Custom exhaust maybe...

[kiwibum]

Sorry didn't describe that too well, they left the standard front header pipes and rear Y pipe and made a 3-into-1 adapter pipe. Let me know if you require more info.

[Tiger]

Sorry didn't describe that too well, they left the standard front header pipes and rear Y pipe and made a 3-into-1 adapter pipe. Let me know if you require more info.

:) Thanks mate, appreciate. You have a nice looking ride there, real nice...great job 8)

                         8).......TIGER....... 8)

[kiwibum]

Thanks, I'm selling it, on the local NZ auction site now and just added my other 400 tonight. It looks good in the photo but the previous owner sprayed the engine with zinc-it or silver paint to cover corrosion with over spray on the frame. Will give the new owner something to do tidying it up to make it look shiny again. It's only done 10,000 miles, pulls really well.

[Extent]

Does anyone have any thoughts on sizing the exhaust?  The dual 1.5's on the front cyl seem grossly excessive to me.  I haven't been able to find any straightforward references for small displacement engines.

I'm thinking single 1.5" merged to 1.75" out to the can.

[Rick G]

Extant,I believe their double wall, Thats why there so heavy .

[inanecathode]

Single wall all the way around (maybe its just really thick where i can't see it) i do agree that its a bit excessive size. However the s*it box of an exhaust the stock is takes care of that back pressure thing.

[kiwibum]

Does anyone have any thoughts on sizing the exhaust?  The dual 1.5's on the front cyl seem grossly excessive to me.  I haven't been able to find any straightforward references for small displacement engines.

Extent: hunt down a copy of the "Piper tuning manual" by Bob Gayler
http://www.amazon.com/Piper-Tuning-Manual-Robert-Gayler/dp/0854292926/ref=sr_1_1?ie=UTF8&s=books&qid=1201246557&sr=8-1

This book gives all the calculations for small two and four stroke engines you will ever want. I borrowed it from the library and used it to build an expansion chamber for a go cart years ago, went really well. When I go to make pipes for my XZ this is the book I'll be using.

[jasonm.]

My 2 cents. USe the stock chamber and change mufflers if you have to. Or make something like the MAC. The stock chamber balances the front and back cylinders' back pressure. In reality the right exhaust only flows 20% of the rear cylinder while the rest of the rear exhaust goes out the left. This is because of the rear has a shorter path. ... The front is split 50/50 left right. I KNOW I cut a rusted one open.

[Blake]

Does anyone have any thoughts on sizing the exhaust?  The dual 1.5's on the front cyl seem grossly excessive to me.  I haven't been able to find any straightforward references for small displacement engines.

I'm thinking single 1.5" merged to 1.75" out to the can.

On the Vision racer exhaust I bought off of Rick G a few years ago, it uses 1.5" pipes for each cylinder and i'd say thats just about perfect.  The bike definately screams to redline (both eagerness and attention wise).  Also note i have k&n individual pod filters on and rejetted so im getting a lot more airflow in to coincide with the ability to get a lot more air out with this exhaust.  I built an exhaust before this one that was 1.75" pipe for each cylinder and the bike simply lost all power above 7k i think. ( it physically wouldn't go past something around 7 or 8k even with extensive jetting.) with that large of diameter for each cylinder you lost all exhaust gas velocity and lost all scavenging effect of the exhaust.

picture of the left side of the bike:


the front cylinder uses a rear Y pipe along with a couple of 1" diameter mandel bent pipes to connect to the exhaust ports. the 1.5" diameter pipe is simply welded to the stock Y pipe.  pretty decent design, in my opinion.  only real issue is that the stock Y pipe is slightly constrictive and hurts the scavenging effect, albeit ever so slightly.


