Mods to the airbox???

[Easy Rider]

Hi to one and all of you :cheers:

I'm on the forum for some time now but that's my first thread unk: I haven't found any specific place in here for intoductions so I'll put few words about me in here :biglaugh:

To cut long story short - I'm a Polish guy living in Ireland for few years now (in Dublin). I have my Max only for a couple of months. It's 2000 with few mods done and few on the way :whistlin:As I'm trying to sort out few things I've decided to start my first thread :biglaugh:

I've done the dyno run today and ended up with 117,5 rwbhp (K&N air filter, jetting, race cans). It turned out that my Max is running a little bit reach. Guy who runs the dyno suggested to drop the main jet by a size or two or increase air flow to the filter. This or other way he recons that after very minor changes I should hit 120bhp at the rear wheel. Well - it's not something unusuall but I'd like to improve it. Now my question is:

Is there any modification which I could do to the air filter box to inrease / improve air flow and amount of air getting into the filter? As I said I have K&N installed in stock box. I don't want to get rid of the box as we have a lot of rain in here and this could affect my carbs if I decide to put individual filters on. So is there any way to improve stock box on the V-Max? :ummm:

Any advice will be appreciated unk:

Keep it between the ditches :rocket bike:

 

[Heretic]

Sean Morley (One2dmax) sells a air box top that has a square cut out of it and fits a K&N panel filter. I have read that 4-5 HP can be had from it. You can click on the upper right advertisement to find a picture of it and/or send him a PM here.

 

[Dezeez]

Info here. http://vmaxoutlaw.com/main.html

Click on Vmax Tech and Info and then air box mods.

 

[johnpclynch]

Welcome, it's always good to see another..... (I was going to say Irish) Vmax-er in Ireland
:cheers:

I trimmed the airbox inlet, leaning out the mixture.
Check out a picture of what it looks like here:
http://www.geocities.com/motorcity/speedway/2476/airbox.jpg

Some more carb info here:
http://www.geocities.com/motorcity/speedway/2476/basics.htm

 

[Easy Rider]

Sean Morley (One2dmax) sells a air box top that has a square cut out of it and fits a K&N panel filter. I have read that 4-5 HP can be had from it. You can click on the upper right advertisement to find a picture of it and/or send him a PM here.

Thanks for the info. I've looked on Sean's site but I'm a bit worried about rain water getting on the filter and into the carbs. I'm not sure if that's the case but I wouldn't like to test it on my engine if you know what I mean unk: But it looks good. I'll have to think about it.

Info here. http://vmaxoutlaw.com/main.html

Click on Vmax Tech and Info and then air box mods.

That's some great technical advice on this page. Lots of useful information not only about air box :clapping: Thanks unk:

Welcome, it's always good to see another..... (I was going to say Irish) Vmax-er in Ireland
:cheers:

I trimmed the airbox inlet, leaning out the mixture.
Check out a picture of what it looks like here:
http://www.geocities.com/motorcity/speedway/2476/airbox.jpg

Some more carb info here:
http://www.geocities.com/motorcity/speedway/2476/basics.htm

Hi John! It's good to see you too :thumbs up: I didn't know you're in here as well.

This trimming sounds interesting but I can not open any of these links you gave me :bang head: Maybe it's my IE :ummm:

 

[Robbarrie]

Changing the jetting will not increase the airflow to the filter. There are many who take out or shim out the Y section to increase the air flow to the carbs a little - but this still doesn't change the mixture. It just makes it less restrictive, You may want change the needle height, raise the clip one notch heigher - to drop the needle and reduce the fuel and lean it out a bit - but I wouldn't change the main jets. You will end up running too lean.

You will have to rejet if you change the exhaust. Other wise in my opinion let it be.
As one member already mentioned before - talk to Sean before you get into anything.

 

[Easy Rider]

Changing the jetting will not increase the airflow to the filter. There is people who cut out the Y section to increase the air flow to the carbs a little - but this still doesn't change the mixture. You may want change the needle height but I wouldn't change the main jets. You will end up running too lean.

You may have to rejet if you change the exhaust. Other wise in my opinion let it be.
As one already mentioned before - talk to Sean before you get into anything.

Changing the jetting will not increase the air flow but will decrease amount of fuel and air to fuel ratio to hit the fuelling range of 13-13,5 :thumbs up: That's what I will do if I won't find a way of increasing the air flow.

I have jetting done on the carbs together with exhaust and filter but it seems that MJ is a little bit to big. To suit it I'd need to increase amount of air getting into the carbs.

Thank for the advice unk:

 

[one2dmax]

Too much air introduced into these carbs creates new problems.

Sean

 

[Lew L]

I've raised the "Y" about 4 mm and trimmed the opening to the K&N ( as well as the filter itself). It helps the top end and keeps the bottom end that is often lost when removing the "Y".
Lew

 

[Easy Rider]

Too much air introduced into these carbs creates new problems.

Sean

What problems you have in mind Sean? I'm new to the V-Max world so will appreciate any additional info unk:

I've raised the "Y" about 4 mm and trimmed the opening to the K&N ( as well as the filter itself). It helps the top end and keeps the bottom end that is often lost when removing the "Y".
Lew

Ok... might be a stupid question but what is the 'Y' :ummm::ummm::ummm: Don't laugh :whistlin:

 

[hubeerjw]

Here is a picture with the "Y" taken off and just sitting on the air box.... some people cout the whole oval shape inside the filter.

