Bonneville America Forums Forums Technical Forums Exhaust Custom Stainless extractors

I've been enquiring with a few muffler / exhaust businesses about Stainless Steel mandrel bend extractors for our America / Speedmaster bikes, but it seems none of them are interested in making them (including D&D who I thought would do so). So anyway the only option moving forward is to custom make them.

The only option so far is for me to have the flanges and lower mounts made by a local engineering firm, send a mock version (normal pipe tacked together) to a mandrel bender to have the pipe bent, then have an exhaust shop (or tig welder) weld them together.

So to my questions - is the balance pipe (under engine) required? is this my only fabrication option? and if so would anyone else be interested in purchase if I were to make multiple sets?

Spercialty Spares was supposed to make a set but never did. Demand? Too bad you are so far away.

The crossover/balance pipe increases exhaust scavenging and increases low end torque and top end horsepower, it's not an absolute necessity but if I were fabbing up a new set of pipes I'd included it for sure. I'd be interested in a set but I'm in the US I could probably have a set made for the cost of shipping from NSW. Hope the balance pipe info helps.

Thanks, I probably will fab a the balance pipe then, I hope to only do this once. As soon as I finish this current round of mods (battery box/lights/chain guard) I'll start saving for this extractor project - can't wait to get rid of the stock ones!

Hey I was serching e-bay and found these Stainless mandrel bends . The store has everything I would need and it would work out quite cheap.

Does anyone know if it would be ok to braze stainless extractors with a sleve inside joint??? Ok with heat etc???

I think the stainless / brass joins would look great with some brass billet trumpet tips on the ends. I have considerable experience brazing push bike frames so it couldn't be that hard.

I can supply you those mandrel bends in stainless from my work at Genie Performance Exhausts in Brisbane. Call me (Richard) on 07 3205 1314.

Cheers for that, thanks for the chat!

I don't like the chrome covers patched all over stock extractors, I think it makes it look too much like a jap bike. I want to achieve an old school classic look!

Update - Mandrel bends ordered (thanks again Richard) and baffles obtained from local harley shop. I got 30' bends coming out of the head, 180' bend which I will cut to form the top and bottom bends, and of course the straight sections to join them all together. Also ordered 2x 30' bends to put an upsweep at the tail. I plan to build them a little bit closer to the frame to give the bike a slimmer appearance.

Currently looking for some brass tips to insert in the end of pipes for that bobber look.

Please give opinions on construction / style / any other general info that may help me as this is a first time exhast project!

Will this look ok?

Yes,
Except for the shruken head light.

How're the headers going?

Headers haven't been started yet, I'm just working on the measurements (photo above) before I start cutting. I should start cutting on weekend then get flanges cut and start welding next week.

P.s. did anyone notice the foot controls above? I think I'll move the headers closer to frame and foot controls 2" forward...... hmmm descisions descisions.....

I reckon that would look sweet. Where did you hide the indicators?

Cheers, No indicator in this photo. I'm making a couple of brackets for them at the moment. I'll mount them the same place as previously ( under headlight and attached to lucus tailight) but I just had to have a ride last week and could't wait for indicators!

I have the pipes and mandrel bends now, so I think I'll do a step by step of how it goes together....



I cut the 180' bends so that the headers will stick out the same distance from the head as stock, but will wrap closer to the stator / clutch cover.



here is a mock up with tape.

Are you going to marry up the tubes into one or run both parallel, I was thinking, maybe the left side of the new Thunderbird s exhaust (debaffled) would handle both pipes. Nice job of small bore pipefittin' by the way.

Cheers - Just running 2 pipes, without crossover, similar shape to previous picture... except I'll make the bottom run a bit longer and the up sweep at the end a bit less.

I'm going to have a ride this weekend then pull the standard pipes and forward controls off (for ever) so should be able to finish the cutting in the next couple of days.

Where you riding this weekend Chris? Love to see your ride in the flesh.

Hey Steve, sorry but the bike is off the road at the moment to work on this last project. Another forum member from down Wollongong also wants to catch up so I'll post a ride date when my bike is back on the road.

So I have pulled the extractors and mufflers off so that I can figure out how to make the flanges etc to attach to the head.....

I have also ordered some universal foot controls so I can move the position in front of the extractors.



I will use a harley style master cylinder and braided hose.

That would be cool Chris. I work every second weekend so we will have to time it right. I have a little work to do on my speedy first too as my parcel from Newspeedmaster is gonna arrive any day now.

I've finally got some more time in the shed, and managed to cut and tack the pipes together, just need to make some brakets now and take them to get finish welded. I only have stick welder so need someone else to TIG weld... though I'd show some pics anyway!


I'm happy with these lines, an they will fit my forward 'forward controls' that I'm making..

This was a difficult bend to get around due to the engine being off set to the right... I wanted to keep even gap from the oil cooler on both sides. Worked ok. I also managed to get away with using 30' bends coming out of the head which is about 10' less than stock on the left side so should give good flow rates.

I wanted to keep the pipes as 'slim' as possible so as you can see they hug the frame a bit tighter than the stock ones.

nice

You sure did a great job of making up those pipes!! What finish will you put on them when you're done?

Thats lookin really cool Chris.
As Keith has already asked, I too am curious what kind of finish are you gonna go for?

Well it's 304 stainless so will polish but I'm looking for a low maintenance and simple (remove everything not needed)bobber look so will probably just have brushed / sanded or exhaust wrap.

Yeah, I could see going with a brushed/sanded look... it would match the covers on the engine.

All finished with the extractors, I ended up just blending the front section welds as I wraped the pipes, but brush finished the rear section with emery strip. They sound about as loud as D&D but without the deep tone. I made some steel perforated pipe baffles to tone it down a bit from straight drag pipes. You can see more picture inthe members rides post.

Are you gonna flap cap the ends as Ian suggested (I thought he had a point there)?

No I don't think so, the tip end is lower than the head so no water could ever get into the engine and the amount of water from rain (negligible) will just blow / dry out in seconds with exhaust pressure... tested today! Of course I will cover them when washing the bike.

P.s. the exhausts performed very well today, power feels the same / maybe a little bit more than D&D's used previously!

They look insane, I wish I could make stuff like that.

Cheers Steve, anyone can make this stuff - just trial and error.

P.s. just passed Rego inspection today!!! had to fill with baffle wool and cap the ends but happy to not have to swap back to stock pipes!!!