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Thread: Flowmaster slimlines discontinued

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    Flowmaster slimlines discontinued

    Unfortunately, it looks like the Flowmaster Slimlines have been discontinued. I was hoping to use the 30 inch ones (13530320) but was waiting to buy them until I was ready for that part of the build. When I first heard about this a couple weeks ago, I managed to find one of the 30 inch ones on Amazon and bought the last two 24 inch ones from Flowmaster (13524320). I've tried calling about 100 places that say they have the 30 inch ones online and have checked ebay, but I keep striking out. This brings me to my questions. Anyone have a clue if it is possible to join the two 24 inch mufflers into a 30 inch one? I assume that there would be an unsightly weld seam, but I'm also concerned that the internals wouldn't work correctly. Any ideas on where I can find an extra one lying around? I suppose I could just use the 24 inch ones, but from my review of the forums it sounds like they are just as loud as the stock pipes. Thanks for any suggestions...
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    Senior Member Gordon Levy's Avatar
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    24" still available from summit
    99/2000 NASA PSO Champion-2005 west coast FFR challenge series Champions
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    Senior Member Gordon Levy's Avatar
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    I can see with the really limited market that they were discontinued, bummer.
    99/2000 NASA PSO Champion-2005 west coast FFR challenge series Champions
    Sponsor Tony B's 2007 ST2 National Championship
    2009 NASA TTC runner up-2010 NASA TTB runner up

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    A muffler like this is not that complicated. It's a simple insert inside of a metal tube. I'd cut them apart and weld them back together in whatever length you need/want.
    .boB "Iron Man"
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    Quote Originally Posted by dncharo View Post
    Unfortunately, it looks like the Flowmaster Slimlines have been discontinued. I was hoping to use the 30 inch ones (13530320) but was waiting to buy them until I was ready for that part of the build. When I first heard about this a couple weeks ago, I managed to find one of the 30 inch ones on Amazon and bought the last two 24 inch ones from Flowmaster (13524320). I've tried calling about 100 places that say they have the 30 inch ones online and have checked ebay, but I keep striking out. This brings me to my questions. Anyone have a clue if it is possible to join the two 24 inch mufflers into a 30 inch one? I assume that there would be an unsightly weld seam, but I'm also concerned that the internals wouldn't work correctly. Any ideas on where I can find an extra one lying around? I suppose I could just use the 24 inch ones, but from my review of the forums it sounds like they are just as loud as the stock pipes. Thanks for any suggestions...

    Just heard about the discontinuation today. I was planning on that upgrade soon and was waiting to buy.

    Found a seller on ebay that advertised three 30" (13530320) in stock, I ordered two, still shows one in stock.
    If you already have one from Amazon, I would try to pick up the other one from the ebay seller - just search for 13530320.
    Hopefully they actually have them in stock, fingers crossed!!!

    Good luck.
    Dennis
    Last edited by d_gatorfan; 12-30-2018 at 09:38 PM.

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    Papa's Avatar
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    Looks like this place may have some: https://thmotorsports.com/8120568-fl...hoCT98QAvD_BwE
    Attached Images Attached Images
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    Dennis - I just checked ebay again and it looks like the seller is "dailyperformance" but I've tried buying the slimlines from them before and they don't have any. I'm not sure why they don't update their ebay website. If by chance your purchase goes through, let me know!

    Papa - I tried calling those guys also. no luck. Thanks for looking! I've seriously placed orders to about 15 places that say they have them online, but when I put my credit card down, they say they don't have them and return my payment. Very frustrating, especially since I managed to get one of them and I need two!

    If there is someone out there who purchased them ahead of time and decides to go with another option, then I'd be interested in buying them...
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    I figured you would have checked ebay - I was afraid they may not actually have them, I'll let you know.

    I plan to move the outlet back closer to the rear wheel, partly for looks but mostly so i can move my heat shields back closer to where your leg lands when getting out of the car.
    The 24" will still let me do that, so really the reason for wanting the 30" is the assumption that they will quiet the car down a little more.
    I wonder if the 30" are that much better than the 24" for sound attenuation, I guess I'll find out.

