cat back is exhaust piping from the catalytic converter back.

and you should buy headers,downpipe and the cat back and the catalytic converter if you want hope it helped

The best system is a complete system from front to back. A cat-back (shorthand term used for an exhaust system that runs from the catalytic converter to the muffler) is the most basic exhaust upgrade. A complete system would include a high-flow catalytic converter (or eliminate the cat altogether) and a large downpipe. For the really serious, a larger oxygen sensor housing and exhaust manifold is an improvement, but that can wait until the turbo is upgraded. I would recommend going with at least a 3 inch (75mm) system from the oxygen sensor housing back, so you have plenty of flow to support higher power.

The exhaust system looks like:
exhaust manifold -> turbo -> o2 housing -> downpipe -> cat -> cat-back

Hey!

-So you have a long way to go on learning about your car, but that's part of the fun. Don't worry if you have questions. But you need to try and search for answers too. I'll try to help get you going.
-Before you modify anything on your car, you MUST do all the necessary maintenance. Spark Plugs, Spark Plug Wires, Check and replace all fluids, Check and replace Timing Belt. You really need to start with these things first.
-About the exhaust, the entire path works like this:

Engine=>Exhaust Manifold=>Turbo=>O2 Housing=>Downpipe=>Catalytic Converter=>Tail Pipe=>Muffler

A "Cat-Back" is replacing Tail pipe and Muffler sections. It leaves everything before it.
A "Turbo-Back" is replacing everything after the Turbo. This is a complete exhaust system.

Everyone will have different opinions on what you need first. I would say the first this is of course, maintenance. The next thing might be a Boost Gauge, as the stock boost gauge isn't very good. There is a section on the forum that outlines an "Upgrade Path" for your car, and this is really a good way to get started. Research each part before you buy it. Get everyone's opinions. Ultimately, it's your decision though. Good Luck!

tragdor said:

-Before you modify anything on your car, you MUST do all the necessary maintenance. Spark Plugs, Spark Plug Wires, Check and replace all fluids, Check and replace Timing Belt. You really need to start with these things first.

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That is the single best piece of advice anyone will ever give you about owning one of these cars. Make sure you do it.

Maybe reading here will help.Tech Guide: 2G 4G63t Upgrades - DSMtuners

And here... Tech Guide: 2G Drag Setup - DSMtuners

thnx for great answers guys , im in awe =)


i've completed the maintenance part of my DSM project ; Replaced timing belt , water pump etc, basicly did the whole "Stage 0 ; Free mods" of the Newbie guide to DSM's

so now i have plans about upping to around 300hp , thats why im asking all these questions

You better make sure you do your homework if you're looking for 300hp. You will need to upgrade your turbo and fuel system as well as have a way to tune the car. Just take your time and understand everything you are buying/going to do before you buy/do it. Good luck

If it were me i would run a turbo back exhaust, I would also go with a 3" exhaust as well. With a turbo the more exhaust flow the better. As tragdor said everyone will tell you what they would do first and im with him on this one. Maintenance then exhaust. bigger exhaust will greatly improve your exhaust flow and help out on down the road when you want to do bigger and better things.

Best cheapest first mod for more hp is a boost leak test! My opinion on this will never change.

ddpmj said:

cat back is exhaust piping from the catalytic converter back.

and you should buy headers,downpipe and the cat back and the catalytic converter if you want hope it helped

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Turbo cars dont have headers, they have manifolds. But yes a catback would be a good start.