Scheduling Muffler Swap For Next Week

Mazer18 · December 11, 2008

I'm planning on having my Flowmaster Super 40 put on my truck next week. There's just a few questions I'd like to have an answer to before I do so.

First, is the only effect to factory warranty the muffler? I know GM isn't going to cover a Flowmaster muffler but say I take the truck in for service and they see it on there. That wouldn't void the remaining warranty on the rest of the truck, correct?

A question for y'all that have had a muffler swap done before: How long could I expect this to take? Would it be quick enough that I could stand there and wait or should I try to get a ride home? More than a day? I'm having this done in a town about 10 miles down the road so walking home isn't much of an option now in the middle of December.

The place in town that I was planning on having do the work just told me the other day that they don't do other "people's" mufflers. I guess "people" meaning Flowmaster. So I called around and found this guy in another town. When I asked him about a muffler swap he asked me what I meant by that. I told him just cut the stock muffler out and put a new one in. He said "WELL SURE!" So as long as he has the extra piping needed to fit the shorter Flowmaster into stock pipes then I'm planning on having this done next Tuesday or Thursday. I'll be sure to get sound clips for y'all.

fbachman · December 11, 2008

I'm planning on having my Flowmaster Super 40 put on my truck next week. There's just a few questions I'd like to have an answer to before I do so.

First, is the only effect to factory warranty the muffler? I know GM isn't going to cover a Flowmaster muffler but say I take the truck in for service and they see it on there. That wouldn't void the remaining warranty on the rest of the truck, correct?

A question for y'all that have had a muffler swap done before: How long could I expect this to take? Would it be quick enough that I could stand there and wait or should I try to get a ride home? More than a day? I'm having this done in a town about 10 miles down the road so walking home isn't much of an option now in the middle of December.

The place in town that I was planning on having do the work just told me the other day that they don't do other "people's" mufflers. I guess "people" meaning Flowmaster. So I called around and found this guy in another town. When I asked him about a muffler swap he asked me what I meant by that. I told him just cut the stock muffler out and put a new one in. He said "WELL SURE!" So as long as he has the extra piping needed to fit the shorter Flowmaster into stock pipes then I'm planning on having this done next Tuesday or Thursday. I'll be sure to get sound clips for y'all.

First, is the only effect to factory warranty the muffler? I know GM isn't going to cover a Flowmaster muffler but say I take the truck in for service and they see it on there. That wouldn't void the remaining warranty on the rest of the truck, correct?

Correct. The only warranty effect is the muffler, which, of course will be gone...

How long could I expect this to take? Would it be quick enough that I could stand there and wait or should I try to get a ride home? More than a day? I'm having this done in a town about 10 miles down the road so walking home isn't much of an option now in the middle of December.

For a good shop, expect 15-20minutes after it's up on the rack. That's what mine took. I stood there, BS d with em and waited.

That fm40 will be LOUD, with a LOT of resonance in the cab. I tried a Delta-FLow 50, and ended up selling that one to a buddy, and went with a Series 70 Big Block II. In my pre-Alzheimers age-range, the interior drone of the 50 was too much for my liking. But, this is a matter of personal preference and taste.

Yes, posted sound clips (before and after) are considered almost mandatory on the forum !!!!!!!

Mazer18 · December 11, 2008

I've been trying to watch a lot of videos of exterior/interior noise with Flowmaster 40's, 44's, and 50's. I like to hear a bit of that power sound inside the cab. I assume if I do end up not liking it, it can just be swapped for another muffler or back to stock just as easily?

fbachman · December 11, 2008

I've been trying to watch a lot of videos of exterior/interior noise with Flowmaster 40's, 44's, and 50's. I like to hear a bit of that power sound inside the cab. I assume if I do end up not liking it, it can just be swapped for another muffler or back to stock just as easily?

It can, of course. You may need to buy a second muffler and sell the first one. Ask the shop to give you the OEM muffler, and ask them to cut it off in sucha way that it COULD be re-attached. If they cut the old one off right at the muffler wall, it makes it much more difficult, if not impossible, to put it back on easily.

jhoff8487 · December 11, 2008

Grumpy Aero Guy covered all the bases really. To have my Magnaflow put in, it took maybe a half hour from when I tossed them the keys. As far as the warranty stuff goes, it should just be your exhaust system that is affected. The muffler by no means changes anything else(significantly) and doesn't matter because of that reason. You'll want to keep that stock muffler since someday, you might want to go back, and they cost a bundle to buy from GM. The list price, even on GMPartsDirect is crazy expensive.

Be prepared to hear it sound different. When I had my MagnaFlow put on I walked over the the dealerships next door and came back. They'd taken my truck off the rack and had it just sitting out in the lot. I went out there and started it up and boy, I was shocked. Let us know your thoughts and maybe a sound clip or two. I still need to do mine...

jhoff8487 · December 11, 2008

DOUBLE POST...

