Quieting down a Thermal catback

[turboglenn]

Just wondering if anyone has ever tried removing the melon-shooter tip on a thermal R&D catback in attempts to make it quieter? I use to like the deep tone of the exhaust but over the years i think the droning has worn on my hearing (definitely worn on my patience) I always think back to the grand nationals we built when i was young and how quiet those cars were and how much power they were making. There has to be a way to either knock our some db's from the Thermal or replace it's straight through muffler with something better that's still free flwoing enough to keep from being a notable effect on HP.

Has anyone just tried removing the tip and running a piece of normal 3" pipe from the end of the muffler? How about fabricating a silencer like some other exhausts have that wouls slip into the tip?

I was thinking about putting a regular piece of 3" on the back end and MAYBE putting a LARGE (like 4") flowmaster where the kitty-cat use to be and seeing what that would do but i don't have the loot for the flows right now so the most i can do is experiement with changing the thermal setup on it's own

anyone have suggestions?\

 

[TJCTalon]

In my opinion I think you should just make a custom exhaust instead of hacking up a perfectly fine thermal exhaust.

If you sold the exhaust you would have plunty of money to do a new exhaust and have money to spare. Besides im sure theres someone out there that would kill for your loud thermal exhaust. They are the best sounding exhausts made for our cars IMO

Get vibrant muffler maybe a resonator or 2 and your exhaust will quiet down significantly

 

[turboglenn]

Well, to be honest i would really like to keep the look and nice size and fitment of the 3" Thermal system (i like the tip but the noise is old as hell after 12+ years)

I REALLY want to see what's teh best muffler i could add in place of the cat that wouldn't create too much back pressure. I forget what we use to run on the old GN's but i swear it was a flowmaster or a borla (but i've always hated borla on V8's)

Even if i lost 10-15hp that i could make up with boost that would be fine, but i don't want to go the traditional OEM muffler and cat-back and have a 3" cut-out, i don't really care for cut0outs, the way they sound is horrible I'd rather have something like the guy had in the thread "finally a quiet muffler" but i don'thave that kind of cash to play with.

I remember MAP saying they got a nice, low but decent sound out of a 3" aluminum exhaust cat-back, but that's a LOT of work and still replaces the Thermal.. I love that big shiny SS pipe but there's gotta be a happy medium out there

Since my "test pipe" is a v-band setup (the one i'm building to go on with the new 3" DP anyway) i figured i'd section out a chunk of that and put something in there to quiet things down but still keep the thermal look and keep the thermal "un-hacked" this would also allow for me to take it out, make changes otr whatever by simply undoing v-band clamps, taking the pipe out and modding it a little

EDIT: I've never cared for theway resonators make things sound, IMO they don't do much really.. i like the idea of the Helmhold (sp?) extra muffler though

EDIT:#2 I've driven 500+ hp factory porshe's that had damn quiet exhaust and were turbocharged, anyone know what they use for OEM mufflers?

 

[dsmjunk]

I know they make a cone type device that you put in I think the exahust pipe or muffler you could try that

 

[LiquidX]

Try this, modify the cat-pre to make it shorter to allow this to be welded in. It has helped a ton with my setup.
MagnaFlow Exhaust Products - For Trucks, Suv's, American Muscle, Diesel, & Sport Compact Vehicles

My setup here is that muffler along with this muffler

DSM Magnaflow exhaust and antilag - YouTube

That idea may help you out. I was also running cat less if that matters.

I know they make a cone type device that you put in I think the exahust pipe or muffler you could try that

The silencers you are speaking of do help, however they will hinder performance by restricting exhaust flow out of the pipes. Good for when you are DD but when you need that power randomly, a cut out would be better.

 

[Bricktop]

Please don't put a flowmaster on a Turbocharged car. Chambered mufflers suck. I had 2 chambers on my Turbo Fox Mustang and I swapped them out for Hooker MaxFlos. Basicly straight through. Big improvement in spoolup, 2 tenths off my eighth mile. They arn't Grand National quiet but, close.

 

[turboglenn]

WEll, I'm gonna try whatever it takes, it's coming to where i need to make the car fit into my adult life or get rid of it. Now that being said i'd rather keep it, tone the noise down, make the suspension a little more comfortable and still have one mean ass car. (well, there is one more option that i can't afford righht now and that's to make this a track only car and buy another DD vehicle, but for many reasons that is not in the cards right now)

From everything i've read i think i'm going to try and get a Dynamax or something along those lines (or I might even make a large aluminum mutli chamber muffler that's large, has some baffling in it and is still free flowing (but that's another hiuge project in the pile of a hundred i already have)

I TT'd my foxbody 5.0 with super ghetto home made kit back in the day and i hooked that into the flowmaster's i had on the car previousely and it was insanely fast but then again i didn't have a "non-muffler" state to compare it to. Although they never handled well i always loved the silent killers, the grand nationals. We had 2 mid 10 second grand nationals when i was in my early 20's and those cars were insane, you could kick in passing gear at 65MPH and the ass end would get sideways on large DOT cheaters when they weren't warmed up good, and the thing was you could talk at a normal level, hear yourself, hear the radio (again at normal levels) and carry on normal conversation, in mycar i'm constantly asking "what'' because people haven't learned to talk over the droning of the thermal R&D.

