cold air intake

[Luke-a-Tron]

I would suggest a resyncing the carbs as the manifold vacuum is going to be way different at #1 and #4, particularly at high revs. Might help with that dead spot. Since you're in school for monkey wrenching, hopefully you'll have top notch tools for the job available to you.

[maverick]

i doubt we have a carb syncer. we rarely see cars with carbs anymore. but that a great idea i hadn't put much thought into that.

[PIMPMYFZR]

mAN THATS totally Tits bro .. came out pretty pimp

[megaloxana]

very very interesting..goes well with the theme of your bike. Im especially surprised your bike still runs fairly well with that.

[Luke-a-Tron]

I had a friend who was a mechanical engineer major. He was involved with Formula SAE team (an open wheel racing "league" featuring cars built by college engineering students). They run 600cc motorcycle engines (CBR last I heard) in chassis they design and build themselves. It's more of an engineering competition than an actual racing competition. The only performance modifications allowed at all are the airbox which must breathe through a 1.5" restrictor plate. The crazy thing is, they spend about 2 years designing each one. There are so many fluid dynamic things happening in there it's ridiculous.

My friend personally spent a lot of time doing finite element analysis on the pressure wave created when the intake valves close and the air up near the valve gets compressed by the momentum of the air behind it. When it rebounds it sends a wave of higher pressure back up through the runner which then interacts with pressure waves bouncing all over inside the airbox. They were tuning the length of intake runners (we've got velocity stacks instead) so that this pressure wave would hit the runner of the next cylinder in the intake cycle just as it's valves were opening. The new r1 and some other bikes (I think MV Agusta was the first) have variable length velocity stacks that move around with the change in RPM and engine load.

I don't really have any advice to add but things like that blow my mind when I start thinking about all the variables. Sometimes I wish I had gone into engineering but I don't thrive particularly well in traditional academic environments and the engineering programs almost take pride in how hard they make it for the students. As if simply surviving for 5 years of that hell is some sort of indicator of real world skill or proficiency. It's a really dumb system if you ask me.

Ok, I'm done rambling.

[bucket]

I love the bike


My buddy is building 2 wide body toyota MR2s as race cars looking at a nutty amount of HP. to get it he needs a sweet intake. He was looking in to rally car style intakes. He found that you can tune the cars power band with the length of the runners to a point. I bet if you have room lengthen or shorten the runners your died spot will move.

[maverick]

well i synched my carbs and it helped a lot with how the bike idled and ran but still had a dead spot. i tried duct tape over part of the filter to see if it was lean and after covering about 60% it went away and runs like hell. this weekend i'm going to adjust my needle clips to rich it up a bit so i can get the most of this new intake.

[The Usual Suspect]

TOTALY BADD ASS!!!

[maverick]

haha thanks man. well i adjusted my needle clips 3 positions toward the flat end. and it seems to have fixed it. i think i set them too rich to begin with but now they're great. pulls hard in first... i went back to 15 teeth in the front but it still reaches for the sky with no clutch.

[mike94fzr600]

that sweet i wish i had the insite to do half of what you do. i just sit and look at my bike and nothing comes to mind

[maverick]

well i don't think anyone can argue i'm creative... i've got a thousand crazy ideas running through my head at any given moment.

[maverick]

bad news from the intake front... i thought i got rid of the stumble but i did not. i thought by taping the filter i was riching the mixture but now i think the filter causes a bad turbulence around 7krpm no matter what throttle position...without the filter it runs fin. i think when i oiled the filter it got worse maybe i'll run filterless untill i can get a stock airbox to modify. any ideas?

[thatkid]

bad news from the intake front... i thought i got rid of the stumble but i did not. i thought by taping the filter i was riching the mixture but now i think the filter causes a bad turbulence around 7krpm no matter what throttle position...without the filter it runs fin. i think when i oiled the filter it got worse maybe i'll run filterless untill i can get a stock airbox to modify. any ideas?

I know with the K&N filters it says you actually want some dirt on the filter after cleaning and oiling. Could be one reason.

[maverick]

i washed the oil out of the filter and it seems to be okay now but i've been fooled before. i'll ride it to school tomorrow and see if it acts up on the highway...

[Luke-a-Tron]

It's possible that the way the wind moves over the end of the pipe that it could be creating a slight vacuum... I don't know if it could be strong enough to cause a problem though. In cars anyway, you usually try to get the end of the intake into stable air.