How many miles do muffler last before they fail?
11-30-2011, 03:59 PM
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How many miles do muffler last before they fail?
Well, maybe not fail but lose its efficiency? Lose its ability to "muffle." I'm trying to convert my track car back to a semi-streetable state so I don't have to trailer the car to events.
At first, I thought my car is so incredibly loud due to a completely gutted interior (all insulation and carpet has been removed). But then I found pictures on the forum (with only the carpet removed) that showed how the car has barely any insulation in the rear to begin with. I plan to add Dynamat and RS carpet kit to help dampen some of the noise.
So that leads me to think, has my muffler failed? What is the average life of a muffler before it needs new fiberglass repack? My current exhaust setup is a fabspeed race headers straight to a dual inlet/outlet muffler.
In the current state, the car is unbearable. I wear earplugs when I drive to/from events. I have to keep the car under 2600 rpm on 6th gear or the car just drones. Surprisingly though, at 3200rpm the droning goes away (but at those speeds, I'm asking for a speeding ticket).
At first, I thought my car is so incredibly loud due to a completely gutted interior (all insulation and carpet has been removed). But then I found pictures on the forum (with only the carpet removed) that showed how the car has barely any insulation in the rear to begin with. I plan to add Dynamat and RS carpet kit to help dampen some of the noise.
So that leads me to think, has my muffler failed? What is the average life of a muffler before it needs new fiberglass repack? My current exhaust setup is a fabspeed race headers straight to a dual inlet/outlet muffler.
In the current state, the car is unbearable. I wear earplugs when I drive to/from events. I have to keep the car under 2600 rpm on 6th gear or the car just drones. Surprisingly though, at 3200rpm the droning goes away (but at those speeds, I'm asking for a speeding ticket).
11-30-2011, 04:03 PM
#2
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I've never seen inside one of the mufflers so I don't know whats in there but I find it hard to believe they contain fiberglass or anything that was degradable. Maybe a weld has broken loose and you've lost some baffling performance. Perhaps its time to send them to FDM and get a Stg2 or 3 system. If the noise is bothering you I'd recommend the 2's.
Perhaps its your cat thats bad. Those do wear out.
Perhaps its your cat thats bad. Those do wear out.
Last edited by CorrdoBrit; 11-30-2011 at 04:53 PM.
11-30-2011, 05:11 PM
#4
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Well heck with no cats and a single muffler.... obviously it's going to be pretty loud. It's probably filled with ss, not fiberglass. And if it's a dual-in dual-out, then it's probably an x-pipe internal configuration (e.g. Magnaflow) which means there's not a ton of muffling going on anyways.
Is installing proper mufflers impossible or something?
Is installing proper mufflers impossible or something?
11-30-2011, 07:01 PM
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You are correct in your last statement. The headers comes straight out towards the bumper, leaving little to no room for any other kind of muffler setup. I do not want to start cutting up my headers.
Looks like this:
Looks like this:
11-30-2011, 08:36 PM
#6
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Yeah, you're pretty much stuck with that then unless you put stock heat exchangers back on. I found that most of these 2-in 2-out mufflers have x-pipe guts, meaning that it's basically a straight-thru muffler. That's what I installed when I ran the p'motive turbo setup. Low restriction but pretty loud.
I can't imagine you'd need to replace it (re-packing would be cost prohibitive since new they're like $200). And even with fresh packing, you won't solve the droning.
I can't imagine you'd need to replace it (re-packing would be cost prohibitive since new they're like $200). And even with fresh packing, you won't solve the droning.
11-30-2011, 08:49 PM
#7
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p.s. here's an example ($119):
http://www.streetimports.com/product...ls.asp?id=1051
You can see pretty much straight through it. And it's not like the packing is highly exposed.
http://www.streetimports.com/product...ls.asp?id=1051
You can see pretty much straight through it. And it's not like the packing is highly exposed.
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12-01-2011, 02:10 AM
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Thx for the link Eric, maybe I'll try another brand's muffler out. Magnaflow/ Flowmaster also sell something similar for around $1-2bills. If there is no improvement, I'll just put the old one back on. Does Fabspeed make their mufflers in-house?
12-01-2011, 11:30 AM
#10
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You're going to spend a LOT of money to swap mufflers, so I wouldn't do that unless you're absolutely sure it'll solve your issues.
12-01-2011, 12:37 PM
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Hi vanguard, our RSR exhaust is a dual inlet dual outlet muffler with an open center chamber and a perforated core with stainless steel packing. After much use and time, the muffler packing goes through a burn in process where it starts to settle and pack in, so you notice sometimes the exhaust gets a little louder. So the muffler system is probably fine, its just the packing has settled and increased the noise. If you want to tone the system down a bit, you can add sport cats to it which will really help bring the sound down or put in vortex cones which are like perforated ice cream cones. A shop can put them into the exhaust somewhere to create a little more restriction and quiet the car down. We designed this muffler to be on the quiet side compared to other muffler designs with an X inside which are louder. Yes the mufflers are assembled in house, but certian stamped end caps and SS packing are brought in. Let me know if you have any other questions.
Thanks,
Thanks,
__________________
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John@Fabspeed.com
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155 Commerce Drive Fort Washington, PA 19034
www.Fabspeed.com
Porsche Performance Specialist
John@Fabspeed.com
215-618-9796
Fabspeed Motorsport USA
155 Commerce Drive Fort Washington, PA 19034
www.Fabspeed.com
12-01-2011, 09:52 PM
#13
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Take off all that you have until such time as you are going on to the track. But for the street......
Put the stock heat exchangers back on:
Get a set of Fabspeed X pipes with 200 cell cats
Put on Fabspeed MaxFlow or a Fister DiPietro Stage i or Stage II mufflers. Both Fabspeed and FD Motorsports are Rennlist supporters, great people too. The MaxFlows are new, the FD Motorsports are modified stock mufflers.
I have a sound clip of this if you PM me an e-mail address...too large to attach.
Before going to my present SuperCups a pal gave me (The price was right) , I had Fab Speed X pipes. 200 cell cats with FD Motorsports Stage I mufflers (Their quietest). Passed 92 dB sound at laguna Seca.
Now stock heat exchangers are hooked up to Fabspeed X pipes, Fabspeed 200 cell sport cats and Fabspeed Super Cups. I just wanted the most noise I could get...love noise.
The sound is awesome, and moderately street tolerable if you keep the RPMs to no more than 2400. I did a street run today...awesome sound, but far from quiet. At WOT, oh lady, but you are then ticket bait!!! You know I had some 2nd gear WOT...couldn't help myself.
Put the stock heat exchangers back on:
Get a set of Fabspeed X pipes with 200 cell cats
Put on Fabspeed MaxFlow or a Fister DiPietro Stage i or Stage II mufflers. Both Fabspeed and FD Motorsports are Rennlist supporters, great people too. The MaxFlows are new, the FD Motorsports are modified stock mufflers.
I have a sound clip of this if you PM me an e-mail address...too large to attach.
Before going to my present SuperCups a pal gave me (The price was right) , I had Fab Speed X pipes. 200 cell cats with FD Motorsports Stage I mufflers (Their quietest). Passed 92 dB sound at laguna Seca.
Now stock heat exchangers are hooked up to Fabspeed X pipes, Fabspeed 200 cell sport cats and Fabspeed Super Cups. I just wanted the most noise I could get...love noise.
The sound is awesome, and moderately street tolerable if you keep the RPMs to no more than 2400. I did a street run today...awesome sound, but far from quiet. At WOT, oh lady, but you are then ticket bait!!! You know I had some 2nd gear WOT...couldn't help myself.
12-01-2011, 09:55 PM
#14
Here are a couple of posts of what the internals in a 993 muffler are. I've highlighted (bold red) the part in the first post where Leland describes the stuffing materials. It's been a long time since I've read through this stuff, but I recall that some members had indicated that some of the stuffing material began to deteriorate and blew out of the muffler.
EDIT: To see the picture in the first post below, you'll need to click on the ">" immediately to the right of "Originally posted by Leland Pate" to pull up the original post. For some reason, the picture didn't copy with the rest of the post.
EDIT: To see the picture in the first post below, you'll need to click on the ">" immediately to the right of "Originally posted by Leland Pate" to pull up the original post. For some reason, the picture didn't copy with the rest of the post.