    Dennis

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    I have the 30" Slimlines and love them, but they are heavy. I am going to have to fab up an additional support bracket in the spring. I would try the 24" and see how they sound. And they will be lighter.

    Wade

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    Mk4 20th Anniversary #8690 (#8 of 20) Purchased 8/18/18----Build Started 8/19/18
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    Senior Member frankb's Avatar
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    Not the slimlines, but this guy sells replacements for the FFR side pipe mufflers: www.classicchambered.com
    FFR MK4 #8317, 393 Cleveland, Lunati VooDoo solid roller, CHI 3V heads and intake, TKO 600, Std roadster seats, 8.8 3.55 diff, 17" Halibrand replica wheels, Ford "Magnetic Metallic", silver ghost stripe. (Sold 10/16/21)

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    Hi frankb, I was looking at those the otherday and emailed with the owner. Do you use these pipes? Are they any quieter?

    Craig

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    Quote Originally Posted by dncharo View Post
    Dennis - I just checked ebay again and it looks like the seller is "dailyperformance" but I've tried buying the slimlines from them before and they don't have any. I'm not sure why they don't update their ebay website. If by chance your purchase goes through, let me know!

    Papa - I tried calling those guys also. no luck. Thanks for looking! I've seriously placed orders to about 15 places that say they have them online, but when I put my credit card down, they say they don't have them and return my payment. Very frustrating, especially since I managed to get one of them and I need two!

    If there is someone out there who purchased them ahead of time and decides to go with another option, then I'd be interested in buying them...


    Daily performance messaged me yesterday and they don't have any stock. Said he his source just ran out.
    I ordered a set of 24" from Summit, but I am concerned they will be too loud.
    I think I am going to send them back.
    One came from Nevada and one from Georgia, so Summit's stock on 24" must be dwindling.

    I found this company in an old post : https://highfloperformance.com/produ...-pipe-inserts/
    They will rework your factory five mufflers at a very reasonable price, about what the flow masters and installation would cost. and/or do something more custom.
    The owner was very helpful says he has done some factory five pipes and has a jig.
    I am considering giving them a try.

    The unknown for me is the sound level compared to what i have.
    I'll keep you posted on what I decide to do.

    Dennis

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    Quote Originally Posted by d_gatorfan View Post
    Daily performance messaged me yesterday and they don't have any stock. Said he his source just ran out.
    I ordered a set of 24" from Summit, but I am concerned they will be too loud.
    I think I am going to send them back.
    One came from Nevada and one from Georgia, so Summit's stock on 24" must be dwindling.

    I found this company in an old post : https://highfloperformance.com/produ...-pipe-inserts/
    They will rework your factory five mufflers at a very reasonable price, about what the flow masters and installation would cost. and/or do something more custom.
    The owner was very helpful says he has done some factory five pipes and has a jig.
    I am considering giving them a try.

    The unknown for me is the sound level compared to what i have.
    I'll keep you posted on what I decide to do.

    Dennis
    Dennis,

    Have you considered Boig's Quiet Pipes? Seems like a good option for what you are trying to achieve with a lot less hassle.

    https://thefactoryfiveforum.com/show...Side-Pipe-Kits!

    Dave
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    Quote Originally Posted by Papa View Post
    Dennis,

    Have you considered Boig's Quiet Pipes? Seems like a good option for what you are trying to achieve with a lot less hassle.

    https://thefactoryfiveforum.com/show...Side-Pipe-Kits!

    Dave
    Dave,
    I have considered those. There was some dyno data floating around a while back that indicated they cost about 60Hp over the factory five pipes. I don't mind losing a few hp, but that is a lot.

    Dennis

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    Quote Originally Posted by d_gatorfan View Post
    Dave,
    I have considered those. There was some dyno data floating around a while back that indicated they cost about 60Hp over the factory five pipes. I don't mind losing a few hp, but that is a lot.

