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Message started by diamond jim on 03/22/09 at 07:23:57

Title: Kamikaze air intake design assessment
Post by diamond jim on 03/22/09 at 07:23:57

http://i255.photobucket.com/albums/hh128/russ_diamond_jim/allsix.jpg

Here are all the designs I tested. I have ranked the designs in the order of performance by seat of the pants testing and airflow model testing. 1-5 utilize the stock tube whereas 6 utilized a shorter-than-stock-tube rubber 2.25" coupler adapter from a hardware store. The initial Kamikaze design is not included since it's been evaluated thoroughly already. The order of fab and testing are 2, 3, 6, 5, 4 and 1 being the final design.

http://i255.photobucket.com/albums/hh128/russ_diamond_jim/S4021783.jpg
1. This one worked the best for several reasons. First, it utilizes the stock tube that appears to be the best length and diameter which, as Verslagen pointed out, was designed that way for a reason. It is the shortest of the six which means there is more airspace between the opening and the frame. The longer setups seem to be slightly affected airflow wise at higher rpm by the more cramped space between the opening and frame/wiring stuffed underneath the seat. This design also has the honeycomb accelerator. With it I noticed:
a) smoother idle.
b) my idle mixture screw adjustment/peak idle rpm was one full turn more out than the exact same setup without the honeycomb. It is at 1.5 turns out now with a 55 pilot jet with bleeder holes.
c) the engine seemed to run super smooth from low to high rpm.
d) power and acceleration felt about the same as without it (it’s hard to tell).
e) while running at highway speed and pulling in the clutch when coming to a stop it came back to idle smoothly. Before it would sometimes feel like it would drop below idle rpm for a moment then bounce back up to normal. For instance, if idle is set at 1100 rpm, when cruising then pulling in the clutch, it used to feel like rpms dropped to say 900 for a second or two then return to idle. Every once in a while my bike has stalled when this has happened. Not often but when it did it was at this point of below idle rpm drop and cut off instead of bounced back.
f) the honeycomb filter is great support for holding the filter material in place without creating extra resistance such as the screened round metal piece I first used when I added internal filter support to the original Kamikaze intake. . The honeycomb straws are 1.75 “ long.

http://i255.photobucket.com/albums/hh128/russ_diamond_jim/S4021785.jpg
http://i255.photobucket.com/albums/hh128/russ_diamond_jim/S4021786.jpg
2 and 3. Number 2 was the next best design although 3 is essentially the exact same performance. Number 2 is when I first experienced the true potential of a good intake design. Why do I feel the number 1 design better? The 1 to 1.25” longer overall length of 2 and 3 added a little bit more resistance at high rpm due to longer tube length that the air has to travel. They also reduced the air space area between the opening and the frame as compared to 1.

http://i255.photobucket.com/albums/hh128/russ_diamond_jim/S4021788-1.jpg
http://i255.photobucket.com/albums/hh128/russ_diamond_jim/S4021787.jpg
4 and 5. Number 4 inspired number 5. Both worked great at low rpm. At high rpm the larger opening/longer length showed me the importance of more air clearance between the intake opening and the frame/wires underneath the seat. 5 has about an inch longer larger opening area than 4. Something interesting about number 5 that I think I forgot to mention in the previous posts. Twice while cruising at 75mph with 5 installed, I got hit by a huge crosswind and each time the bike surged for moment. I think this is because of the large opening and air reservoir between the rubber tube and the outside air. The high air pressure of the gust combined with the different air pressures of the air reservoir and the tube created a momentary airflow disturbance. With 1,2,3,4 and 6, I never experienced this with crosswind gusts that were even more powerful.

http://i255.photobucket.com/albums/hh128/russ_diamond_jim/S4021789.jpg
6. This one just doesn't have the low and midrange power like the others even though it has more airflow area than all the other models. Of all of the prototypes, it the one that felt most like having a pod filter on the bike at low to midrange, Performance at higher rpm was better than a pod filter though. Recall this is the prototype that had the hardware store rubber coupler that was shorter than the stock tube. The stock tube also has a ¼” progressive narrowing from opening to carb mount which provides some additional air acceleration which a straight rubber tube would not. Also, with this model, the air had to bend to get into the tube.

Title: Re: Kamikaze air intake design assessment
Post by Big Nix on 03/22/09 at 07:31:37

hey what did you use for #1 are those just regular drinking straws or what? and did you just use a pvc pipe fitting there to hold those and some Nu-foam under that for the actuall filter? Just wondering this is one of my next mods. Most definitly need that stock airbox off the bike.

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 03/22/09 at 08:13:42

The honeycomb was made from drinking straws from Krystals. They are common size straws. I say "common" because there are few fast food joints that use larger than common diameter straws but using them would require making the honeycomb another 1/2' longer. The honeycomb length should be 6-8x longer than the diameter of the individual straws. The honeycomb was made by cutting several pieces and applying some silicone to part of the outside of each straw using a small artist's brush and sticking them together. I added 6 smaller straws on the outside for a snug fit. To mount it in the PVC I slipped the honeycomb into the front opening about a third of the way in, put silicone on the outside of the honeycomb and then slid it in the rest of the way until flush. Clean off any excess silicone that may ooze out the front.

Here's how I made the opening. I used 2" PVC pipe for the housing and a 2" coupling for the outer ring. Here they are before cutting.
http://i255.photobucket.com/albums/hh128/russ_diamond_jim/4-11.jpg

Here is the final product. The housing is narrowed to fit snug into the tube while the wider, un-narrowed portion of the 2" pipe fits snug into the enlarged opening that the clamp covers. It will stay in fine without the clamp but I still use it to hold the filter on. The outer ring is glued on with super glue.
http://i255.photobucket.com/albums/hh128/russ_diamond_jim/1-23.jpg
http://i255.photobucket.com/albums/hh128/russ_diamond_jim/2-19.jpg

The inside edge of the PVC is tapered so the air has a smooth transition from PVC to rubber tube.
http://i255.photobucket.com/albums/hh128/russ_diamond_jim/3-18.jpg

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 03/22/09 at 08:32:20

My filter is made of 4 layers of gauze (cheesecloth). Right now I prefer to make my filter after doing testing and seeing how effective well made DIY filter is. An alternative that is more plug and play and has only a minimum performance loss compared to prototype number 1 combined with the above filter is to put a section of 2" PVC pipe into the rubber tube with about a 1/2" of pipe protruding out from the end of the pipe. Attach your 57mm pod filter to the PVC pipe and viola! The effect on performance is minimal (slightly longer tube/slightly increased restriction at high rpm, air has to bend more) but the trade-off, again, is easy plug and play.

If you ride like a grandma and love to squeak every possible mile out of every gallon of gas that runs through your bike then I suggest you pass this mod up. It is performance oriented and your mpg will drop maybe 10%. I don't have good numbers for that yet but I'll post when I do. I prefer grins per mile!

Title: Re: Kamikaze air intake design assessment
Post by verslagen1 on 03/22/09 at 17:31:37

Can you tubilator be applied to a stock air box?

http://www.savageriders.com/verslagen/images/oilcatcher-2.JPG

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 03/22/09 at 18:12:23

Anti-Turbulator? LMAO!

I guess so. From what I've learned about them it would, in theory, help. I'm guessing the air develops turbulence as it passes through the filter and sort of forward and up into the tube. I may have my airbox drawing dimensions off since I am going by memory. The air has the length of the tube to get straightened out and settle down before entering the carb mouth. The more straightened the air the better. Doing a honeycomb at the entry of the tube would likely help the air get straightened and settle down earlier in the tube. The air path resistance would be decreased to some unknown amount which would allow an unknown additional amount of air to pass through. It makes sense in theory. It may do nothing or it may surprising. I don't know. I think the more air you move the more beneficial the honeycomb becomes. Therefore, combined with a K&N replacement filter would likely be the best setup.

Title: Re: Kamikaze air intake design assessment
Post by verslagen1 on 03/22/09 at 19:21:20

I think that would be a good place for it. I've seen some honeycomb around the shop. Have to see if there is any left over. ;D

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 03/27/09 at 07:36:24

Here's an interesting filter for this design.

http://images.channeladvisor.com/Sell/SSProfiles/82000081/Images/3/8152.jpg

Title: Re: Kamikaze air intake design assessment
Post by sluggo on 03/27/09 at 11:29:26

i tried a pvc adAPTer a p trapp and it did have air flow problems at hiigh speed;

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 03/27/09 at 12:35:54

3D223B2929214E0 wrote:

i tried a pvc adAPTer a p trapp and it did have air flow problems at hiigh speed;

I'd imagine so. If you have a filtered opening pointed into or somehow catching the wind and it's fed to an airbox, the airbox will do a lot to handle the increased air pressures. But fed directly into a carb the pressure would increase with speed. It wouldn't draw much fuel through the opening. I know you know this already but allow me to explain it for other member's benefits. With that setup, air is being pushed through the carb instead of being sucked through. It creates air pressure in the carb that is greater than the air pressure outside of the carb. The carb needs pressure that is lower than outside air. It is that low pressure that creates a vacuum effect and pulls the fuel up through the jets. Pressurized air may in fact push into the jets and make it harder for the gas to come up from the float bowl. That type of setup works best when combined with an airbox and FI.

Title: Re: Kamikaze air intake design assessment
Post by saluteTOme on 03/28/09 at 13:37:19

Would you be as so kind and list the items you used to make #1 and lengths, and where you could get them? I have a good idea already on how I am going to go about this but others may not

And what you use to keep the "honeycomb" together?

Title: Re: Kamikaze air intake design assessment
Post by saluteTOme on 03/28/09 at 13:39:07

and oh. by the way, how you keep the filter material on there? It looks like it would just fall off. Do you put another "cap" on to keep it flush on the honeycomb and from not falling off?

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 03/28/09 at 18:12:46

2F3D30292839081331395C0 wrote:

20323F262736071C3E36530 wrote:

and oh. by the way, how you keep the filter material on there? It looks like it would just fall off. Do you put another "cap" on to keep it flush on the honeycomb and from not falling off?

Get these items:
http://i255.photobucket.com/albums/hh128/russ_diamond_jim/S4021863.jpg

Your tube, PVC opening with turbulator (optional), sponge filter (optional), K&N air filter oil, round gutter leaf strainer/guard, electrical tape, cheesecloth and scissors. The optional sponge filter can be shaped and placed inside of the metal frame pictured below. I'm more than happy without it. The turbulator is optional. The tube setup works very good without it. It just that it works better with it. I suggest you try the intake without it first then make one later if you want to. To build the turbulator, I cut even length pieces of straws, dipped a brush in silicone, applied the silicone and stuck 2 straw pieces together, brushed and added another, and another, and so on. Some have made a big deal about the straws coming out and getting sucked into the carb. Whatever. I trust my work.

Although I'm showing the steps of how my filter is set up, you could use a pod filter on the end instead.

I've improved my filter by doing the following:
http://i255.photobucket.com/albums/hh128/russ_diamond_jim/howtibuildfilter-2.jpg

And mount the intake to the carb:
http://i255.photobucket.com/albums/hh128/russ_diamond_jim/S4021860.jpg

You can also place a hose clamp on the end over the electrical tape, where the wire overlaps the tube.

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 03/29/09 at 10:30:21

I ordered this 5" 20 degree K&N filter to experiment and see how well it works with my setup.

http://www.knfilters.com/search/product.aspx?Prod=RU-1710

Title: Re: Kamikaze air intake design assessment
Post by AngloSaxon on 03/31/09 at 11:09:09

I'm thinking that in place of the PVC you could use one of those little piss pots they give you at the doctors. They have a thinner wall and a screw top.
I had an idea for filter material. My daughter has a tropical fish tank with a filter. The material used as the pre-filter would be excelent for this application as it is about half an inch thick and because it's in water all the time it's quite strong and stiff.
PS. Where did you put your battery?

Title: Re: Kamikaze air intake design assessment
Post by Savage_Amusement on 03/31/09 at 19:36:40

1639303B3804362F3839570 wrote:

It is in his saddle bag.

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 03/31/09 at 19:51:50

I'm not familiar with that type of filter. It might work. I was surprised several times when testing to find out that a potential filter material that seemed like it would work out great actually had very little airflow and way too much restriction. Likewise I was surprised by some that did pretty decent when I was sure it wouldn't. One of the things I want to try one day are the filters in the full face respirators. They filter very small particulates yet flow air with the little bit of vacuum created by normal breathing. But I don't know how they would do with higher flow rates.

Yep, in the saddle bag with my other electronic crap!

Title: Re: Kamikaze air intake design assessment
Post by AngloSaxon on 04/01/09 at 08:22:09

Thanks for the battery info. It's a nice look. As for filter materials, your local tropical fish store should have several options both fibrous and foam.
Try here - http://www.aquariumguys.com/mechanical.html

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 04/01/09 at 08:35:54

Thanks, Saxon. I'm gonna see if I can find some of these then:
http://www.aquariumguys.com/fluvalfoam4.html

Some of the sleeves look interesting as well.

Title: Re: Kamikaze air intake design assessment
Post by saluteTOme on 04/08/09 at 17:42:22

Hey guys. I was eating yogurt today and as I am at the bottom of the cup. This big ass light bulb goes off in my head. This thing is a perfect shape for a filter housing. 3.25" OD of opening and about 5cm under 2' at the bottom. Cut out the bottom and glue in a screen and or honeycomb item and even glue on 4 points of the filter and you're good to go.

The cup has a perfect bell shape on the opening. it's the Breyers Fat Free light cups with fruit. (my girl picked these out. I just eat them so shhh)

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 04/08/09 at 19:36:00

Yep, you're right. I imagine it would progressively speed up the air and focus it prior to entering the carb. I was amazed to discover how such little design changes make a big difference. Some more so at the lower end, some more so at the higher and some seemed to work pretty dang good across the rpm range.

Title: Re: Kamikaze air intake design assessment
Post by High-Def on 04/09/09 at 09:20:50

78757D717372787675711C0 wrote:

I ordered this 5" 20 degree K&N filter to experiment and see how well it works with my setup.

http://www.knfilters.com/search/product.aspx?Prod=RU-1710

How did this work out for you? I'm very interested.

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 04/09/09 at 11:07:14

73525C53167F5E5D3B0 wrote:

[quote author=78757D717372787675711C0 link=1237731838/0#13 date=1238347821]I ordered this 5" 20 degree K&N filter to experiment and see how well it works with my setup.

http://www.knfilters.com/search/product.aspx?Prod=RU-1710

How did this work out for you? I'm very interested.
[/quote]

It seems to idle, ride and accelerate similar to a pod filter. I was hoping is would perform more like the Kamikaze due to the shape and the presence of a small section of tube between filter and carb mouth. But not really a noticeable difference. Noticeable difference, though, compared to the Kamikaze. Primarily a loss of the low end torque. It's funny cause when I put this K&N on I seriously thought my clutch was suddenly slipping. I had gotten used to the torque after riding with the final Kamikaze design for about two weeks. This weekend I'm gonna pull the K&N off and look to see how I can add a turbulator to the tube of the K&N that will extend maybe an inch into the inside of the filter.

Title: Re: Kamikaze air intake design assessment
Post by High-Def on 04/09/09 at 11:11:00

5E535B5755545E5053573A0 wrote:

[quote author=73525C53167F5E5D3B0 link=1237731838/15#21 date=1239294050][quote author=78757D717372787675711C0 link=1237731838/0#13 date=1238347821]I ordered this 5" 20 degree K&N filter to experiment and see how well it works with my setup.

http://www.knfilters.com/search/product.aspx?Prod=RU-1710

Title: Re: Kamikaze air intake design assessment
Post by verslagen1 on 04/09/09 at 11:30:20

2E232B2725242E2023274A0 wrote:

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 04/09/09 at 21:16:28

That's what I'm thinking. It would essentially extend the intake tube length and increase air speed. It wouldn't actively increase air speed but rather eliminate or minimize those factors that reduce air speed and introduce those factors that maximize flow. I'll have to determine the length then find straws or other tubing that has a diameter that is between 1/6 to 1/8 the length of the individual pieces. A 2" long turbulator, for instance, would need to be made up of 3/8" to 1/4" diameter tubes. It would look something like this:

http://i255.photobucket.com/albums/hh128/russ_diamond_jim/kandnwturbullator.jpg

Awesome news- I just learned today that there's a guy that lives about 3 miles from where I work who tunes bikes. He's got a shop on his property. Apparently he was injured maybe 15 years ago when he got ran over by a garbage truck. He got a huge settlement. With that money he built his shop. In his shop is a dyno he uses for tuning. Guess where I'll be going sometime soon with the Kamikaze intake and what I expect will be an improved K&N filter?

Title: Re: Kamikaze air intake design assessment
Post by JohnBoy on 04/10/09 at 07:41:45

Diamond Jim,
Let me start by saying thank you.
It is nice to see that the backyard engineer is still alive and well in America. Your ideas of redirecting airflow “inside” the filter are inciteful. Using soda straws and PVC to smooth air flow is pure shade tree. The fact that you are documenting all of this and keeping us up to date is greatly appreciated. I hope to see dyno results duplicating your road test.

I would like to get your input on two possible tweaks you might try. First, you expressed the concern by some, that a soda straw might break loose and get sucked into the intake. A quick pass of the bundle across the face of a Teflon coated clothing iron should melt (lock) the straws together without distorting their shape too much. Second, if you made the tubes longer and twisted the finished bundle slightly could you create a vortec intake manifold for a savage?

Title: Re: Kamikaze air intake design assessment
Post by diamond jim on 04/10/09 at 09:16:07

JohnBoy, thanks for the feedback.

As far as the straws coming loose- it's just not gonna happen anymore likely than the stock rubber tube desintegrating and getting sucked into the carb. It's amazing how much pressure it took to pull out and pull apart the first turbulator I made. I had to bash it out then had to use needenose pliers and plenty of pulling and twisting to get the straws to start to come off one by one. The teflen iron idea to fuse the opening edges together is sheer brilliance. I don't know if it can be done without causing even the small deformities to the ends but regardless it's a brilliant idea. I don't know about the vortex idea. I'm thinking that works better when you are pushing air through rather than sucking the air through. But who knows. It might work great. Thanks for your input.