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Nice job cleaning that up! I bought one of these systems brand new from SLP in the early 2000s, and it didn't look any better than what you have pictured above when it came out of the box. Please tell us more about the "aluminum brightener" - is that the exact name of the product? Was it NAPA house brand? Looks like good stuff. It would be a whole lot of work to clean it up like that with standard metal polish.
I'm in the same 45+ age group, but I couldn't imagine adding cats AND a resonator to a system that quiet, unless maybe it was a daily driver. I still like my toys to have a bit more noise, and some exhaust aroma. In fact, as I continue to age and my hearing begins to deteriorate, I'll probably want more volume rather than less.
Thanks RPM, this is the stuff (acid based) it took two passes with a nylon scrub brush and done. No metal polish, wire brushing, or anything of that sort.
I’m in love with how quiet my new to me 02 is. Such a pleasure to drive. I’ll soon be swapping everything over (that never hit the road yet) from my ‘96. I recently killed all of my build threads but I’m sure you know where to find them lol. Working to make life more simple for myself and thin the heard.
Nice job cleaning that up! I bought one of these systems brand new from SLP in the early 2000s, and it didn't look any better than what you have pictured above when it came out of the box. Please tell us more about the "aluminum brightener" - is that the exact name of the product? Was it NAPA house brand? Looks like good stuff. It would be a whole lot of work to clean it up like that with standard metal polish.
I'm in the same 45+ age group, but I couldn't imagine adding cats AND a resonator to a system that quiet, unless maybe it was a daily driver. I still like my toys to have a bit more noise, and some exhaust aroma. In fact, as I continue to age and my hearing begins to deteriorate, I'll probably want more volume rather than less.
Is it the cats that make the stock exhaust so quiet? They aren’t very long but they’re relatively wide (that’s what she said). I bet maybe there’d be a little more rumble w/out the stink if one could figure out a way to get a set of $30 universal “high flow” cats in there. They’re 11” which I think might be a little longer than the stock ones, but they’re not near as wide, so maybe they wouldn’t cancel the noise as much.
I once put a set on a car that didn’t have any cats prior and it was indeed quieter with the cats but it was still sufficiently loud. I was looking at pics of the stock cats and it looks like it might be a little more involved fitting and welding a universal one in there than on other vehicles. Imagine credit goes to @RPM WS6
Thanks RPM, this is the stuff (acid based) it took two passes with a nylon scrub brush and done. No metal polish, wire brushing, or anything of that sort.
Great information, thank you!
Originally Posted by Y2K_Frenzy
Imagine credit goes to @RPM WS6
I thought that looked familiar. Just for the record though, those are the 2000-02 cats. The 1998-99 cars used a noticeably different passenger side cat:
Originally Posted by Y2K_Frenzy
Is it the cats that make the stock exhaust so quiet? They aren’t very long but they’re relatively wide (that’s what she said). I bet maybe there’d be a little more rumble w/out the stink if one could figure out a way to get a set of $30 universal “high flow” cats in there.
Perhaps, but this presupposes that the smell is a problem. I guess it might be for some, but I just don't see the big deal personally - especially if the engine is internally stock and it's a well-tuned EFI setup. When I had a stock LS1 that was catless, I barely noticed the smell compared to the Gen I 355 SBC in my '71 with a moderate overlap cam and an old Holley toilet bowl on top of the intake.
I thought that looked familiar. Just for the record though, those are the 2000-02 cats. The 1998-99 cars used a noticeably different passenger side cat:
Perhaps, but this presupposes that the smell is a problem. I guess it might be for some, but I just don't see the big deal personally - especially if the engine is internally stock and it's a well-tuned EFI setup. When I had a stock LS1 that was catless, I barely noticed the smell compared to the Gen I 355 SBC in my '71 with a moderate overlap cam and an old Holley toilet bowl on top of the intake.
Once I lived near a town that smelled like cow poop. You could smell the town for miles. Those passing through naturally thought it was horrible but the locals said it smelled like money.
I’ve had two cat less cars. One I hollowed out the cat and I can’t say if it smelled or not honestly. I was a kid and it’s been nearly 25 years. My most recent cat-less car was something like 10-12 yews ago and it had a stink prior to adding high flow cats. It wasn’t horrible but it smelled like a gas pump kind of.
Last edited by Y2K_Frenzy; Mar 2, 2024 at 07:37 AM.
