Halfway To Thunder Stealth Air Intake Mod for 1500 Kawasaki Vulcan - My Story

[Washbrook]

capnconch,

Thanks for the update. Some photos showing what you did to get your faux "Mean Streak Drifter" would be nice. Check out: http://cruiser.mototribe.com/photo/surgery , Heresy fitted a Mean Streak transmission to his Drifter and likes the results. I liked the matching dog bowls on each side so have left them both even though the LHS one is now effectively "retired from use".

I'm not much of a mechanic so I too the safe option and had the PC III installed just to avoid me stuffing things up.

I have noticed that I need to use the choke [throttle assist] to start and warm up whereas before I did not but hey it is not a big issue. Hopefully in summer I will not need to do this. WE do not have Florida weather all year round here in Melbourne AUS. I might put on some "long johns" for my ride this weekend.

I've just fitted the 444 Series Progressive Shocks to the rear and have the Progressive Front Springs to install on the front when I get time. I chose not to lower mine as I am happy with the height, I'm about 6'1''.

[capnconch]

Too Cool, I love it, I just retired the Right side AC cover and filter and put the Spectre  9", part number 47722, round red high flow washable air cleaner with the red colored filter lid on my '04 Drifter 1500. Very neat! These are currently available on ebay. 3 years ago I custom painted over the silver areas on my '04 Drifter 1500 with candy apple red for a more vintage look, this particular filter matched perfectly and looks amazing! Spectre no longer makes these air cleaners. This guy on ebay has a bunch of them for 49.95 free shipping.I did the half Caddman and totally plugged the air intake from the Left side; Who needs HOT preheated intake air from BETWEEN THE FRIGGIN HOT CYLINDERS flowing in when you live in SW Florida? So now it's a cold air intake (relatively speaking; Cape Coral current temp 92 with 94% humidity.) I happened to have bought on ebay 4 yrs ago, total Black air cleaner covers left and right with all the stuff still on from one of those Mean Streak SE 1600 (flat black with red flames,) that someone took off a new one...I put that on the Left side got rid of the chrome dogfood pan cover so now it says Vulcan Mean Streak 1600 in neat graphics, Oh yes I also swapped in the Mean Streak 1600 engine in the Drifter! (or did I? It says 1600 on the L side air cleaner....who knows,  they look the same......) I do not hot rod my Drifter So I am going to keep a close on the plugs to see if I can avoid having to put on a Power Commander to richen the fuel mix, It seems Like my '04 always ran rich anyway. So, Eliminated the cold start solenoids (yeah really need 'em in SW FL,) Idles the same, no adjustment needed so far,  Try to post pics soon.
I bought this Drifter new and last month replaced the fork springs and shocks to Progressive 1" lower, Easy mod if you do not take off the forks, totally not necessary, did the lowering for looks...excellent!  rides great but watch the corners. Ill never sell the Drifter, some things you can't replace.

[Washbrook]

Troll,

I read all your posts about your experimentation, fuel gains etc. In the past I have ridden the Drifter changing gears early and letting it lope along at lower RPM. I think I'll have to change my mind set to push the revs a bit more, especially a low speed, ie probably need to use 1st gear a little more. Time will tell.

[Troll]

Nice job. I noticed a slight reduction in low end torque, too, but I thought it was my imagination... No problem, you'll get used to it pretty quickly. The throttle response is greatly improved. The same thing happened when I did an air box mod on my W-650...the power band got definitely "rowdy"...I like it! The engine will probably gain the most from the power band from 4000 rpm, up. I just did 2500 miles of combination mountain road/interstate riding, probably 20% mountain twistys, and 80% 70-75 mph...I averaged 46 mpg for the trip. I have normally been filling up at around 170 miles and my push me soon light now comes on at about 160....This is the whole reason I embarked on this voyage of discovery.. I hate having to stop for fuel. The plugs are running a nice clean light gray color, as are the exhaust outlets. They used to be black, and a little sooty.

[Washbrook]

Part B

The Results - How Does it ride?

The Thunder Air modification certainly made a noticeable difference to the responsiveness of the engine. There was more power on tap when I wanted it and the acceleration was better. I have not Dyno printout to verify this merely my feel of the bike and how it responds to my riding.

With the addition of the PC III, I can only give feedback on the ride back home as it has been up on the jack ever since as I added some more changes [not mechanical] to the bike. I need some more time on the bike to give a full appraisal and will add comments in future, however my first impressions:

Since I have owned the Drifter it has had smooth acceleration and has been very forgiving if I was in the wrong gear, i.e. it easily pulled from very low rpm in 2nd gear and as I wound on the power it come smoothly and in a civilised manner. So far I have found the bike a lot more "twitchy" than in the past. When I accelerate the power is there very fast and in a sightly "less civilised" manner. The issue that I need to get re-used to is that the bike is no longer forgiving in 2nd gear. I actually stalled in 2nd gear just idling along [coming to an intersection] where in the past the bike would have just kept going. This means that I need to change my riding style or have adjustments made to the PC III controller. My mind is not made up on this point.

I'd like to acknowledge and thank the following for their comments and suggestions:

   theturbo [aka Steve] from the CCC forum
   Easyrider [aka Matt] from the Australian Kawasaki Riders Forum
   Madcow [aka James] from the Australian Kawasaki Riders Forum and Vulcan Baggers Association forums
   Troll from the Vulcan Drifter Riders Forum
   Toddles [aka Trish, aka my wife] from no forum in particular, she knows I did this modification but has no idea of how much I really spent and I hope it stays that way.

[Washbrook]

Halfway To Thunder Stealth Air Intake Mod for 1500 Kawasaki Vulcan - Part A

This write up has been compiled as a result of gentle prodding by some who will remain nameless. Let me state up front that I am not a mechanic and that I make no assertions whatsoever that this is an appropriate project for you to undertake. Should you choose to do so it is entirely at your own risk [Ok the lawyers should be happy now]. The following information has been compiled based on my fitment experience combined with information from the following sources:

•   Gadget's Fixit Page
•   Thunder Manufacturing
•   K&N Filters
•   Cruiser Customising Community Forum [aka CCC] – various members
•   Australian Kawasaki Riders Forum [aka AKRF] – various members
•   Vulcan Drifter Riders [aka VDR] – various members
•   Vulcan Riders and Owners Club [aka VROC] – various members posts
•   Vulcan Baggers Forums – various members posts
•   Power Commander [aka Dynojet Research Inc]
•   Dynoverks Pty Ltd

Ok I think I have noted enough sources [though there may have been others] that I have sufficiently distributed the blame to everyone except myself.

Background

When I first got my 1999 Kawasaki Vulcan Drifter 1500 I was more than happy with the way it rode, accelerated etc. One of my concerns with the bike was that it was very quiet. The bike was so quiet that I could easily be riding and nobody around could hear me there at all, my explanation that "the bike was almost as loud as a push bike" was not much of an exaggeration.

To overcome this minor problem I fitted some Vance & Hines Longshots with the Vortex Tips. This certainly made the bike louder though it did not have any appreciable impact on power or responsiveness, not really a problem because that was not what I was going for at the time. Check out this short video clip for the results.

Ok so like most guys I cannot leave things alone so it did not take much prodding by various people I know to make me investigate how get a little more power out of my Drifter. I reviewed a number of options, the ones I can remember include:

•   The Caddman Kit
•   Low and Mean Spike Performance Air Intake Adaptor [& various other similar kits]
•   Kuryakyn Hypercharger Kit
•   The Woody conversion
•   Baron Big Air Kit V- 95

After some research and recommendations I purchased the parts for the "Halfway To Thunder Stealth Intake Mod for 1500 Kawasaki Engines" . There was no 1 definitive reason why I made this choice however I did want to retain the standard look and needed an easy install given my lack of mechanical aptitude. The Gadget website quoted a parts cost of $230, being $80 for the Thunder adapter kit [part 20203A] and $149 for the Thunder air filter and backing plate kit [part 30101A-NC]. The current cost [May 2013] was $89.95 and $176.95 respectively plus shipping of $54.40 giving an all up cost to me of US $321.30. This was not the cheapest option that I looked at so you need to judge for yourself if cost or other issues are the most important to you when deciding on which kit to buy.

Troll from the Vulcan Drifter Riders Forum actually made his own backing plate and mods for considerably less. You can read about his efforts here: http://www.vulcandrifterriders.com/forum/index.php?topic=11026.0 . Interestingly he did not add in an aftermarket fuel management system as he modified the control settings and voltages himself. His experiences are outlined in the above link.

As with the Air Kit, there were a number of options to choose from regarding which fuel management system to install. Why install one at all I hear you ask, good question!

Options considered:

•   Dobeck FTI [and branded copies, ie Kuryakyn Wild Things Fuel Injection Controller]
•   Power Commander III
•   Power Commander V
•   Cobra Fi 2000
•   RevTech DFO

As with the Air conversion, there was no one reason why I chose the PC-II Fuel Management Computer however I did take into account comments and feedback of the various products from a number of forums, price, ease of purchase fitment and tuning, flexibility of tuning and descriptions of the suppliers websites. I had settled on the PC-V, however when Dynoverks confirmed that they had a "supply, fitment and Dyno package" for the PC-V it sealed the deal given the convenience factor. One issue was that I had to go dfor the PC III and not the PC V due to the newer version not being recommended nor supported for older bikes by Power Commander, I bowed to their advice. See below for the performance results.

The Thunder Manufacturing Kit Air conversion install

I installed the kit in about 90 minutes including reading and going back & forth between the Gadget Website, Thunder Manufacturing Instructions and Drifter Service manual. This does not take into account the several times I read most of this when I was making my decision so the real time would be a lot more. I did not install the Power Commander [aka Dynojet Research Inc] PC III, I left that to the experts at Dynoverks Pty Ltd who also put the Bike over the Dyno.

Ok guys I am about to show my ignorance so all you mechanics please read this from a layman's perspective.

Mechanically this conversion was very simple and easy to complete.

Before starting the process I re-read the instructions from the Gadget Fixit Page for the Stealth Conversion and compared them with the instructions supplied with the Thunder Manufacturing parts kits. This bought up the first area of confusion. The Gadget page basically gave the following instructions:

1.   "If you never plan to take the intake back to stock, remove the left side air cleaner and backing plate, air tunnel and right side air box cover and backing plate. If you want both sides of the engine to look the same when you're finished just leave the stock (left side) air cleaner in place and remove the right side air box cover and backing plate.
2.   Screw the air temperature sensor (brass coloured thing) you removed from the air box backing plate into the hole provided in the Thunder adapter. Connect the crankcase vent to the supplied plastic elbow and bolt backing plate to throttle body using supplied bolts. Plug the brass pipes that used to supply vacuum to the cold idle solenoids with the supplied rubber caps.
3.   Attach the filter backing plate to the adapter with supplied bolts
4.   Place the K&N air filter that came with the 30101A-NC kit on the backing plate
5.   Pick one of your OEM covers and place that over the top of the filter and attach it to the backing plate using the bolt style of your choice. There may be one supplied with the backing plate but it will look like the one in the photo at the top of the page.  Not pretty.
6.   Tune your TFI or other aftermarket computer as needed.
7.   Go ride and enjoy the extra 10 horsepower and 10 lb ft of torque you just granted yourself."

Pretty simple instructions. However!!!!!!

The Thunder Manufacturing instructions start off:

1.   Remove the Seat
2.   Remove the Dash Plaque
3.   Loosen tank mounting bolts
4.   Lift tank from rear
5.   Lift tank
6.   Remove chrome from air cleaners and then things get back to being similar to the Gadget Fixit page instructions.

Oops. This is not the same. Do I really have to take the fuel tank off? Being basically lazy I chose to take the simple Gadget Fixit option and not take the tank off working on the basis that if it became all too hard I could always remove the tank if I had to.

The next issue: Common sense would dictate that the Gadget Fixit page instructions, the Thunder Manufacturing instructions and the Drifter Service Manual would all use the same terminology for the various motorbike parts, well they don't. If you are not fully conversant with the terms and what does what and what descriptions are interchangeable, like me, this could cause you delays. These are the variances I found:

•   Cold Idle Solenoids [Thunder mod website] = ISC valves [Service Manual] = Sensors [Thunder Kit instructions]
•   Crankcase Vent [Thunder mod website] = Oil Reserve Tank Hose [Service Manual] = Crankcase Breather [Thunder Kit instructions]
•   Item Not mentioned [Thunder mod website] = Vacuum Switch Valve Air Hose [Service Manual] = Fresh Air Hose [Thunder Kit instructions]
•   Air Temperature Sensor (brass coloured thing) [Thunder mod website] = XXX [Service Manual] = XXX [Thunder Kit instructions]

Ok 1 more:

The supplied K&N filter says to oil before use but no oil was supplied with the kit. I checked the Thunder site and the K&N site and whilst they refer to maintenance and cleaning when used, I saw nothing that suggested that the filters do not come pre-oiled. So let's check the filter instructions themselves, easy, not! The K&N filter has only A070A6 as a reference number on it and this does not coincide with any K&N filter part number [I checked]. I then checked the details on the Thunder manufacturing website, they reference a K&N filter being part of the kit but do not say which one and it is not mentioned on the invoice either. By this stage I am getting a little peeved. So I looked up replacement parts on the Thunder Manufacturing website and they quote a part number E3402. I then referenced this on the K&N Filters website to check the size spec etc and yes the E3402 appears to be the correct filter. So does it come pre oiled, who knows as they do not say. Eventually I find the following hidden on the K&N website:

"10. Do K&N air filters come pre-oiled or must they be oiled before using?
Almost all K&N air filters come pre-oiled and ready to use. The filter oil we use is red. A new oiled filter will appear red-pink in colour. Some crankcase vent air filters come un-oiled, however, they come with a small packet of K&N filter oil so they can be oiled before use. There are also a limited number of filters with specialty uses which are not pre-oiled. These items will be clearly marked as unoiled. Using an unoiled K&N filter will greatly reduce the filter's efficiency and void our product warranty on filters that come pre-oiled from the factory. If you receive a filter that is packaged in its cellophane wrapper and is unoiled, contact K&N's Customer Support department at (800) 858-3333."

Conclusion, my filter is reddish so it comes pre-oiled. I had posted the question on several forums whilst I also searched for an answer and got a variety of answers from pre-oiled to not pre-oiled. Based on the above K&N description everyone was right depending upon which filter they had experience with. So if you get a white one, oil it, if it is reddish, it is oiled. I suggest that everyone considering this takes up Steve's suggestion and get a K&N maintenance kit to keep for when needed.

Some things I did not know:

a.   The crank case hose, usually the width of a finger, is there to recycle / vent gases and fumes back into the filter to assist with emissions requirements. Given that it is such a small amount one must question the actual usefulness of this. This is what attaches to the white angle connector in the kit.

b.   Cold Idle Solenoids [Thunder mod website], ISC valves [Service Manual] or just plain Sensors [Thunder Kit instructions] are only there to give a fast idle on cold start, sort of like an automatic choke sort of. Removing them from the system apparently has no impact on the system except that the bike may be harder to start in cold conditions. Given that the bike also has a "choke" or more properly referred to as a "Idle advance" [do not quote me on this term] they can be seen as non essential. I am reliably informed that letting the bike idle for any more than a few minutes to warm up is pointless as the bike will warm up quicker if just ridden normal to easy for the first few kilometres allowing the oil to be warmed up quicker hence doing less damage (wear & tear) to the engine.

c.   The kit requires that you remove the fresh air hose (which appears to be the Vacuum Switch Valve Air Hose in the service manual) and plug it with a supplied plug. Initially I was not sure that these were the same and what this actually did. Apparently according to Troll this is an easy issue to answer.

"The air system Kawasaki uses is similar to the system G.M. used on the later non computer controlled Chevettes. That system was called PAIR for pulse air injection reaction. It was a passive system that relied on exhaust port vacuum to draw fresh air into the exhaust manifold to burn off any left over fuel on deceleration. The vacuum switching valve under the tank is like the valves that cars with air pumps have, except it's passive rather than being force fed air. The 2 square boxes on the cylinders with the 1/2" hoses on them are reed valves that prevent exhaust gas from entering the air system. There is a small vacuum hose that maintains a vacuum signal on the switching valve to allow small amounts of air to enter the exhaust during idle. If you close off the air intake to the valve with the engine idling, you can hear the exhaust sound change a little. The whole thing is necessary for emissions purposes to ensure "legal" levels of CO and unburned hydrocarbons at the exhaust pipe. When you close the throttle at speed, say to go down a hill, the air intake stops, creating a high intake manifold vacuum. Most systems use a computer trick called deceleration enleanment  (the fuel is actually shut off on deceleration) to prevent fuel in the system from trying to burn with a limited amount of oxygen, which gives a high unburned hydrocarbon and  CO content due to incomplete combustion). The combustion takes place in the exhaust system. When you marble the air system, or put on coasters, you are defeating the emissions hardware. Will it hurt the engine? NO...see I told you it was simple."

The modification bypassing this has been referred to as "marbling" of the reed values or "the coaster method". The Gadget Fixit site instructions for the simple "marbling" advise:

"This is the easy fix which will take maybe ten minutes of your time. On most 1500 fuel injected bikes simply remove the right "air cleaner" (misnomer) cover and look at the black mounting plate about the 2:00 position. You'll notice a fairly large piece of rubber hose routed into the cover. This is where the reed valves get their air. Pull the air injector solenoid away from the backing plate, put a marble into the hose and you have effectively disabled the system."

This report is going on long enough as it is so if you want to know about the coaster method read the Gadget fixit site yourself: http://www.gadgetjq.com/rv_removal.htm

Power Commander Install and Results

From my reading and other comments I was led to understand that the mods would make the drifter run a lot leaner and hence needed a properly mapped aftermarket fuel management computer such as the PC III or similar to fix the problem.

Interestingly Troll advised that he was "not experiencing anything that would indicate the engine is running lean, as a matter of fact, I think it could go a little leaner
I find your comment about your bike not running lean interesting." Given all the tweaking he had done as part of his "home brew" system, he may have addressed and overcome the issue as part of his adjustment process. I suppose my adding the PC III is in part the generally accepted an easier, yet more expensive, approach to solving the issue.

The Dyno printout shows that my Drifter now has a maximum Torque of 79.61 (ft-lbs) at 3000 – 3300 rpm and maximum power of 58.33 hp at about 4900 rpm. Unfortunately I d-d not get the bike Dyno'd prior to fitting the Vance & Hines nor the Air kit so I do not know what my actual starting point was. The Dyno report merely shows the improvement of the bike pre & post PC III fitment

According to the Vulcan Drifter Riders sit spec sheet the bike originally came out with Torque of 113 N.m (11.5 kgf-m, 83.1 ft-lb) @ 2800 r/min (rpm) and max power of     47kW-64PS-63.12HP @ 4700 r/min(rpm). If these figures are correct it would appear that even after the upgrades my bike has less Torque and power than the original specs. I would be interested to hear some feedback on this.

If you disagree with any of the above information please let me know however remember that I have compiled this from a range of sources and added my experiences, I am not advocating that this is the bible on the subject.

Part B and more photos to follow