Well, it seems many have voiced the need for a muffler that is a bit louder than RSR's but not to the extreme of the supercups or the like. I have formally volunteered to be the lab rat for this experiment. Tonight I cut open a muffler and am now contemplating how to go about modifying it. This is totally hit or miss, I know. I may end up worse off than before.
Here is a picture of a muffler cut open I swiped from a recent thread. I'd like some imput as to how best to go about modifying the pipe.
You can see the inlet and outlet and basically how the gases flow through the muffler. What you can't see in the photo is steel wool wrapped aroound the perferated pipe and matted against the perferated section of the inner wall. The rest of the void on the 'outside' of the wall was filled with fiberglass crap (I know because I'm itching from head to toe). The "wall" I'm refering to is the piece that seperates the two pipes on the back of the muffler as pictured. The space behind the wall was open.So, after looking at what I got I have a few ideas. I have to be careful not to make a cut that is irreversable only to find out it sounds like crapola. I'm thinking a stepped approach might be best. For instance, I can re-wrap the perferated pipes with steel wool and loosely repack the can with new fiberglass and put it back together. I could then tack weld a coupple spots to hold everything together. Then I could temporarily use some metallic tape to cover the unwelded gap and go for a test drive. This way if it is obvious they are no good, I can easily grind the tack welds and try something else.
I've looked long and hard at the factory setup and am having a hard time figuring out how to rearrange or modify the pipes for a better sound. I want to start out modest and get more drastic as I try the easy things first.
So, now I open up the floor. If you were in my shoes, what would you try?
Feel free to draw arrows and circle bits on the photo to use as visual aids for your ideas.
Let 'em rip!
Here is a picture of a muffler cut open I swiped from a recent thread. I'd like some imput as to how best to go about modifying the pipe.
You can see the inlet and outlet and basically how the gases flow through the muffler. What you can't see in the photo is steel wool wrapped aroound the perferated pipe and matted against the perferated section of the inner wall. The rest of the void on the 'outside' of the wall was filled with fiberglass crap (I know because I'm itching from head to toe). The "wall" I'm refering to is the piece that seperates the two pipes on the back of the muffler as pictured. The space behind the wall was open.So, after looking at what I got I have a few ideas. I have to be careful not to make a cut that is irreversable only to find out it sounds like crapola. I'm thinking a stepped approach might be best. For instance, I can re-wrap the perferated pipes with steel wool and loosely repack the can with new fiberglass and put it back together. I could then tack weld a coupple spots to hold everything together. Then I could temporarily use some metallic tape to cover the unwelded gap and go for a test drive. This way if it is obvious they are no good, I can easily grind the tack welds and try something else.
I've looked long and hard at the factory setup and am having a hard time figuring out how to rearrange or modify the pipes for a better sound. I want to start out modest and get more drastic as I try the easy things first.
So, now I open up the floor. If you were in my shoes, what would you try?
Feel free to draw arrows and circle bits on the photo to use as visual aids for your ideas.
Let 'em rip!
Here is the picture for the comparison. The by-pass tube is almost an after thought from Porsche, the very early 993 mufflers do not have this by pass tube at all, I believe it was added after so many complaints from Porsche owners that complaint about the sound, and Porsche continued with this approach by adding a large diameter pipe to give more sound, thus the motor sound option.
Interestingly enough 993s headed for Swizerland do not have the by pass tube at all, and also the RS 3.8 muffler does not have this tube either.
A plasma cutter is a must have if you like to cut open stuff, it is amazingly fast, clean and efficient way to cut metal open. Also a TIG welder would be nice too to put them back together nicely. :P
Interestingly enough 993s headed for Swizerland do not have the by pass tube at all, and also the RS 3.8 muffler does not have this tube either.
A plasma cutter is a must have if you like to cut open stuff, it is amazingly fast, clean and efficient way to cut metal open. Also a TIG welder would be nice too to put them back together nicely. :P
12-02-2011, 04:19 PM
#15
Burning Brakes
Alex is dead on about the packing "settling" and the mufflers becoming louder with time. Correct me if I am wrong, but the Fabspeed perforated tubes are probably wrapped with a layer of stainless "steel wool" and then packed with a material like Basalt. The chances that this packing has degraded to the point that it is no longer working (basically meaning it fell out) is very very slim.
