Open up the Airbox

[chris2992]

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I wanted to open up the airbox lid to let more air in. I got the idea from a few folks on here but didn't see a post on it so here it is. If there already is one, delete this one.

I started by cutting the opening that is connected to the snorkel in half. then the side closest to the middle of the airbox I cut along the flat of the air box so that I could remove it. I then cut the flapper valve opening off as well. Then cut a square out of the top symmetrical with the half of the snorkel opening on the other side. Then by the use of epoxy, I affixed the cut off half to the side that I just cut out. Then used some abs plastic from a black trash can to fill in the holes. Final I sealed all the holes with some silicone sealant. I now will wait for the epoxy to cure for 24 hrs, then final sand and be done with it. It don't look too pretty but opened up the face of the box by about 400%. Now I will get to fiddle fart with the PCII to come up with a good map. Here are the pics.

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I plan to cover the opening with some form of chicken wire to keep the leaves out and large stuff. I will see how the epoxy dries, If it looks really bad, I may shoot it with some flat black paint to cover it up. Hope this makes sense to ya'll.

Edited March 14, 2006 by HispanicSlammer

[Veefer800Canuck]

I dunno, can you provide more pictures of your lovely and talented spokesmodel who is carefully displaying the airbox lid? :salesman:

[The Phantom]

I dunno, can you provide more pictures of your lovely and talented spokesmodel who is carefully displaying the airbox lid?  :salesman:

<{POST_SNAPBACK}>

Agreed, can't quite see enough in the first pic to be able to make an edumacated comment :lol:

[cozye]

Stupid airbox lid is in the way :D

[chris2992]

She wanted to make "silly" faces in the opening until I told her that I was putting them on here. She isn't quite as brave as some of the other lovely ladies of this board.

[Guest hammer]

Cool special effect. If you look at the first picture long enough, eventualy you will see an air box. :thumbsup:

[chris2992]

Kind of like those hidden image photos from the mid 90's.

[Guest Swiffer]

Now all we need to know is if it does any good (the bigger airbox lid i.e.), or if it's just another "seems like a good idea" project. We want hard data!

[chris2992]

I got the idea from VFRMonkey, he said that it gave him a boost in hp. I will be accompaning this with RatFinks K&N air filter mod. I'll get all of this done then slap it on the dyno in the spring. In theory More air is always better provided you can modify the fuel curve to suit. We'll see.

[Baileyrock]

I dunno, can you provide more pictures of your lovely and talented spokesmodel who is carefully displaying the airbox lid?  :salesman:

Thank God, for a minute I thought that maybe chris just dressed a little wierd! :beer: I'm glad it's not him. :thumbsup:

[COS_VFR]

I dunno, can you provide more pictures of your lovely and talented spokesmodel who is carefully displaying the airbox lid?? :salesman:

<{POST_SNAPBACK}>

I would assume that is her in some of his gallery pictures.

[chris2992]

Thank God, for a minute I thought that maybe chris just dressed a little wierd! :beer:  I'm glad it's not him. :thumbsup:

<{POST_SNAPBACK}>

I have been known to run around in female attire, it is much more comfortable. :beer:

I would assume that is her in some of his gallery pictures.

<{POST_SNAPBACK}>

Yes you would be correct. Just about a month ago, I locked her down to only me, and we are to be married Oct 7th next year.

[COS_VFR]

Yes you would be correct. Just about a month ago, I locked her down to only me, and we are to be married Oct 7th next year.

<{POST_SNAPBACK}>

Congratulations, yesterday marked 23yrs for the missus and me.

[chris2992]

Congratulations,  yesterday marked 23yrs for the missus and me.

<{POST_SNAPBACK}>

Wait 23 years from Oct 7th then we will see. :beer: In all seriousness Thank you, we have been together for 4 years now, so it is basically a formality.

[Baileyrock]

Yes you would be correct. Just about a month ago, I locked her down to only me, and we are to be married Oct 7th next year.

Awesome and congrats ! :warranty:

Let us know what the airbox mods do too!

[enzed_viffer]

... we have been together for 4 years now, so it is basically a formality.

<{POST_SNAPBACK}>

Mebbe.

My woman-thing and I had been together about 4 years before we married, and I thought it wouldn't make much difference, but it did. We both felt more secure, more committed, happier. That was in 1982.

Or was it '81? :warranty:

I do know it was September 4th. :goofy:

[Guest vfrmonkey]

My bike puts down a lot of power and sounds even better - with the airbox opened up you can really feel the intake puilses in your chest, especially at WOT/ mid rpms & climbing...

