Kawasaki Vulcan Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
41 Posts
Discussion Starter #1
Got the cover shimmed out with stock air filter still in k&n should be here tomorrow. Left the air intake tube in the back open may block it off later but very impressed with results. Has much more take off through the gears now and no hesitation. Heres a couple of pics for now may modify it some more.
 

Attachments

·
Registered
Joined
·
320 Posts
Interesting result for a seat of the pants feel.So you actually feel you have more bottom end power?How much noise are you hearing at part throttle with this mod?
 

·
Registered
Joined
·
481 Posts
I always thought the limited air flow was the tunnel between the two air boxes so I'm interested in the outcome of this mod.
 

·
Premium Member
Joined
·
1,667 Posts
During my initial dyno session with my Vaq back in May 2011 I experimented with modifying intake air flow. One of the tests was to space out the left airbox side cover similar to what smblackmon did, tho my spacing was not as large, prolly about half as much.

The follow up dyno runs showed gains from the beginning of the run(albeit small) until about 3000rpm where there was the start of the larger gains in power.

H.P. gains as [email protected] + 1.2, @3500rpm + 1.8, @4000rpm +3.5, @4500 +3.3.

Here was the start of some interesting facts we learned bout the 1700 intake system. At 5100 rpm the power with the shimmed out a/b lid tapered/fell off and matched the runs with the a/b lid bolted in it's normal place. From there the power fell of drastically with a 3.5 hp loss at 5700rpm with the shimmed out lid!

Now me being the motorhead and wanting it all I proceeded make a big hole in the center of the air box lid, directing airflow right into the filter element (which was already a K&N). I bolted the lid back in it's stock location. That is where the severe loss of power occurred thru ought most of the powerband.

Obviously the spacing out of the a/b lid has benefits at the smaller throttle openings/lower rpms as smblackmon found (certainly the most used area of the 1700's powerband), but at some rpm/large throttle opening point there will be that loss of power as the airflow "packs" into that tunnel.

As long as the benefits are felt in the rpm areas where the skoot is mostly ridden, that is certainly a good thing.

RACNRAY
 

·
Registered
Joined
·
41 Posts
Discussion Starter #7
Did u have any fuel management or just stock. Im running an ejk and still playing with the setings with this air mod
 

·
Premium Member
Joined
·
1,667 Posts
Did u have any fuel management or just stock. Im running an ejk and still playing with the setings with this air mod
This was done during the first dyno session so no. It was shortly after finding out the limitations of modifying the left side a/b that I designed my own BAK that breathes primarily on the right side of the engine. Totally eliminated the high rpm/large throttle opening loss of power as a result of left side mods.

RACNRAY
 

·
Registered
Joined
·
29 Posts
Is it safe to do this mod without any fuel management. My Mufflers seem to have the baffles punched as well. I just bought this bike.
 

·
Registered
Joined
·
41 Posts
Discussion Starter #10
Is it safe to do this mod without any fuel management. My Mufflers seem to have the baffles punched as well. I just bought this bike.
I shouldn't hurt anything it just opens the air flow up with cooler air. you could try its completely reversible If you don't like it.
 

·
Premium Member
Joined
·
1,703 Posts
I shimmed my air filter cover 3/8 actually it is a hair wider than 3/8 inch, whatever the metric equivalent is, this morning. I used some 5mm rubber post extender/dampners that I had from my Venture days... one side 5mm bolt, other side 5mm female...

I wish I had a way to see if it actually draws in cooler air. It is still sucking air off the side of the engine. But the air going in is not as restricted.

Have not ridden it yet..... misty rain this morning and I washed it yesterday. So............. it is in the garage today..... Now I need to get out there and convert the wife's new Yamaha 125 Zuma scooter (will do 70 mph) from two headlight horizontal position to single vertical headlight system with 4 inch driving light on top... it will take me about an hour or so.....
 

·
Premium Member
Joined
·
1,703 Posts
Did a few miles.... seems like the turbo lag feel cranking it at 35mph in 3rd gear is not so bad... same for 4th....... didn't notice any intake noise, but I keep my 70's/80's Rock & Roll cranked up loud enough to annoy everyone....

I will need to modify it some. Need the top edges flush with a gap at the bottom. With the top out 3/4 inch it changes my LED light pattern on the engine from the led's I have mounted under the gas tank... but that shouldn't be a problem doing that... not shim the top and shim the bottom.... the cover is metal, it can take being tweaked a bit....
 

·
Registered
Joined
·
41 Posts
Discussion Starter #14
Sounds great bubba. Ive use half a tank of mid grade gas and the meter is showing 41 mpg and climbing still running great
 

·
Premium Member
Joined
·
1,703 Posts
But I did hear pre ignition clatter for the first time today... But I was in 4th, going 30 and cranked it..... it was over 90 degrees here again today....

I have already figured out how I am going to re-fit my cover.... bottom end open, top end closed.... I will need to go to the hardware store and get some more pretty chrome or stainless metric bolts... Just need to get my tired old butt out there and do it. And put the lower triple tree air deflector back on I took off last week....
 

·
Registered
Joined
·
41 Posts
Discussion Starter #16
But I did hear pre ignition clatter for the first time today... But I was in 4th, going 30 and cranked it..... it was over 90 degrees here again today....

I have already figured out how I am going to re-fit my cover.... bottom end open, top end closed.... I will need to go to the hardware store and get some more pretty chrome or stainless metric bolts... Just need to get my tired old butt out there and do it. And put the lower triple tree air deflector back on I took off last week....
took mine for a ride this afternoon had a little sputter going down from 4th to 3rd may just be the ejk still setting it was pretty warm today so may have to dial it down a little. I also had to go down from the 3/4" shim to a 1/2 due to couldn't find long enough bolts but gonna stay with top and bottom shimmed for now.
 

·
Registered
Joined
·
320 Posts
I just cut the bottom edge off the left metal air filter cover about 1 inch to clear the plastic base by 1/2 inch for air flow to the K&N filter.My guess I have added about 50% more air flow compared to the stock internal inlet from under the tank.No sound difference ,but I feel the extra air flow from the bottom only ,should help some what.Standing back from the bike you cannot even tell it was cut.Did not want to space out all the way around,just to reduce hot engine heat intake and try to maintain some pressure internally for high RPM Power.
 

·
Registered
Joined
·
41 Posts
Discussion Starter #18
I just cut the bottom edge off the left metal air filter cover about 1 inch to clear the plastic base by 1/2 inch for air flow to the K&N filter.My guess I have added about 50% more air flow compared to the stock internal inlet from under the tank.No sound difference ,but I feel the extra air flow from the bottom only ,should help some what.Standing back from the bike you cannot even tell it was cut.Did not want to space out all the way around,just to reduce hot engine heat intake and try to maintain some pressure internally for high RPM Power.
are you running it stock or have aftermarket parts
 

·
Registered
Joined
·
29 Posts
I'm going to try this as soon as i have time. Maybe even today. I just dont want it to lean out to much and cause any issues.
 

·
Premium Member
Joined
·
1,703 Posts
Well one thing I noticed today. I had to crank the gas to get out of an idiots way that was on the wrong side of the street/highway (4 lane). And it seemed to jump a lot quicker than before shimming. I had just went into second, no hurry, saw the oncoming car and pegged the throttle and I was gone, hit second and I was way out of the morons way by then. Yes I had to go left into the on coming traffic lane a bit. But I used to do that a lot when I was a Motor Officer. Even with oncoming traffic not that scary... as long as you got room to be over there.

But that was the first time since I owned this Voyager that I had to make an escape jump. There was a state Trooper trying to catch up to him. Probably one of the many drunk drivers here.

Worst drivers on the planet are here in Corsicana Texas. Most no drivers license or insurance... I have been around the world twice and it is the truth....

One thing about my Voyager... bone stock... it definitely is not running lean by any stretch of the imagination. In fact it is running a little rich by the look of my exhaust pipes....
 
1 - 20 of 29 Posts
Top