I've seen lots of information about aftermarket exhaust systems on this site, but I'm thinking about something different. I really like the look of an under seat exhaust since I saw ver4's thread about his new, very sexy Yamaha FZ6 http://gstwins.com/gsboard/index.php?topic=61278.0

I did a quick search for under seat exhausts here, but didn't find anything. Has anyone tried to fit one to their GS?

It's not mine but I found A pic of one.

Hey, nice find. That's pretty much what I had in mind. A cleaner execution might be nice, but it's good to know someone else has given it a go. I'm not keen on swapping out the tail section, though. I figure I need a hugger, and I can pull out the factory undertail/underseat bit. I might need to weld in a heat shield of some sort, and a place to keep the tool kit, but I think it's do-able. Now I just need time to get at it.

The outside pipe to undertail is hideous in my tiny two cent opinion.  Think there is any other way to do it?

and +1 "ver4's thread about his new, very sexy Yamaha FZ6"

I don't think there's another way to do it. Not much clearance through the swingarm, or behind the engine.

If you pay attention, a lot of undertail exhausts are routed that way. 03+ CBR600RR and a bunch of Ducati come to mind.

it's probably fixable with a good paint job 

Burn,



'ats just a wee bit different good sir!  Guess I didn't notice, errr pay attention because it is so well done and not hanging out in the open looking hideous.

It's all about the execution, really. And I don't think that the terrible exhaust wrap on that example is helping matters much. Since it will all have to be custom made anyway, I'd go with a stainless pipe, or ceramic coated. And you have to spend some time making it fit the lines of the bike, not just whacking it on there.

 Here is mine. All the build pictures are on here.

Quote from: cbrfxr67 on July 19, 2012, 11:26:30 AM
'ats just a wee bit different good sir!  Guess I didn't notice, errr pay attention because it is so well done and not hanging out in the open looking hideous.

Execution is everything. Making a kit like that look nice is all in the details.

http://gstwins.com/gsboard/index.php?topic=59686.0

Can sticks out a little too far for my taste, but I think it looks pretty slick with the black pipe against the black frame.

Quote from: dgyver on July 19, 2012, 01:48:37 PM
Here is mine. All the build pictures are on here.

what kind of swing arm is that?

Quote from: rebel_rocket on July 22, 2012, 02:20:42 AM
what kind of swing arm is that?

It is from an RGV 250. One of the few swingarms that are narrow enough to fit.

RGV as dgyver said. I strongly advise against doing the swap - it's not at all trivial.

Interesting that Japanese manufacturers have abandoned underseat exhaust systems as 'inefficient' in their ongoing quest for greater performance.

If you are trying to saev weight, an under-seat exhaust is really not helpful at all, unless your exhaust comes out the back of the engine over the tire, but why have all the un-necessary piping? i like the look of it as well, i'm just saying from their viewpoint thats my assumption

Anyone who thought there was a performance benefit was a fool. For weight centralization and weight reduction, under-belly seems to be the best bet. But, sometimes the reality of engine placement requires moving the exhaust system to the conventional location.

A titanium or carbon muffler just isn't that heavy to begin with.

I always figured it was to improve ground clearance for when you're leaned way, way over. As for the GS, I just think it could look pretty cool if done right.

the underseat exhaust in racing is set at a pacific angle and aids performance .It is not there for centre of gravity effect .I think it was ducati or one of the other major teams had it set wrong and were handicapped in performance before they discovered there problem ,it is for the streamling effect .The benifit must be worth it to have the extra bends in the exhaust.

Quote from: twinrat on July 25, 2012, 02:27:45 AM
the underseat exhaust in racing is set at a pacific angle

As opposed to an Atlantic angle?