^ Eh, I'm a Gasophile so the smell is generally pleasant to me rather than bothersome. It's only bad if the engine isn't running right with severe misfires, etc.
You can get true duals and headers, along with the necessary panhard relocation bracket from speed engineering. Comes with everything you need. I think all in is under a grand.
The best sounding exhaust I've tried is the Hooker aerochamber catback, which is actually pretty quiet at lower throttle. I stupidly replaced the one I had with a Magnaflow about 10 years ago. The Magnaflow is OK, but not as nice sound, and louder than either the Hooker or stock, and also it hangs down too low over the axle and haven't found a good way to fix that. Also I hated the Magnflow tips, and replaced the entire tailpipes with turn-down ones that were used on the 90's era firebird that I really like. If I go back to an aerochamber I'd have to have the tailpipes replaced with my current ones, since the tips that come with it are also crap.
The best sounding exhaust I've tried is the Hooker aerochamber catback, which is actually pretty quiet at lower throttle. I stupidly replaced the one I had with a Magnaflow about 10 years ago. The Magnaflow is OK, but not as nice sound, and louder than either the Hooker or stock, and also it hangs down too low over the axle and haven't found a good way to fix that. Also I hated the Magnflow tips, and replaced the entire tailpipes with turn-down ones that were used on the 90's era firebird that I really like. If I go back to an aerochamber I'd have to have the tailpipes replaced with my current ones, since the tips that come with it are also crap.
The Hooker Aerochamber is a good choice, and also one of the few catbacks/mufflers that doesn't really have any serious rasp/Kazoo sound with an ORY. It's very similar to the Bassani system that I have on my '98, but Bassani discontinued their 4th gen F-body catback at least 15+ years ago. This is not to be confused with the Bassani true dual system that was also offered long ago; they had a 'normal' catback as well with two muffler choices - Street Competition or Quiet Thunder. I went with Street Comp and it was perfect (QT was supposed to be quieter, which would certainly have been too quiet for my taste). The Street Comp sounds nice with stock manifolds and cats, but was pretty loud (though totally Kazoo-free) with headers and ORY. Probably not going to find one of these systems used though, they were pretty rare when still offered and they've been gone for so long I doubt many other folks even still have one.
When I bought my car it had the SLP Loudmouth exhaust. Having just the one tiny muffler it wasn't awful, but I had cats. Still going through a drive through wasn't any fun. I had to shout to order my food. So I bought the Magnaflow and added a resonator in the tunnel. Better but not super quiet, gf still said it was still a little too loud for her.
Has anyone tried the Gibson exhaust? PN's 320000 and 620000? This has their chambered muffler with the "X" inside it, I think they use that muffler on their truck stuff so maybe its quietish.
It would be really nice if someone did a stock replacement or SLP Dual Dual knockoff in 409 stainless. I'd buy one of those!
Fast forward until now and I have a turbo kit on my car with the Magnaflow with resonator but no cat. Its still a little loud (or maybe I'm just too old!). The shop installed a boost cutout but it and the whole exhaust sit too low and the exhaust tips are crooked. So I have a few ideas.
1) Put a cutout in a spot that doesnt drag. Add a 200 cell metal cat and add a couple baffles in the exhaust tips, essentially turning them into glass packs.
2) Try the Gibson with the cat, a resonator in the tunnel and two small resonators/glasspacks right before the tips.
3) Go back to the SLP Loudmouth, but on the pipe leading to left exhaust tip put a Walker Quiet Flow muffler and then a glasspack to the exhaust tip. On the pipe leading to the right side exhaust tip put another cutout. So basically making it like the Borla with cutout. Probably would be a little quieter and I have all the parts.
Anyhow, if anyone has any other custom solutions I'd love to see pics!
Small diameter restrictive exhausts muffle the best. They also happen to be the cheapest. Get your cutout situated. Then run a single 2.25" (or even 2") back to any factory replaqcement muffler that fits well. Walker sells a ton. Factory cat back units work well. Will have a factory quiet sound when the dump is closed.
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I bought one of these systems brand new from SLP in the early 2000s, and it didn't look any better than what you have pictured above when it came out of the box. Please tell us more about the "aluminum brightener" - is that the exact name of the product? Was it NAPA house brand? Looks like good stuff. It would be a whole lot of work to clean it up like that with standard metal polish.
Just for the record though, those are the 2000-02 cats. The 1998-99 cars used a noticeably different passenger side cat:
