Anyone ever see a V-6 Thunderbird engine? I helped a friend part one out last weekend, and the cats were attached right at the end of the shortie headers, literally hanging right next to the block, and then connect to a Y-pipe. Is this possible in a 3rd-gen V8 F-body? Would it burn out the cats?

 

Off the top of my head, I'd say no it's not practical, but I'm sure it is possible. Why would you want to do that in the first place?

 

It sounds practical to me, especially if I want to convert from single to dual cat exhaust. That's the only real reason I could think of, except maybe to allow space for subframe connectors. Would the cats get burned out that close to the block?

 

well the stock dual cat setup on 3rd gens is similar to that....the cats are located in the "branches" of the y-pipe, before the 2 pipes converge. i really wouldnt bother converting a single cat setup to a dual cat one, unless you were going to run true dual exhaust and still needed to have the cats to pass emissions.

just get some nice shorty headers, good mandrel bent y-pipe, cutout, a highflow cat (if you need cats), and then a nice 3 inch mandrel bent cat back (or you could run the cutout open all the time......i would do this but you might not like how loud it is)

 

Actually, that's exactly what I want to do; dual cats for true dual, with two mufflers. Very similar to the one that was posted not too long ago on here. This project is still far down the road for me, but I like to plan ahead. I'll need 2.5" piping at most.

 

i am running true duals w/o cats.......2.5 inch piping, and 2.5 offset in, centre out hooker aerochambers. i have flowtech shorty headers, 1.5" primaries. i love the sound.

if you dont need the cats to pass emissions, then dont use'm

 

NJ emissions testing is a bitch, trust me. I hear Canada doesn't have to worry about emissions as much as the states do, but NJ is one of the worst when trying to pass, next to California. I definitely want to go true dual and still have cats and mufflers.

 

ontario has emissions testing, and i will have to be tested next year for the first and last time. there are ways around it though, so i should be okay.

 

Anyone tried gutting (cleaning out the insides) of your dual (or single) cats and just leaving them on?

i talked to a guy who had this done and he swore he didn't loose any low end torque - which is a negative side effect of removingthe cat's altogether - but instead FELT a noticable improvement in power thru out the power band.

also, by leaving the shell of the cat's connected he doesn't throw codes (SES light) all the time.

giff

 

The closer up you put them, the less of a restriction they'll be. A lot of newer cars I saw up at the chicago auto show are designed this way now, a good half of the engine cutaways even had the cats attached to them and cut open. Must be doing it for a reason.

Its still funny for me to hear about "dual" cats, I've got 6! Well, the camaro has none... and the stand will too soon.

 

If you even think your going to have emission problems don't throw money away. Get a set of quality smog legal headers that go into a brand new 3 inch cat. There are companys that build the mandrel bent 3 inch exhaust intermidiate pipe for our cars and then get the 2 1/2 tail pipes seperate for much cheaper than a catback costs, then put on a 48083 flowmaster muffler and some chrome tips and you gotta sweet exhaust system that looks like nothing but money.

Also depending on the year, Most T-bird v-6's have 2 pre cats right off the manifolds that assist in lighting off the main cat/s to finish cleaning the gut wrenching air they puke out. There is nothing special about it except it helps them to get by emissions and they cost a fortune to replace.

 

The LS1 F-bodies have a setup similar to what you're saying the Thunderbird does.

Having the cats closer could hurt them, but no more than running lean does. Most cats are good for temps up to 1600*, so you gotta watch how close they are. It's not hard for headers/manifolds to reach 1300*, so that's only a 300* margin.

AJ

 

Question about this Thunderbird: Was there another cat after the y-pipe?

The vehicles I've seen with the cat right at the exhaust manifold also had one in the "traditional" location. The reason for that was they are two different types of cats, to handle different types of pollutants. The first one (I forget its exact type) needs a lot of heat to operate properly, so that's why they put it close to the engine.

FWIW, emissions laws require the cat to be located in the factory location, where the factory had it when the vehicle was certified.

 

my friends dodge conquest 2.6 liter turbo has a cat right after the turbo/manifold, looks weird, it points down. i guess it works