airbox mod poll

[OB_THE MOTORHEAD]

50 some odd pulls so far on the 99tried the longs on my 2ooo and it only has 300 miles and is a wimp so far 15.4 stock and 93.6#torque.totaly unmolested.put all long and get153.9hp and96.4#torqueand this made the bike leanout from13.0-1 upto13.35-1 so some things happenin here what it is aint exactly clear. OH sorry thats a song damn flashbacks!i'll get the sheets scanned so you guys can compare to whatever .i gotta tune a little in the mid where theres a did and a slight fat spot.also gotto have doug send my ti pipe before i get too carried away on the stock system.

 

[OB_THE MOTORHEAD]

do they make a bmc or other fiter for the box with no floor ,just the lip?i had to make one.i don't know about long stacks with pipes i havent played with that yet.to many bikes to do i'm 20 bikes behind now and more commin .see ya!

 

[Frank Adams]

I done this airbox mod for My 1360:

I cut about a half inch out, away from the flapper valve box. Removing all burs, making it smooth as possible.(Burs will cause a disruption in the way the air flows, causing a hp loss)

Removed the vaccum valve and pluged the hole.

Put "4" 25mm short stacks on.

Installed fiber glass screen between the airbox and frame tubes. And also sealed this area.

Heres My opinion:

It's a "Must" to do a large air box mod on a built motor.

I'm still unsure if it's a good ideal to do it on a stock motor?

The more you open it up on the bottom, the longer it's going to take to pressurise the airbox, resulting in hp loss through the mid-range?

I maybe wrong?....and these are NOT facts, just My opinion.

I need to hear from somebody thats run both type of box's on a Dyno-Jet 250?

That, should tell the story!

 

[OB_THE MOTORHEAD]

dj250 and 200 of mine on a full pull is the same i just cannot run under load at a certain sustained rpm.if you did not remove the entire floor of the box your loosing ramair efficiency.the air has to hit thatledge and deflct ub and around and common sense will take you 95% of the way in mods .those stacks should be perfect for a ported head setup like yours.

 

[OB_cbxchris]

right now full airbox mod with short stacks...I`m going to fit a car K&N filter to box and in-large opening as big as I can...I`m looking for a box off a wreck now...this is with a ported large valve head.....

 

[Gixx1300R]

I didnt do the Airbox mod.If you see my Dyno chart for my stock Busa you will understand why.Maybe after I install my exhaust.

 

[OB_Johnnycheese]

been stock untill now if the swingarm fits air box is next.

 

[OB_THE MOTORHEAD]

don't need to you can make more with box done and dyno will not truely show how much more efficient the ram air will be.or are you saying you cannot get it better?

 

[OB_BUSA1]

air box mod justed removed the plastic under the stock filter. happy with the mod feels faster , idle fine small stumble at 2600 / 2900 sometimes . but i try stay at 3100 or better rather have the gains on top. also removed pair, hindle pipe and pc 2.

 

[OB_THE MOTORHEAD]

stumble on mine near there was lean condition!

 

[OB_THE MOTORHEAD]

who has it done? and to what extent and whos filter?

[This message has been edited by THE MOTORHEAD (edited 24 March 2000).]

 

[OB_badbus]

Cut around the lip, short stacks and BMC.

I might have to try the long stacks next.

 

[OB_Dirty Pete]

Cut out the whole bottom, sealed the intake tubes, BMC, going to long stacks on your advice.

 

[OB_KawAbuser]

Good poll Mr. Motorhead,

I have not messed with airbox mod as I am not convinced it works in regards to midrange applications = mountain twisties.

The first airboxes from Japan should be released 3/30 or 3/31 from yesterdays notice.

There has been a Japanese road race team working in the shared developement, maybe this will be a "Better Moousetrap"!

Disclaimer: No offense Dangermouse! or Mr Cheese, some people are sensitive to mouse/cheese jokes.

 

[OB_THE MOTORHEAD]

mr.abuser my 99 makes103#torque with stock pipesmakes over80#from 3400to10700 is that a torque curve or what?andover 90#from5400-9700.100#from6400to8200 with 103#peak avg.through 20 pulls with gutted box all long stacks and un modified stock exh.horsepower is over 150 from7600 to10800limiterover 160hp from8400 to limiterwith a peak hp.of 168 avg.through the same pulls.oh and 60# torque at 1800 rpm.short aluminum stacks willwork better for ported throttlebodies so ive been told and do believe,or if your head is ported.

 

[OB_vortech347]

So would putting the long stacks on a completely stock motor help? If so where do you get them and how much do they cost?

 

[OB_GSXRTURBO1]

Those numbers border on unbelievable. Good job Motorhead, I'll bet it took alot of work to get there.

 

[OB_tinhead]

Cut out floor. all short stacks, will change to long ones and see how it feels. Filter is still stock, waiting for K&N.

 

[OB_maniac marshall]

i have a micron ss oval, block off plates, pc2, and a bcm to put on as soon as i get my break in done. my question is should i gut the airbox and get stacks? if so what stacks should i get long or short? where do you get these stacks from and how much are they? do the stacks run with the bmc?

maniac

 

[OB_TOJ]

I ditched my stock airbox (it doesn´t matter how much you carve in the stock airbox it´s it´s still a poor design in my opinion for max hp) and built a new one thats bigger and better wich mean I can play araond more with the stack lenght and choose wich pulse I want to play with.