Amfab

I'm doing a set of LPMMs. The pipe is 1.75 and I placed the pipe a little further down than LPs.
Before I go and grind the holes and weld, can anyone think of any reason; heat, clearance, or any other, why having it down a little further would be a problem?

Its a little over an inch off the muffler body. I cant think of any problems, other than maybe it will be a little harder to get the welder in there.

The first one just ended up there and it looked good so I did the other to match.

TIA

993_Pilot

That's the only reason that I can think of. Good Luck.

epj993

It might be a tad more difficult to weld, but probably not an issue for a good welder. Otherwise, it looks great

cowtown

I've got mine even closer to the can than that. It's fine.

Amfab

Thanks for the quick response guys. Tomorrow I'll weld them in...oop I mean cut the holes first then weld them in

Garth S

Nice work on the saddle cuts!
For what it's worth, from there, the muffler pipes were scribed and the center cut out with a hole saw ... then the dust flew with a die grinder to trace within a 1/16" of the scribe to get the max opening and a strong weld.
You'll love the result

BobbyT

Mine were RSR'd already, so I did a one-inch LPMM. That was too conservative--it makes very little difference in the sound. I may do them over with larger pipe.

Amfab

Thanks Garth, the saddle cuts were a very complex compound angle interaction.

This is how I made the cuts, maybe this is the standard way, i dont know I just kinda made it up as I went along

Get 2 and a half feet of Stainless tubing and some 80lb card stock or other heavy paper
Cut about 10 inches of stainless tubing for each muffler (measure first the pipe lengths varied very slightly from muffler to muffler for my set)
Cut a 3 inch piece of stainless tubing off what is left over
Deburr and radius the cut edges of the tubing so they are smooth
Get some heavy card stock and roll it tight around the 10 inch piece, tape it securely and slide the stainless tube out
Cut the paper tube you have just created in half and use scissors and to trim the paper pipe halves to mate well with the inlet pipe and the outlet exhaust pipes on the muffler
Cut each half down 1/2 inch or so on the non saddle cut side so the two paper pipe halves together are about an inch too short to span the gap
Join the 2 halves together with the 3in piece of stainless by sliding the two halves over it - This allows rotation of the two ends and you can slide the length longer or shorter to fit.
Once it is making a nice fit, wrap another piece of cardstock over the center where the 3in tube is slightly exposed and tape this tube in place to hold the 2 halves firm
Slide the 10 inch stainless piece into the paper tube and force the 3in piece out.
Take a sharpie and trace the outline of each end of the paper tube onto the 10inch stainless tube.
I used a cut off tool to get close to the sharpie line, and did final fitting with a die grinder,
I dont know how else I could have got anywhere near having a tight fit. It still isnt that great everywhere.
Again, the manufacturing tolerances on the original mufflers aren't that great, so I had to make a new template paper pipe for each side as they were slightly different.