Have searched a ton and it seems that the older our cars get, sadly the less available certain systems are that were all the rage in 2008. I have a mostly stock 2001 WS6 (SLP lid, ported TB, full suspension) that despite putting 100k miles on it over the years still looks like it rolled off the showroom a couple years ago. I've had the car since 2007 and don't plan to ever part with it, so I'm not opposed to investing into it but at the same time don't want to go overboard because I have other vehicles that will always be faster, but none that will ever have the heart and soul or be as fun to take out on a sunny day. I overhauled the suspension a few years ago and next on the list is letting the engine breathe better with a full exhaust, but I'm looking to keep the decibel levels close to stock at least during normal driving, and I want to keep ground clearance a factor since the car is lowered 1.25" already. I'm pretty happy with the way the car sounds right now and not looking to wake the dead on a Sunday drive. I live in Texas and know I generally want longtube headers based on searches, but the concept of catted Y vs offroad Y and then what exhaust pairs well with what I'm trying to achieve is something I'm unclear on. I've noticed that it seems to be something I mostly part together myself versus seeing any "full exhaust" kits that include everything from headers all the way back. Any guidance would be greatly appreciated.

 

If you want the volume level to remain as close to stock as possible, then you'll definitely want a catted Y-pipe. Deleting the cats will certainly increase the volume level no matter what system you use, including the factory catback. So plan to stick with cats if maximum quiet is your goal.

You are correct that many of the exhaust systems that were once readily available (brand new) for these cars have gone away over the years, leaving the only option being a used system (or something custom made with a specific muffler(s) if you want something very specific that was recommended in the past. The ideal system for what you're trying to accomplish would have been the SLP dual/dual catback, which hasn't been available new for a very long time but was offered as a factory option on LS1 SS cars and standard on LS1 Firehawks (therefore many systems were produced). But shipping used exhaust systems around the country is very expensive, so unless you can find a local system for sale this might not be the best option.

There are things you can do to pretty much any catback system to reduce the volume level without having any significant impact on flow. The most obvious option would be to add resonators/bullet mufflers to the I-pipe (or instead/additionally to the tail pipes). There are small diameter, straight-thru products of this nature that will fit in tight spaces and tone down the volume a bit. This might be something that you will have to do if you want an aftermarket system to be as quiet as the factory system.

Exhaust sound/volume recommendations are extremely difficult to make as everyone has a different definition of "wake the dead". Personally, I find the factory LS1 system to be MUCH too quiet for a performance V8 car (to the point of being boring), so what I consider to be a "good" sound of reasonable volume might be super loud to you. It's just so subjective.

 

https://www.borla.com/products/chevr...t-system-14780

I had this catback system on my 99 Z28 and I liked it. It’s adjustable but I kept the one side capped completely off. It was a little bit louder than stock but certainly not obnoxious. I didn’t have headers and used the stock y pipe.

Keep in mind that headers will increase sound especially if your y pipe has bigger tubing, but it’s not over the top.

 

If you want a quiet rumble that's just slightly louder than stock get a magnaflow catback. Check youtube for sound clips theres millions of videos out there of catback exhausts on fbodys.

 

No cats and Magnaflow!! After 3 different setups that’s what I settled on and I’m finally leaving it the hell alone. Nice, deep rumble (no drone) that still gets really rowdy when you lay into it.

 

I thought about a Magnaflow for a second but I found the idle rumble to be lacking with stock everything else. I’m not a mega loud advocate but the Magnaflow is too stock esq for the money for me. That being said, the muffler I went with was a little quieter than I was expecting as well.

 

Me too. I was surprised what little a muffler swap did as far as increasing how loud it is.
What about this for an idea. What about a Y pipe with just one cat? I have a car that came with duals and it had 4 cats. I removed two and the sound volume increased quite a bit. It’s OBDI though, so there weren't any check engine lights to contend with.

 

Engine Masters tested different set-ups. From single to duals. Mandrel bent to crushed bent. Cheap "turbo" mufflers to pricey ones. Header collector lengths was a different episode. It was very interesting and worth watching . The HP range was more than just slight.

