Chef

ok, got the CAI and tune. addicted now. whats next ? exhaust? how many horse do you get? what is x pipes? what is a cat back?

CrazyAl

There are many parts to an exhaust system. Starting from the engine:

First is HEADERS. These replace the OEM cast-iron manifolds. There are two kinds on the market. Shorty headers and Longtubes. Shortys are a waste of money, IMHO. They are worth 3-5 HP. Longtubes, on the other hand, are worth about 20 HP.

Second is the midpipe. Midpipes are available in two basic types: H-pipes and X-pipes. This describes the shape of the pipe. H pipes sound more "old school" compared to X-pipes. However, X-pipes have a slight flow advantage. The stock setup is an H-pipe. You can get these without catalyic converters (called an "off road pipe") or with high-flow cats. Offroad pipes are worth up to about 10 HP and are NOT street legal. High-flow catted versions aren't quite as good, maybe 5-7 HP.

Third is over-axle pipes: a set of tubes that travel from the midpipe back to the mufflers. Nobody replaces just these. However, see below:

Fourth and finally you have the mufflers themselves. Replacement mufflers are also called "axle back" becasue the mufflers begin right after the rear axle. Some dealers sell a package that includes mufflers and new over-axle pipes--which is called a "Cat-back". These are functionally the same thing, though the cat-back kit is more expensive. This is not worth any more HP, but is a popular mod becasue it changes the way your car sounds.

As you can see, Longtube headers is really where the power is. Unfortunatley, they are expensive and time consuming to install. Wether they are worth it or not is up to you.

There are various other mods that are a much better bang-for-the-buck, such as underdrive pulleys (UDPs), CMCP delete kits, and so on.

Chef

very helpful, thanks brother

Doomtroop

[quote]ORIGINAL: CrazyAl

There are many parts to an exhaust system. Starting from the engine:

First is HEADERS. These replace the OEM cast-iron manifolds. There are two kinds on the market. Shorty headers and Longtubes. Shortys are a waste of money, IMHO. They are worth 3-5 HP. Longtubes, on the other hand, are worth about 20 HP.

Second is the midpipe. Midpipes are available in two basic types: H-pipes and X-pipes. This describes the shape of the pipe. H pipes sound more "old school" compared to X-pipes. However, X-pipes have a slight flow advantage. The stock setup is an H-pipe. You can get these without catalyic converters (called an "off road pipe") or with high-flow cats. Offroad pipes are worth up to about 10 HP and are NOT street legal. High-flow catted versions aren't quite as good, maybe 5-7 HP.

Third is over-axle pipes: a set of tubes that travel from the midpipe back to the mufflers. Nobody replaces just these. However, see below:

Fourth and finally you have the mufflers themselves. Replacement mufflers are also called "axle back" becasue the mufflers begin right after the rear axle. Some dealers sell a package that includes mufflers and new over-axle pipes--which is called a "Cat-back". These are functionally the same thing, though the cat-back kit is more expensive. This is not worth any more HP, but is a popular mod becasue it changes the way your car sounds.

As you can see, Longtube headers is really where the power is. Unfortunatley, they are expensive and time consuming to install. Wether they are worth it or not is up to you.

Very helpful. Thank you.

GT John

You asked what should be next..........I would go with rear end gears.

In my opioin the exhaust system would be the last mod.

cyberjock4hire

You did not mention what type of transmission you have. If you have a manual, you will probably find yourself fishing around for 3rd gear or not quite getting it in the gate when you are shifting quickly now that you have freed more ponies. If you do have a manual, I would certainly suggest you get the k-member brace and torque limiters from che. There is lots of discussion about them here just do a search.
I recently installed them, BIG difference, no missing 2 -3 shifts here. Well worth the money.
If you have an auto, perhaps gears.

Silencer06

I agree, but really, is there such a thing as a "last mod"?

Daniel60

There was S197 last night at the strip and he was running 4:30 gears? Is that the right number? anyway it was an automatic and it ran like a mother. It also had longtubeheaders, underdrive pullys and CAI/with pred. tune. Another interesting fact the car only had 3000 miles on it. He's retired and single. I'm not retired or single and the wife is already working on being a communist dictator.