Triumph Rat Motorcycle Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
Well, I just got my 'salvage' '04 Thruxton up and running three weeks ago. It took a month to fix all that was smashed/bent/missing and I only got in four rides before the snow started to fly up here in Ontario. Man, I love this bike - fixing it up was fun and a learning experience - but looks like its going to be winter storage for me. Looking to do some winter mods (I got the wrenching bug) especially seeing if I can get some sound out of the exhaust. I've read the forums on Bonneville bafflectomy but have not seen anything (pictures would help as well) on modifying stock exhaust on the Thruxton. Anyone out there in cafeland got ideas??
 

·
Registered
Joined
·
4,870 Posts
Just grab your angle grinder and a sanding disc.Lightly go round and round on the end cap,and don`t stay in one place too long or it will blue.In a couple minutes the end cap will be loose,pull it and the little tube free and that will open the can to all sorts of burning,drilling,pounding and general gutting fun.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #3
Thanks for the advice - any details on how to or how much to remove - I'm looking for more of a TOR sound not preds??
 

·
Registered
Joined
·
4,870 Posts
There are several chambers inside,connected by small diameter tubes.Just perforating the various baffles that separate the chambers will increase the sound level.Once you get the end cap ground away,there is a steel cone that is the end baffle.I cut a couple out with a torch,very messy looking. But the last set I did,I used a pipe reaming stone in my angle grinder.Its about 1-1/2" od,shaped like a cone.It left a very clean hole into the last chamber,so You can see the work area inside the can.A big drill or my favorite,an angle cut piece of 3/4" pipe,can be hammered through as many baffle plates as you need to get the sound you`re after. Oh,and try not to tear into the perforated steel liner that holds the fiberglass against the outer skin of the can.You need that liner and `glass to keep a mellow tone.
 

·
Registered
Joined
·
14 Posts
Hey Skidman. I wanted to get some mufflers to replace the stockers on my '06 but I couldn't afford the $500 or so to get some. I thought I'd try something with the factory mufflers and if I messed them up too much I would then go to plan B. First,I removed them and ground the outlet ends off with my bench grinder,rotating them to keep the grinding as even as I could.After a bit of grinding I was able to remove the short piece of tube at the rear of the muffler.This grinding didn't blue or chip the chrome and with some very minor filing the ends looked real good.The opening ended up being about two inches or so. I used a wire made into a hook to pull out the steel wool inside.I then used a foot long tapered punch/pry bar tool to punch holes in the baffle plates in each end.I piled up a thick bunch of rags and leather gloves in a plastic bucket to set the mufflers on while I pounded the holes in them.I hoped this would absorb the shock of pounding the punch and not distort the opposite ends and it worked well.I sharpened the punch and it worked great.The baffles are quite soft and were easy to punch holes in.No specific pattern,I just punched as large and as many holes as possible in them.They're dark in there and I figured nobody would see them so I didn't care if was pretty.I tried to keep things even and equal though.In the outlet end they were roughly about 9/16 inch holes and in the inlet end about 5/16 inch.About a dozen holes in each end.It runs so much better now.It sounds so sweet I don't even want to get aftermarket pipes anymore.They roar accelerating,gurgle and crackle decelerating and just make the bike so much more fun.It sounds like a big engine now,even just idling. Everyone loves the sound.I had my son take it past the house a few times to hear it go by and I knew I'd pulled it off. It's better than I'd dreamed it could be and cost nothing.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #6
Rennfield and Rodburner - thanks for the excellent advice. I too figured that if I screwed up the stock parts, I'd get the TORS anyway. I'm looking forward to my winter project - I'll let you know how it goes and sounds. Did you have to rejet or shim the carbs after?
 

·
Registered
Joined
·
4,870 Posts
You don`t HAVE too,but even a bone stock Bonnie will run better with a bigger main jet. A 115 is a good start.
 

·
Registered
Joined
·
14 Posts
My engine is all stock,I just did some of the simple mods I've learned from the great forum members here. I've removed the baffle in the airbox and opened up the inlet to the air filter.The air injectors have been removed and the main jets replaced with a #130.Stock pilots still. I ride at 1000 to 2000 feet above sea level and I think it can handle bigger mains than that. Next year I'll try some.
 

