intake modifications

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Major Softie
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Joined: Tue Aug 03, 2010 1:46 pm

Re: intake modifications

Post by Major Softie »

twist wrote:I just want it to cool the air in the intake, didn't cross my mind that it's co2. another hair brained idea!
Originally I thought you were just making a sarcastic joke. I never considered that you might have forgotten about the CO2. :lol:
MS - out
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twist
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Re: intake modifications

Post by twist »

waz a joke!
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vanzen
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Location: Hidin' in the Hills

Re: intake modifications

Post by vanzen »

twist wrote:waz a joke!
Actually, I do believe that this actual method and strategy has been pursued –
but only in the venue of drag-racing and LSR.
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Roy Gavin
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Joined: Tue Aug 03, 2010 11:21 pm
Location: Adelaide Australia

Re: intake modifications

Post by Roy Gavin »

Thanks Steve, I think that was a quote I would like to have found, although I think Rob went into a bit more detail in another thread, as I cant remember the reference to raising the top of the air box.

Looks like I am guilty of the same error I was suggesting others might be making , that is, of taking a fact which is true in one particular set of cicumstances, and suggesting that it applies to every configeration/bike.

Going back to an earlier post regarding step free carb to head adaptors it was suggested that these are a plumbing adaptor, possibly used for connecting different types of pipes, perhaps 1 1/4" UPVC to 1 1/4" Copper or something of that nature, but there is no figuring on them to give me a clue.
Adelaide, Oz. 77 R75/7. 86 R80 G/S PD, 93 R100 GS, 70 BSA B44 VS ,BMW F650 Classic
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George Ryals
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Re: intake modifications

Post by George Ryals »

For those of you interested the why's and wherefores of resonate airboxes this might interest you.
http://motorcycleinfo.calsci.com/Airboxes.html
Smile it's contagious!
'74 R90S, '67 /2 Conv w/sc, '66 R50/2
'74 Harley FXE, '72 Harley FLH w/HD sc
'69 BSA 441 Victor Special, '74 R90/6 Basket case
'85 R80RT wreck for parts
Roy Gavin
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Joined: Tue Aug 03, 2010 11:21 pm
Location: Adelaide Australia

Re: intake modifications

Post by Roy Gavin »

Had a look at the link , and dont think much of it.

Most of what isnt gibberish is stuff and nonsense - he talks of air box intake snorkels 800 sq cm, or around 28" by 28" square, of reving a DL to 12000 RPM when it only revs to 9500, doest factor in the fact that modern engines overfill the cylinder by around 10 %, etc, etc.

On most bikes I have owned the area of the airbox intake snorkels have been around the same or less than the area of the inlet tracts, yet he tells us that 30 to 50 times the size is the norm on "modern" air boxes.
He talks as if the only factor which affects the torque of an engine is the airbox resonances .
Cam, ignition, injection and exhaust designers most probably would have contrary views to that.
He makes no mention of the inlet valve to carb dimension which is genereally considered to be more critical than the plumbing downstream of the carb, or the differences in the speed of sound in different materials - it isnt the same in a mixture of air/fuel as it is in air and it varies with the temperature of the air, which he hasnt factored in.

All in all not worth looking at - not everything in writing is fact and this is at the extreme end of the bullshit spectrum.
Adelaide, Oz. 77 R75/7. 86 R80 G/S PD, 93 R100 GS, 70 BSA B44 VS ,BMW F650 Classic
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vanzen
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Re: intake modifications

Post by vanzen »

Roy Gavin wrote:Had a look at the link , and dont think much of it ...
Also read the article – and thought it to be a bunch of noise ...
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twist
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Re: intake modifications

Post by twist »

so I got the square air box and filter. One of my friends gave me a practically new starter cover to match, (black with dam and vents in top, BMW letters, no model designation). So I'm itching to install and see if I like it any more than the drilled round air box. I need to pull all the emission control solenoids and other junk out and plug the holes first. Any one else done this? I noticed that the crank case vent tubes are split between the intakes so each side gets a dose of oil mist. Also there are little fins on those tubes, kinda like that awesome insert major softie suggested not long ago for the intake track. :lol: These are unfamiliar parts to me.
Chuey
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Joined: Mon Aug 02, 2010 11:56 pm

Re: intake modifications

Post by Chuey »

Do not throw away the rubber sleeves that connect things inside the square box. As I recall, there is one on each side that you need part of to make things fit. You will know when you need it. The holes you need to plug can be plugged by timing hole rubber plugs.

Are you going to try to do any testing such as a timed run of some section or timed acceleration to see if the air box made a difference? That would be more interesting than what it "feels" like...even though that is relevant.

Hey, are you still coming to So Cal?

Chuey
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