What does a GT triple pipe look like inside?

[advant63]

as requested.


the pipes are thick as tank armour. it's hard to believe they would rot out so badly or need the mesh to cut any resonance. the centre partition is between the two scallops in the uncut section.
another thing i learned today:
my existing silencers are straight through but these are plugged between the rear ward two sets of holes, forcing exhaust out the centre set of holes and back in the rear set of holes, then past the packing and out the rear.

[Suzsmokeyallan]

Thats definately different in the frontal section of those 550 pipes than what Dave and i saw on those Buffalo pipes we opened.
I believe those were 74 models we cut open, and maybe they used the raised mesh on the rectangular plates for that year, or whatever year they felt like it
There definately wasnt such a large expanse of the mesh in the front at all,maybe they changed design ideas during the years of 72 to 77.
Well ok what didnt they modify slightly on all the parts i should really be saying.
That large mesh sheeting would tend to make the pipes note sound heavier and not so tinny, probably it was an effort to make the 550 sound like the Buffalos with a deeper exhaust note.
The original baffles have two sections in them where the flow is diverted out of the centre and back in via three sided flues. This would send the gases into the spaced chambers you see as the disks in the pipe and then back into the baffle as it moved further to the rear.
This creates a back pressure of sorts and silences the higher pitched sound waves.
Ive not seen a GT baffle youre speaking of that has a straight through flow design, technically thats a resonator youre describing there.

[tz375]

Is that a stock 550 baffle tube?

The 750, as Allan said, has sections where the gas flows out of the baffle tube into the chambers between the plates and then back into the baffle tube etc.

That pipe is clearly the front part of an expansion chamber plus the parallel belly section. "all" it needs is convergent nozzle and stinger and you are good to go.

In fact, thinking about it, the first baffle plate acts like a convergent nozzle with a 90 degree angle to flow so it would send back a short duration stuffing pulse that would only work at one rpm (or the harmonics).

Anyone got a spare single cylinder test mule 550 motor to play with?

OK so a set of JEMCO pipes would be cheaper and easier....

[Craig380]

Wow, thanks Advant63 for posting (and for cutting the pipe) ... that certainly answers my original question!

@ TZ375, on the 380s the baffles all seem to be perforated tubes with no "vents". However on the GT250s, the baffles did change, some models did have vented baffle tubes with vanes inside.

[jkevinlilly]

Thanks for the pics Advant. Life got in the way of my pipe disection project.

Kevin