    Dennis
    I don't have any data to refute it, but 60 h.p. seems pretty high. That would be 15% on a 400 h.p. motor. Reading through Boig's thread that I quoted, he estimates a 3-5% power hit over non-baffled pipes. That would put you at a more reasonable 20 h.p. loss on a 400 h.p. engine. Unless you are racing the car, that's probably insignificant. Also, there are some data out there that indicate torque gains with some more restrictive muffler designs, so if you loose 5% h.p. and gain some torque, the trade could be a good one.

    Dave
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    Senior Member Avalanche325's Avatar
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    Here is the thread where the Quiet pipes were dyno'd.
    365HP to 294HP. 71HP loss.

    https://www.ffcars.com/forums/17-fac...iet-pipes.html

    "The RWHP dyno results for my FR 347 are:

    Breeze Quiet Pipes: 294 HP (quite "quiet")
    Classic Chambered Mufflers: 365 HP (borderline obnoxiously loud but potent HP)
    Stan's Modified Classic Chambered Mufflers: 333 HP (very nice compromise sound and still enough HP to scare me)"

  18. #18
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    Quote Originally Posted by Avalanche325 View Post
    Here is the thread where the Quiet pipes were dyno'd.
    365HP to 294HP. 71HP loss.

    https://www.ffcars.com/forums/17-fac...iet-pipes.html

    "The RWHP dyno results for my FR 347 are:

    Breeze Quiet Pipes: 294 HP (quite "quiet")
    Classic Chambered Mufflers: 365 HP (borderline obnoxiously loud but potent HP)
    Stan's Modified Classic Chambered Mufflers: 333 HP (very nice compromise sound and still enough HP to scare me)"
    Wow! I never would have imagined that significant of a difference introduced by a muffler.

    Dave
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    Senior Member frankb's Avatar
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    Craig:
    Sorry for the delay in answering ...I don't have them yet, but plan to make the change this summer.
    FFR MK4 #8317, 393 Cleveland, Lunati VooDoo solid roller, CHI 3V heads and intake, TKO 600, Std roadster seats, 8.8 3.55 diff, 17" Halibrand replica wheels, Ford "Magnetic Metallic", silver ghost stripe. (Sold 10/16/21)

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    No problem. I emailed with Erik the owner and I am intrigued. I might try them myself. Would be great to hear from someone that has used them.

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    Senior Member Mike N's Avatar
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    I would say that it is definitely not a simple task to extend a 24" or make your own version of the Flowmaster design.

    Mike............

    FFR2100 - 331 with KB supercharger - T5 - 5 link rear 3.08's and T2 Torsen.

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    Quote Originally Posted by d_gatorfan View Post
    Daily performance messaged me yesterday and they don't have any stock. Said he his source just ran out.
    I ordered a set of 24" from Summit, but I am concerned they will be too loud.
    I think I am going to send them back.
    One came from Nevada and one from Georgia, so Summit's stock on 24" must be dwindling.

    I found this company in an old post : https://highfloperformance.com/produ...-pipe-inserts/
    They will rework your factory five mufflers at a very reasonable price, about what the flow masters and installation would cost. and/or do something more custom.
    The owner was very helpful says he has done some factory five pipes and has a jig.
    I am considering giving them a try.

    The unknown for me is the sound level compared to what i have.
    I'll keep you posted on what I decide to do.

    Dennis
    Thanks Dennis for following up. I still haven't found another 30 inch slimline. I also have the 24" ones, but am also concerned that they will be too loud based upon some forum posts I've read. The two things I liked about the slimlines are that they were quieter, but also cooler to the touch so that there is less of a chance of a "snake bite". I'm also considering both the Boig Quiet Pipes and the Gas-N side pipes, but both are going to get pretty hot and I may need to think about a heat shield if I go in that direction.
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    Dncharo,
    I have been there. I have done the research. Now I am just enjoying my FFR cruising in Florida with my Boig Motor Sports Quiet Pipes. Here is a repost of my experience with hope I can save others some time and frustration. Here's my test findings and delight with Boig Motor Sports level of support and quality workmanship.

