Anyone replace muffler in stock catback?
Thread Starter
Joined: Jan 2002
Posts: 4,069
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From: Casselberry FL
Anyone replace muffler in stock catback? I'm wondering how much of the power loss in the stock cat-back comes from the muffler vs. the I.D. of the tubing. What kind of gains could be seen from switching to an aftermarket muffler and keeping the rest of the stock catback on a 400-430rwhp car?
What type of muffler does the SLP Dual/Dual come with? Would that hook-up to the stock tubing without major headaches?
What type of muffler does the SLP Dual/Dual come with? Would that hook-up to the stock tubing without major headaches?
on my lt1 i replaced the stock muffler with a flowmaster 40series single in/dual out setup, noticed a big difference in speed and sound of course. probably coulda picked up a few hp with the catback system but i think it was fine as was.
Launching!
Joined: Mar 2003
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From: McKinney
Originally Posted by hourang
on my lt1 i replaced the stock muffler with a flowmaster 40series single in/dual out setup, noticed a big difference in speed and sound of course. probably coulda picked up a few hp with the catback system but i think it was fine as was.
This could be because I had stock tips with 2.5 inch pipe after the muffler. You can see my dyno #'s at my webpage below for exact #'s. Hope this helps.
I think with 3inch pipe after the muffler may have netted me a little more power
but I just recieved my Hooker catback and will put it in with dyno results later. This magnaflow is a few months old if you want it. I would take 50 bucks for it.
Good luck, sounds like a nice car you have there!
Derek
I went w/ a Flowmaster muffler as a quick fix for the sound I wanted, and did get HP and gas miliage out of it. It's been 2 years, and I haven't found a need to change it out. I'm sure I could get maybe 5 more HP out of a full aftermarket catback, but why spend that kind of $$ for 5 hp?
Staging Lane
Joined: Apr 2004
Posts: 96
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From: SC
I have a bid on a SLP SS muffler for $40 bucks on this forum but have not heard back from him. I would be interested in your Magnaflow. I have an 02 Z28 and would like to keep my stock tips and just replace the muffler. Do you have a part number for the Magnaflow, just to make sure it will fit my 02 Z28 . I want to make sure all I have to do is take the muffler to the shop and have em' put it on without any trouble. Any pics of the muffler?
Launching!
Joined: Mar 2003
Posts: 240
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From: McKinney
[QUOTE=GRAYZ]I have a bid on a SLP SS muffler for $40 bucks on this forum but have not heard back from him. I would be interested in your Magnaflow. I have an 02 Z28 and would like to keep my stock tips and just replace the muffler. Do you have a part number for the Magnaflow, just to make sure it will fit my 02 Z28 . I want to make sure all I have to do is take the muffler to the shop and have em' put it on without any trouble. Any pics of the muffler?[/QUOTE}
PM me for info on Muffler, I don't want to hijack the thread!
thanks,
Derek
PM me for info on Muffler, I don't want to hijack the thread!
thanks,
Derek
Originally Posted by apexman
I have a cam and headers car and have a semi stock catback with a magnaflow with stock tips and over the axle pipe. The i pipe is 3 inch with a cutout. I dynoed 365 hp and around the same torque thru this setup and dynoed right after thru the cutout and gained 12 hp and 10 tq across the whole power band.
This could be because I had stock tips with 2.5 inch pipe after the muffler. You can see my dyno #'s at my webpage below for exact #'s. Hope this helps.
I think with 3inch pipe after the muffler may have netted me a little more power
but I just recieved my Hooker catback and will put it in with dyno results later. This magnaflow is a few months old if you want it. I would take 50 bucks for it.
Good luck, sounds like a nice car you have there!
Derek
This could be because I had stock tips with 2.5 inch pipe after the muffler. You can see my dyno #'s at my webpage below for exact #'s. Hope this helps.
I think with 3inch pipe after the muffler may have netted me a little more power
but I just recieved my Hooker catback and will put it in with dyno results later. This magnaflow is a few months old if you want it. I would take 50 bucks for it.
Good luck, sounds like a nice car you have there!
Derek
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On The Tree
Joined: Jan 2004
Posts: 188
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From: Houston/ Austin, TX
i think the stock muffler is the most restrictive part, but when you start to produce alot of power, then you can see some huge power loss through a restrictive setup.
A guy i know gained 60 HP by opening his cutout on his 429 (i think) LT1. He had a flowmaster muffler and stock piping. The cutout was after his y-pipe with longtubes.
