650sx build by: my650sux

[Vumad]

Thanks guys, I started getting notifications from all the posts and was that "what the h*ll?" Come to find out it's someone telling me to go back to what I already had, don't read books do math and build things. I wanted to reply with "have you been drinking?" but decided to let it go. I'm no master of the English language but I can't even understand what you're trying to say. It's like someone is texting me about something I posted on Craigslist for sale. "U still got it? whut u take 4 it? I bet your a volunteer fire fighter and drive the fastest stock mustang they ever made. I normally don't point fingers and attack people on a personal level but you asked for it bro.

Don't hate on firefighters or we're going to have beef.

It's a modern world, so we can have some tofu if you're vegan. I like to respect the choices and lifestyles of others.

You can hate on mustangs though. We're cool there.

 

[BigV]

What diameter is your new pipe? I'm hydro forming mine and I'm making my chamber a hair under 7 inch in diameter. I did the math and I would like a 2.5 in outlet but will settle for stock waterbox size for now

 

[Joe Dart]

@Vumad my bad haha. I was hating more or the "I know everything but have actually done nothing kinda guy." The truth is my chances of failure are much greater than success but, there is no greater feeling than success after a long journey of failures. I feel like any "do it yourself" kinda guy would agree. Sorry for the double post but to respond to to @BigV I'm going to get my wackbook pro. Typing on my phone is kinda lame.

 

[Joe Dart]

@BigV
From what I read in the two stroke tuners handbook the smaller the diameter of the pipe after the expansion chamber (to a point) the more power and back pressure but the balance is crucial because when you go smaller the heat in the engine and exhaust will increase. Going to small will lead to engine failure. There is a formula in that book that lets you calculate the size of pipe you need (inside dimension) based off the header diameter and port size I think. It was a long time ago when I did the math and somehow when moving homes, I lost or threw it away.
So, my expansion chamber dimension is the same as the west cost "black momba" pipe because I used the first half of the pipe in my build. I also used the flange for the second half of the pipe. I believe this is called a V-band flange. When ever I am fabricating a belt or cone I always use an OD tape. they make for much more accurate measurements than simply holding a standard tape up to the opening. This is because the "round" thing your measuring probably isn't "truly round" unless it was machined. The formula for calculating a belt is shown below in the pics. I have never seen anyone hydro-forming a pipe and I'm very interested. Please thread jack me and post some pics of the process.OD tape reading of: 2+(41/64)=2.640625" O.D.
1.754" pipe O.D. 1.624" Pipe I.D. This is the largest part of the Pipe and it measures 4.496"
I.D.

 

[BigV]

Like always great work, I forgot where I did my formula but I measured it against port size and a target rpm of 6500, might of been a little too high but I can always make it smaller.

I want to do the same as you and jacket mine as well so it's a true dry pipe. Basically I use stainless and cut two identical pieces, weld the seams, then use high pressure water to ballon it to its shape.

 

[Vumad]

Like always great work, I forgot where I did my formula but I measured it against port size and a target rpm of 6500, might of been a little too high but I can always make it smaller.

I want to do the same as you and jacket mine as well so it's a true dry pipe. Basically I use stainless and cut two identical pieces, weld the seams, then use high pressure water to ballon it to its shape.

Why 6500 RPM? Seems low

 

[Joe Dart]

So how much pressure are we talking about? And I thought it should be more like 10k rpm?

 

[BigV]

In my 650sx I figured 6500 should be good between top end and acceleration as I should be around 6500 a lot of the time. I can always make it bigger or smaller as you know. As for water I actually just use my pressure washer hooked up to a 1/8 npt fitting! And thanks for the formula page layout, very helpful

 

[anthonystempak]

@anthonystempak and his 20 replies that could be condensed into one post:

@my650sux You're fab work is beautiful. Can't wait to see the rest of it. Some haters just don't understand the fact that the fab is half the fun.

 

[anthonystempak]

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[anthonystempak]

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[anthonystempak]

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[BigV]

Timmy you don't make any sense.

 

[smoofers]

Apparently 20 year old magazine adds are his "experience".

 

[x2mafia]

Dude it's all this kid does.

More pipe pics! @my650sux

 

[BigV]

He's on pwctoday, is he just a horrible troll or is he serious?

 

[x2mafia]

Both but let's not pollute any more of people's threads with his nonsense. You should have seen some of the stuff that mods deleted

 

[BigV]

Thank you for the enlightening, it's a shame he does this as the op has such profound talent I need more alerts to his posts in here!

 

[anthonystempak]

Got something from pjs

 

[anthonystempak]

The only 700sx ipro