    Quiet pipes are the real deal. I had damaged my Sidepipes and bought a new set FFR Stainless Steel Sidepipes. After a spirited season of driving throughout New England my wife asked if there was something I could do to quiet the car down so she could enjoy it more. So, the search was on for an exhaust system that would give that classic deep muscle car sound without vibrating the neighbor’s windows or setting off car alarms while driving through parking lots or having my neighbors stop me to complain about the noise!

    I did the research, reviewed articles, called several different manufacturers and narrowed my choice down to Boig Motorsports Quiet Pipes and FlowMaster Slimline mufflers “designed for the Cobra.”
    With the help of great friends I was able to conduct an analytical sound level test on my vehicle with three different sets of sidepipes. We conducted all test under identical conditions to verify results.
    Each sidepipe muffler assembly was new, installed with new gaskets and aligned with the hangers fitted.

    I’m running a Ford Racing 351-W, bored to 392-C.I. @ 430-H.P. With a Holley Ultra 750 – CFM Double Pumper Carburetor, non-catalytic 4 into 4 Headers and Factory Five Stainless Steel Sidepipes.

    Sidepipes tested:
    1. FFR Stainless Steel Sidepipes. (Used as the standard reference.)
    2. FlowMaster Slimline 24" Sidepipes fitted to FFR flanges, pipes and turnouts.
    3. Boig Motorsports Quiet pipes.

    Test Conditions:
    Engine full hot operational temperature, outside in an open area.

    TEST FFR FlowMaster Boig Motorsports
    RPMs Stainless Steel Slimline Quiet Pipes
    Idle 750-800RPM 104dB. 105dB. 90dB
    1,500RPM. 106dB. 106dB. 92dB
    2,000RPM. 107dB. 107dB. 98dB
    3,000RPM. 111dB. 114dB. 104dB

    RESULTS
    1. The FFR Polished Stainless Steel Sidepipes look great on the car. They created a clean sound that rolls like thunder, but they leave your ears ringing after driving a long distance on the highway and having a conversation is difficult. As they age, they get louder.
    2. The FlowMaster Slimline Sidepipes when started spun heads as they barked loud and raspy. As we increased RPM’s FlowMaster Pipes got progressively louder making conversation difficult at a 45 MPH cruise and impossible at highway speeds.
    3. Boig Motorsports Sidepipes is the clear winner. These Sidepipes generate a muted, classic deep pulsating muscle car sound that lets you know there is something special under the hood with no loss in performance. The Quiet Pipes allow for a conversation at wide open throttle and you can continue that conversation at highway speed. The precision welding, the fit and alignment of the Boig Motorsport Sidepipes made installation easy as well as putting a beautiful finishing touch to my build!

    My son and I drove the Roadster to Florida, 1,350 miles, most that at 75MPH+. It was easy to carry on a conversations at any speed. Today the Boig Motorsports Sidepipes look and sound as good today as the day they were installed.
    Craig

    Picked up April 2004, completed June 2006 - Ford Racing 351-W, Bored & Stroked to 392ci, 430HP - 475ft/lbs torque. Holley 750 D.P., Tremec 3550, 3-link, FFR 15 Wheels, Color: Indo Ink Pearl with Super White stripes.

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  25. #24
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    Quote Originally Posted by Blue Classic View Post
    I have been there. I have done the research. Now I am just enjoying my FFR cruising in Florida with my Boig Motor Sports Quiet Pipes. Here is a repost of my experience with hope I can save others some time and frustration.
    (...)
    Sidepipes tested:
    1. FFR Stainless Steel Sidepipes. (Used as the standard reference.)
    2. FlowMaster Slimline 24" Sidepipes fitted to FFR flanges, pipes and turnouts.
    3. Boig Motorsports Quiet pipes.
    I went through the same route, with the same pipes. Here is my story.

