Small diameter exhaust u bend? DIY exhaust.

So i am working on making my own exhaust. i have the bike together and running pretty good but it is loud as hell. i am adding a baffle to the current setup but inorder to make it a little less harsh. but to get the length i want, to keep the weight off the exhaust port and mounting bracket, i am going to make the exhaust do a u bend.

where can i find the bend i need?

when i google exhaust bends and pipe i always get stuff that is too large for the application i am using it for. should i just go to home depot and buy a straight piece and then go to a shop and ask them to bend it?

Re: Small diameter exhaust u bend? DIY exhaust.

Overpriced Parts /

Buy a conduit bender

Re: Small diameter exhaust u bend? DIY exhaust.

Dirty30 Dillon /

Old steel lawn furniture or folding chairs.

Pretty much any steel you buy at HD, which is only galvanized conduit (hrew) and schedule 40 (hrew) to my knowledge, isn't gonna bend very well. Also, the first will make you very sick from welding it, and the second weighs a shit-ton (get it? cuz it's poop pipe?)

Re: Small diameter exhaust u bend? DIY exhaust.

http://www.globalindustrial.com/p/plumbing/plumbing-tools/pipe-tube-benders/model-no-312-300-series-plumbing-bender-34-tube-size-2-78-bend-radius?infoParam.campaignId=T9F&gclid=CJGe9pGwncACFQwV7AodaxQA3g&gclsrc=aw.ds

somthing like what is listed above? this costs more then just going to buy a pipe. this would work though. have you ever used one? does it kink the pipe at all?

Re: Small diameter exhaust u bend? DIY exhaust.

lol, yeah i get it. i figured HD was not the place to go. but i have no idea where i can go. i am looking for probably a 3/4 inch pipe bent at a 3" radius.

Re: Small diameter exhaust u bend? DIY exhaust.

Cut up some handlebars? Bicycle/moped and small mc bars are 7/8 OD, Big mc bars are 1" OD. You can also make a bunch of pie cuts and weld it together.

Re: Small diameter exhaust u bend? DIY exhaust.

MopedGarmy . Wrote:

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> Cut up some handlebars? Bicycle/moped and small mc

> bars are 7/8 OD, Big mc bars are 1" OD. You can

> also make a bunch of pie cuts and weld it

> together.

This.

Re: Small diameter exhaust u bend? DIY exhaust.

that would work, but i would get better flow with a bent tube rather then w/ a bunch of welds.

Re: Small diameter exhaust u bend? DIY exhaust.

Curtis Alonzo Wrote:

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> that would work, but i would get better flow with

> a bent tube rather then w/ a bunch of welds.

That is all based on how well you can weld and prep. There are some siiick two stroke and even four stroke bikes out there that are entirely made up of small sections of pipe cut and welded together.

Re: Small diameter exhaust u bend? DIY exhaust.

i can make the out side look good no problem but the inside of the pipe would have ridges. i may end up doing this as it would not be too much of a performance issue, but smoothe would be better if i can find it. i think i have some old bars sitting around that i could use i may end up going this route in the end.

Re: Small diameter exhaust u bend? DIY exhaust.

In all honesty you can probably get the bend you want using only two sections...so just one weld.

Re: Small diameter exhaust u bend? DIY exhaust.

I've used old handlebars before, but that was a small diameter and not a full U

Re: Small diameter exhaust u bend? DIY exhaust.

i think what i might end up doing is make a collector box to transition from chamber to muffler. any ideas on how a collector box vs a pipe will effect flow through the expansion chamber?

Re: Small diameter exhaust u bend? DIY exhaust.

Mikey Antonakakis /

It will be bad.

If you can cut and weld, and you are patient, get sheet steel, cut out cones, and weld them together like this:

Re: Small diameter exhaust u bend? DIY exhaust.

i don't see a photo of what u r describing. but it sounds llike you are talking about how to make an expansion chamber. i already have one of those. i need to make the exhaust do a u turn coming out of the pipe. what i am thinking is i will weld up a triangular collector box and have an inlet and an outlet on the box. i attached a rough scetch of what i am talking about.

collector box.png

Re: Small diameter exhaust u bend? DIY exhaust.

Dirty30 Dillon /

I seem to recall you having a little pocket bike/motor-bicycle, kidney shaped chamber on it.

You should really just run a stinger and hang the silencer at the rear stock exhaust hanger, with the bends.

Better than all that work, is to just buy an actual expansion chamber and modify that.

Re: Small diameter exhaust u bend? DIY exhaust.

i am building the set up in the photo but i need it to bend the other way, i am using the stock hanger location and i even welded the stock hanger to the new pipe. i am thinking of adding more volume to the expansion chamber i have, but, i dont want to make it worse.

Scooter_exhaust.jpg

Re: Small diameter exhaust u bend? DIY exhaust.

Dirty30 Dillon /

Is that the pipe you have, or the pipe you're copying?

If you don't know how to measure your port timing or needed power range, don't attempt to modify a chamber.

Re: Small diameter exhaust u bend? DIY exhaust.

that is not the pipe i have, i am building off the current pipe, partially copying the desgin of the one in the photo.

Re: Small diameter exhaust u bend? DIY exhaust.

just so people know what i am working with/ what i am talking about. see attached photo.

at the cut line i have the OEM header welded and the other end will be cut down further and turned back in a U shape to add the baffle

expansion chamber.jpg

Re: Small diameter exhaust u bend? DIY exhaust.

Dirty30 Dillon /

Did you buy the silencer yet?

My buddy did the same thing with his fa50, used this https://www.treatland.tv/exhaust-chamber-p/chamber-black-28mm.htm

and enjoys it.

For 35 bucks, it's hard to beat. Although, he tuned the length of the header to his needs to get better mid/hi's

Re: Small diameter exhaust u bend? DIY exhaust.

wicked suggestion i wish i'd seen that b4 i bought what i got. it is actually less money then the POS i have. but honestly does not look to be too much different.

the attached photo is what i had in mind

expansion chamber.jpg
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