How Are These Pipes Made?

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Smoker
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Re: How Are These Pipes Made?

#181 Post by Smoker » Thu Sep 27, 2018 9:27 am

I've seen custom 2-stroke pipes chopped into all kinds of shapes and sizes.

Wish I had dyno numbers for unorthodox chopped pipes.

Maybe the HP loss is not much. :smt102

In my opinion, this looks WAY better than 3 huge pipes!!

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kenny
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Re: How Are These Pipes Made?

#182 Post by kenny » Fri Sep 28, 2018 5:57 am

I designed one for the RZ350 and Glyn built and tested it and it was about 15% down on power to the normal 2-2 systems but made a great sound lol.

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Smoker
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Re: How Are These Pipes Made?

#183 Post by Smoker » Fri Sep 28, 2018 11:11 am

kenny wrote:I designed one for the RZ350 and Glyn built and tested it and it was about 15% down on power to the normal 2-2 systems but made a great sound lol.
Thanks, Kenny. Good info.

I actually remember that pipe and evaluation. Wish there was more info like that.

Finally found someone in my part of the world to make custom pipes. Drove over 14 hours in one day to get the first bike to Jeff Henise. Starting with stainless gp pipes. Will have some one-off touches to the pipes I haven't seen before.

If things go well, titanium pipes next.

lost1750GTV
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Re: How Are These Pipes Made?

#184 Post by lost1750GTV » Fri Sep 28, 2018 12:48 pm

glad you are up for a big drive, look forward to seeing the pipes

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Jeff B
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Re: How Are These Pipes Made?

#185 Post by Jeff B » Fri Sep 28, 2018 2:21 pm

Smoker wrote: Will have some one-off touches to the pipes I haven't seen before
I like one-off touches!!

MK
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Re: How Are These Pipes Made?

#186 Post by MK » Fri Sep 28, 2018 2:23 pm

Keep in mind that Kennys 2-1 looked like a 2 stroke pipe and that pic above is justp pure crap.
I bet it's at least 50% down on the already low stock performance.
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Martin

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Jeff B
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Re: How Are These Pipes Made?

#187 Post by Jeff B » Sat Sep 29, 2018 8:59 am

I thought I heard that twin cylinder snowmobiles with a single pipe had better mid range and less peak hp.

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Re: How Are These Pipes Made?

#188 Post by MK » Sat Sep 29, 2018 11:43 am

Yes, with a pipe.
But performance wise that pic above is plumbers work but not a twostroke pipe.
Bye
Martin

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Re: How Are These Pipes Made?

#189 Post by Smoker » Mon Oct 01, 2018 1:17 pm

Someone, please explain these pipes.

Why have I never seen this done before?

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Jeff B
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Re: How Are These Pipes Made?

#190 Post by Jeff B » Mon Oct 01, 2018 2:18 pm

Smoker wrote:Someone, please explain these pipes.

Why have I never seen this done before?

Image
It's common on snowmobiles. I think they are ugly and that's why you never saw them on bikes. I think the exhaust needs to exit somewhere between the largest part of the pipe and the back. I am a little surprised we never saw them under the seat on these 4 cylinder bikes.

silverstrom
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Re: How Are These Pipes Made?

#191 Post by silverstrom » Mon Oct 01, 2018 2:40 pm

Doesn't having an exit forward of the convergent cone defeat the purpose of the pipe's design? If the pressure wave has an exit before the convergent cone won't that mean some of the pressure wave will exit at that point and, thus, not all of it will be reflected back up the pipe toward the exhaust port?

And yes, it looks rediculous.

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Smoker
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Re: How Are These Pipes Made?

#192 Post by Smoker » Mon Oct 01, 2018 9:43 pm

Right.

Didn't realize that the rear of the pipes are probably closed.

Those cans are probably silencers.

I think I've seen something very similar in the past.

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kpke
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Re: How Are These Pipes Made?

#193 Post by kpke » Tue Oct 02, 2018 10:44 am

Interestingly my Nitro RC cars had pipes like that. Little suckers screamed around at 25 to 30,000 RPMs. Fun stuff.

I would never have thought I would see that design on a motorcycle.

I just recently sold those toys.
Ken's Garage YouTube Channel :smt023
https://www.youtube.com/c/KensGarage1

1985 RZ500 (R6 suspension & body work)

MK
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Re: How Are These Pipes Made?

#194 Post by MK » Wed Oct 03, 2018 12:44 pm

Nobody said the stinger has to be at the end.
It's even quieter to have 'em like that.
Other possibilities would have the last cone pointing not rearwards but into the straight section and having a big dia flat ending.
Have a look at kart twostrokes where design space is limited.
Bye
Martin

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Re: How Are These Pipes Made?

#195 Post by Smoker » Sun Oct 14, 2018 7:46 am

kenny wrote:I designed one for the RZ350 and Glyn built and tested it and it was about 15% down on power to the normal 2-2 systems but made a great sound lol.
Here's a more recent one by Shearer.

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