    I participate in track events with my Coyote powered roadster. I was worried that I would not meet Calabogie race track sound check with FFR Stainless pipes. I installed the FlowMaster Slimline 24", they barely pass the 100dbA at 15 feet (measured in the paddock at 5000rpm). Before going to Le Circuit Tremblant which is more stringent, I installed the Boig Motorsports Quiet pipes. Mont-Tremblant limit is 92dbA at 50 feet measured at WOT on the track and the test station is mobile.

    Quiet pipes are much quieter at idle. WOT is still loud and I was still worried going down the track. After talking to spectators, I was no longer the loudest so it went well.

    For sure, the car is not slower with the Quiet Pipes than the Slimline. They were compared on different tracks, on a different days but compared to other usual competitors, I was faster. I compared the engine log files and it appears that the maximum air mass flow rate is 3-4% lower with the Quiet Pipes, so I would tend to agree about the 3-4% number for power loss. Nothing like the 60+HP quoted before. I have a stock Coyote with a mild tune. A race engine with large cam overlap might be affected more by exhaust back pressure.

    Driving in the street is much pleasant with the Quiet pipes. I discovered that with loud pipes, I was often resticting throttle to limit the noise: while leaving my house or at busy downtown traffic lights. It's no longer the case. More power is usable with Boig Motorsports Quiet pipes!

    R.

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    Hi Craig and Totem,
    The Boig ones sound great. But your comparisons were with the 24 inch Flowmasters. The 30 inch ones appear to be much quieter from what I’ve read.
    Turns out a guy in Germany had a single 30 inch Flowmaster and I’m going to trade him that for my two 24 inch ones. So it all worked out for me!
    David
    MK4 Roadster #9138
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  27. #26
    Senior Member FFRSpec72's Avatar
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    Quote Originally Posted by totem View Post
    I went through the same route, with the same pipes. Here is my story.

    I participate in track events with my Coyote powered roadster. I was worried that I would not meet Calabogie race track sound check with FFR Stainless pipes. I installed the FlowMaster Slimline 24", they barely pass the 100dbA at 15 feet (measured in the paddock at 5000rpm). Before going to Le Circuit Tremblant which is more stringent, I installed the Boig Motorsports Quiet pipes. Mont-Tremblant limit is 92dbA at 50 feet measured at WOT on the track and the test station is mobile.

    Quiet pipes are much quieter at idle. WOT is still loud and I was still worried going down the track. After talking to spectators, I was no longer the loudest so it went well.

    For sure, the car is not slower with the Quiet Pipes than the Slimline. They were compared on different tracks, on a different days but compared to other usual competitors, I was faster. I compared the engine log files and it appears that the maximum air mass flow rate is 3-4% lower with the Quiet Pipes, so I would tend to agree about the 3-4% number for power loss. Nothing like the 60+HP quoted before. I have a stock Coyote with a mild tune. A race engine with large cam overlap might be affected more by exhaust back pressure.

    Driving in the street is much pleasant with the Quiet pipes. I discovered that with loud pipes, I was often resticting throttle to limit the noise: while leaving my house or at busy downtown traffic lights. It's no longer the case. More power is usable with Boig Motorsports Quiet pipes!

    R.
    This is odd as I have a 337 engine with the 24" flow masters and I'm below 95bd with turn outs to the side like normal cobra side pipes. The tracks I run at have db limits and I have to be below 95 db and these 24" flowmaster get me to that point on a 520hp 337 engine
    Tony Nadalin
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    As many of you will recall I did some dyno testing on mufflers a few years ago. The 30” flowmasters were the best. However, I also tested some inserts that would slide into 4” pipes. Since the Flowmasters are no longer available it may be time to revisit this option. They were 20” long and almost as quiet as the Flowmasters. Had I not gotten the flowmasters I would have used the inserts and made my own sidepipes. The interesting thing is you can get them in any length or diameter you want. Had I used a longer insert I’m quite sure they would have been the quietest. They also do not cost ANY horsepower at the 500HP level. This is an insert designed for boats, but works great in a dry environment also. I’ve used them for over 15 years in boats as much as 1000 HP to get the db down to a legal level. They are a straight thru design and use a noise canceling technology. Check out their web site https://marineexhaust.ggb.ca/.

