DR650SE Index Topic #11- EXHAUST

The factory muffler is not nearly as restrictive as things are on the intake side, but there is some corked-up power to be found by switching mufflers. But often the attraction of swapping exhausts is just as likely to be the weight savings, as the stocker weighs in at nearly 15 pounds.

Please share your exhaust improvements...


-GSXR MUFFLER
-AFTERMARKET MUFFLERS
-HEADER GRIND
-OVERSIZED PIPES
-SPARK ARRESTORS
-POLISHING HEADER

ground header welds & gsxr muffler here.

ditto. Works great. SOunds nice. Not even a little loud just nice. Much lighter and with the carb/airbox mods made a nice improvement. Also it just looks better than the stocker.

i managed the header grind a couple weeks ago, definently sounds like it breathes better, got a little throatier.

the over-weld was a good 1/4 inch all the way around with a spot where the welds overlapped to about a good 3/8

scored a mis-labeled gsxr1k can last week off fleabay and saving up for the mid kit now,,, unless i can do as good with homemade. might still checkout the home brew route.

Stock exhaust dimensions:

Inlet: ID = 1.4"; OD = 1.51"

Outlet: ID = 1.135"; OD = 1.265"

If they removed the stock inner tube (the one that sticks out about 1/4"), when gutted, that will leave a hole; ID about 1.386"

FMF Model #S9000 Approved Spark Arrestor (thanks to mx_rob)(also available at Dennis Kirk, I think), is 1.650" OD and 3.38" long

For reference the GSXR muffler x40F0x outlet; ID is 1.680"

GSXR install (again thanks to mx-rob):
https://docs.google.com/present/view?id=0AQWvKsxuKZQbZGp3ZDQ0al82OGZkc203OWhm&hl=en

for the cost the gain in my opinion is not great enough, I just assume put that money into a bigger piston or suspension mods.

D&D with 2 brothers mid pipe

Bump

The bike had the Dynojet carb kit & cut airbox when I bought it.
I added K& N Filter, FMF Q4 Muffler W Powerbomb Header.
Big savings in weight & improved power, but a little loud!

gsxr-1000 TI can
a bit vocal for me, but hard to hush a big thumper without killing it

http://www.advrider.com/forums/showthread.php?t=621819

http://www.advrider.com/forums/showpost.php?p=15582503&postcount=46996

I'm using a cheap CZR pipe for the winter so it can take the beating from the salt instead of the stocker.
Really too loud for my tastes but, it's not like I'm off-roading the thing in the winter (more commuting). F.W.I.W. Since I had already rejetted for the air-box mod she really came alive all over the rev-range. What's really funny is that even after re-gearing 4 teeth bigger on the rear, my mileage has stayed the same with an avg. of 54mpg.
This spring I'll be looking into the 2-bros pipe with the added noise restrictor. (I've really grown to like the big singles sound...just not quite this loud)

Sometimes these changes come at the expense of loss of bottom end power which on a DR is a no no. You can easily gain top end and drop a little weight get more noise which you think means more power but lose that precious bottom end. Fine idea on a sreet bike but lousy on a dualsport. You usually end up losing gas milage too. So be very careful with so called power mods.

Thats not going to happen with this bike,but hey the pumper carb will take care of that.

2001-2003 GSXR muffler, with the modified Two Brothers mid-pipe as sold by Kientech (it includes muffler gasket and mounting hardware).





OEM header pipe, after an evening with a wire wheel, emery cloth, steel wool, cotton buffing wheel, Autosol metal polishing cream, and lots of elbow grease.

http://www.advrider.com/forums/showthread.php?t=117546&page=50

i've put together a comprehensive post about this mod here.

the pic below is a GSXR1000 pipe 2003 can on my dr650.
click on the photo below a slideshow showing the flange, stainless steel mid pipe, brackets etc.



impressions? saved a huge amount of weight and it looks much better than the standard pipe. its got the suzuki markings so little chance the cops would hassle you about it. its not much louder than stock but has a beautiful deep note.

definitely is less restrictive, can feel a definite improvement in low and mid range power now - there's a dyno chart showing gsxr versus stock and FMF pipes. only decrease in power is the final 500rpm, but how often are you going to be flat lining your DR? this pipe makes a world of difference in the revs you'll be using 98% of the time.

Thanks to Lex:
http://www.advrider.com/forums/showpost.php?p=15558556&postcount=46811

It is my understanding that ALL street bike stock mufflers ARE spark arrestor equipped. It is only offroad vehicles that may or may not come stock with a spark arrestor. And only offroad (meaning not meant to be licensed for street use) will have the muffler stamped that it is a spark arrestor.

A spark arrestor may be an indirect flow type or a fine screen type.
The indirect flow (Krizman patent) just means any burning material cannot go straight out the pipe. Instead of a straight-through design muffler there are a variety of ways to make it low (to none) restriction by offsetting a tube inside. That is how the Suzuki GSXR mufflers work. There are no baffles and just a very thin layer of sound deadener on the inside of the can itself, and two tubes that overlap each other which means any burning particles will hit the inside of the end cap while the gas swirls around and goes out the outlet tube. The muffler itself is light because there is next to nothing inside it! Just a very good use of sound wave modification.

The old standby test performed by Rangers and others with ticket books, was to see if they could insert a stick or similar long thin object into the muffler and have it go in past the muffler showing it was "straight-through" and therefore NOT a spark arrestor type. I don't know if they still test in this way or not. They may only look for it stamped on the muffler itself now.

Anyone else have more info on this?

wow, that makes sense.
who's to say you cant ride a factory-stock street bike in the woods?
its not stamped "for street-use only"... is it?