I've ordered my SR 4-2-1 headers and I have a few questions about them and my exhaust.

1. Will it hurt anything to install the headers the way they come, or should I get them ceramic coated or heat wrap them?

2. I need to get a high flow cat, but I don't know which one to get. I called Summit Racing, and they said I need to know the inlet/outlet size, and the length and the width of the cat I want. They carry them in 12in., 14, 16.5, and 18in. lengths.

3. I have a 5 speed, and was wondering if I should keep my 2.25 exhaust or go to 2.5. I'm looking to get the most performance out of it without affecting the normal drivability of it too much.

Any help will be appreciated very much.

 

1. I think it will be fine without any external coating.

2. You need 2.5 inlet and 2.25 outlet. I am not sure about length though.

3. Your 2.25 exhaust should be perfectly OK.

 

If you install them the way they come, wipe them down with a rag soaked in rubbing alochol before starting the car for the first time. Otherwise you will have fingerprints permentantly etched into them. Ceramic coating keeps them looking nice, and helps them to perform better. For about $120 to $200, it's hard to go wrong. Heat wrap also works, but is the "budget alternative" to ceramic coating. The Ceramic coating looks 1000% better, but the heat wrap should cost you less than $100. For the performance gain and appearance gain, if you can afford it, get them ceramic coated inside and out.


There is a group buy going on cats. You might want to get in on it. If you keep your stock exhaust, you should stick with 2" in and out, that is what the stock system is. If you want to go with a whole new exhaust, go with a cat that has the same dimentions as your chosen exhaust. 2.25 in and out with 2.25 exhaust. 2.5" inlet and outlet for a 2.5" exhaust.


If you have an aftermarket 2.25" exhaust you should be fine with that. If you are talking about the stock system, upgrading to a aftermarket 2.25" or 2.5" would help. The 2.5" exhaust may hurt your "low down" torque, but help your top end. Since you got the 4-2-1 headers, the headers should help offset this. If you go with the 2.25" exhaust, you should have load more midrange but not quite as much top end as the 2.5" system would give you. the 2.5" system will also be louder.

 

The 4-2-1 headders are 2.5" out, or mine were, before you get a cat wait for the headers and make sure of the size. Please do the whole exhaust with the headders, you won't get much of a gain on the stock exhaust with the headders.

 

Thanks for the help guys. I would get in the group buy for the cat, but I guess I'm just too impatient. I want to get one as soon as possible so I'll be ready to go when my headers get here. I'm still a little unclear about the cat though. I know about the inlet and oulet sizes, it's just the length and width of the cat that I need to know about. Should I just get the same size cat as the one that's on there now, or a bigger one?

 

Just wondering if you could explain exactly what ceramic coating is and where it can be done. Does it keep the chrome look of the headers or does it change them

Thanks

 

Robert. Since you are going to have a custom exhaust built to match your headers and new cat. The length of the cat really does not matter. Depending on WHOSE cat it is, usually the longer length means more catalyst material inside, and cleaner exhaust, but more backpressure.

In general, try to get one to equal the length of the stock cat. Also, find out if the manufacturers length is "end to end" or just the length of the cat itself, minus the end pipes.

redturbulance-
Ceramic coatings come in many different types.

In general, exhaust and intake parts should be 'dual coated'. The inside should be "flow coated" (each company has their own way of saying this). The flow coating helps improve the air flow, no matter if it is intake or exhaust. However the exact compostion of the coating is different. the exhaust coating needs to be much more durable.

The exterior exhaust should have a "heat absorbing" coating that keeps the heat of the exhaust IN the pipe. Intakes should have a "heat reflective" coating that keeps heat OUT of the pipes.

There are many companies that offer ceramic coating on various different engine bits. Pistions, valves, headers, intake manifolds..etc..etc..

Microcoating Inc.
High Performance Coatings (HPC)
Swain Tech Coatings

There are many others out there too. I suggest you do an internet search on "Ceramic coatings" to find more compaines.