OEM Exhaust Mod-Cutting the Stock muffler open
 

So, @manic and I've seen the "oem exhaust mod" mentioned here a few times, and its relatively popular among the BMW crowd-so why not try it ourselves?

The MAIN purpose of this is to try and free up some sound-any power we gain would just be icing on the cake (and once we have a final version of this mod done, we can do a before/after on the dyno to see if we get any free hp!).

Here's a quick teaser of us cutting it open!

[ame="https://www.youtube.com/watch?v=2AX7IVXaQbA"]FRS Muffler Cut Open-Teaser for OEM Muffler Mod - YouTube[/ame]

Stay tuned for progress!

reserved for updates

*Hype intensifies*
http://i.imgur.com/YYfXLjz.gif

hmmm... Interesting application for a motorcycle helmet. I usually just throw away my outdated, but not crash-tested, helmets. Maybe I'll just keep them from now on for this kind of use.

haha, right? Our tech was like, "uh you know I have safety glasses or the welding mask you can use..."

Like the noble native americans, we use every part of the modbargains.

There's a similar thread I remember from back in the day.

http://www.ft86club.com/forums/showthread.php?t=41620


Curious to see your final mod

Yep, that was our inspiration.

But it's a hard hat, hearing protection, eye protection, and welding shield (if you use the tinted visor) all in one. And instead of looking goofy in all that safety equipment, you look cool. :D

If your bike helmet is tinted dark enough to be safe when welding, it sure as heck is NOT safe for riding.

There was definitely plenty of enthusiasm. When we realized that we couldn't reach the pipes we wanted to cut with the saws-all, we got a little carried away and opened it like a Christmas present. Should still be easy enough to weld shut.

Well, performance gains would definitely be minimal if any. The primary restriction is still the headers. This should however produce more sound theoretically. Now the decision is whether we try to seal the holes we've exposed or leave them be. I think to actually get a significantly better sound, the holes would have to be sealed and muffler packing placed into the side chambers.

The primary goal is to keep the exhaust gases in that central chamber while minimizing the amount of additional welding. That way, at least we reduce the amount of baffling the gases have to go through.

Is this an i'm just bored and i have a grinder+motorcycle helmet let me hack up my oem muffler thread ....if so subbed.

Yeah, but shields can just be swapped. But, I don't know if I would use a helmet for riding that is probably pitted and burned from welding and grinding sparks and scraped up from being thrown around in a shop. That's why I would use an old outdated helmet instead of a $600 usable one...

I feel like this is how the aftermarket mod industry was founded!

We support Charles and his motorcycle-helmet antics! :bonk:

I did this mod yesterday.

Cut the center 4" section between the separating walls weld spots, chopped out the center section pipes, and welded it back shut.

Sounds great, you really only hear the difference under acceleration. Otherwise sounds mostly stock, maybe 15% more growly.

High recommend for anyone wanting a LITTLE more than stock sound. $150 for a welder and welding helmet, and about $10 in bent sawsall blades.

I'd recommend this though:

- Cut open BOTH SIDES of the canister
- get 10" long sawsall metal blades.

That way you can not smash your fingers and hands and destroy a bunch of blades trying to cut out the center pipes.

And, added bonus, you get to learn welding a little more if this is a first time or you.

Got any pictures?


humfrz

pics
 

No, you just cut a big "U" on both sides in the center as in other pics, then a long metal blade wont smack into the muffler case and bend. its 2x the welding, but well worth it.

TRUST ME, it's a PITA to cut out the center pipes if you only open up one side of the muffler.