 

Just found out that my 2002 T/A WS6 I just bought has Borla cat back on it. Previous owner paid $1600 for the system. 1400 and 200 to install it back in 2006. Same system is $1100 at Summit today. I found the paper work in the glove box.

 

How much power was the engine making? It’s rare to see a “parts shootout” where they test the parts or a stock or “stockish” motor. For example I read a muffler comparison article where they were using a 600 horsepower motor to test them. Well, that’s cool but a muffler isn’t going to choke down a 300 horsepower motor the same way it will a 600 horsepower rig. The articles seldom if ever state that, so now the general public thinks that X muffler is costing their 300 horsepower car power. I get why parts mfg’s and vendors always test their parts on motors that make too power for stock parts, (so they can show that their parts can add power) but it’s a fairly bogus tactic.

 

I'm not positive. It might have been a 351 Windsor with roughly 420 hp or maybe it was their famous 406 SBC. I believe some of the episodes are on you tube. I really like the Borla system and the main reason is I didnt have to pay for it ( so to speak) I would not drop $1100 for an 8 to 12 claimed hp increase. IMO 8 to 12 means 0 to 4 . I owned the car for 2 months and just noticed different chrome tail pipes. I was on the creeper and noticed they weren't just bolt on tips so I went thru the paper work for the car. I'm not altering anything else on this car it has only 6600 miles on it. Still learning the ins and outs of the LS1 engine. I also own a 1978 Trans Am with a 406 SBC with an estimated 450 hp. Hedman headers, flowmaster exhaust, etc... it is very fun to drive.

 

That thing is sharp.

 

Among all this should I delete AIR and EGR if I go to American Racing or Kooks longtube headers? Anything else I should be factoring in?

 

There would be no EGR to delete on a 2001 model, they didn't come with it.

I think AIR delete is a given though. Does Kooks or ARH ever offer an option to retain the AIR system?

 

Why go "Y" when you can go "H" and be emissions compliant?

Hooker Headers

I run this on my 98 Z28 - excellent fit, though I had to lose the conv't floor brace

 

That system you have posted above is nice, and would pass inspection if using the version intended for the stock Y-pipe (thus retaining stock manifolds & cats). But no system will technically be emissions compliant if the OP plans on LT headers (which he has mentioned a couple times above), regardless of a Y or H pipe arrangement. Any LT headers will necessitate a relocation of the cats, rendering the car unable to pass the strictest of visual inspections - but that's not necessarily a concern in some locations (and even less of a concern as these cars are now reaching 25 year old status, making new exemption options available in some areas).

On a side note, the "50 state legal" version of that system is listed for 1998-2002. But it can't possibly be a direct bolt-on for a 1998-99 car as the passenger side Y-pipe would have to be cut after the cat. On your '98, did you weld it place or just do some sort of clamp or custom flange on that passenger side?

 

IIRC I needed to cut off the flange on the existing "Y" and weld it on the "H" piece. I had a lift at the time and as a journeyman metalworker it was no issue.

Headers did not enter the picture as I wish the car to be emissions compliant for resale if needed.

 

I’m in TX where emissions are just a computer scan and not a visual so a tune takes care of that, and in a couple years my 01 will hit 25+ status and be exempt anyways.

How does a full Hooker long tube plus H pipe setup like the one you suggested compare to something like an American Racing LT, Y pipe, going to a Magnaflow/Borla/Corsa exhaust given the weekend warrior use case of the car?

 

Any time you go with a true dual setup (H, X, or no crossover at all) it will eliminate the Kazoo-on-crack sound that is a risk with many ORY systems. But if you plan on cats either way, this isn't really a concern.

For me, I never incorporate cats into any of my custom exhaust setups, especially ones that involve headers, so true dual is always my preference whenever there is a way to make it fit. Only way I would consider leaving the cats is if/when I don't have any intention of pulling the manifolds.

 

Im getting ready to take the Kooks true dual exhaust off my car. The exhaust has no cats and it will be for sale. If you are interested shoot me a pm please.