Double exhaust

[Olivieeeer]

  Hi guys !

  It's been a long time I haven't post in your forum. One more time : HI ! 

  I'm actually making a double exhaust for my modified GS. It's a " cafe racer " now. I have a pair of a Norton like exhaust. ( Sorry if my english is bad )

  I'm wondering how to make it for having best torque and perhaps best power. On the OEM, there's one pipe at approximately 1 foot from the head. I guess it is not really necessary, just for reducing sound. It is what I read in technical reviews. Ninja 500 and european Honda CB500 twin don't have it. The second pipe between the two main pipes is about 70-80cm ( ~ 25 inchs ) from the head. I think it is necessary to have it for exhaust accordance, and good power. But I'm not sure if it is necessary. I try to have best torque, it is a road bike, with non modified cams but improved head ( porting, head milled, 36mm carbs and 5 degrees ). What are you thinking about ?

  Just for fun, a highly modified GS with double exhaust on a dyno, it is awesome !  http://www.youtube.com/watch?v=11Mike0d-lk

  Mine is like that. There are just 2-3 more stuffs since this pic :



  As I'm here to speak, I would like to say hello to former forumers like Srinath or Bob Broussard if they are already there. Last year I worked in Quebec and spent 1 month in United States, doing a big trip from Quebec to Vancouver in a minivan. I was in New York, Niagara falls, Chicago, Saint Louis, Memphis, New Orleans, Dallas, Colorado Springs, Las Vegas, Salt Lake City, Yellowstone and Seattle. I met great and cool american peoples. I want to come back now and work for a year, if I can. I'll have to improve my english, before. 

  Regards

[tt_four]

Hey man, that's a great looking bike. I'd love to see some more pictures. What kind of exhaust is that? If I'm thinking of the right part, it's a pipe that runs between the headers to equalize the pressure.

Very clean, and I love the shiny engine cover!

[burning1]

If you want performance, your best bet is probably going to be a single exhaust. A 2nd muffler adds a lot of weight, and I highly doubt it's going to give you any real power advantage.

[O.C.D.]

Holy hell that is a nice cafe/GS!!!  More pics please!!!

I too am in the mindset to try a dual exhaust.  Been reading a lot here and there and it seems that a GS is not a good platform to do so.

[Homer]

Details on the seat pan, please.
Didja make it yourself, or modify it from something that fits something else? 
How's the foam for daily riding, and is there a pinch-point where it meets the tank? 

[The Buddha]

I have heard this story of this guy who's 300 lbs and to "make his bike faster" he put titanium bolts on it everywhere. Cost him like 1500 bucks.
Yea very smart ... a dual can is the same way. A lot of work and $$$ for what I would definetly classify as minimal gain.
Cool.
Buddha.

[cboling]

I can say that I had been riding my bike with only a straight pipe. This past Friday, I went to a muffler shop and had a small mid pipe welded to the straight pipe (header) and installed the D&D exhaust I had been waiting on installing. I believe the bike has been more responsive with the muffler on than without. I am not sure if that goes the same for running each cylinder separate but if it is anything like running without a muffler, it might "feel" like the bike performs worse? Just my thoughts.

PS. MORE PICS, MORE PICS, MORE PICS, MORE PICS. The more I see cafe style bikes, the more I likes. 

[tt_four]

I'd be interested in seeing what you came up with, but I also have to throw in my uneducated opinion that a bike as small as the GS wouldn't do as well with 2 exhausts. Engines need a certain amount of back pressure, and most modern pipes are just going to be too big to do that. Most bikes you see with dual pipes all have large motors, usually 1000cc or more. I feel like the double exhaust would be like cboling said his bike felt with only the header.

There are smaller bikes that have dual exhausts though, so if you find the right kind I think you'd be fine, and it could come out looking alright. Ninja250s have dual exhausts, so obviously it can be done on smaller engines, but just definitely make sure you find the right exhausts if you're going to go through with it.

[Homer]

I like your tail.

[cboling]

HAHA! That smiley reminds me of Wren and Stimpy!

[The Buddha]

That smiley reminds me of the guy that put Ti bolts on his bike.

I have heard hayabusa fools wonder out loud why they dont have chrome bolts in titanium.

The cut off header vs pipe is a valid one, it will run better with a proper muffler. It needs that muffler to provide it a scavenge effect. The separate pipes also is in theory valid, it sorta does a self scavenge and does so without intervention from the other cyl. However it has a resonance freq, like a certain rpm where it works right and every where else its not as good and in a different rpm range its down right negative. if you design the pipe right you can get such negative locations out where you wont be much, and the positive where you will. Say you need 7-8K for highway runs. You need 2-3K for town and take offs. You can build it with that in mind. Will get you a whole tenth of a horsie ... yea ... 1/10 ...
Lots of work and little gain. OK fine a whole horsie. Prolly not, a dry clutch barely gave em 2 for the GSXR 750 limited edition in 1986.
Cool.
Buddha.

[the mole]

Yeah, I heard that those titanium bolts didn't help that much, but then he filled his handlebars with helium and WOW!!!

[Homer]

Since you didn't deliver on the tail, I now side with the other guys. 

[Toogoofy317]

They make leathers that big.?!?!?!?!? Wonder how many cows had to die for that suit?

Nice bike btw!

Mary

[smaeda]

more pics!!

[Olivieeeer]

  Hi guys !

  Last pic is :



  I have the double exhaust done now. But no pics yet.

[O.C.D.]

Don't make me call shenanigans!!!!

[jeremy_nash]

Don't make me call shenanigans!!!!

I'd better go get my broom!!

[tt_four]

 

  I have the double exhaust done now. But no pics yet.

hmm.... mail me your old one. It looks way nicer than the V&H I have.


The issue isn't even that guys leathers, but the fact that he still felt the need to slap some knee pucks on there!

[pandymai]

The issue isn't even that guys leathers, but the fact that he still felt the need to slap some knee pucks on there!

maybe he needs them because the bike just tips over when he's turning and it's the only way to keep it from hitting the ground? im no math wiz but im sure there needs to be a lot of forward motion to keep that bike from just dropping straight down in a lean..