ditching my air box

[roadpilot3]

Just taken my carbs off......again - this time for a stuck float valve.

Whilst its in bits, has anyone on here got rid of their air box and fitted 4 conical k&n filters directly to the carbs?

If so what was the result? I know it will need a jetting kit but did it produce any more HP or was it a disaster? Is it worth the grief? I have considered the standard k&n replacement but everyone does that!

Also can anyone help me out with some k&n part numbers? My carbs have a 50mm inlet diameter and I trust you guys and girls more than a random sales assistant!

I might do it for the hell of it!

Thanks, looking forward to some replies.

[darrsi]

I think @domtrails is yer man for that answer!


Click on photo:      [size=78%]http://foc-u.co.uk/index.php/topic,7283.0.html[/size]

[Gnasher]

In a word "dont" fit a K & N and enjoy.

[carrier]

Dom something.. a user here, has done that. He said he re jetted it and really liked it, but for him its a weekend toy... hopefully he'll comment.. I'd like to do this too.. if I get my bike working.

[darrsi]

In a word "dont" fit a K & N and enjoy.

Are they hard work or something?

[Gnasher]

The air box is an integral part of the the bikes fuelling/induction system if you remove it everything becomes a trade off regardless of what jetting you do and it's not just jets, needles will also need adjusting or changing to get some of the drive back not to mention dyno time.  Sure you can just change the mains and it will run of sorts but it will not be running at optimum, fuel consumption will rise and it may well improve the induction noise but that's about it.

At large throttle openings you may well improve things slightly (I mean slightly) mid and low range will suffer, as will torque in the low to mid range not to mention poor wet water performance.

Think about it the bike is a late 90's design producing at the crank almost 100bhp from a 600 early 90's 1000/1100's were not producing much more out of the crate.  Air boxes are one of the ways of getting high output with good manners, name a modern bike that doesn't have one, most sports bikes employ ram air or pressurised air box/induction tracks.     

The Fazer engine is already highly tuned as standard there is virtually nothing to be had with old school tuning tricks open carbs, stacks and individual filters as a way of gaining a few bhp are a thing of the past this side of a drag strip.

What works and gives you 1 - 2 bhp and improves the low to mid range is a K & N and a can fit and enjoy.

[carrier]

The air box is an integral part of the the bikes fuelling/induction system if you remove it everything becomes a trade off regardless of what jetting you do and it's not just jets, needles will also need adjusting or changing to get some of the drive back not to mention dyno time.  Sure you can just change the mains and it will run of sorts but it will not be running at optimum, fuel consumption will rise and it may well improve the induction noise but that's about it.

At large throttle openings you may well improve things slightly (I mean slightly) mid and low range will suffer, as will torque in the low to mid range not to mention poor wet water performance.

Think about it the bike is a late 90's design producing at the crank almost 100bhp from a 600 early 90's 1000/1100's were not producing much more out of the crate.  Air boxes are one of the ways of getting high output with good manners, name a modern bike that doesn't have one, most sports bikes employ ram air or pressurised air box/induction tracks.     

The Fazer engine is already highly tuned as standard there is virtually nothing to be had with old school tuning tricks open carbs, stacks and individual filters as a way of gaining a few bhp are a thing of the past this side of a drag strip.

What works and gives you 1 - 2 bhp and improves the low to mid range is a K & N and a can fit and enjoy.

but.... it looks so good

[Gnasher]

Yes if you like that sort of thing, it can be done but you would need to change the carbs to non CV type to get the best out of it.

Anything can be done within reason if you throw enough money at it, that said on a Fazer you wont really improve on what is already there performance wise.   

[roadpilot3]

Darrsi - thanks for the link, I will send Domtrails a PM as that is exactly what I wanted to achieve, I knew that someone on here would have done it - the power of the internet…..and now I’m thinking about ripping off my fairings as well…..

Gnasher - point taken on board - you are the voice of reason.  It’s obviously not as simple as I was first hoping for and I don’t want to ruin what is effectively a really great bike.  I am going to put it back together on Friday as it was (its MOT runs out next week) and will slow time look into this.  I could just buy a faster bike - but I love my Fazer and so far have spent about £2.00 a mile on fixing it!

Carrier - it looks really cool and I want one!  Trouble is it IS my only form of transport, although I do cycle to work and my wife has a car…..so it’s not really my only method of transport if I need to justify it to myself!

Any other thoughts, views or experiences??? 

[Chris]

To be totally honest I think it leaves too big a gap between the frame and the engine if you remove the airbox but that's just my personal feeling on it.

If you want to do it then go for it but it seems to be a lot of work and expense for something that has little improvement over a K&N replacement box filter.

Chris

[clayt74]

Im with Gnasher on this.
Just cos you can, , doesnt mean you should!!!  :eek

[domtrails]

If its your only form of transport buy a decent airbox filter and clean it every 2/3000km as the conversion means a thirsty bike. However if you really want to play with your bike and learn about carbs, airflow etc and are not afraid of the conversion then go for it. One way or the other you will need to balance your carbs after and that took me a while after putting cones in....