stock fast pipe, stock slow pipe?

[gingerbreadman]

lemme see what i can dig up, i have a pipe bender at my dads work, so if it will bend it, then ill make some pipe downtubes. and then maby i can make bigger downtubes for you noiseguy and you can make even better pipes... if your interested,

as for this being a fast pipe, yes it can be but it all comes down to tunes, there is a very wise mine here in hawaii with a small motored elite s that kills full built strokers... hes running a small bore, 18/19 carb?? and allot of stock things and im guessing somewere in the 70's hes hitting... just take a dremel and hone out the metal washer on the ports... no need for rewelding and replacing j sections... this pipe is fine the way it was made. good luck bro

[noiseguy]

lemme see what i can dig up, i have a pipe bender at my dads work, so if it will bend it, then ill make some pipe downtubes. and then maby i can make bigger downtubes for you noiseguy and you can make even better pipes... if your interested,

Yes I'm interested... find out if he has access to a 1" OD pipe bender that can do some small radius bends. If so I'll get you a pattern to copy and we can bend some up.

[noiseguy]

as for this being a fast pipe, yes it can be but it all comes down to tunes, there is a very wise mine here in hawaii with a small motored elite s that kills full built strokers... hes running a small bore, 18/19 carb?? and allot of stock things and im guessing somewere in the 70's hes hitting... just take a dremel and hone out the metal washer on the ports... no need for rewelding and replacing j sections... this pipe is fine the way it was made. good luck bro

I agree; proper sizing is the most important thing on engines... bigger is not alway better.

That said, what I'm finding on the small overbores (even 65-75cc) is that the downpipe is significantly smaller than the ports. This is on older Elite and Spree engine (which we are still screwing around with because they're cheap and available.) From what I understand, the Dio engines have a larger downpipe which is more appropriately sized... though I haven't personally verified it yet. I've been told in the past that this is a restiction... I'm following up on that now.

My plan is to build two Spree pipes. One chamber pipe based on my previous design, and one "stock" pipe with a larger downtube on an adjusted stock muffler. I think the stocker will work a lot better across the board.... only a build/test will tell.

[gingerbreadman]

sounds about right but hey thats the best way, trial and error... good luck with your prodject id like to see some pics when your finnished?

[gingerbreadman]

oh i see i thought he was talking about the pipe on the bottom which resembles the original s "goshi" pipe

[se50]

I'm thinking about putting a pocketbike exaust on my SE50. I put one on my Ciao, and gained about 7 MPH. My elite is going 25-26 right now, with shaved head, larger tip on the exhaust, UNI filter, upjetted carb, etc.

[hagstrbh]

Did anything over come of this? I definitely have the muffler shown with the skinnier down tube, and I do ~27mph on my Elite, just as described by Se50.

[MySpree]

yes, the bender isnt hooked up yet...

[se50]

Ok. Here's my thought, now. I just pulled up a pic of a spree exhaust, and it was the big kind (like in the pic in the original post). So, I got to thinking, Honda slowed down the Iowa's by putting the washer in the end of that larger exhaust. Is it possible that the SE50's exhaust is the same size as the washer, all the way through the header?

I'm going to start building a new, larger header tonight for my Elite. I'll post with my speed results when I'm done.

I know a larger header is being made by someone else, but my plan involves taking a chunk of scrap tubing, and cutting a bunch of angles and making bends (and welding it together). I made a header for my Ciao that way.

[noiseguy]

That will work. You'll find that the Spree and early Elite have a 19mm ID downtube, and that the washer was smaller. I think that a 23mm ID (1" OD tubing with .060" wall) would be more appropriate.

Have fun welding and tell us what you find out. Keep in mind that you'll need to expand (if needed) the inlet to the muffler.

[se50]

I biked up to my grandpa's junkpile up the road, and got a chunk of scrap conduit, but it was too small. I think I'll buy some 1" conduit.

[hemlockz]

(click the thumbnail for a full size image... just like *)

This is the view, the speed pipe is on the bottom. The one my SE50 came with is on top. The biggest difference is the head pipe. There is also a minor difference that prevented me from directly bolting on the speed pipe. The two grooves for the exhaust studs are cut about 1/4" too shallow, and needed to be adjusted with a cutting wheel in order to line up with my cylinder's exhaust port.



After making that little adjustment to the flange I bolted it up and took off. Impressions: It idles well and the power curve is smooth. I have not topped out yet, but run out of road around 43-45MPH. I bet it could get close to 50MPH. There is no "second power band" like I found on my Proma expansion chamber, this just pulls well throughout the entire range. It is very smooth. Compared to the stock pipe with skinny primary, this speed pipe kicks is *. I could get 35MPH with a tailwind maybe using the stock pipe. Now I almost do wheelies just starting off and can pull past 35MPH going uphill. (mods: UNI filter on a stick, Highspeed pulley, and Proma 63cc bore kit. ) Yes the only difference was the pipe, I had these mods already and couldn't pass 36MPH with the stock skinny pipe

There is another more technical difference; my stock pipe (skinny primary), says it is rated for 70dB. The speed pipe has a metal plate welded to it and says it is for approved for 80dB. (Noise emissions control sticker). So it might not be a totally legal modification. The noise emissions sticker on my SE50 does not match the motorcycle code on the speed pipe.


(I dont recall the exact code, but is was sometihng like HOND20049 for the speed pipe and HON15049 is the sticker on my SE50)

[hemlockz]

My Scoot... with speed pipe



EDIT: I took it out after work yesterday afternoon and found it does do about 50 MPH. Its a slow and steady pull, but I had the speedometer needle up to the "m" of "mph" in about 7 blocks... like a spree style speedometer that visually looks to be about the 50 MPH mark.

[noiseguy]

Interesting... what did the "speed" pipe bolt up to originally? And where did you get it, Ebay?

I'd like to know the pipe ID on the faster pipe.

[hemlockz]

Interesting... what did the "speed" pipe bolt up to originally? And where did you get it, Ebay?

I'd like to know the pipe ID on the faster pipe.

its the same diameter for the first 4 or 5 inches, then it tapers out to about 1" by the time it meets the muffler. I couldn't tell you exactly what it looks like on the inside without taking apart the muffler.

I got it off ebay and it was listed as a 1987 SE50 muffler. Maybe it is SE50P vs. SE50 kind of deal. Mine is originally SE50P (Elite LX), maybe this is for SE50. But now I just looked up the part number for the cylinder and its the same so I have no clue.