Zembonez · December 11, 2008

I've been trying to watch a lot of videos of exterior/interior noise with Flowmaster 40's, 44's, and 50's. I like to hear a bit of that power sound inside the cab. I assume if I do end up not liking it, it can just be swapped for another muffler or back to stock just as easily?

It can be swapped out easily. If you like loud, the flowmaster you mention will be fine. The other questions have already been answered (very well too).

Silverado4x4 · December 12, 2008

The thing I would worry about is how he is going to install the new muffler being welded in, is he going to install it butt to butt or sleave it like it should like say 3" OD to a 3" ID, If he butt welds it to the exhaust pipe after the convertor the welds will rust fast and leak, make sure he sleaves it.

Mazer18 · December 12, 2008

The thing I would worry about is how he is going to install the new muffler being welded in, is he going to install it butt to butt or sleave it like it should like say 3" OD to a 3" ID, If he butt welds it to the exhaust pipe after the convertor the welds will rust fast and leak, make sure he sleaves it.

I've got a 3" in/out muffler with 2.75" stock piping. Would that setup require a sleeve weld or could it still be butt welded?

I know I'm paying for it and it's my truck but I still don't like giving the impression that I'm trying to tell him how to do his job. Would the size differences in muffler diameter to pipe diameter perhaps prevent any problems?

Zembonez · December 12, 2008

The thing I would worry about is how he is going to install the new muffler being welded in, is he going to install it butt to butt or sleave it like it should like say 3" OD to a 3" ID, If he butt welds it to the exhaust pipe after the convertor the welds will rust fast and leak, make sure he sleaves it.

I've got a 3" in/out muffler with 2.75" stock piping. Would that setup require a sleeve weld or could it still be butt welded?

I know I'm paying for it and it's my truck but I still don't like giving the impression that I'm trying to tell him how to do his job. Would the size differences in muffler diameter to pipe diameter perhaps prevent any problems?

As long as there is a good 1/2 inch or more of overlap at the joints and they are welded tight, I think it will be fine. My shop had some sort of zinc / aluminum exhaust paint in a spray can (rattle can) that he used on the welded joints. It hasn't been on there too long but it has held up to the heat and still looks like it did the day he did it. The aluminized tubing should last 5 years in a caustic environment... maybe more.

Mazer18 · December 13, 2008

I went on down today and checked everything out with the guy at the shop. He looked at it and said everything should be OK. The only problem he said would be fitting new pipe for the shorter Flowmaster muffler. I don't know if he makes the new pipe himself or what though because he was saying how it is a totally custom shop and he said it would take about half a day and $50.

Anyway, I'm scheduled for Tuesday morning and should have my truck back to me by lunchtime. I'll try my best to get video/sound clips up. It'll be my first time posting a video so I'll have to try to learn how to do it first.

Thank you all for your help. I appreciate it so much.

fbachman · December 13, 2008

I went on down today and checked everything out with the guy at the shop. He looked at it and said everything should be OK. The only problem he said would be fitting new pipe for the shorter Flowmaster muffler. I don't know if he makes the new pipe himself or what though because he was saying how it is a totally custom shop and he said it would take about half a day and $50.

Anyway, I'm scheduled for Tuesday morning and should have my truck back to me by lunchtime. I'll try my best to get video/sound clips up. It'll be my first time posting a video so I'll have to try to learn how to do it first.

Thank you all for your help. I appreciate it so much.

The half day surprises me... the $50 seems pretty reasonable. I think my shop charged me the exact same. CAR-X wanted $135 just to put the muffler ON, assuming I supplied it...

They put a section of pipe on mine too. FM was about 4" - 6" shorter than the stock muffler, if I recall. That OEM muffler was a monster.

The 50 was even shorter than the 70... LOL (the 70 is quite a bit beefier than the 50)

Mazer18 · December 13, 2008

I'm not sure if the half day is because they are just that custom or what. I don't mind the half day though as long as it's done correctly. I'm off work that day anyway so I'll get to mess around with a new muffler .

The stock muffler definitley is a monster. I think I measured it at something like 21"-23" not counting the inlet and exit.

When I get my muffler put on will I have the "true" sound from the first startup or will there be a break-in time before it sounds the way it was build to?

fbachman · December 13, 2008

I'm not sure if the half day is because they are just that custom or what. I don't mind the half day though as long as it's done correctly. I'm off work that day anyway so I'll get to mess around with a new muffler .

The stock muffler definitley is a monster. I think I measured it at something like 21"-23" not counting the inlet and exit.

When I get my muffler put on will I have the "true" sound from the first startup or will there be a break-in time before it sounds the way it was build to?

In my case, the sound was there with the muffler. As you drive some, it will "burn in" a bit, and the note will change a LITTLE... but it will "be there" as you say, on start-up.

again: DON'T FORGET THE SOUND CLIPS..... ( )