BLKZ28VERT

After searching this board for the last few months, i have decided against true duals, to go with a y pipe. With that said, i have some money coming back on taxes, and i wanted to replace my stock exhaust. It seams as there is a good deals on Kooks products right now. Other then a lid, this would be my first mod, and definately my first major mod.

With that said, it is to my understanding that i can either get headers with EGR / AIR fittings on them or Kooks race headers.

1. As far as i understand it, the EGR / AIR is not something that i need. I am leaning towards getting race headers and removing all of this crap as i live in MN and do not have any omissions. Any suggestions on which headers to get or what experience you have had?

2. I am leaning towards a catted y pipe. Going to an ORY typically leads to a "raspy" sounding exhaust. Any suggestions?

3. I have listened to LS1sounds and know what i want as far as sound. I am looking for something that is relatively quiet at idle, but sounds great when i get on it.

4. Is it difficult to remove and plug the EGR / Air?

Thanks,
BLKZ28VERT

Greekey

iTrader: (3)

1) Dont go out and spend 1000 on some headers, its bullshit. Some 300 to 400 dollar headers is all you need. I have used pacesetter and BBk headers in the past, and the bbk headers were the best fitting headers I ever used. And they tucked up extremely well under the car for clearences. You cant go wrong with either one.
2) Magnaflow is queit at idle, and sounds good at Wot
3) Piece of cake.

BLKZ28VERT

What about the catted y vs. ORY??

RPM WS6

iTrader: (3)

If you live in an area with no emissions testing, then you will be fine with removing AIR and EGR.

Furthermore, there is no reason to spend money on cats if you do not have emissions testing. Even the best flowing cats will not outflow an ORY, so you will be spending more money for less performance. IMO, this is counter productive to the purpose of buying headers, and unnecessary since you don't have any sort of sniff/visual emissions testing.

Rasping can be an issue with an ORY, but if you use a high quality Y-merge (something built like the Flowmaster Y-merge) and a one of the mellower sounding mufflers, rasp will be minimal. If there is still enough rasp to bother you, then Dynomax race bullets can be added to the I or Y pipe. These are cheap, flow better than cats, and normally will remove any rasp in combination with most mufflers.

babbage1109

iTrader: (11)

I have an ory and am about to buy some high flow cats to cut down on rasp...lol just get it and save the headache

BLKZ28VERT

you say lol......are you kidding or serious. I have the money now, and really would like to do this once, which is why i am leaning towards getting the catted Y. Are the CATS that are on the Kooks catted Y considered high flow cats??? Or am i better off buying an ory and purchasing higher flowing cats.

Also, if i am deleting the EGR / AIR, i read that i may need to plug a line that runs to the back of my intake??? Do you know if this exists on a 98 z28? If so, i would rather replace the ls1 intake with an ls6, and really get it all done at once.

Pitbull329

iTrader: (3)

My exhaust set up sounds great. Sounds great while cruising. Sounds awesome when you get on it lol

WSsick

iTrader: (13)

As RPM said, you can add a bullet to the exhaust if it's too raspy for your tastes (mine were $45/each). THe only real reason I would go with cats is to cut down on the fumes associated with any non-catted, free flowing exhaust. They won't be much at all, but some people can't stand the smell at all so I can see it from all perspectives.

BLKZ28VERT

...fumes associated with non catted free flowing exhaust? So when removing the cats, it creates an odor? By using cats, how much hp am i really sacrificing?

Like i said before, i really only want to do this once, which is why i am asking the questions.

Race headers = Best Choice

ORY = better flowing and more HP
CATTED Y = possibly causing odors?

WSsick

iTrader: (13)

Have you ever been in or around a car with true duals with no cats? I own one with that setup, and my girlfriend complains all the time about how I smell like exhaust. Cats + running the exhaust out the back help cure this. You aren't giving up a ton of power as such a low power level 10hp max.

I'd get the race headers so you don't have to deal with the EGR nonsense.