·
Registered
Joined
·
31 Posts
Holy resurrected thread batman!

I was wondering if anyone has preformed the bafflectomy on any of the new '09 EFI thruxtons and if the process is still the same? I'd like to make the bike sound like a bike and not a sewing machine. Pics would be awesome!
 

·
Premium Member
Joined
·
7,036 Posts
poor mans bafflectomy

I was wondering if anyone has preformed the bafflectomy on any of the new '09 EFI thruxtons and if the process is still the same? I'd like to make the bike sound like a bike and not a sewing machine. Pics would be awesome!
Hi Klantz, FWIW I have some cheap 2009 EFI Thruxton mufflers I picked up off eBay but that are now mounted on my 2006 (carbed) model. Last night I took a small holesaw about 15mm diameter (bit over 1/2 inch?) and using a long shanked coach head bolt instead of the drill bit that runs through the centre of the holesaw, managed to poke it up the hole at the end of the muffler to drill a hole through the last baffle. It was late and raining so didn't get a chance to ride it but firing up in garage it was a definitely louder than stock. Drilling took about 20 seconds per muffler. NB I did not remove the back of the muffler - the only hole is inside so from outside it looks stock.

I may be a bit off with holesaw size (I am at work). If you are interested I will send pictures and what it sounds/performs like later tonight.

Oh yeah - my first post! Love the forum, have been lurking a while.
 

·
Registered
Joined
·
31 Posts
That sounds exactly like what I need right there... Maybe if I just used me a "good 'ole pokin' stick and got in there" I could get to the back couple of baffles through the current hole without crinding the whole rear plate off.
 

·
Premium Member
Joined
·
7,036 Posts
more on poor mans thruxton bafflectomy

Due to rain, getting home late and alcohol haven't had a chance to try my bafflectomy out since I did it but attached are images of the tools I used. NB the hole saw is actually 19mm (3/4in) not what I said earlier. It is just right to fit in existing muffler outlet.

It is a 'De Walt' hole saw with 19mm cutter. I removed the standard drill bit and used a long coach bolt as pictured instead (see 3rd picture)

The first muffler took literally 10 seconds from start to finish to drill, the second required a bit of jiggling - there is a pipe from the internal baffle (offset to one side) that extends rearwards and on the second muffler intruded 2mm across the path of the saw as I inserted it. (On the first muffler, the saw cleared that pipe fine).

Took about a minutes worth of jiggling and drilling to get the hole saw past the pipe on this one bit but once done and the saw snugly against the baffle, again it took about 10 seconds to drill. Worth shinning a torch down the pipe to see if the tube fouling the saw is going to be an issue (or use a narrower saw to get past it easier).

Result is a 19mm (3/4in) hole in the internal baffle on the centerline of the muffler. No change to external appearance of the muffler and on idle in garage was certainly louder than stock but hard to comment on the 'tone'.

If rain eases off tonight will try and take it for a run and see if I like it!
 

Attachments

·
Premium Member
Joined
·
7,036 Posts
poor man's bafflectomy

If rain eases off tonight will try and take it for a run and see if I like it!
just took it for a quick blat - it is definitely louder, barks and chortles quite pleasantly but it is not over the top. Not a real deep sound - but not tinny either.

Hard to tell but I got the impression the motor was reving and pulling a little more freely (but that is very subjective - being able to hear the exhaust note may make it just seem like it has more go!).

I will play with jetting/mixture but at the moment like the sound. Cheap, quick mod (if you are willing to sacrifice the stock mufflers).
 

·
Registered
Joined
·
31 Posts
just took it for a quick blat - it is definitely louder, barks and chortles quite pleasantly but it is not over the top. Not a real deep sound - but not tinny either.

Hard to tell but I got the impression the motor was reving and pulling a little more freely (but that is very subjective - being able to hear the exhaust note may make it just seem like it has more go!).

I will play with jetting/mixture but at the moment like the sound. Cheap, quick mod (if you are willing to sacrifice the stock mufflers).
Thanks for the update, I have been thinking this one over and I might go with some cheap slip ons in case I ever want to take it back to stock.
 
1 - 15 of 15 Posts
Top