I actually started on another exhaust, a 4-2-1, that i copied off of a Buell design i once saw but never quite completed it (cut pipes for the 4-2 but never welded together).  if you're looking for a 4-2-1 do 1" from head, and merge those two into a 1.5" pipe, and for the final single pipe i had it going to a single 2" pipe.  I tried to design it like a set of car headers, so that if you keep the lengths of pipe for the front and rear cylinders equal, when you put them into the larger 2" pipe it'll help with the scavenging effect.

[jasonm.]

Blake, you hit it exactly...maximum "VELOCITY" at all engine speeds.

[Extent]

Doing a tuned 4-2-1 on the V would be pointless performance wise since to the exhaust gasses the system will still look like a 2-1.  As long as you can keep the first stage runners equal length it should be better to merge them as quickly as possible (like right outside the head) and save weight on two pipes per each cylinder.

[Blake]

Doing a tuned 4-2-1 on the V would be pointless performance wise since to the exhaust gasses the system will still look like a 2-1.  As long as you can keep the first stage runners equal length it should be better to merge them as quickly as possible (like right outside the head) and save weight on two pipes per each cylinder.

that's exactly how i did it.  agree 100% since its just 2 ports per head flowing the same.  merges as close from the head as possible.  I just said 4-2-1 since theres 4 exhaust ports when in reality its a 2-1 system.  but as best as i can describe it (cant seem to find a picture), the rear exhaust comes out the right side between that little frame gap right behind the rear cylinder and loops around the clutch cover.   the front and rear 1.5" pipes merge somewhere right underneath the clutch, then go to a single 2" pipe up and under the seat.  definitely requires a heat sheild but i just found the look interesting. 

[Extent]

I gotcha

[Rick G]

Hi Blake , a while ago we were discussing the vision races exhaust and I posted (with help) some pics .
Some wondered if we could get a sound bite of it . can you provide it?

[Blake]

Hi Blake , a while ago we were discussing the vision races exhaust and I posted (with help) some pics .
Some wondered if we could get a sound bite of it . can you provide it?

I'll look around my computer and see if i can find a video.  I dont have the bike with me here (Been in a shed since last summer) so i cant take any new video/sound.

[Tiger]

:) I've now got a buddy of mine to make a "Y" pipe, to link the two exhaust pipe's into the R6 muffler. Once I get it back I can see how it all fit's and looks... ::), get her fired up and see how she runs...when the snow goes away!!!

Barrie, my Goldwing buddy has a nice home workshop...Three lathes, surface grinder, mill, drill press, welding equipment, etc He's a retired machine guy who used to work in the aerospace industry...a really handy guy!!!

Several months ago, he took a 46mm combination wrench, (belonging to CanadianLou), parted off the ring end, faced it and "cold welded" on to it a piece of steel pipe, which he had capped and fitted a 3/8" drive, using an old socket... and viola, a custom made 46mm socket that you can use a torque wrench with and fits over the shaft when doing that thin, 46mm nut, located behind the flywheel...yes, you know the one I mean...the one that the installation guy's in Japan didn't bend the two locking tab's in place and causes the nut to loosen :o cost, including the wrench, time, material's and polishing...only $90.00... 8)

Anyhow, today he delivered a custom "Y" pipe, to connect the two exhaust pipes into the R6 muffler...what a superb bit of fabricating/welding he's done. Made from three pieces of pipe, cut, welded, polished, etc. Cost, including time and material's only $85.00 8) I didn't have time to hook it up this evening, however it will get done in the next week or so 8)

                   8).......TIGER....... 8)

[Night Vision]

can you send me some pics before it gets all knuckle blooded?

[Tiger]

can you send me some pics before it gets all knuckle blooded?

;D Sure can. I'll do it after work... ;)

[Cdnlouie]

Looking forward to seeing that creation!  Sounds like fun!  ;D

Cdnl

[Tiger]

 :) I took some picture's, downloaded them into my computer, but for some reason I can't get them to load up for an e-mail to you N_V... ??? I'll try again a wee bit later.

                       8).......TIGER....... 8)