GStwin.com GS500 Message Forum

curious here, was contemplating removing the stock can from my bike, and fitting a muffler from a buell blast? underneath. the question is, will the heat from the muffler have any ill effects on the bike? thanks :thumb:

Um... First the obvious:

How are you going to stuff two headers into the one collector that goes into the Blast exhaust?

Next:
Its not likely to work very well. The Blast!* can is designed for a loping thumper, not a 280 twin.

Sorry Charlie.
:dunno:

We've thrown the thought of a Buell-like exhaust for the GS500 around before, and what it comes down to (like many of the other more radical mods thrown around here) is......it's possible. Why the hell not  :dunno: If you have the skills with a welder and bending pipe go for it. I think that it would be sweet if someone could make it work. The engineering bits that you need to consider are things like clearance (pipe to ground) and maybe choosing a pipe from a bigger (900cc) Buell.

Yeah the problem with swiping a Buell exhaust, besides the tuned lenght problem is that all the Buell exhausts have the primary collector before the headers go into the can. That makes the primaries VERY short. Grafted onto a GS, that would make them have to be about 12 inches long, which is way too short, unless you did something silly like have them twisted in an "S" shape (which is what they had to do on the XB12).

However, I do think an under engine "pod" style exhaust does have potental. I've looked at some drawings of the way Buell put the exhaust together. It is very much a car muffler style baffle box design. The housing is divided into chambers. The header comes into the box and goes to the back chamber where it ends. Then in the same "bulkhead" another tube goes back the other way, and you have a third one that goes back again and has the final outlet tip. So the exhaust gases snake back and forth 3 times.
This design has the benifit of not requiring very acute 180 degree bends, but I'm not sure what it does to flow, and I'm sure trying to figure out the resonances would be a nightmare.  But it would be a fairly simple and cheap fabrication I might try this year sometime, if I ever get this GS put together and drag it up to Atlanta for some dyno time...

My idea for trying to mount an under-engine system was to use a Kerker or Supertrapp slip-on (they make smaller than stock ones...) and just have to rebuild a set of headers and connecting pipe.  I was thinking I could just cut the stock pipe as close to the 2-into-1 joint and run a pipe the same length as the stock system but it would be bent with a couple bends so the pipe coming from the joint would be an oddly shaped "S".  Kerker makes a small slip-on you could use as the canister.  OR I could cut the header pipes make my own connector and that way the "s" bent pipe could be shorter...

Hmmm...
Seems simple enough, but I'm not an exhaust guru so who knows...


Rolly

jamesG, yeah sorry bout that, was planning to possibly hire a welder, (or have a friend of mine who builds exhausts for a living ,in a plant, make one up for me), my bad, thought the blast was a 500, guess i was wrong

I've looked at it too.  The problem is there isn't enough room between the collector and the back tire to fold up the pipe unless you twist it up like an intestine, and that many sharp bends (at least 2) will screw up flow.
So you are damned if you just cut it short (loose low end HP & all torque) and damned if you create some kind a octopus plumbing (loose top end).

My idea was to build a "box" with a small exhaust "hole"?  A few custom bikes use the same idea... Ghezzi and Brian used the same idea on their Moto Guzzi powered bikes...
Here's a link to get an idea of what I'm talking 'bout:  You'll need to look around a bit, but the metal box under the bike is the exhaust.

http://www.ghezzi-brian.com/models_furia.htm

Not sure where you would stuff a box the size of 2 loaves of bread but you never know...


Rolly

what about using the stock headers, cut after they merge, and putting in a short cherry bomb (glass-pack) :dunno: or possibly a small flowmaster?

Quote from: yamahonkawazukiwhat about using the stock headers, cut after they merge, and putting in a short cherry bomb (glass-pack) :dunno: or possibly a small flowmaster?

Now you've got my curiosity peaking about what a small drag muffler from Flowmaster would sound like on our bikes.  I bet a bullet style muffler could work too.  They would probably be better because of the perf'ed tube design as opposed to the glass pack design

Dynomax race mufflers and Ultra Flo Welded mufflers.  
http://www.dynomax.com/race.stm
http://www.dynomax.com/ultrafloweld.stm

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=4226&prmenbr=361
Here's a bullet muff that's "2-1/2'' In/Out, 12'' Long" and its only $32 :lol:
Paint it black, weld on a turn down aimed somewhere and I bet it would be cool


Here's the small Flow I was thinking of
http://store.summitracing.com/partdetail.asp?part=FLO%2D325108
Its 2.5" center in/out
Case Shape Oval
Overall Length 9 1/2 in.
Case Length 5 1/2 in.
Thickness 3 in.
Width 8 in.

You'd probably get a few funny looks but I bet it could be made to work  :) :dunno:

(http://static.summitracing.com/global/images/prod/norm/flo-325108_m.jpg).hmmmmmmmmm :mrgreen:  :mrgreen:  :mrgreen:  :mrgreen:  :dunno: