3.8 N/A exhaust question

Jae 'Bird

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Dec 11, 2023
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19
Location
Edmonton, Canada
Vehicle Details
1990 Ford Thunderbird Base with PEP 151A, 3.8L NA V-6
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I've got a question for my fellow 3.8 na brethren. Do any of know how the sound on our cars change if the rear muffler is removed? Also, what about gutting... ahem... accidentally having the large last cat become empty or deleted? Reason I ask is I don't want to chop into my exhaust before knowing what it would sound like, I have a stock motor and I fully understand that it will not produce any hp gains, I just love the deep tone these v-6s make at lower rpm and just want it a little bit louder /deeper/throatier. I would also be open to changing the rear muffler to something like a flowmaster or something if it sounds good, all suggestions/inputs/sound clips are greatly appreciated! Btw, since I'm in Canada, there's no emission testing and cats accidentally coming off is not any problem with law. Thanks all
 
Get a trubenz setup for your car, the 4.6 sounds best with 2,5" duals and an x pipe. IDK about a 3.8, but just gutting the cats sounds like crap.
 
The 3.8 doesn't make a good sounding exhaust note, maybe some engine work like cam and headers it could. Just doing a muffler or cat delete it will probably sound like an old clapped out Ford Taurus.
 
Get a trubenz setup for your car, the 4.6 sounds best with 2,5" duals and an x pipe. IDK about a 3.8, but just gutting the cats sounds like crap.
Thanks for the suggestion, I looked them up and it says their systems are only for 92-97 cars while mines a 90, would it still work? I think it might be because my exhaust goes around the gas tank rather then under it, I figure?
 
Correct, Gas tanks are different.

I'm not a fan of 3.8s with exhaust, most of them sound ricey
 
I'm not a fan of 3.8s with exhaust, most of them sound ricey
^ this. With all intent of not sounding like a douche, if you wanted it to sound deep and rumbly you should've gotten a V8.
 
Check out some clips on YouTube. I find the 3.8 in the MN12 to have a hollow rasp that can be minimized so it doesn't sound like crap while still retaining the deep tone, or you can amplify it so it sounds like the worst V6 short of the industrial blender Nissan VQ35DE in the Infiniti G35 Coupe.

The 3.8 sounds much better in the MN12 than in the SN95, I'll give it that.
 
A bit off topic and not really an answer to your question since you are seeking low rpm improvements, but still a useful side note:

Removing the entire intake silencer assembly noticeably improves the sound at higher rpm under load, say 3,500 and above. It sounds less labored, and the tone becomes lower overall. It's no louder though.

Regarding the exhaust, I like mine to be quiet so I haven't given it much thought. Frankly I think in stock form, it doesn't really have any sound at all, at least none you hear inside the car.
 
^ this. With all intent of not sounding like a douche, if you wanted it to sound deep and rumbly you should've gotten a V8.
Without wanting you sound too mad... you should have read my first post about being new here, then you would know that I never had the choice/ never intended to buy a v8, long story short it was my dads that he passed down to me, that's why I'm wondering what I could do to my car. I appreciate the input though, I would buy a v8 if I could ever find/afford one.
 
A bit off topic and not really an answer to your question since you are seeking low rpm improvements, but still a useful side note:

Removing the entire intake silencer assembly noticeably improves the sound at higher rpm under load, say 3,500 and above. It sounds less labored, and the tone becomes lower overall. It's no louder though.

Regarding the exhaust, I like mine to be quiet so I haven't given it much thought. Frankly I think in stock form, it doesn't really have any sound at all, at least none you hear inside the car.
Thanks for this suggestion, I did remove the air silencer under-fender portion of the air box and figured it would help a little, but are you saying to remove more than that? How would I go about it?
 
My Buddy Chris_Murder put a trubenz kit on his 93 SC with a magnaflow x muffler in the middle where the third cat was and magnaflow mufflers in the rear. He also has kooks headers and it sounds really nice. As others have suggested the V6 can sound bad if you don't choose carefully. Considering yours is a 1990 with the original style fuel tank, Maybe get a Maganaflow 2 into one x muffler for the middle where the 3rd cat lives and put a magnaflow out back. Run a larger pipe from the middle to the back.
Unless you want to convert to the later style fuel tank. Which honestly I don't know if that is a simple or difficult change as I haven't done that type of fuel tank swap.
 
  • Agree
Reactions: Irv
Another option would be to have an exhaust shop Y pipe the rear exhaust past the differential and you could have two mufflers out back. Just a thought.
 
Subjectively, what I think works and doesn't work for the 3.8:

(y) Magnaflow, Dynomax
😐 Borla (love it on the 4.6, meh on the 3.8)
(n) Muffler delete, straight pipe, Flowmaster
 
The cyliders are the same volume as the 4.6, so other than the cadence, I'd expect them to sound similar, with the same pipes.
 
The cyliders are the same volume as the 4.6, so other than the cadence, I'd expect them to sound similar, with the same pipes.

That’s like saying the eagles sounds similar to megadeth because they use the same instruments 😆

You can get a good exhaust note with a 3.8 but it’ll never ever sound like a V8, I actually liked the sound of one of my friends previous SCs with mandrel bent true duals Borlas and a mid mounted x pipe resonator, it sounded like a 2JZ at certain RPMs.

Gutting cats/ muffler deletes on the 3.8 just make it sound like the exhaust fell off
 
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One of our local marching bands won some award from Metallica, but they do not sound the same, lol.
I get your point; nothing sounds like a v8. I mean "Moby Dick" by Zeppelin proved that, even for people not exposed to drag racing. :)
 
I feel like muffler delete will just make 90s beaters aggressively pass and race you more than they already do. I saw some guy buying a V6 in a parking lot, and I saw him later. A muffler delete was the first thing he did, and he showed me and it was cool and stuff, but I didn't really like that he was so quick to do it
 
No mufflers at all, on a set of gutted cats sounds like dick, lol. I hear that a lot, headed for the projects, lol.
The Red Cougar got the rebar treatment, and a set of mil eliminators. I'd post how to make them, but it's a defeat device, and illegal. Let's not get busted. :)
I have a brand new MBS box waiting to go in.2.5" duals with an x pipe.
 
My Buddy Chris_Murder put a trubenz kit on his 93 SC with a magnaflow x muffler in the middle where the third cat was and magnaflow mufflers in the rear. He also has kooks headers and it sounds really nice. As others have suggested the V6 can sound bad if you don't choose carefully. Considering yours is a 1990 with the original style fuel tank, Maybe get a Maganaflow 2 into one x muffler for the middle where the 3rd cat lives and put a magnaflow out back. Run a larger pipe from the middle to the back.
Unless you want to convert to the later style fuel tank. Which honestly I don't know if that is a simple or difficult change as I haven't done that type of fuel tank swap.
This is some of the most useful info yet, along with irv it sounds like magnaflow is more the way to lean, do know how long the center cat is? And I can only seem to find single in dual out magna's, any tips? I'm now looking at Dynomax's and they seem to be pretty good too, do you think if I just removed the rear muffler and replaced it with something like a magna or dynomax it would sound good?
Subjectively, what I think works and doesn't work for the 3.8:

(y) Magnaflow, Dynomax
😐 Borla (love it on the 4.6, meh on the 3.8)
(n) Muffler delete, straight pipe, Flowmaster
 
This is some of the most useful info yet, along with irv it sounds like magnaflow is more the way to lean, do know how long the center cat is? And I can only seem to find single in dual out magna's, any tips? I'm now looking at Dynomax's and they seem to be pretty good too, do you think if I just removed the rear muffler and replaced it with something like a magna or dynomax it would sound good?
Well, Even if you upgrade the system later on I think you have nothing to lose by putting a nice Magnaflow muffler on the original system to see how it sounds. Even if you changed the pipes and rear cat later you can reuse the muffler.
On a 1990 I don't know the size of the rear cat. On my v8 cars we are able to fit a magnaflow 11385 where the 3rd cat was pretty easily. It's a 14" long muffler. I'd imagine it wouldn't be much different in your case. If you can't find a magnaflow. Look for something else in a similar length.
 
Well, Even if you upgrade the system later on I think you have nothing to lose by putting a nice Magnaflow muffler on the original system to see how it sounds. Even if you changed the pipes and rear cat later you can reuse the muffler.
On a 1990 I don't know the size of the rear cat. On my v8 cars we are able to fit a magnaflow 11385 where the 3rd cat was pretty easily. It's a 14" long muffler. I'd imagine it wouldn't be much different in your case. If you can't find a magnaflow. Look for something else in a similar length.
Thank you so much for the help!
 
My first Tbird was a 3.8 when I was 15, I put a flowmaster 40 series on it, at the time I thought it sounded good, fast forward 19 years later and if I had that car today I would think it sounds god awful. I would just keep the factory exhaust.
 
Ok update, I found a magnaflow that I think will sound good replacing the old rear stock muffler, its a 11224 center in offset out and its a 2". My question is this, according to the article posted by theterminator93 I have 2" pipe, which should mean 2" outer diameter, and I googled it and apparently mufflers are measured with inner diameter which would mean that if I buy a 2" muffler it should pretty much fit right on the existing pipe, is this true? I just wanted to confirm if this is true, I definitely like the idea of not needing any adapters or anything.
 
14" is too long for the rear; I bought a set when I did the tbird, and the guys called and asked " where do you want us to put these"? I just bought the cheapest set that would fit for 25 bux each, and it's the best exhaust sound I've heard.
 
ah, ok that definitely helps. what was the brand of the ones you did put on? Or does a shorter, still 2" and offset exit magnaflow exist?
 
I'm sort of reviving a dead thread here but I have done some research and have some questions. I heard that an 18 in. muffler will fit midbody on the car and I was wondering if that means the body length of the muffler or the overall length? I think this one should work but I just want to make sure. https://www.magnaflow.com/products/...ght-through-performance-exhaust-muffler-12288

and then I was told by Grog6 that 14in. muffler wont fit in the rear where the oem was sits, what size then can I fit there? one might say that i could just leave the stock one but, since im taking it to the shop, i should do both at once so that I don't need to/ don't want to go back/ pay again. and lastly does magnaflow make a smaller than 14 muffler, that would fit? Thanks again for the help, its still cold here in Canada although its warming up so I'm planning how I want to start working on the bird as we creep into spring, although I'm still very busy with school.
 
You can still fit longer mufflers out back, you just can't tuck the long ones up in the recesses under the trunk (between the wheel and bumper cover) like the factory ones when they're too long. It's not a concern with a midmount muffler, as it just rests under the drive shaft ahead of the gas tank behind the cats.
 
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