Sport Bikes banner

Anyone modify an airbox?

39K views 113 replies 44 participants last post by  rc5695 
#1 ·
I have 1000miles on my FZ6 and luv it but seems really choked. When applying 50% or more throttle you can hear the motor trying to spool up but just never really kicks. After some investigating i found the air box is 45% smaller than the one on a R6! And the air inlet is 60% smaller! That's not even considering there is no ram air on the FZ.So I removed the top of the air box and took it out for a quick ride. What a difference. I looked up how much a new airbox top costs and it's only $9. So I am going to buy a couple and screw around modifying them until I get good power results, with good air filtration(so I won't have to clean the air filter every 1000 miles). I'll keep ya posted.
 
#2 ·
#11 ·
Alright, got some good seat time so I can give my opinion on this mod.


First impression, you can hear the intake even over the Scorps. Bike does seems to have more power especially in the previously dead spot, i.e. midrange. When accelerating in first it picks the front end up 1-2 feet whereas it used to be only 1-2 inches. I could get the front end to power wheelie 1-2 feet easy but only with a certain body position, now it does it anytime. Of course, this is just my butt dyno. Kinda like changing the oil and now the front end came up!:neener Eitherway, I recommend this mod to anyone running a powercommander. My Scorpion/K&N map ran really rich (smell test only) anyway. Definately makes a difference, took about 30 minutes (including pull the lid on the air box), and was free. Worth it IMHO.


I say it makes more power, more noticable in the 4-7 K range and at 10k plus, but take it with a grain of salt. I have no dyno evidence to support this, may be damico has had a dyno done.
 
#13 ·
TheHun said:
did u guys just cut the silencer off..
No not exactly, well I don't think so. I cut the airbox lid exactly like the pictures in the thread. The silence does come off, but the opening gets larger. I'll give you a picture of what I cut off, may be that will help.
 

Attachments

#15 · (Edited)
Cool

Damico...Is your bike stock?

Here are a few thoughts from my understanding.

What would be the benefits to a stock bike here?
Would it lean or richen the motor out? I seriously doubt it.

I don't think there would be much of a performance change to a stock bike even with a low restriction filter installed. (I could be wrong however)

In an automotive application with FI, opening up the air delivery (flow) makes little difference in the A/F ratio. In computerized MFI the injectors pulse width are handled by the PCM. The Throttle body and plenum only supply air.

However....
When I looked at the airbox my immediate reaction was "WOW what restriction".

I would suspect that the bike would be louder with little power change unless there truely is excessive restriction in the OEM airbox intake. Yamaha might have done that to quiet the bike down for touring.

I know with a low restriction exhaust and a "Piggy-Back" controller (PC) installed, this is a MUST Mod!


I'm just thinking outloud.
Tell me what you think.

Bill
 
#16 · (Edited)
If an ECU can not make minor changes to air flow then its very primitive. Think about this....when ur riding in humid weather or rain....the air is total different then dry....more dense....the easy should have certain perimeters to allow adjustment within reason. i am too just thinkin out loud

But if u think u might be running a lil lean u can be on a safe side by upping the octane number....in our bikes 15cents aint much to pay extra....

But even an off the shelf system like a PC can not 100% tune your bike....it has to be on a dyno getting tuned
 
#18 ·
Did the mod, Scorpions and no PC or air filter changes.

There is a considerable increase to the growl, especially if you hammer the throttle around 4-5k rpm in 6th gear. Didn't notice anything around 2k, but then again I never have the engine there anyway.

Butt-dyno didn't register anything really, maybe it did something, maybe it didn't. Then again, I didn't notice a problem before. Sure is fun winding it up to redline though :)
 
#22 ·
i did a similar mod to my kawi airbox, and just have two questions:

1. Why did the manufacturer add the extra material?

2. Does this mod affect "harmonic resonance" and stuff?


edit: i did not notice a difference from the mod i did, i wish i could of heard more air after it, but oh well, freebie.
 
#24 ·
Wrhinehart said:
The reason for the very small snorkle is noise. They sacrifice power for quiet.

No harmonics that I can feel, my buzzing sound was a connector rattling against the fairing.

The airbox mod is detailed elsewhere on this fine board.
Search for it. It's here.

Bill
I believe Bill is correct. Oddly enough, the GM 3.8l Supercharged motors came with stock airboxes with small openings, and a few baffles for all the rediculous right angles. One of the most popular first mods, is to go to Home Depot and spend about $50 to bolt up a 3.5" -4" open cone, fender well intake. The mod for the car is twofold. 1. you want to remove restriction, and 2. You want to put the open cone sealed to the fenderwell to pull cooler, more dense air.

By opening the airbox, we are addressing the restriction. It would be nice to somehow channel cool air up into the airbox.

FYI, the car definitely increased the "sucking" noise with the open cone, vs the sealed box so I'm sure it increases on the bike as well.

FYI x 2 - this is from the FZ1 site:
Here are the specs on my wifes bike. Nikko racing slipon no cat Power commander w/ user submitted map #2 FBF BMC airfilter AIS reeds flipped The dyno results were 91.89 HP and A/F ratio was between 13/14.
(I wanted to note that this guy posted a user submitted map for that setup so the guys with the PC may be interested)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top