RZ350 Super Motard

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Smoker
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Re: RZ350 Super Motard

#946 Post by Smoker » Thu Apr 12, 2018 1:15 pm

Had a bitch of a time figuring out how to attach the armature wire to the pipe flanges for a rough mockup. Solution was easy, just took me some time.

Will make a small loop on the wire end, so it can't slip out. These plates will mount behind the flanges.

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Smoker
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Re: RZ350 Super Motard

#947 Post by Smoker » Sun Apr 29, 2018 3:16 am

Made new mockup pipes.

Toomey dimensions. About 42 inches long.

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Re: RZ350 Super Motard

#948 Post by Smoker » Thu May 03, 2018 9:05 am

First mockup pipe still in the Toomey size. Crosses under in the front.

Touching the frame now, would need a small gap.

On the bottom, the string is tied at the distance the side cover protrudes.

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justind97
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Re: RZ350 Super Motard

#949 Post by justind97 » Thu May 03, 2018 10:06 am

That pipe mock-up is awesome! Stellar idea!

MK
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Re: RZ350 Super Motard

#950 Post by MK » Thu May 03, 2018 1:44 pm

Don't use that 90 deg bend at the belly. Looks like moto cross pipes from the 70's.

The radius must be much smoother as the exhaust gas won't like going round sharp corners. Should look like the RSK 500's
https://pbs.twimg.com/media/C3A7PkuXAAEUYJ4?format=jpg" onclick="window.open(this.href);return false;
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Smoker
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Re: RZ350 Super Motard

#951 Post by Smoker » Thu May 03, 2018 9:45 pm

MK wrote:Don't use that 90 deg bend at the belly. Looks like moto cross pipes from the 70's.

The radius must be much smoother as the exhaust gas won't like going round sharp corners. Should look like the RSK 500's
https://pbs.twimg.com/media/C3A7PkuXAAEUYJ4?format=jpg" onclick="window.open(this.href);return false;
Okay, thanks. Working on it. More pics, soon.

Remembered when I did my first mockup pipe for this bike, long ago. Slinger sent me a PM saying exactly the same thing.

I already know it's not good for making horsepower. But, I don't know how much that sharp bend will decrease horsepower. This isn't a race bike, it's a custom. So, looks takes priority over power.

If I knew the HP would be decreased by 10%, I would be okay with that. :smt023

If the HP would be decreased by 30%, that's a problem. Or, if it would be too difficult to tune, or create some bad HP curve, I also would not want to do it. I know very little about pipe engineering, and only need enough info to get decent pipes made for my bikes.

When you say my pipe looks like a 70's motocross pipe, that's very encouraging to me! I have even thought of making flat pipes, like this '70's bike.

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What would specifically happen if I kept the steep bend in the pipe, or made flat pipes? :smt102

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Re: RZ350 Super Motard

#952 Post by Smoker » Fri May 04, 2018 5:39 pm

Second mockup. More gentle bend on the belly. Still Toomey dimensions.

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Working on mockup pipe #3.

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Re: RZ350 Super Motard

#953 Post by MK » Sat May 05, 2018 10:01 am

Much better.
I was not only referring to performance, but also to being able to manufacture.
If the bend is too sharp, the inner length of the cone section becomes zero or less. That's impossible to weld...
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Re: RZ350 Super Motard

#954 Post by Smoker » Sat May 05, 2018 1:16 pm

MK wrote:Much better.
I was not only referring to performance, but also to being able to manufacture.
If the bend is too sharp, the inner length of the cone section becomes zero or less. That's impossible to weld...
Oh, got it.

Will try to be aware of the minimum cone thickness in the bends.

Thanks!

LC Cnd
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Re: RZ350 Super Motard

#955 Post by LC Cnd » Sun May 06, 2018 12:02 pm

Smoker a bit off topic but you got me inspired to think I should build my own set of pipe for a project - never done it before but interested. Did you used household electrical wire to create the mock up model? Suspect you will be using mild steel for this set.

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Re: RZ350 Super Motard

#956 Post by Smoker » Sun May 06, 2018 1:58 pm

LC Cnd wrote:Smoker a bit off topic but you got me inspired to think I should build my own set of pipe for a project - never done it before but interested. Did you used household electrical wire to create the mock up model? Suspect you will be using mild steel for this set.
Dude, right on topic! :smt023

I found it incredibly interesting and enjoyable shaping the mockup pipes. Still have plenty more mockup work to do, though.

One set of the cardboard cutouts is from the first mockup pipe I made long ago. That's when I figured out that up-pipes are going to suck, and so are down-pipes. Not a good frame choice for 2-stroke pipes. When I made the first mockup pipe, the engine cradle wasn't fabricated, so it was just a rough estimate.

I spent a ton of money and time fabricating the silencers and tips. Not even sure I'll be using any of that. I need more mockup time to figure things out. Obviously did things out of order, but I still have a lot to learn. Sometimes I have to learn the hard way, but it won't stop me.

I'd prefer titanium pipes. If the pipes are going to get bashed, stainless might be better. I'd sure like to fabricate the cone work, but have no experience. I'm also running out of time, so hoping to find someone capable.

The mockup pipes are made from cardboard cutouts, 1/4 inch armature wire, and blue tape. Art supply stores usually have armature wire. The mockup pipes are just to help me decide how to route and shape the pipes. Might be helpful for making paper cone templates, but not sure.

I got inspired when I saw photos from Alex Arletti making one-off pipes.

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Re: RZ350 Super Motard

#957 Post by Smoker » Sun May 06, 2018 6:44 pm

Still have a lot to do, but this is where the 3rd mockup is going.

Need to mockup the brake pedal/rear master, and a shifter, for clearance.

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LC Cnd
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Re: RZ350 Super Motard

#958 Post by LC Cnd » Wed May 09, 2018 9:20 pm

So how do you figure where to place the baffles to obtain the correct resonating frequency - that's a lot of R&D that needs the backing of a corporation or calculus no? Not that I'm not intrigued. Martin didn't you write an article on the subject that you had offer for sale on the subject or was just on tuning? I suspect I have a lot of reading to do to discover what it takes/costs for such an adventure.

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Re: RZ350 Super Motard

#959 Post by Smoker » Thu May 10, 2018 2:34 am

LC Cnd wrote:So how do you figure where to place the baffles to obtain the correct resonating frequency - that's a lot of R&D that needs the backing of a corporation or calculus no?
The baffles are located in the silencers. The silencers bolt onto the exhaust flanges. So far, I'm using Toomey pipe measurements for the mockup pipes.

When the mockup pipes look as good as possible, I may modify the dimensions to fit the bike better. The cone diameters for the actual pipes should be decided by the pipe fabricator, or at least someone that knows more than I do.

Will try to make serpentine style mockup pipes next, in order to bring the pipe bellies more forward of the lowest part of the frame.

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Re: RZ350 Super Motard

#960 Post by Smoker » Thu May 10, 2018 11:34 am

LC Cnd wrote:So how do you figure where to place the baffles to obtain the correct resonating frequency - that's a lot of R&D that needs the backing of a corporation or calculus no? Not that I'm not intrigued. Martin didn't you write an article on the subject that you had offer for sale on the subject or was just on tuning? I suspect I have a lot of reading to do to discover what it takes/costs for such an adventure.
I know very little about pipe design, but I suspect stinger length is not critical to pipe performance. Only because I see so many bikes with the silencers at the end of the converging cone, and so many with long stingers. I'm also guessing that stinger diameter is more critical.

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