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Discussion Starter · #1 ·
Hi all,
I’m making this thread to thank everyone on this forum and as well to post my progress of my 1991 3000gt SL over the past year. I pretty much learned all my mechanical knowledge from this car and found out what I want to base my career around through it. I took my time on this car as funds were short but in the end it’s been worth it and I’ve grown extremely fond of the car.
anyways, The car is almost completely done and all I have left is to press new front wheel bearings Into the knuckles and switch out my cv axles.
As This car comes to being completed (driveable) I am reaching the point where I want to start making it my own. Mainly an exhaust. I would like to hear from someone who has previous experience messing around with the stock exhaust. I’m not interested in power gains quite yet. I just want a louder exhaust that sounds good, without getting too raspy or overpowering. I’ve heard that the stock exhaust sounds pretty good when you get a flowmaster on there. I’m thinking of putting one on mine but I wanted a second opinion first. I am open to any suggestions anyone might have as well.
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Lovbyts
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Gut the cats or better put in down pips, test pipes and that will make a big difference. You can change the rest later if it's not loud enough for you and you will get some HP boost.

Is that your garage? You have a lift?? Life would be so much easier if I had a lift. 40 years of working on cars laying on the ground, cardboard or a creeper removing exhaust, transmissions, rear ends etc. lol
 
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LS3S
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Just my opinion, I wouldn't go flowmaster, chambered mufflers in general are not the best sounding. Sounds like you should either go with either what Paul said or just get a generic cheap ebay catback. Search youtube to see what sound you like.
 

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Discussion Starter · #4 ·
Gut the cats or better put in down pips, test pipes and that will make a big difference. You can change the rest later if it's not loud enough for you and you will get some HP boost.

Is that your garage? You have a lift?? Life would be so much easier if I had a lift. 40 years of working on cars laying on the ground, cardboard or a creeper removing exhaust, transmissions, rear ends etc. lol
Life is much easier with a lift 😂. There is so many things I’ve done to this car which would be a pain in the a** without it.

I also didn’t think of gutting the cats. What would be the process of that, just get a screwdriver up in the Downpipe with a hammer? My only concern is that the exhaust is too rusty to unbolt without stripping something.
 

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LS3S
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Maybe toss a cutout right before the big muffler out back? Cats do a great job of smoothing out the sound, so it should not be raspy and won't be too loud...you can also make it quieter when you want.
 

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Discussion Starter · #7 ·
Yeah I don’t like the idea of gutting a cat 🐱 but If I got a test pipe along with a cutout how would that sound? I just really don’t want my car to sound like one of those riced civics ripping through neighborhood's at 3am.
 

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I have a 92 VR4 that I gutted the pre-cats and put a test pipe on in place of the main cat. I absolutely love how it sounds. I haven't turned on my stereo in two years since I did the exhaust mod. It's not too loud or raspy, definitely not like a loud civic. It has a real nice burble when you let off the gas and no back firing. Gutting the pre-cats involved a drill and a longish spade bit, gloves and a good dust mask and goggles. Mabey 10 minutes each? This was the cheapest rout for me and am super happy how it turned out.
 

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LS3S
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A cutout after the stock cats will not sound like a riced out 3am civic. Is there a flange near the back of the car, before the muffler? If so, just disconnect that and see if youlike the way it sounds. If you do, weld a cutout back there.
 

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Discussion Starter · #10 ·
A cutout after the stock cats will not sound like a riced out 3am civic. Is there a flange near the back of the car, before the muffler? If so, just disconnect that and see if youlike the way it sounds. If you do, weld a cutout back there.
😂😂 So I did some research on a cutout and now I’m thinking of getting a valve kit for it. I have an extra red safety racing switch I bought from Canadian tire I’m gonna hook it up to as well as gutting my cats. Either go big or go home right. I’m gonna take the flange apart and see how it sounds first but that’s probably what I’m going to do. I will post videos afterwards of the setup.
 

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LS3S
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If you gut the cats AND do a cutout, it may not be the exhaust note that you are searching for, unless there would still be a muffler or resonator before the cutout.
 

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Discussion Starter · #12 ·
If you gut the cats AND do a cutout, it may not be the exhaust note that you are searching for, unless there would still be a muffler or resonator before the cutout.
What about just a test pipe and a cutout? If I did the cutout I like the idea of a variable exhaust note.
 

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LS3S
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test pipe = gutted cats. There may be slight differences in sound because of the shape of the piping, but a test pipe just eliminates the cat. Gutting the cat does that as well, just in a different way.
 

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Discussion Starter · #14 ·
test pipe = gutted cats. There may be slight differences in sound because of the shape of the piping, but a test pipe just eliminates the cat. Gutting the cat does that as well, just in a different way.
so Sl's have no precats correct? If I mocked up a test pipe it would purely be to get $ for scrap value on the cat. now if I put the cutout right at the end after the "muffler style resonator" how would that sound with the test pipe. ill do some messing around with the exhaust tomorrow and see what sounds best.
Thanks for the input all.
 

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LS3S
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I am not sure how the exhaust is designed on your car, but a cutout after cats and a resonator would likely sound pretty good and smooth. Have a picture of your exhaust?
 

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dragonsteel12,

I have a 93 3000GT NA, manual transmission, also white like yours that I recently installed this exhaust from 3SX Performance, 3SX NA Catback Exhaust System w Quad-Tips Stainless Steel Cat-Back. I love the way it sounds, but it's much louder than the stock exhaust. I also installed 3SX's "Test Pipe" to replace my catalytic converter. Since I don't have the turbos, I don't have the pre-cats, and since you have an SL, I don't believe you have the pre-cats either. Being in North Carolina, I have to re-install my catalytic converter each year when I take the car to get its yearly inspection. I had to do that a couple months ago and it wasn't too difficult, even without a lift. I have to use jack stands.
 

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Lovbyts
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I gutted my cats (PITA) and had to use a 1in or larger flat wood drill (Spade), hammer and chisel and should have worn a mask due to all the dust from the cat. Ive since replaced the precats with cat back down pipes and a test pipe for the main cat. I have 2 of these (attached picture) resonators for over 10 years and still love the sound. Not loud at all unless I'm punching it but has a nice low tone so you know its there.

I like the cut out idea for those times you want to be obnoxious but would use an electronic cutout. If your car has the dual tone exhaust like the TT you could wire it to that switch. I have always though about doing that but never got around to it.

Yeah like I said I can only imagine how much easier life would have been with a lift. Guaranteed I have done everything you are doing at least 2x over the last 25 years Ive owned the car. Now imagine doing that only using jack stands and/or ramps. lol
 

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Discussion Starter · #18 ·
Alright guys, been doing some more research into the subject and I’m not sure about the cutout anymore. I’ve seen videos of people doing muffler deletes on these cars which is pretty much the equivalent of a cutout before the muffler.
- skip to 10:40 for sound clip.
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so In the video they cut the exhaust right about here which is right about where I’d install the cutout. It sounds like shit.I have 3 items on my exhaust right now. Headers >> 1 cat >> resonator >> muffler. I really like the sound of a cat delete and I may end up just gutting my cats. But I really really like the idea of an electronic cutout. Now Im debating wether I should just get an aftermarket resonator in place of my cat and still do a cutout. What do y’all think? I want more of a similar sound to this clip but throatier.
 
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