    Bob
    Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017

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    Bob-

    Thanks for your post about the marine muffler inserts. Did you use the 4" diameter? Also, what length did you work with? It looks like we could easily use any of the three (12", 16", or 20") lengths. Just curious what your experience was, so I know where to start.

    Thanks again for your help with this!

    Regards,

    Steve

  30. #29
    bobl's Avatar
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    Quote Originally Posted by WIS89 View Post
    Bob-

    Thanks for your post about the marine muffler inserts. Did you use the 4" diameter? Also, what length did you work with? It looks like we could easily use any of the three (12", 16", or 20") lengths. Just curious what your experience was, so I know where to start.

    Thanks again for your help with this!

    Regards,

    Steve
    I used the 4 x 20 in my testing. I'm sure they could make up any length or you could combine different lengths to get the package you want. They pretty much base the price on the number of "rings" in a unit. I personally think a 24" insert package would easily be as quiet as the 30" flowmaster.

    If you talk to them you might mention my name. Some of the dyno test results on their website is mine.

    Bob
    Last edited by bobl; 05-14-2019 at 05:48 PM.
    Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017

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  32. #30
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    Quote Originally Posted by bobl View Post
    I used the 4 x 20 in my testing. I'm sure they could make up any length or you could combine different lengths to get the package you want. They pretty much base the price on the number of "rings" in a unit. I personally think a 24" insert package would easily be as quiet as the 30" flowmaster.

    If you talk to them you might mention my name. Some of the dyno test results on their website is mine.

    Bob
    Bob-

    Thanks for the response and additional details. I think this might be a very workable solution. Plus, a heck of a lot cheaper than new slimlines (if you can find them) or Boig's pipes!

    Thanks again!

    Regards,

    Steve

  33. #31
    Senior Member frankb's Avatar
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    Bobl:

    So these would be placed inside the FFR muffler after removing the factory packing, etc? One would need to cut the FFR muffler open to do this, correct?
    FFR MK4 #8317, 393 Cleveland, Lunati VooDoo solid roller, CHI 3V heads and intake, TKO 600, Std roadster seats, 8.8 3.55 diff, 17" Halibrand replica wheels, Ford "Magnetic Metallic", silver ghost stripe. (Sold 10/16/21)

  34. #32
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    Quote Originally Posted by frankb View Post
    Bobl:

    So these would be placed inside the FFR muffler after removing the factory packing, etc? One would need to cut the FFR muffler open to do this, correct?
    I cut the ends off the ffr mufflers right at the weld where it goes from 3 1/2 to 4 inch. Then weld a new section of 4" pipe the length you want, install the insert and weld on the turn down in the same manner. You can also buy new 3 1/2 to 4 inch transitions pretty cheap.
    Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017

  35. #33
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    Just wanted to push this thread back to the top. I am running the stock FFR pipes with a 351w making 520 HP and I too missed out on the 30” flowmasters before they were discontinued. The company that bobl provided the link for has an error message on their website indicating their product isn’t available until 2020.

    The primary issue I am trying to resolve with my car is the loudness of the side pipes really at any speed and even lower RPMs. I fully appreciate the comment that your tendency is to drive the car very timidly while riding in the neighborhood because it is so loud. Sometimes I think the RPMs must be higher than they really are because it is so loud and I shift way too early into a higher gear.

    Does anyone know if Flowmaster replaced the slimline 30” with another model? I am also very interested to hear more about people’s experiences with Boig’s quiet pipes. It is a painful reality to have to fork over $1,000 for pipes (excluding the additional cost of having them chromed) before having any confidence they will reduce the dBs enough to be worthwhile. If they were that effective, then the cost would be very minor in relation to the higher amount of usage and enjoyment I would get out of the car.
    Thanks
    Glenn

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    Look up car chemistry for inserts

  37. #35
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    Well, this thread 8s back and still no mention of Gas-N pipes? I switched from FFR to Gas-N and the sound difference is very noticeable, and in a good way.

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