A guy i know gained 60 HP by opening his cutout on his 429 (i think) LT1. He had a flowmaster muffler and stock piping. The cutout was after his y-pipe with longtubes.
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Originally Posted by disco192
i think the stock muffler is the most restrictive part, but when you start to produce alot of power, then you can see some huge power loss through a restrictive setup.
A guy i know gained 60 HP by opening his cutout on his 429 (i think) LT1. He had a flowmaster muffler and stock piping. The cutout was after his y-pipe with longtubes.
A guy i know gained 60 HP by opening his cutout on his 429 (i think) LT1. He had a flowmaster muffler and stock piping. The cutout was after his y-pipe with longtubes.
Launching!
Joined: Mar 2003
Posts: 240
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From: McKinney
Originally Posted by hourang
again your talking about running no muffler compared to running one plus all the pipeing. the topic asks if getting a catback is a big difference than just replacing the muffler, i think the catback pipes are not that restrictive compare to a catback, though this is just in theory and would like to see if anyone had actual numbers?
The stock over the axle part looks a little more restrictive than the Hooker over the axle piece(as well as other aftermarket pieces). I think that there has to be some reason the aftermarket pipes are 3in. campared to 2.5 in. I have seen people dyno only 4 to 5 hp more with a cutout from a good flowing exhaust such as Hooker. That is why I posted my info.
Before my cam, I dynoed only 292 HP and 298 Tq with a bullet in the I pipe with a lid. Only picked up a few horsepower over the stock muffler.
Derek
Thread Starter
Joined: Jan 2002
Posts: 4,069
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From: Casselberry FL
I found a used D/D setup, but he bought the car used and it has a flowmaster muffler on it. Something I really liked about the D/D was the sound (or lack thereof) in the cabin. How will the noise/volume change with the Flowmaster, as I'm pretty sure that's not the original mufler which comes with the D/D, is it?
TECH Enthusiast
Joined: Jul 2002
Posts: 618
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From: Pensacola, FL
The stock pipe is 2.75", stainless, and mandrel bent...
Sounds pretty good to me.
I used a short bullet and dumped my stock muffler. The bullet is 3" id and flows like open pipe. Helped me a bunch.
Anyway, .25" larger pipe is hardly a reason to spend mega bux for a whole cat-back. The stock muffler is the restriction.
As for tail pipes and tips, larger pipes after the muffler, or big tips, are meaningless... Think about it, the exhaust goes through a single pipe that is around 3", you could have two 2" tailpipes and still flow the same as the one 3" I-pipe. Going any larger is cosmetic. Not to mention that exhaust gasses shrink as they go back through the exhaust. That means you could go with progressively smaller pipe and still flow the same out back as up front.
I have just a bullet and lid, on the dyno with other F-cars, I pulled the same/more power than cars with a full cat-back and lid.
I also saw guys with conventional mufflers and lid keep right up...
Except Blowmasters
, they are nearly as restrictive as stock.
Dave
Sounds pretty good to me.
I used a short bullet and dumped my stock muffler. The bullet is 3" id and flows like open pipe. Helped me a bunch.
Anyway, .25" larger pipe is hardly a reason to spend mega bux for a whole cat-back. The stock muffler is the restriction.
As for tail pipes and tips, larger pipes after the muffler, or big tips, are meaningless... Think about it, the exhaust goes through a single pipe that is around 3", you could have two 2" tailpipes and still flow the same as the one 3" I-pipe. Going any larger is cosmetic. Not to mention that exhaust gasses shrink as they go back through the exhaust. That means you could go with progressively smaller pipe and still flow the same out back as up front.
I have just a bullet and lid, on the dyno with other F-cars, I pulled the same/more power than cars with a full cat-back and lid.
I also saw guys with conventional mufflers and lid keep right up...
Except Blowmasters
, they are nearly as restrictive as stock.Dave
TECH Apprentice
Joined: Jul 2003
Posts: 329
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From: Virginia Beach
I actually got a dynomax ultraflow which fit right in. Sounds really nice, a low rumble to it. And it is a strait through muffler, they showed it to me before they welded it up. I have been very happy with it.
TECH Enthusiast
Joined: Jul 2002
Posts: 618
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From: Pensacola, FL
Originally Posted by poweredbyv8
i was looking at magnaflows site and they dont sell mufflers that are 2.75". is it easier for exhaust shops to expand a 2.5" or should i get a 3" muffler?
Dave