BLKZ28VERT

Yes, i used to have a true duals on my 80 malibu. I did smell like gas fumes when i drove with that car. I thought that maybe removing the cats caused a different smell then typical exhaust fumes.

Are there any other parts that i am going to need to do the install for Kooks Race Headers, Kooks Catted Y pipe? I would assume that i would need new header gaskets and i am planning on buying some new header bolts as well. Anything else that i would need?

CLRD4TO

iTrader: (4)

My wife complains about the exhaust smell every time shes in the car. To be honest, it is very annoying. Im considering cats myself.

1) Race headers. You will be surprized how much junk you pull out of the car when you take all the EGR/AIR parts out. The AIR pump weighs a ton! No performance gain but does clean up the engine bay.

2) Your decision. I have a pacesetter ORY and was disappointed when I got it. The merge sucks, just a hole cut in one pipe and the other welded to it. It does have that nasty rasp between 2200-2500 rpm.

I bought my car with a custom Y-pipe with bullets in place of the cats. The left bullet hit the floor board under accel. Poly engine mounts fixed that, but added engine vibration into the car. Also, long tube headers and ORY got more louder/raspy with my cam.

I have a Magnaflow cat back for sale if you're interested. Im in Burnsville if you have any questions or need some help.

Bramlok

iTrader: (7)

What's annoying? The wife complaining or the exhaust smell? But seriously, I'm considering doing the same and getting a catted Y. The exhaust smell gives me a headache after a while.

dutinsss

iTrader: (2)

i'd get an ORY and just use a muffler that's a little on the quiet side to cut down on rasp. a hooker aerochamber would be a good choice. i can smell fumes with the exhaust dumped but with it ran out the back i don't even think it's enouth to notice. besides emissions purposes, cats are a huge waste of money in my opinion. as said, any rasp can be cut down with a quieter muffler, a good merge, and if it's still there, put a bullet muffler in the I-pipe.

TechCam97

iTrader: (5)

Honestly man you'll just have to pull the trigger on a setup and see if you like it. People can go back and forth on here about what sounds good to them, or smells bad, or whatever else. The only way to find out what works best for you is trial and error. I've gone through a couple different exhaust setups before I settled on my longtubes and true duals run out the back with no cats. Personally I love my setup. No Y-Pipe setup can compete IMO, but that's just my taste. If after all the sound clips and research you want to run longtube headers with cats, y-pipe, and something like Magnaflow then go for it and see how you like it. If you don't like it, then there are always other setups you can try. I know that you want "to do this once" and do it "right", but that's just part of the hobby. I've redone things on my cars tons of times. Either it wasn't what I wanted or envisioned at first, or I just grew out of it and moved on to something different. Like I said though, line something up that fits your parameters and make the purchase. If you like the sound, keep it. If not, tweak with the sound a bit by swapping out mufflers or removing the cats. You'll eventually fine tune your car's sound to exactly how you want it.

RPM WS6

iTrader: (3)

Guess I'm lucky, neither myself nor the wife have ever had issues with the smell. My Nova has a super dirty exhaust (performance carb, cam, and of course no cats - ever), much dirtier than any stock LS1 without cats. It's only a problem if I have the car running in the garage for more than a few minutes (even with the door open, the fumes will still build up). Outside though, it's never been an issue.



This is another key consideration. I think a lot of the people that are bothered by the smell are people with exhaust dumped under the cabin. If you run it out the back of the car it shouldn't really be noticeable. I've had it exit just behind the tires as well as at the bumper, and neither one has ever bothered me in the least.



I agree completely. Over the last 10+ years I've gone through about 10 different exhaust setups on various LS1s and at least 3 on my old SBC. Since exhaust note is subjective, nobody is going to be able to tell you what will sound best to YOU. Like said above, listen to the sound files and such, but at the end of the day it's still going to be a bit of a gamble. If you don't nail it the first time, that doesn't mean you have to live with it forever. Don't feel bad if you have to make a change; we've ALL been there at some point.