I'm really new to 4th gens as I just got a 98 Z28, but I need some help on my exhaust setup. The car currently has Edelbrock LT headers and the Edelbrock ORY into a dynomax bullet muffler. This setup is way to loud for me and I live in CA so I need to get some cats on there and a reasonable catback. I looked through the stickies but the only y-pipe I can find for long tubes are sold as a combo for the pacesetters/y-pipe package at TSP. I have the stock catback that I think I will put on but where can I find that catted Y that I need so I don't get a ticket? Thank you for any help.

- Rob

 

Not sure which will mate up perfectly, but anything is possible. The TSP catted y can be adjusted (it's in pieces), so you could probably make it fit. If worst comes to worse you can get an exhaust shop to do a little fab job and make it fit. Some 3-bolt flanges would be sweet.

Do a search for edelbrock and see if anyone is running cats.

 

What you want to do is have new cats welded (or flanged...) into your current ypipe.

This will save you tons of cash and be virtually perfect since you have no problems at the moment. Find a competent exhaust shop to do the work and you'll be done in less than one hour.

 

Thank you for the quick responses. I think I will try to have cats welded into the current Y-pipe. As for the that, will any hi flow cat work with the setup? Are there universal cats that I can use, or are there certain 4th gen cats that need to used? I have the O2 sensors from the stock ones, will those work with aftermarket cats? Thanks

 

cats are cats the only thing you would look for is diameter. all cats are - ceramic with holes in them.

 

Some of the cats have fow better than others, they have "bigger holes" in the catalyst. Search 3" magnaflow cat on eBay, I have the $55 ones.

 

They most certainly are not, there's 3 very different kinds and amoung each flow rates and performance vary a massive amount.

 

There are several issues here. However firstly if you live in CA then LT's are illegal PERIOD.

This is because they move the stock location of the cats, if you feel you can get away with this then it's your choice but sooner or later you'll likely get pulled up on it.

Passing a sniffer and OBDII is easy. A catted Y and tune out any SES warnings via EFI Live/HP Tuners. But you will fail a visual.

The only manifolds which are legal in CA are shorties, and strickly only CARB certified ones.

Sadly on a n/a setup shorties are pointless as they don't scavenge so you will loose HP moving over too them. LT's don't flow any better but they do scavenge which is what gives you the extra HP.

If you plan on FI then either shorties or LT's would work the same as scavenging doesn't tale place due to the intake air being forced into the cobustion chamber above normal atmospheric pressure.

The choice is yours on which route you go.

As for a catted Y, there is not one available (at least yet) for the Edlebrock's and they will not be making one either. So this means you will have to fab cats into the existing Y pipe. This will likely require some work as it's not simply chopping and welding them in. Catted Y's are angled to allow clearance of the cats. It's perfectly possible for an exhaust shop to carry out this for you, however in CA you may not find many shops willing to do this for you.

If you opt to do this then you'll want some good CATS. CATS vary a great deal and there many different types. A high performance cat for a 4 cylinder engine will likely choke a large displacement V8.

As a budget CAT the Maganflow Carsound CATS are very good (as used by TSP in their catted Y for Pacesetter headers). You'll want the 3" core ones. This are pretty decent on a bolt on/cammed LS1 and will hardly affect flow or HP.

If you plan on a serious FI setup then you really ought to step up to the next level of cat, which is Metal Matrix. these are offered by Random Technology (7000 Series). Again you'll want the 3" core variant and they are good for zero flow loss on over 500bhp. I believe Maganflow also has some of these metal matrix cats one the way or newly released.

If you check Ebay you can usually buy new Magnaflow parts way cheaper than from Magnaflow themselfs.

Lastly, catback. Well if you want a more sedate setup then take a look at some of the other systems, Magnaflow, Hooker, SLP Dual Dual are all know to obe quieter. But there are a lot too choose from. Essentailly any FULL system using a full size muffler as opposed to a bullet will generally be quieter.

 

Okay, update. I did have the LTs, ORY, Dynomax bullet. Now I have the LTs, ORY, 3" catback piping, stock muffler. Now I just need a nice muffler and tips.

Right now it is insanely quiet, sounds almost like a V6. So I've decided I hate bullets, and I hate stock mufflers. I need it somewhere in between. I thought Borla would have been good, but from what I read the Borla is just as obnoxious as a bullet. I guess what I like is tone, but I guess its just difficult to get that with LS1s and their exhuast setup. I'm still undecided on what to get, but at least its quiet now.

Any quick comments? Any muffler in particular give the most tone that a LT, ORY setup can have? Been searching for 4+ hours and still completely clueless.