I had a big ride yesterday with the new HMF Quiet Core with Spark Arrestor. It is not as identical to my modded end cap as I first thought. The HMF does not have as much low end punch, but may have a little more on top. It does narrow and raise the powerband, much like the stock exhaust. I spoke with Hans at HMF, talked to him about my stock end cap mods, told him I was tired of sending pipes back. He wasn't sure which "quiet core" I had so I went out and pulled it. The quiet core and spark arrestor are one piece, and show potential. I told him I would be willing to experiment with it and he said he would send me some pieces to try.
.....Right off I think it is too short, and the small hole in the end should be closed up. It needs to have a longer length and slots instead of holes. The narrow strips of metal between slots can be bent into the tube creating mini baffles, that's what I did on my end cap. My philosophy is the design for a good exhaust needs to be free-flowing but circuitous, reducing pulses and sound waves to mere pressure.
......Opened up these things rock. The fit and finish are great, and it weighs pounds less than the stock exhaust. But it has to perform. The inside is a large diameter, essential for getting the gases out and around and back into the end piece.
.......Meanwhile, I sent my "butt ugly end cap" to Buttfungus for him to try. What could be more fitting? When he is done with it he is going to send it to Knutz.
......I am going to make this work. What I learned with the modded end cap will work here. Stay tuned. [img]i/expressions/face-icon-small-cool.gif[/img]

 

I look forward to getting and testing it. I'll send you dyno #'s when I do.

 

That's funny!

 

I just went out, chopped off the HMF quiet core and made a longer one with slots. A quick ride around our fields indicates the Low end punch is back, but I am going to need to take it out to our riding area where I was yesterday to give it a real evaluation.
.....Hey Knutz, Buttfungus may want to keep my endcap for a while, but I have his endcap all cut up, just sitting here. (that's the way he sent it to me). The stainless factor screwed me up, that and lack of interest, but for the sake of testing, how about I make you one out of his parts? It won't be pretty, he hacked it up pretty good, and I will burn out the chrome and nickel welding it. But the DYNO doesn't care about looks. Have you done your dyno tests yet? I think my mini-baffle slots work pretty well, maybe I could patent it. If you like it and use the idea, maybe we could work something out. [img]i/expressions/face-icon-small-cool.gif[/img]

 

Fourlix, I am going to ship end cap to Knutz. It came to the house today. I will wait a let you guys get some dyno numbers and test results. I can use my temporary end cap until you guys are done testing. I would like to see some results myself.

 

BUTTfungus- bring that butt ugly end cap to the dunes, friday. What cap was on your bomb last week? did you make any runs against rooster and hurycne? How did you do? I was only 50% against hurycne last week. That will not make mr. yamaguci very happy with me.

 

14mins, No I was running my end cap. My ds was staying real close to the other two dirt doos when I had the stock 16 tooth sprocket on. I switched to the 15 tooth which is why I quit running with you big boys saturday. I'll just bring what I have to Kermit and take my chances..he..he.he...I wish I had some paddles though! maybe next time.

 

Fourlix and Knutz, the infamous "butt-ugly end cap" designed,developed, and field tested by Fourlix, was shipped out today and is now on it's way to Knutz Concepts to be tested and compared with other designs.


Later.....

 

Well, are you ready for BUTT UGLY II ?? Seriously, I can make yours up in a jiffy as long as I don't have to keep it stainless. BBQ paint has been the hallmark of shadetree custom exhausts for many decades...

 

Fourlix, yeah that's fine! I am good with spray paint! I don't care if it's loud either. We don't have to worry about that yet down here in Texas.