550 exhaust...so I got bored today

Well I got bored today and started taking the 550M exhaust system out. What a pain. I was going after the central muffler and the only way to get it out was to make enough space by taking off the bumper! Anyway, here are some datapoints:

550M
Central muffler weight 25lbs
Rear muffler 34lbs each!


I'm going to weld up some straight pipes to replace the central muffler tomorrow. I think I have to find another solution to the rear cans. It is just wrong to put back 68 unnessesary pounds back in the car. I'll post up some pictures later if you guys are interested.

 

Let me know what it sounds like,I think I might do the same.Are you going to bring the central ones to a local guy to make straight pipes as a replacement?Let me know what it cost you.Thanks.

 

FBB- For sure. Any idea on the rear mufflers yet? Make sure and try it with stock mufflers and the straight pipes to see how you like it. You can always try with the valves wired open to see if you like it better. If you are happy with that sound bypass the solenoid. Unfortunately 550 valves are closed at idle (575M valves are open at idle), so that tames the idle sound quite a bit.

Taz
Terry Phillips

 

No...I'm dangerous with cutting tools and a welder. So far it has cost me 40 bucks or so in pipe. I hope it sounds narly nasty loud and makes me some horsepower.

 

pics pretty plz

 

and sound file too, please!

 

Even so, the idle sound is very sporty. Certainly not loud but that comes when the valves open.

 

You forgot to mention all the whiney baby fussing you were doing before I started to remove the wheels so that we could get to the bolts.

Hahahahahaaa!!!!

 

But yes boys, those mufflers are HEAVY!!!

We actually actually took guesses as to how much they weighed.

Guess who was closest.

 

Or you can leave the central one in and replace the rear cans with straight pipes. That's what I did for a while. Then I also replaced the central one with FF's silenced X pipes, but it's now quite loud.

 

Yes I thought about leaving the central muffler but while straight through like a resonator it has this factory ovalized restrictive crimp in it for some unknown reason. It sounds not too loud with just the central. What was it like for you to drive it around with factory central only as a daily driver?

 

The rear cans seem to only silence the low rpm grumble while the central can seems to silence the higher rpm volume. So when I was running only the central can, it was louder than stock at idle but as you run up the rpm range the engine sound level seems to get disproportionately quiet. A strange sensation for me anyways. That's why I later opted for FF's silenced X pipes. Now the sound is nice through out the rpm range and engine revs much quicker to red line, which no doubt is due to removal of OEM oval restriction. I did not notice much loss of torque as there is plenty of it to start with.

 

OK so here it is on my race scale which is calibrated. Rear exhaust can 34lbs.

The central muffler/resonator is 25lbs.

And this is what it looks like out of the car.
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So because I was lazy and did not want to take the time to fabricate from mandrels I cut the shaped nose off the central muffler and the shaped pipe after the central muffler. I figured there was no way I would put the central muffler back and I could weld it back if I wanted to but why? Also, who would buy such a POS? No value so I cut it.

Then I cut a piece of 2.25" OD 23.75" long and TIG welded the old nose and the old tail to the new straight section.

It now weights 14lbs for both. I took out 11lbs of crap and a giant exhaust restriction. If you look back at the central muffler you can see the squished section just aft of the muffler.
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So here is my new set of straight pipes cannabalizing the ferrari ends. And a picture of where they go just aft of the cats and the final fitment on the car. I still have to put the bumper back on. I'm going to dinner now so I'll start the car tomorrow and report.
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FBB,

I think that was a great way to fabricate your straight pipes. It saved you some mandrel bending and welding for sure. Plus you didn't have to make new hangers and weld them to the pipes. I think you'll be pleased with the straight pipes and stock valved muffler set-up. If you have the chance, take a picture of the outlet end of your center muffler looking directly into the muffler body to update the one I posted of stephens unit. It would show just how much of a restriction that "squished section" produces.

Barry

Here's stephens' picture of the outlet restriction:
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FBB- Looks great. If I had any idea what to do with a welder, which I do not, that is what I would have done. I am much better with a fly rod.

I gave away my stock 575M rear mufflers, valves and all. Cannot believe your central muffler would have been worth more. Might be a market for the straight pipes, though, if you can find the end pieces.

Taz
Terry Phillips

 

alright! practice before I bring my car over

 

Do you think its possible to cut the center section out without removing the rear cans if you are going to use it as a donor for the ends?

 

I do not think you will have the room because you will need to move the intermediate pipe and cans rearward to slip in the center straight pipes. The length of the two slip-on ferrari lips are about 3" and you have maybe 2" to play with. So I would think you would have to at least loosen the bumper and slide it back on its bolts for that last inch. The other is how do you squarely cut the center section out? The front slipon is slanted and the rear had weld blobs on it so you can't use that slick muffler cutting tool with the carbide roller wheels. You will have to get a sawzall blade in there and it is difficult to be square because you want to be when you weld it to your straight section. My cut and weld are very precise. I used very little TIG filler rod infact . While the whole process is a pain it is easy just time consuming and of course it is hard for one guy because you need 3 hands and then cans are heavy and the bumper is heavy. So for part of the job a friend to hold things really helps. By the way the reason I reused the ferrari tail section is that looking into the pipe it is mandrel and not crush bent so the exhaust velocity should be unchanged. I think I'll go finish this project and take the car for a drive.

 

I'm thinking maybe put a V-band clamp in the new pipe section that way you could slip the pipes in and join them with the V-band clamp.

 

Please don't flame me too much for a <gasp> pcar picture - it's only here to make a point. Which is ... 550/575s are reaching the point where not-well-heeled DIY'ers like me can consider them. I couldn't see paying $4k for a 911tt exhaust, so I worked with a fabricator buddy to create this one. I designed it and spun wrenches, he cut and welded the stainless. We also made straight pipes that could be quickly swapped in place of the lower mufflers. I got a lot of compliments on the sound.

Jeff
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Jeff- That looks very good. Your friend is a pretty handy welder. Looks like a lot of mixing going on where those pipes meet. Should have a very nice burble.

Taz
Terry Phillips

 

Really a nice job in design and execution.

 

+1 - great job!


Onno