hi guys, Im far from an oxy and in a country where postage frequently goes missing so Im doing a budget mod on a set of standard mufflers...

first up I drilled out the rivets and removed the end caps then chopped out the angled pipe, leaving a 10mm ring to keep the perforated baffle intact...



this gave it a better sound but I still felt it was restricted after a few days riding, so I continued chopping...

i then removed the next plate (with 2 pipes connected) leaving the pipe that ran through to the next plate...



then i removed the last plate and punched a few holes through the cat.
the cat was really hard to remove as it was quite thick, so I just left it there.





Ive mixed the shots up a little but Im sure you guys can see where Im coming from. The large volume of air swirling around in there is sure to cause some popping and maybe some flames at night but we will see.

later ill smash the cat apart to get it out and fit a 2 or 3" thick perforated baffle to it and wrap it in fibreglass, ill slide it down the throat and weld a large washer shaped plate to the baffle then popweld it to the 10mm ring ive left there at end of the can.

I hope Ive explained this process right. Ill take more pics as i go and post them.
I'll test ride the bike soon to see if its made any improvements. I guess I wont feel anything until i open the airbox up a little and mod the filter...


next Ill mod the airbox and later fit a pair of pro-circuit T4 cans to it...
I wouldnt recoment this mod to everyone but Im in a country with no emission or noise restrictions... and loud pipes saves lives here!

yesterday I rode 1hr to the city after the can mods and blocking off the AIS pipe. the bike went well although when it was cold if you hit the throttle hard (from idle) it would stall. it seemed better when it was hot. Im guessing this is because i still have the cats in the cans, despite whacking 3 holes in each cat.

Im happy with the mods and love the sound. just need to totally remove the cats to get her flowing more.

any comments appreciated guys! come on dont be shy!

finally got one of the cats out today. took alot of hacking though, man they are tough!
next I need to smooth out the interior of the can by removing any excess metal.
then Ill buy a perforated pipe and run it straight through to some new end caps Ill get made up (possibly the same as a T4 or a staintune design).

Ill wrap the perforated core in fibreglass.

but for now ill just run the standard ends and the big hollow interiors of the cans...
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luv this thread

Hey hypoboang i want to remove cat from exhaust,is it worth doing it.Any better performance or its just louder?Do you have still stall problems?
Thx

mate my mod made it really loud. the baffle removal would have done most of the damage there. removing the cats wasnt easy but it did get the bike flowing better. I also removed the AIS (most just block it off), and the snorkel from the air box. I did notice a difference in power, it seemed snappier, and didnt stall after the mod.

I did it in asia so there was no problem with emission standards there... dont know about here in oz though... later i fitted a new baffle to the bike that worked sweet, made it quieter, but deeper sounding with the same performance. ill see if I can dig up he pics of that final mod.

just running them straight thru like that did make the pipes kinda cackle loudly if thats the right way to put it! cheers!

I read elsewhere that any mods that flow better (intake or exhaust) require optimization of the injection (such as Kev's temp sender mod box).

You also mention getting better flow by eliminating the cats. In general, cats are not the most restrictive part of an exhaust system, IF the system was designed well. Yamaha not being slackers, I suspect that the stock system is designed pretty well indeed. SO, removing your cats probably did not help you after all, especially if you left those sharp pieces of metal we see in your photos, causing beaucoup turbulence.

You will get more sound by all the mods you have shown, but I seriously doubt that you will get any more power. You may even lose a fair amount of low-end torque.

HTH

__________________
Stuck in soggy France; riding when the weather is decent. 2007 XTR for now but pining for ST12, Strom, KTM, or Versys1k.

Hi,
After looking at this thread I am going to do the same. I have just bought two lengths of 50mm X 500mm perforated stainless tube and two bags of baffle packing, �20.00p Bargain..lol. I will do this over Xmas and let you know how it goes. I will also do the rear light mod the same time.

MERRY CHRISTMAS TO YOU ALL

Croxalla

Wrong country but where do you find 50mm X 500mm perforated stainless tube?

Hi,
I bought the tube and packing from a local exhaust manufacturer.I realise that its the wrong country but if it helps here's their address and telephone number.
Longlife Swansea
Unit14a Cwmddu Industrial Estate,
Fforestfach,
Swansea SA5 8JF
Phone:01792 359326
Cheers
Allan
I just found a company in Sweden that may help you ...RAY Metallfabrik AB - Lagmanshagav�gen 1 - 514 55 LJUNGSARP - SWEDEN