 

[Easy Rider]

Here is a picture with the "Y" taken off and just sitting on the air box.... some people cout the whole oval shape inside the filter.

Thanks a lot :thumbs up: Now I know what it is. Will have to check what the chances are for water to get in there and probably remove it :thumbs up:

Thanks

 

[maleko89]

If you cut the oval or go with the modified airbox then most likely will need air correctors in the main air jet bleed. Also, it's okay to get water in the air box. There's a drain hole in the front part of the air box.

Mark
#1098

 

[Hulign]

Our trip back from Topeka last year was some of the hardest rain I have ever ridden in...we seen speeds of close to 100 MPH in the wet stuff (145+ indicated when it dried up) and I have a stage seven with a Louvered faux tank cover (individual filters) . I had absolutely no problems from this trip. I don't think I dried out till a few days later.

Sad part is I spent the whole trip trying to keep up with Deb on her HD Sporty.

However I will warn you... although the dyno shows that you are running rich. I dropped mine a bit more lean and the bike doesn't run near as well. On the way down It would lift the front tire on a good snap and it hasn't done it since, of course it's more fun when I'm in Mark's rear view...lol


Frank

 

[johnpclynch]

Hi John! It's good to see you too :thumbs up: I didn't know you're in here as well.

This trimming sounds interesting but I can not open any of these links you gave me :bang head: Maybe it's my IE :ummm:

I just noticed your login and put 2 and 2 together, it's a small world after all

Ok, here's the full link (take out the space): www.geocities.com /motorcity/speedway/2476/basics.htm
(maybe the geocities site is blocked on your server)
here is the pic of the cut airbox, you can always put the 'Y' back on if it allows too much air in

 

[Easy Rider]

If you cut the oval or go with the modified airbox then most likely will need air correctors in the main air jet bleed. Also, it's okay to get water in the air box. There's a drain hole in the front part of the air box.

Mark
#1098

What type of correctors you have in mind? Is this kind of DIY thing or I'll have to buy them somewhere?:ummm:

As to the water - I'm not worried about the water in the box itself as there is a drain hole indeed. I'm more worried about water getting onto the filter and then sucked in through it to the carbs :whistlin: I'm not sure if that's the case...

Thanks :thumbs up:

Our trip back from Topeka last year was some of the hardest rain I have ever ridden in...we seen speeds of close to 100 MPH in the wet stuff (145+ indicated when it dried up) and I have a stage seven with a Louvered faux tank cover (individual filters) . I had absolutely no problems from this trip. I don't think I dried out till a few days later.

Sad part is I spent the whole trip trying to keep up with Deb on her HD Sporty.

However I will warn you... although the dyno shows that you are running rich. I dropped mine a bit more lean and the bike doesn't run near as well. On the way down It would lift the front tire on a good snap and it hasn't done it since, of course it's more fun when I'm in Mark's rear view...lol


Frank

Thanks Frank :thumbs up: It's good to hear that you haven't got any troubles because of stage 7 in the rain. Is it possible that the water which got onto the surface of the air filter will be sucked through the filter into the carbs? And if not water itself - what about 'wet' air (high humilidity) because of wet filters? I'm not sure if it would cause any problems but from my experience the dryer the air is the better A/F mix you get

I just noticed your login and put 2 and 2 together, it's a small world after all

Ok, here's the full link (take out the space): www.geocities.com /motorcity/speedway/2476/basics.htm
(maybe the geocities site is blocked on your server)
here is the pic of the cut airbox, you can always put the 'Y' back on if it allows too much air in
View attachment 2178

Thanks a lot John :thumbs up: I just went out of the office to have a look on my air box and... my 'Y' is already removed... :ummm::ummm::ummm: It looks like the previous owner got rid of it and I wasn't even aware of that. Now I dont have this 'Y' to put back but that's not the problem as I'm looking for some air flow improvement so it's fine. It also looks like the water didn't get in there so far. Maybe I should remove this box, put stage 7 filters with larger jets and see what happends :coolgleamA::rocket bike:

What stage 7 kits would you recommend lads? :ummm: And which shops are worth considering?

Many thanks unk:

 

[one2dmax]

Here's an experiement for you. Go ahead and remove the airbox and see if the bike will rev or even ride. You'll find that too much air introduced into the carbs will not let it rev which is why on stage seven and my jet kits there is a special plug installed to reduce the airflow into certain circuits.

Sean Morley

 

[one2dmax]

Small amounts of water being sucked into the carbs will not hurt the engine at all. In fact in some high compression engines (or turbo/surpercharger) they intentionally inject a water/alcohol mix into the intake tract to help cool off the charge to make more power.

Sean Morley

 

[Easy Rider]

Here's an experiement for you. Go ahead and remove the airbox and see if the bike will rev or even ride. You'll find that too much air introduced into the carbs will not let it rev which is why on stage seven and my jet kits there is a special plug installed to reduce the airflow into certain circuits.

Sean Morley

Thanks for clarification Sean :thumbs up: Do you sell your stage 7 kits internationally? Please drop me a pm if you do unk:

Small amounts of water being sucked into the carbs will not hurt the engine at all. In fact in some high compression engines (or turbo/surpercharger) they intentionally inject a water/alcohol mix into the intake tract to help cool off the charge to make more power.

Sean Morley

I didn't know that :thumbs up: I'm now seriously considering stage 7 for my max :ummm:

 

[one2dmax]

The farthest so far is Bulgaria. So I will ship anywhere.

Sean