Baffled - Racing / Track rules about exhaust systems

[Ductard]

Hi,

I have a motard (KTM 520SX) that was set up for the track by someone else. When I was working on it the other day I noticed that the muffler packing has been removed and the baffle is just kind of clanging around loose inside.

I was thinking about removing the baffle it altogether, but are their any rules about that for either track days or racing?

[csmutty]

I would put packing back in it. It will most likely run better with packing as it has a better amount of back pressure and will keep the exhaust valves slightly cooler.

[Rada]

Generally a tightly packed silencer will produce better power that an empty rattly can. Not to mention it quieter.

[Jewcati]

Hi,

I have a motard (KTM 520SX) that was set up for the track by someone else. When I was working on it the other day I noticed that the muffler packing has been removed and the baffle is just kind of clanging around loose inside.

I was thinking about removing the baffle it altogether, but are their any rules about that for either track days or racing?

Maybe the packing fell out when you endo'ed it at NYST!

[tls25rs]

There is a good chance the previous owner didn't intentionally remove the packing. It tends to blow out of the motard exhaust cans. I usually replace mine whenever I notice it is missing.

[OreoGaborio]

Maybe the packing fell out when you endo'ed it at NYST!

Osnap, that was him? At TTD? I watched that happen. It was awesome. SICK SUPERMAN!

[Ductard]

Maybe the packing fell out when you endo'ed it at NYST!

Osnap, that was him? At TTD? I watched that happen. It was awesome. SICK SUPERMAN!

What, you guys never hit that section of whoop-de-doo's on the outside of corner 11? I was on a friggin' dirt bike after all

Check out the go-pro footage in this dropbox link. I had the camera mounted under the bike behind the front tire, so you get a nice view of the terrain right before the bike does a complete end-over-end somersault and lands rubber side down. And if you stop the video ~0:32, you can see my shadow, completely parallel to the ground before I land in front of the bike. It's amazing how much time you have to think about how a neck brace wouldn't have been a bad idea when you're 5 feet off the ground headed in face-first....

Also, I went back last weekend and you can still see the 10 foot long, 12 inch deep canyon that my front tire made....almost saved it before I hit that mud...

https://www.dropbox.com/s/d6apjz3q1p...20520%20SX.mov

[Paul_E_D]

I believe that crash actually PACKED his exhaust, and everything else with mud. I've never seen such a muddy roadracer.

[Jewcati]

That was AWESOME! Great video!

What, you guys never hit that section of whoop-de-doo's on the outside of corner 11? I was on a friggin' dirt bike after all

Check out the go-pro footage in this dropbox link. I had the camera mounted under the bike behind the front tire, so you get a nice view of the terrain right before the bike does a complete end-over-end somersault and lands rubber side down. And if you stop the video ~0:32, you can see my shadow, completely parallel to the ground before I land in front of the bike. It's amazing how much time you have to think about how a neck brace wouldn't have been a bad idea when you're 5 feet off the ground headed in face-first....

Also, I went back last weekend and you can still see the 10 foot long, 12 inch deep canyon that my front tire made....almost saved it before I hit that mud...

https://www.dropbox.com/s/d6apjz3q1p...20520%20SX.mov

[Rada]

9.5 on the dismount!!!

[Pittenger5]

Da fuq?

[Chippertheripper]

I'd punch a sick baby in the face to rip a tard around nyst.

[Paul_E_D]

I'd punch a sick baby in the face to rip a tard around nyst.

It is a sublime experience, second only to ripping a 125GP bike around NYST...

[Chippertheripper]

I'm comfy on a motard. Notsomuch a lil zinger.

[Rada]

Riding a fucking Vespa around NYST is a good time. A tard looks like retarded fun..

[Kat_man]

I believe that crash actually PACKED his exhaust, and everything else with mud. I've never seen such a muddy roadracer.

+1

I think he spent half of the day cleaning the mud out of that bike. And he was covered head to toe in mud.

[Ductard]

I'd punch a sick baby in the face to rip a tard around nyst.

Hmmm...there's a lot of interest in taking a 'tard out for a spin. Maybe I should rent it out...not too easy to do a lot of damage to it...although (knock on wood) I haven't had to get it rebuilt yet...

Chip, the only time I'm in need of some sick baby punching is on a long flight, so unless you want to meet me at Logan sometime maybe we should work out another currency

[Ductard]

I would put packing back in it. It will most likely run better with packing as it has a better amount of back pressure and will keep the exhaust valves slightly cooler.

Ok, sold on that - maybe it will cut down on the backfiring when I let off the gas going into T8 at NYST.

Any suggesting for packing material? I've never done it before but I did a quick google search and it looks like there's 1) bulk fiber 2)fiberglass mat 3) steel wool 4) pre-formed pillow.

I'm not seeing a lot of guidance except that the bulk fiber is the most time consuming and the steel wool / pre-formed pillows are the most expensive, with pre-formed pillows being the easiest. It's suggested that performance will be similar with all.

That said, the expense is pretty negligible ($30 vs. $15) so should I just go with the pre-formed pillows? I don't have a lot of extra time to work on the bike so if it saves half an hour or so that would be great (it's stored at NYST, so I'm likely to get in after 10pm on a friday night and try to put it in then).

I guess one thing is if I buy the bulk packing, can I just "top it off" as it blows out or do you still have to do a full re-pack?