Villopotos yz125 PC pipe Question

nch209
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NoVa, VA US
6/1/2019 6:58pm Edited Date/Time 6/3/2019 4:43pm
Anyone know the story behind the pipe in this pic? More recent race pics look like the standard pipe---but I was wondering if the one below was just for show, or modded for go. Off topic, I recall Pastrana running a chopped up bare FMF at steel city when he was racing out of a box van at a national many moons ago--- heck, it may have been an amature day on the pro weekend due to his age... it was that long ago. I asked him about it a few years but he didnt know much about it. I still long to find the pic I snapped of it.... but his was modded closer to the silencer. Anyway, and ideas on Ryans pipe?

http://gatedrop.com/villopotos-yz125-ready-for-racing/
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-MAVERICK-
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Ontario CA
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6/1/2019 7:19pm Edited Date/Time 6/1/2019 7:35pm
Custom pipe.



PC off the shelf for comparison.


5
DynoDan22
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Victorville, CA US
6/1/2019 7:31pm
Almost looks like they cut up a production PC rack pipe and put a PC KTM mid section and welded it all together. Kind of a "Franken-pipe". I'm purely speculating but that mid section looks really familiar.
2
nch209
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NoVa, VA US
6/1/2019 10:04pm
Looks cool, ehh? Different rear shock, and obviously some other changes- cluch, brake, etc
CPR
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AU
6/2/2019 1:13am
I'd say for more top end at the sacrifice of lower power. Something us mere mortals couldn't keep up in the curve enough to take advantage of.
1

The Shop

Helda
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AU
6/2/2019 3:35am
No S/N
2
piscokid
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OH US
6/2/2019 5:38am Edited Date/Time 6/2/2019 6:35pm
Looks very similar to the 2019 KTM 125 pipe design. Before 2019, the 125 pipe looked like all other 2 stroke pipes, a fat expansion chamber. If one were to review the 2018 KTM 85, it will show the pipe takes on a similar shape. KTM improved the exhaust ports for better port timing on the 85. The exhaust port change warranted the pipe shape change. This design change in ports/pipes carried over to the 125 in 2019.


1
dedi684
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8/21/2009
Location
Ravena, NY US
6/2/2019 6:24am
He said mitch built him a special pipe
6/3/2019 10:34am
They did 200+ dyno runs on that bike and tailored it to a preference Ryan was asking for. The pipe has a lot more bottom to mid with that motors particular porting and ignition setup. That pipe pictured will not rev out on a production setup. The production pipe offers more performance for a production setup.
2
6/3/2019 2:43pm
when you build performance two strokes you GENERALLY end up wiht higher ex durations. In the case of the YZ this is generally true
In doing so - a pipe designed around production ex duration is GENERALLY too short.
A little length in the right place goes a LONG way. My Instagram feed shows a modified HGS we used to do for ktm85 and 105.
It was worth almost 3 hp vs std HGS pipe - with better curve. However that pipe would LOOSE power on a stock engine...

Pipes are built for the engine combo - and everything has to work together. This applies to ignition curve as well

A truly really highly tuned 2 stroke requires all of these to work with each other, especially now days.
4
BAD10
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San Diego, CA US
6/3/2019 3:01pm
Looks like they added about 10mm length to the midsection....
Jrewing
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Location
AU
6/3/2019 4:10pm
when you build performance two strokes you GENERALLY end up wiht higher ex durations. In the case of the YZ this is generally true In doing...
when you build performance two strokes you GENERALLY end up wiht higher ex durations. In the case of the YZ this is generally true
In doing so - a pipe designed around production ex duration is GENERALLY too short.
A little length in the right place goes a LONG way. My Instagram feed shows a modified HGS we used to do for ktm85 and 105.
It was worth almost 3 hp vs std HGS pipe - with better curve. However that pipe would LOOSE power on a stock engine...

Pipes are built for the engine combo - and everything has to work together. This applies to ignition curve as well

A truly really highly tuned 2 stroke requires all of these to work with each other, especially now days.
I reckon you could build s stronger motor for him!
What simulator do you use btw?
Zesiger 112
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6/3/2019 4:43pm
Looks like it's a smaller diameter from the I.D. plate back.
6/3/2019 5:41pm
I heard they also swapped the pull rods for a little extra torque.

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