs require a calculated volume of 'static' air immediately available at the mouth of the carb in order to transition smoothly and respond according to the demands of the rider turning the throttle. This static air (best delivered by an appropriately sealed airbox) at the carbie mouth makes it possible to turn the throttle more smoothly at any given speed without surge or stumble, all while getting reasonable mileage. When you remove that static air you actually rob the bike of that ability to smoothly transition. CV carbs are not especially well-designed for race use and adding velocity stacks increases available air volume which is then dumped into the intake manifold(s), often well past their design capability or requirements. With slide carbies, flat or round, using velocity stacks, you can whack the throttle open, and if the engine has been designed and tuned correctly, ie, cams, jetting, compression ratio, spark advance - and the velocity stack's length has been considered - the result is a smooth, direct rush of air and fuel, in order to make the best power, usually in race or otherwise high RPM demands.


__________________________________________________
"A long ride is the answer to a question you will soon forget!" ~ Anonymous
1977 R75/7-100, '93 K11/K12 Big Block, '93 K1100RS, '95 R100 Mystic, '96 K1100RS, 2 x '98 K1200RS, '06 K1200R & '09 K1300GT
    

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