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I've had a set the crappy pod filters mounted on my bike for over a year and now that I'm making a genuine effort to fine tune the carbs I decided that I needed to eliminate the problems caused by the inside lip of the pods blocking the ports.
Also, I've always wanted velocity stacks.
I've read other peoples threads on how they created velocity stacks using either pieces salvaged from a stock air box, or plumbing fittings. The latter appealed to me more since in my previous career I was a plumber and I have a certain familiarity with the parts and fittings.
The inspiration came from reading the tech tip: Pod filters w/ stacks pictorial.
I went to browse the plumbing isle at my local Lowe's and found this:
It's a rubber coupling meant to join 1-1/2" pipe to 2" pipe. TC's tech tip uses straight 1-1/2" rubber couplings, which is fine, but I wanted the volume reduction to achieve the velocity stack effect. I found that the 2" side of this coupling has an outside diameter only slightly smaller than that of the pod filter, and that simply butting the two together and securing with a few wraps of black electrical tape made for a strong, leak-free connection. As an aside, I don't think it looks too terrible. As TC correctly points out in his pictorial, you have to stretch the 1-1/2" end a bit to get it onto the shoulder of the carb, but I also found that once it's been on there for a while (i.e. 2 days) the rubber seems to conform a little and it's much easier to put on the second time.
I had to cut the end off of the 1-1/2" side so that the hose clamp would tighten down on the shoulder of the carb body:
This was easy to do by putting the end of the coupling onto a piece of 1-1/2" pipe to hold it still and secure, and then I cut the lip off with my trusty razor knife.
Here is the one of the final products mounted on the bike:
The pod just clears my side cover. If this clearance were an issue, one could simply cut an extra 1/2" or 1/4" of off either end to obtain the proper clearance.
I've only taken one quick ride with this mod, but I immediately noticed my 4-5K stumble was almost gone and the throttle felt much more crisp. The only other thing I think needs done before I consider this mod complete is to increase the size of the opening in the base of the pod:
The lip created by the shell of the pod is a flow restriction that looks to me like it can be easily remedied with the dremel. I want to remove this restriction and maximize the amount of air that I can pull through this setup.
$20 bought me (4) 1-1/2" x 2" rubber couplings (they come with stainless steel hose clamps) and I already had the electrical tape and razor knife.
Total Cost: $20
Build Time: 30 minutes
A bike that pulls your arms from their sockets @ 6K RPM: Priceless
Also, I've always wanted velocity stacks.
I've read other peoples threads on how they created velocity stacks using either pieces salvaged from a stock air box, or plumbing fittings. The latter appealed to me more since in my previous career I was a plumber and I have a certain familiarity with the parts and fittings.
The inspiration came from reading the tech tip: Pod filters w/ stacks pictorial.
I went to browse the plumbing isle at my local Lowe's and found this:
It's a rubber coupling meant to join 1-1/2" pipe to 2" pipe. TC's tech tip uses straight 1-1/2" rubber couplings, which is fine, but I wanted the volume reduction to achieve the velocity stack effect. I found that the 2" side of this coupling has an outside diameter only slightly smaller than that of the pod filter, and that simply butting the two together and securing with a few wraps of black electrical tape made for a strong, leak-free connection. As an aside, I don't think it looks too terrible. As TC correctly points out in his pictorial, you have to stretch the 1-1/2" end a bit to get it onto the shoulder of the carb, but I also found that once it's been on there for a while (i.e. 2 days) the rubber seems to conform a little and it's much easier to put on the second time.
I had to cut the end off of the 1-1/2" side so that the hose clamp would tighten down on the shoulder of the carb body:
This was easy to do by putting the end of the coupling onto a piece of 1-1/2" pipe to hold it still and secure, and then I cut the lip off with my trusty razor knife.
Here is the one of the final products mounted on the bike:
The pod just clears my side cover. If this clearance were an issue, one could simply cut an extra 1/2" or 1/4" of off either end to obtain the proper clearance.
I've only taken one quick ride with this mod, but I immediately noticed my 4-5K stumble was almost gone and the throttle felt much more crisp. The only other thing I think needs done before I consider this mod complete is to increase the size of the opening in the base of the pod:
The lip created by the shell of the pod is a flow restriction that looks to me like it can be easily remedied with the dremel. I want to remove this restriction and maximize the amount of air that I can pull through this setup.
$20 bought me (4) 1-1/2" x 2" rubber couplings (they come with stainless steel hose clamps) and I already had the electrical tape and razor knife.
Total Cost: $20
Build Time: 30 minutes
A bike that pulls your arms from their sockets @ 6K RPM: Priceless
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