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[chris2992]

Awesome and congrats ! :warranty:

Let us know what the airbox mods do too!

<{POST_SNAPBACK}>

I should have "read the rules" prior to piping that ring out.

That was in 1982.

Or was it '81?

I do know it was September 4th.

<{POST_SNAPBACK}>

:lol:

[chris2992]

Here is the final product, I painted it with black krylon fusion paint to make it all black and added aluminum screen to the front to keep leaves, bugs and other large things out.

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[enzed_viffer]

Here is the final product, I painted it with black krylon fusion paint to make it all black and added aluminum screen to the front to keep leaves, bugs and other large things out.

<{POST_SNAPBACK}>

Why didn't you paint it after adding the screen?

[chris2992]

Thought I might like the look of the screen being silver, but think I will just repaint after the epoxy cures. As if it really matters what it looks like seens how you can't see it. Just so that it is functional.

[keithbob]

Congrats on lockin' her in! Good job on the airbox, too. I think I'll do the screen idea. I opened mine up in a similar way last year, and now find all sorts of odd bugs and stuff on the filter.

Remember, bug-infested air has to get to that big new opening now, and that's not easy the way the VFR is designed. I put some 1/4" spacers under the front mounting tabs, and found some longer stainless bolts at the marine supply store here. I just used a couple of 6mm (I think) nuts slipped over the bolts. The tank is still firmly held in place, and I often use a large tank-bag loaded with all my stuff.

The result is more air coming in under the front of the tank. I haven't had it dynoed yet, but the tank lift seems to help in the midrange, which is where we need it. Sounds great, too.

Keith

[enzed_viffer]

I put some 1/4" spacers under the front mounting tabs, and found some longer stainless bolts at the marine supply store here.  ...... The result is more air coming in under the front of the tank.  I haven't had it dynoed yet, but the tank lift seems to help in the midrange, which is where we need it.  Sounds great, too.

<{POST_SNAPBACK}>

That's interesting, and it would be good to find out if it does help, as it's easy to get misled by wishful thinking or it sounding more powerful.

No, I'm not saying this is the case with you, Keith.

I had a VF500, which has a snorkel that sits more on top of the airbox than in front of it. Because it wasn't glued on properly, it could rotate, so I tried it a few times with the opening facing forwards rather than backwards. I'm sure it helped, especially with headwinds, as I had this theory that there was a negative pressure area under the rear of the tank, and it made it harder for the engine to suck air in with the snorkel facing backwards.

I do know that having an aftermarket foam filter AND the snorkel facing forwards caused my carbs to ice up on one ride.

[keithbob]

Enzed is right - I don't know if lifting the tank after opening up the airbox is actually better on the dyno. I do know that after installing the PCII and O2 elim. and getting a good map in it, I still had a very moderate flat spot around 4500-5500. Opening up the airbox has eliminated it, and the tank-lift was done at the same time. I don't know if there is more top-end power, but the mid-range is much improved.

I looked at where the air has to pass through to get to the airbox openings, and it's a lot of small spaces. Collectively, they all add up, but turbulence and drag is (generally) higher for multiple openings than for a single one of the same area. Lifting the tank just a quarter inch actually makes a pretty big difference in the area exposed along the lower front edge through which air can flow.

The real question is, is this change actually helping air to flow to the airbox, and, more importantly, is there a favorable change in airflow through the intake system and its resonant characteristics that results in more usable power and better throttle response?

Throttle response is indeed improved. Power? Only the dyno will answer that question. I've read that it takes about a 10% change in power before the average street rider really notices it, and can easily believe it. I will be having the bike dynoed and the PCII map adjusted next time I'm up in Seattle - I'll report what I find.

Keith

[chris2992]

Well got my bike back together this weekend, and after all the 50 and 60 deg days we have had, sunday was like 30 and rainy. So atleast I got a quick ride in on saturday afternoon. Initial seat of pants is good. Alot more low end power, didn't get to get into the upper revs, but pulling from stop lights and accelerating arround cages is much quicker and smoother. 4k to 6k was the biggest difference. I don't know which mod to place the glory on because I did many, but I would do all of them again.

1 Airbox

2 Custom K&N

3 Pair Valve Removal

4 Valve sync

5 Power Commander II (using map 101-008 : Staintune and K&N filter)

I have not yet come up with a spacer to "jack" the front of the tank up, but that is on my list of things to do. I'll keep yall posted.