2.5" Magnaflow kit install

[sigtauenus]

I finally got around to installing that 2.5" kit that a bunch of us bought 2-3 years ago.

I wanted to clamp it in position to mock it up, then once everything was in place, pull it out and weld up the seams.

I've seen several horror stories of guys taking this to a local exhaust shop for the install and it not going well, ie, bent and crimped pipes, non-stainless tubing used to hook up to the headers, tips too far out or too low, etc.

My plan may take some work, but with me doing the cutting and a neighbor doing the welding with stainless rod, I can have control over the fitment. I also thought it would be easier to weld all the way around the pipe without splattering the underside of the car (which is freshly detailed) with the exhaust off the car.

Problem I have though, is that the first clamp I tighted down never squeezed the pipe enough to hold tight. This was the x-pipe piece to the muffler that I started with. The bolt on the clamp snapped and right now its stuck on there tight enough to not come off the muffler end of the pipe, so I have to cut it off, but it never got tight enough to hold the muffler from freely rotating on the pipe. If I could have just gotten it tight enough to hold in place, even if I could still rotate it with some force, that would have worked to mock up the mounting brackets and cut the pieces for the headers.

Did anybody do the install themselves, and if so, did you get the clamps to work? If so, did you position the clamp on the end of the outer piece, ie where there are some slits cut in the pipe, or further up the pipe where the pipe was not slit?

Any other tips for the install?

 

[lethal289]

i positioned the clamps on the slits. Everything tightened down just fine for me. As added insurance though, i had the car at a stainless exhaust shop while i was getting custom pieces bent from HIPO manifolds to the 2.5" magnaflow kit, i had him tack every joint just to make sure nothing comes apart without some effort.

 

[johnpro]

That's a nice kit, although, I was never quie sold on the sound of the mufflers. We had that kit on my daughter's '69. I use a very good exhaust shop, that built the exhaust for my '69. The kit was SOOOOO far from coming close to fitting on the '69, that I just took the entire thing to the exhaust shop and told them to bend it, cut it and weld it up. They did a fantastic job.

 

[sigtauenus]

This may be a dumb question, but do exhaust shops weld it up with it hanging on the car? If so, how do they keep from spattering weld all over the underside of the car?

 

[MarkStang]

I aligned the slit of the clamp with the slit of the pipe just like the tie rod ends for toe in and toe out. I do not think the tie rod clamps would tighten properly either if the slits are not lined up.

 

[sigtauenus]

I found a local speed shop, 2 miles from my house, that will do the install for me at $115 per hour and then do a dyno tune for $250 plus parts (jets, etc).

Seems like a plan, as I haven't touched the car in 6 weeks and summer is going to fly by. If I want a chance at driving the car this season, I'm going to have to farm out the work or accept waiting another year...

 

[johnpro]

This may be a dumb question, but do exhaust shops weld it up with it hanging on the car? If so, how do they keep from spattering weld all over the underside of the car?

The place I use, welds it with the pipes on the car. Someone that can weld well, won't splatter on the car. Even a really bad welder shouldn't be splattering that far away.

 

[SELLERSRODSHOP]

i agree, the only way the welding would damage the bottom of the car were if it was upside down. the splatter is going to fall down to the ground. if you are concerned, why not tape some pieces of cardboard to the floorpans over the areas near the joints to be welded.
if you want to take the pipes off the car to weld, postion everything in place on the car & use a sharpie to mark alingnment points on the joints. that way if something moves during disassembly of transport, it can easily be moved back to the proper place by lining up your marks then welded permanently. a little lacquer thinner will clean up the marks afterwards.

 

[opentrackerSteve]

I have that on my car. Reason John didn't like it is he kept hearing it from my car....

Clamps worked ok. I re-tightened them all after some seat time. like it, and it's DONE.

I used JC Whitney collectors and stainless flex pipes (woven) for the interface between my Doug's headers and the Magnaflow kit...