BUT the WORST of all is that since i put the new larger turbo on (and i think this is the mild steel 2.5" DP's fault) but i have that horroble "rasp" that hondas all have on mid throttle acceleration and I can't stand that! I'm finishing my heavy gauge 3" down pipe today to try and combat it (i know it may get louder) but i'm hoping it stiffens the system up enough to absorb that rattle i now have.

 

[LiquidX]

Glenn, in all honesty if you need something that is super quiet from the sound of it, I would just sell the Thermal and make a custom exhaust. Do a 3" downpipe with a cutout installed and then from the cat-back, go 2" pipe or smaller with a large multi chambered muffler, that will significantly cut the noise out but you will choke the turbo unless you open the cutout.

I would stay away from chambered mufflers as well unless you are 100% set on performance as they do restrict flow which is bad for power. The 2 I listed are race stye mufflers that are straight through pipe.

 

[turboglenn]

WEll, if i take the thermal off i'm going to need to sell it as i can't justify it sitting in the garage/storage going to waste, and i'll hve to do the new setup in SS as well, but i just hate cut-outs I'd like to have one of those mufflers from the thread below this one that i bumped by osting in last night.

EDIT: There's FAST and QUIET factory turbo cars (for instance the porsche at over 600WHP) what exhaust system design do they come with????? Never gutted one but i've driven one a few times I"m just saying there's got to be a way around it although my examples (porsche and GN) are 6 cylinders there's got to be a wy i can have a fast and quiet 4 banger (either that or it's time to sell the whole thing and put my turbo, FMIC, EMS system and whatever else will fit onto a 6 cyildner car )

The next guy before my last post in the thread is making 450'ish and his car sounds like something i could deal with but as most of you know there's reasons i just don'thaave money to go buying stuff like that to put on my car. in fact most of what i get/put on the car these days comes free except for those mandatory investments like i've had recently

How much you think i wouls seriousely rob frtom the car at the 500hp level if i were to put a large (4" in/out) dynamax/flow master where the cat used to be? HOnestly i want the look of the Thermal still, just not it's noise Hell even putting a cat back on would quiet it down but i would think a muffler would be less restrictive than a cat at this level. Defintely not going with a cut-out though (number one i don't have one, number 2 i can't afford one ) I have to work within my budget here which is very tough being a person in your mid 30's that can no longer work except for what you pick up in fabrication/tuning and variouse odd jobs (it's not my choice believe me, i work doing what i can because i'm not the tyupe to sit back and drain the system by drawing a check off the govt, so i do what i can) Just so happens i bought all my fab equipment back when i was more able bodied and had a lot of money rolling in, so i can make stuff easy, but buying is much harder

What if I made a muffler/box that although it wasn't "mandrel bent passages" still have an area of travel that was larger than a 3" ID pipe would be.. Then put "walls" in it that have muffler packing seperating the center passage from the walls of the muffler for more sound deadening??? Couldn't drain much, and like i said i'm up for a 10-20hp loss just to be quiet, hell i'll just get on the spray more often (not like i ever need it anyway, a 400+ WHP steet car is rarely touched around here)

But honestly, lets say i go cut-out + quiet OEM style exhaust.. HOw much can i get for the Thermal R&D catback on average???????????
If the sale of the thermal can fun the new exhaust build that would be ok.

 

[99gst_racer]

The silencers you are speaking of do help, however they will hinder performance by restricting exhaust flow out of the pipes. Good for when you are DD but when you need that power randomly, a cut out would be better.

I think he's referring to the cone inserts that Dynatech offers.

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These are used in circle track raicing and as you could imagine, they don't do much at all for noise reduction.

 

[99gst_racer]

HOw much can i get for the Thermal R&D catback on average???????????

Not much, unfortunately. I recently sold one and was a bit disappointed at the lack of interest it generated. It was a 2G AWD Thermal system mated to a custom 3" SS downpipe and custom SS O2 housing. Everything was v-band connections too. I got like $350 shipped out of it and it took me a year to sell it here. With as cheap as the China cat-backs are, nobody wants to pay the money for a nice cat-back anymore.

I was in your shoes 7 months ago with a loud Thermal on my DD 2G Talon. My Talon is an A/T and with the RPM that it rode at between 55-70 mph, it droned horribly. And being that most of my daily commute was in the speed range, I had to do something before it drove me insane. Here's the best two options in my opinion:

1) Hack off the muffler and source out a GReddy EVO muffler. GReddy used a huge body on them and they offered great flow while reducing the noise better than ANY muffler I've ever heard on a DSM. PIC I used to have one of the GReddy cat-backs back when my '99 was FWD, and I really miss it. If fact, if you can find one of these cat-backs, scoop it up! I know you'll love the way it sounds as well as the lack of interior drone. I couldn't find a muffler like this when I was looking to quiet down my Talon, so I opted for my option #2.

2) Add a high-flow race cat. This may not be a great option for a really high HP car, but it worked great for my 250 WHP DD. I used one of the racing cats from Magnaflow. They're stainless steel, cheap as hell, and rated to flow quite a bit of CFM. I noticed no change in spool with it welded in place, and it cut down 90% of my drone issue. You could also try a muffler instead of a cat (like LiQUiDx suggested), but I cannot attest to how well that would work. It's bound to help to some extent though.

Amazon.com: Magnaflow 94009 Universal Catalytic Converter (Non CARB compliant): Automotive

 

[turboglenn]

I have wondered how effective (if at all) it would be to make an insert for the tip similar to liek the apexi comes with and some other brands? I didn't think they'd work all that well so i haven't bothered with them, but i guess it's an option although i'm looking for a more permanent one

 

[1983gsp]

I'm very happy with my magnaflow 3" in dual 2 1/2" out on a press bent 3" exhaust. Was a little loud at first but I also added a 3" glasspack in place of the cat. Great flow and reasonably quiet. At less than 2500 rpms it resonates a little but I rarely cruise below 3000 rpms.

 

[turboglenn]

How much boost/HP you pushing out of your HX-35 and did you notice a loss when adding the extra muffler?
\
I'd love to hear a movie or sound clip of your car, thanks for the recomendation

 

[99gst_racer]

I have wondered how effective (if at all) it would be to make an insert for the tip similar to liek the apexi comes with and some other brands? I didn't think they'd work all that well so i haven't bothered with them, but i guess it's an option although i'm looking for a more permanent one

I had one of those mufflers on a '95 GS about 10 years ago. There was absolutely no sound/noise difference with or without the "silencer" attachment. It's just a selling gimmick. Drone can only be corrected at the muffler or before the muffler.

 

[turboglenn]

Cool,thanks for all the great input paul. I have a bookmark saved on some "turbo style" muffler tests a magazine did and ai found a bit of inspiration.

They tested all the popluar mufflers on a 3" setup on a car that was almost 500hp (but not turbocharged, it was NA v8 power, but still throughn a single 3" system.

The quietest and the BEST flowing was a unit called the Dynomax Walker 17749 (with the 3" flowmaster being dead last in place for both sound and flow with an average of 7 other mufflers between the two)

This might be a great choice to install where the cat use to be located. Even tested against an open header setup that was properly tuned they barely gave up any flow or power and got the most sound deadening from it, and supposedly i saw where i found the link that it retails for 50 bucks

This isn't the one i'm talking about but this is jkust like a straight through setup but with a spring actuated valve and a LOT of packing to help kill noise, something like this probably wouldnb't hurt power too badly

http://www.summitracing.com/parts/WLK-17156/?rtype=10

Also, check this out, not only is it pretty free flowing but it has a manual cutout built into it

i'm liking the idea of this, maybe jsut add an electric valve to it in the future

Flowtech 50560FLT - Flowtech Warlock Bypass Series Mufflers - Overview - SummitRacing.com

 

[99gst_racer]

The quietest and the BEST flowing was a unit called the Dynomax Walker 17749 (with the 3" flowmaster being dead last in place for both sound and flow with an average of 7 other mufflers between the two)

That's one of Dynomax's Super turbo series mufflers. I've been selling these for years. They're leaps and bounds better than a flowmaster, but it is still a chamber style muffler so I'd be hesitant about running one on a turbo'd car. Dynomax's "Ultra Flo Welded" mufflers would be a better fit for our cars. Something like a 17220 or a 17223. They are a straight-through flow design with lots of fiberglass packing to absorb resonance.

Also, check this out, not only is it pretty free flowing but it has a manual cutout built into it

i'm liking the idea of this, maybe jsut add an electric valve to it in the future

Flowtech 50560FLT - Flowtech Warlock Bypass Series Mufflers - Overview - SummitRacing.com

I like the idea. It probably wouldn't flow great with the cut-out closed, but if you're just putting around town with it, then it shouldn't matter much. And just open the cut-out when you're ready to have some fun with boost.

