Air Box and exhaust mod.

[Wyotech kid]

I havent' modded my airbox yet but have very curious to do so and since i have a dyno at my disposal i just might try it, but Id prefer to wait til I get a PCIII so I can tune it and get the best results. I have done dyno runs with just a filter and cans and the results weren't what i expected. People swore up and down that with just those mods they got 90+ hp. I have to call their bluff on that one. With the airbox lid on i got 78 hp with a 4th gear roll on. took the lid completely off and did another 4 runs and got consistent 81 hp. I had forgotten to change mph to rpm on the graph when i was done but the 6k ''dip" and 8k spike are still there. Although i did notice a slight lag with lid off. It took a second or 2 longer to reach redline than with the lid on. If i had a PCIII i could probably tune it so i could get rid of that lag. Ill try and post pics of my dyno run on here (if i ever figure out how lol).

 

[Wyotech kid]

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[Cali rider]

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Thanks for posting some hard data. There is no denying that you increased both torque and horsepower by removing the lid, although that means no air filter as well.

Rep sent your way..

 

[Wyotech kid]

Thanks for posting some hard data. There is no denying that you increased both torque and horsepower by removing the lid, although that means no air filter as well.

Rep sent your way..

thanks for the rep. :thumbup:

but im curious as to wonder if ridding myself of the airbox completely and using 4 cone filters on the throttle bodies will do. Plenty of airflow then, but I kno there are drawbacks.....water being the biggest concern plus the engine wasnt made to support that either.

 

[Bikebiz]

I had my morning commute to work just now, 45km. I noticed no difference at low throttle openings to performance or sound, other than the high frequency whirr now gone. On wide openings it clearly growls louder which sounds nice and rough. It also felt like it pulled harder. And not just butt dyno, but the front wheel pulling up off the ground in 1st gear where before it didn't. Happy with the result for sure.

 

[RJ2112]

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Interesting that it 'filled in' the 6K dip somewhat, just by letting it breathe...

If it were me, I'd look at sawing off the front end of the air box cover, leaving the lid intact where it would hold the filter in place, so the filter would still have a seal around it's edges.

The temp sensor is in the 'filtered' section, isn't it? So's the EGR valve; so you wouldn't lose anything you really have to have.

 

[Wyotech kid]

Yea the temp sensor and EGR is in the "filtered" section. Ive been tempted to cut the front out and test it again, but Im hopin to get a PCIII to help straigthen out the curves and dips. With all that air being in the box, the ECU can only allow the injectors to supply so much fuel with factory settings.

With the airbox lid off there was a slight lag more than usual, but my guess is cuz the ECU didnt know what what to do with all that air, and did the best it could cuz I maxed out all the adjustment capabilities. Hence the need for a PC3.

 

[urbanj]

My stance is still the way it was when I modded my air box way back when just like Bikebiz has shown. The volume of the box is essentially the same. Only the ease of drawing it in when the pressure drops has changed. modding anything in between the airfilter and combustion chamber is going to change the tuning. I also said in my previous thread that throttle response plays a big part in the way the box is set up and how the pressure waves are tuned and Wyotech kid noticed it when he completely removed the lid. I'm sure it's safe to say almost all modern say intakes are tuned to be quiet. I'm glad his test's verified this for me.

 

[Wyotech kid]

My stance is still the way it was when I modded my air box way back when just like Bikebiz has shown. The volume of the box is essentially the same. Only the ease of drawing it in when the pressure drops has changed. modding anything in between the airfilter and combustion chamber is going to change the tuning. I also said in my previous thread that throttle response plays a big part in the way the box is set up and how the pressure waves are tuned and Wyotech kid noticed it when he completely removed the lid. I'm sure it's safe to say almost all modern say intakes are tuned to be quiet. I'm glad his test's verified this for me.

Nice to hear my test results are being of some use. Hopefully soon i'll some more solid test results before i graduate, just gotta get a PC3.

 

[CrazyBiker]

This is how I modded mine:
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[Bikebiz]

Fark! What's your verdict? And had you tried the usual version firstly?

 

[Wyotech kid]

This is how I modded mine:
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Do you have to worry about any water getting in the intake? Thats looks to be more than a simple cut out, am I correct? Have you had that dyno'd at all or used the butt dyno? Cuz I'd like to know how many points you went up or down when using your PC.

 

[RJ2112]

This is how I modded mine:
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Did you happen to measure the dimensions of that?

I remember the snorkel being about 4" wide by maybe 2" 'tall'. someone could check that.... This would be at least 6" wide by over 8" 'tall'. That's a HUGE increase in volume... on the order of 8 square inches OEM, to 48 plus.... much lower intake resistance.

And it retains all of the OEM mounting points for the air box lid.

 

[CrazyBiker]

I don't have dyno numbers but have butt numbers and they agree But I think I lost a little mpg but have great throttle response in return and ofcourse intake growl.

 

[CrazyBiker]

Did you happen to measure the dimensions of that?

I remember the snorkel being about 4" wide by maybe 2" 'tall'. someone could check that.... This would be at least 6" wide by over 8" 'tall'. That's a HUGE increase in volume... on the order of 8 square inches OEM, to 48 plus.... much lower intake resistance.

And it retains all of the OEM mounting points for the air box lid.

I did the airbox mod on my FZ1 and used the same logic for the FZ6. I took as much area as possible without affecting the mounting points and the foam pads. At FZ1 forums we have found that open the airbox as much as possible. Give the bike as much air as possible. Dyno proven.

 

[Wyotech kid]

I don't have dyno numbers but have butt numbers and they agree But I think I lost a little mpg but have great throttle response in return and ofcourse intake growl.

When you modded the airbox like that did you have a PCIII to change a/f ratios to help the throttle response or did you leave everything stock?

 

[CrazyBiker]

Left the PC3 as it is. I am sure dyno time will help but there is so little to gain on this bike compared to the FZ1 so spending $350 on a dyno to get 2-3bhp is not for me.

 

[Wyotech kid]

Left the PC3 as it is. I am sure dyno time will help but there is so little to gain on this bike compared to the FZ1 so spending $350 on a dyno to get 2-3bhp is not for me.

True 350 for 2-3 ponies aint quite worth it. I just have concern about the engine being to lean due to the extra air and not enough fuel. Heard a few horror stories about getting to much air and burned up the motor.

 

[CrazyBiker]

I checked the spark plugs and the exhaust. No soot in the exhaust and sparkies were nice brown. Good enough reading to know engine was running right.

 

[Wyotech kid]

Well spark plugs dont lie, if they brown then i guess the a/f ratio is good. :thumbup: