My take on a PVC intake...

I repaired the broken float pillar Friday, so Saturday I needed to build my PVC intake. I think it turned out pretty darn cool. The 45 degree bend the pod sits on will probably be swapped for a 90 so it's a little more out of the way.
The intake will get some bondo to fill gaps and then a coat of paint.
Next up: Sportster mufflers and new handlebars.

 

Have you taken a ride with the intake like that? I'm just going over this in my head, and it doesn't look like the carbs on the other end of the intake are going to get the same type of airflow as the one closest to the filter. You may want to put another filter on the other side to equalize the airflow.

Other than that, it looks sweet. Any chance of getting some video of this in action?

 

I did a short ride (a couple miles) with my dad. It kept up with his 1350cc H-D just fine. I didn't want to go any further because I have to change the oil filter. This all started when a float needle wouldn't close. It filled my crank case with gas. The oil has been replaced, but not the filter. I'll drain and refill with new oil and filter again before more riding ensues.
It felt like it performed like it did with the stock air box.

 

Too many bends, I would bet that you will have some probs with that set up. Keep an eye on your plugs for sure. It does look cool, but I would go back to stock airbox if it were me. Just my 2 cents.

 

Looks a little restrictive having the four cylinders pull through that tiny filter. Because there is no plenum, the furtherest and closest cylinders might be rich and lean as well. Great ingenuity though.

 

If there's any way you can make it so there are 2 filters dropping down into the empty spot behind #2 and 3 that would be great.

 

Looks great did mine similar, I think the carbs should be able to take the air they need from a set up like that, although I haven't got a chance to tune mine yet (just did it saturday) I think the mixtures should be able to be turned to get the plugs the color they need to be.

 

should be fine. run it how you want.

 

Exactly. Its your bike.
I just wanna know what kind of performace you got with that thing. Let us know how your plugs look. Or tell us how your colortune went. That kinda stuff I'm interested in.
TTR I was thinking EXACTLY what you were thinking when I saw this. That'd be a great set up. And if that was too lean just try one right in the center.
I'm tempted to try this...
-Chris

 

@streetbrawler750, dwcopple, and SLKid: Thanks. Sometimes there's too many people that keep saying to put the stock box back on. That's never going to happen. If we were supposed to leave things the way the engineers designed them, then there would be no aftermarket companies for anything. No Lingenfelter, Roush, Jardine, Vance & Hines, K&N, etc.

I'll keep you posted on how it runs. I still need to get an oil filter and fine tune the carbs. No colortune, though. I still do things by sight, smell, sound, and seat-of-the-pants performance. Things should get done next week since it's spring break. Hopefully there's not too many honey-dos on the list.

If it's stock, it's not "yours." IMO

 

I have been thinking the same thing for my bike. I think with the 4 pods sticking out of the back of the carb is kinda cool looking but I want one pod on either side of the tank. Was thinking about doing the same set up but trying to find metal tubing unless PVC can be painted well.

 

im getting 4 pods for mine, thought about 1 on 1 side, and 1 on either but decided to do 4 ... until i change my mind again.

 

The air Flow should be more than good enough i think. The stock airbox opening on my XJ550 is under the seat and it faces up and back towards the rear of the bike. If anything, air flow may be less of an issue. On the other hand, the filter will require more cleaning due to the fact that it will be exposed to direct air. Otherwise that looks wicked cool. Almost looks like a snorkel some off-roadin guy would put on his truck.

Are you making an amphibious motorcycle? lol

 

Ya, keep us posted on the tuning. I messed with mine tonight with little progress, I am pretty sure I have larger issues than the intake and pilot tuning

 

i plan on doing something very similar only putting a filter on each end and pointing them forwards

 

call me crazy, but - i keep thinking about hyperchargers now:


i'm thinking 1 on each side - separate 1 and 2 from 3 and 4 if ya catch my drift.

not that i know anything about hyperchargers . . .

 

A hypercharger mounted on the left of a bike will have a big gaping hole at it's top. That's how they keep from messing up the air/fuel ratio when the butterflies flap.

They're fake.

 

Looks to me like having the intake sticking out the side would be right in the way of your leg on that side? I've seen them pointed forward, not so far out may look better. Once it's painted, it'll look great!

 

That's what I was thinking, that's right where my thigh would want to be.

I'm thinking of making a PVC intake, except have the inlet under the seat like I've seen another user do before. Not looking for any gains, just trying to eliminate the stock airbox when I get ready to move the battery and such.

 

I bought a brand new hypercharger for my bike for 100 smacks off ebay, the flaps are spring loaded to stay open, then vacuum pressure at idle closes them, and as you rev it, the vacuum decreases, and it opens up, but yep, and time said, its fake, just a fancy moving air cleaner... it works on my bike... just havent mounted it yet

 

got rid of the pods on my maxim x. installed my pvc 2 pod under the seat air intake. it seems to run better then before the carbs have been rejetted . before i couldnt get the thing to start it has not been started since december . a quick shot of starting fluid fired right off. the previous owner said he had a carb guru go thru the carbs and they were perfect boy was he full of it the carbs are so far out of sync if you let it idle more then about 20 sec or so it will drop a cyl or 2 if you bump the idle just a little it will idle at 2500 when you let up on the gas idle comes down to about 2k hangs there then drops. i did not want to pull the tank to get to he idle screws and sync ports. till i finish my virago project swapped out hitachi carbs for mikuni but its next .will see if i can tune the x with the pvc intake at low rpms will let you know

 

If you don't "pull the tank" you'll have to be a surgeon with special tools to get to th "idle screws and sync ports". Without th tank on, it's easy.

 

What size PVC fittings are you guys using?

 

1 1/4, and 1 1/2 rubber connectors for the carbs

 

That's what I thought. Guess they line up pretty well on a 750, but not so great on a 650 :/

 

Doh! Read AMCWood's write up. You've got to cut about a half inch or so off the tees! Makes sense now!

 

I set mine up in a similar way, but with two pods under the seat where the stock airbox used to be. After I cleaned the carbs, it ran way better than the pod on each carb. It doesn't look as cool, but I like it. Everyone told me to go back to the stock airbox too, ha!

 

UPDATE: The bike is finally back together! Life got in the way for a bit, but I took the bike out for a quick spin last night. The fuel levels are spot on (yes, clear tube method). My o-rings for the pilot screws should be here early next week so I can fine tune that aspect. Thanks, Chacal! The mixture is in the ballpark right now. No hesitation at all. The idle didn't fall as fast as it should, though. I would let off the gas and the RPM's wouldn't drop for awhile. After I stopped and chatted with my dad, I hopped back on and it seemed better. I'll be checking into that issue today. But, all-in-all, the bike runs great with the new air intake!



EDIT: Oh, yeah. One of the reasons it took so long to get it back together was the fact I had to find a new carb body. The J-B Stik didn't hold up under gas to repair the float pillar. So, after my experience with it, I would not recommend J-B Stik for float pillar repair.

 

I built a pvc intake, with the filter between 3 and 4. I used a dual foam uni dirt bike filter for trips in thr rain. I have it tuned great, especially after a year running pods. Been planning on taking pics, will try to post some tomorrow.

 

i just replaced my pods on my maxim x with a duel filter pvc intake i still have to ajust and sync my carbs. the bike was very hard to start before especially when cold and sat a while. if it would sit a week or so it wouldnt crank. now with the pvc it fires right up after sitting a week so i think its going to work just fine. i also use uni filters the k&ns medal flange hits the frame

 

What about a pvc system with a pod on each end, plus one or two between the second and third carb, which would make the pvc tubing the same as a small chamber.

 

I'd think more along the line of making the PVC intake with the filter in the center (between 2nd and third carb) to balance the intake air more, am I right? That's what I'm thinking of doing when I get around to it.
The idea of one filter on each end of the PVC is another good idea, but I don't like the idea of them sticking out and getting in the way. I have forward controls and it looks like they'd have to be tucked in to work on my bike.

 

Hey there (PainterD) how's your bike com'in along, thought it looked real sweet with that back fender, and the springs seat. Plann'in on the same set up myself this year for my 1980 XJ650 but without the ape's though. Would appreciate some info on the fitment of the fender, part#, and source and such things of that nature. You can send me a pm, or my email address is (streetmaster42@msn.com)

 

It seems like the rest of the world gets 6 months of sun and 6 months of snow... here in the pacific north wet I'd recommend aiming the elbows that go to the pods DOWN to keep out some of the rain while you're parked at the bar.

I'm running the stock boots to 4 individual pods but have been keeping my eye out at the hardware store for some rubber elbows with a 45deg bend to help stay dry. for now this rat rider just lays his glove over the right side pod while on the (left) side stand.

 

any chance that this will fit as it is? LOL
http://pvcfittings.com/graphics/manifold1.jpg

 

They look to close together to me.

 

definately to close together

 

I used two P-traps for an intake. Had the bike idling with them on but have not taken it for a good run yet.



Both filters stay under the seat out of the rain.

 

Steve:

Make the 's ... [IMG]'s ... and the Photo will appear with your text.

I'm afraid your design does not take into consideration the PROBLEM of Turbulence ... which NEEDS to be overcome.

Your design "Marries" two opposing Intakes.
There will be created inside the "Plenum" ... Massive turbulence.

Anyone who has hooked-up a Vacuum Gauge to an XJ Manifold without a Restriction device ... will tell you that there is a Very HEAVY "Pulsation" of Vacuum at the Manifold.

Whet your design does is INTENSIFY the Turbulence, ... as the L, R, L, R, L, R Vacuum "Pulsations" will get progressively Stronger and Increase in Frequency as the Engine's RPM's rise.

The AIR Stream entering the Back-side of the Carb NEEDS to be made a Swift Moving COLUMN of Air that will:

Cause a Pressure Reduction at the "Top" of the Emulsion Tube :::
(Which draws Fuel UP into the Air Stream)
Cause BOTH "Lift" and a Pressure Reduction at the Opening on the Bottom of the Diaphragm Piston :::
(Causing the Pressure INSIDE the D-P-A to Lower and the Piston to be raises by the Vacuum caused by the Rapidly Moving Column of Air.)

The AirBox Rubber Boots act as VELOCITY STACKS to BOTH Shape and Increase the Speed of the Intake Air.

Eliminating Turbulent Intake Airflow if a major obstacle to overcome in order to make Pods even begin to let the XJ Engine with Constant Velocity "CV" Carbs "Breathe" right!

 

liking the PVC idea,im going to run something likewise,was wondering what size K&N filters are on the end?

 

Like Rick is saying you have to restrict airflow to pull a good vacuum either by the filter or by the size of the intake. I think you could play around with a restrictive baffle inside the pvc tube and tune the size of the restriction. I'm playing around with a setup using pods with the rubber velocity stacks and a plastic washer to restrict the air to the carbs still in the protype phase but I think it is showing promise on the bench using a vacuum and a carb.

 

what would happen id you use a 1.5 to 1 inch pvc adaptor hack the 1 inch almost flush so you could still use your 1.5 inch k@n you wouldn't see the reducer

 

That may be an option would have to play around with it the more. Good thing is pvc is cheap and easy to play around with but I think you could be on to something.

 

You could also cut it where its tapering to ajust restriction size

 

I have often thought that a "Restrictive Baffle" inside the Pod which doubled as a Velocity Stack would get you closer to defeating "The Pod Dilemma".

I envisioned a Pod :::
> with an internal Velocity Stack ... that was OPEN ... only at the far end.

(Air enters the Pod and is drawn-in at the far end of the Pod.)

+ The Internal Column >> Removable
+ The COLUMN end fitted with Restriction Mesh Caps
(Screens and Perforated Caps of Variable Density >> Multiples fitting)

The Carb Horn "Drilled-out" at the Atmosphere Opening Orifice.
The HORN Side of the Atmosphere Orifice >> Sealed.
+ Atmosphere to allow Air Supply to the Main Air Jets would be drawn through the Drilled-Out Holes.

Getting the Picture???

 

I think I came up with something like what your talking about Rick since I'm better with bikes than I am with computer's I can not figure out how to post pictures so I will try to describe it to you. I took the rubber side gas tank mount and some how this fits perfectly into the rubber mount for the pod I cut a 3/4" hole in the center of it and inserted a 3/4" x 2 1/2" piece of pvc pipe into it. I hook a vacuum and a vacuum gauge up to it before this mod I had barely 1 inch of vacuum at wide open throttle and now it has 3 but I don't know if this is to restrictive.

 

One of our resident Math Geniuses should be able to calculate a Value.

I think it would be 25% of the Gross Cubic Feet per Minute drawn through the Airbox Intake Port at 5000 RPM's.

 

http://i1177.photobucket.com/albums/x35 ... 1082-2.jpg

 

http://i1177.photobucket.com/albums/x35 ... C01087.jpg

 

http://i1177.photobucket.com/albums/x35 ... C01083.jpg