Similar to what Matt found here: http://www.dsmtuners.com/forums/bolt-tech/345139-finally-good-quiet-muffler.html

 

[turboglenn]

Sometimes i forget you sell allsorts of aftermarket auto parts I guess talking to you is about the closest i can come to having an inside man at Summit/Jegs , what about the warlock bypass mufflers? Thta's a pretty free flowing design, i don't mind giving up a little power, as long as it's not tons causing me to not even hit the desired boost levels i'm aiming for

I was thinking about making something like the warlock, but making the holes in the pipes much much larger, that way it stil breaks upthe sound pulses but should have little restriction what ya think about that
?

 

[99gst_racer]

Sometimes i forget you sell allsorts of aftermarket auto parts I guess talking to you is about the closest i can come to having an inside man at Summit/Jegs , what about the warlock bypass mufflers? Thta's a pretty free flowing design, i don't mind giving up a little power, as long as it's not tons causing me to not even hit the desired boost levels i'm aiming for

I was thinking about making something like the warlock, but making the holes in the pipes much much larger, that way it stil breaks upthe sound pulses but should have little restriction what ya think about that?

Paul knows parts. /BoJacksonVoice

We sell the Warlock mufflers, but I don't think I've ever sold one personally. I don't know how they flow or how they sound. The internal design looks very similar to the Super Turbo mufflers, with the addition of the straight through bypass section. With that section open, I have no dopubt it will perform fine on a DSM, but I don't know how quiet it will get with the cut-out closed (or blockoff plate attached).

In my experiences, the mufflers that have the most fiberglass packing are the quietest. They still sound great, but they heavily reduce drone. So if you're considering replacing the muffler only, I'd try to source out one of those types of mufflers.

 

[mike96]

I have wondered how effective (if at all) it would be to make an insert for the tip similar to liek the apexi comes with and some other brands? I didn't think they'd work all that well so i haven't bothered with them, but i guess it's an option although i'm looking for a more permanent one

I am kind of surprised you haven't made something yet just to see what it would sound like. Then if you like it you could make it more permanent. You could even do something a little different with it, something like a supertrap muffler...

Flowtech 50560FLT - Flowtech Warlock Bypass Series Mufflers - Overview - SummitRacing.com

Hahaha... hahaha... it is way to late for me to make any comment on that one...

 

[turboglenn]

Well, i started making a slip in baffle for the board member el Cuervo a long time ago and became ill and was hospitolized before i got through it, then after i got out i was really week for a month or so and never got back on the project, I intended to make one for myself too but due to the situation and the manythings i had taking up my time i just haven't bothered figuring it would jsut be rattly sounding and not do much

AS fo rthe warlock, i don't know why it's too late, I asked for info on it andhaven't gotten any, and i haven't made any changes to my setup yet as i'm still waiting for a good idea to run with and info on mufflers, so tell me about the warlock, please!

 

[Colt4G63 also]

I made two slip in baffles for my muffler, and it makes a huge difference. I have a 3" Ansa Silverline straight through muffler with two 2.75" outlets. I made inserts that knock the outlets down to around 1.75" each, and it eliminated the thruway drone, and got my noise violation ticket dismissed.

They only slowed my 1/4 mile time by a couple tenths of a second, but with an allen wrench and a pair of pliers, I can remove them in a couple minutes.

 

[Imback]

I know it's a late reply but you should look for a rsr muffler. By far the quietest muffler. While driving on the parkway it's barely noticeable but sounds mean at WOT.

 

[TheRaspberryKing]

Turboglenn if you still interested, I am having a straight through magnaflow installed in place of my test pipe. Current set up is 3" all the way through no cat, and thermal R. Dynoed @ 366hp at 26lbs on 110, and will re dyno after the install, on e85 now too (this friday) The car is SO LOUD I fear even driving it as it obviously doesn't have a cat and cant afford to get pulled over. luckily its not a primary but id like to drive it more than I do. I will post a before and after video.

I went with the Magnaflow 14419 and to be honest, i'm kind of worried as its on the small side. The 13741 would have probably been a better purchase but oh well. I might add a second one to be honest. They are both straight through, so hp wise you should be fine. After its all said and done I will let you all know.

 

[94exa2]

i would (if you can) just buy 2 3" vibrant ultra quiet resonators, one in place of the cat and one later as a resonator and a 3" vibrant stealth muffler

http://www.dsmtuners.com/forums/ven...-quiet-resonator-flat-black-mufflers-too.html

scroll down to post 17, theres a video of a dsm with cat and thermal catback with vibrant muffler, sounds great and is pretty quiet. probably be even more quiet with a vibrant ultra quiet resonator or 2