# finally getting my exhaust



## hondakillerZX (Aug 16, 2004)

hey guys i finally saved enough for my exhaust. i was just wondering what kind of system would get me the most noticable torque. Im getting 3 inches i know that but I don't know which one to get 3 inches lol. cat back , strait pipe or any other suggestions, thanks guys.


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## hondakillerZX (Aug 16, 2004)

oh ya and do hi flow cats usually pass smog if you drive around a little to warm them up.


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## asleepz (Feb 24, 2004)

check out www.certifiedmuffler.com


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## Z_Spool (Sep 27, 2003)

*Mmmmm... Tasty!*


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## hondakillerZX (Aug 16, 2004)

should i go cat back or turbo back. are these both legal because this is my daily driver and it has to pass smog.


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## Zen31ZR (Mar 24, 2004)

You can get a turbo-back with a highflow cat, and it should pass smog easily.


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## Xorti7 (Dec 27, 2004)

How hard is this for someone to do themselves?
Edit: what i meen is, does it all match up and bolt up like the stock exhaust?


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## Zen31ZR (Mar 24, 2004)

Xorti7 said:


> How hard is this for someone to do themselves?
> Edit: what i meen is, does it all match up and bolt up like the stock exhaust?


Yes, it should.


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## hondakillerZX (Aug 16, 2004)

but im moving to 3 inch pipe isnt the stock pipe smaller like 2 or 2.5.


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## Zen31ZR (Mar 24, 2004)

hondakillerZX said:


> but im moving to 3 inch pipe isnt the stock pipe smaller like 2 or 2.5.


It's 2.5 inch, as far as I know. Should still fit, though. Depends on if you get just a catback or the full system, but my catback bolted up to the back of the catalytic converter just fine. 
The catback pipes are larger, but also thinner walled material. The stock exit from the cat is very thick and surpasses 3", but the actual ID is about 2.5 inches. A catback will fit fine, and with the supplied gasket in the CM system, won't leak. 
If you get a full system, the downpipe and cat will be replaced anyway. The downpipe is made specifically to fit into the turbo outlet properly, your only problem will be removing the old pipe. After 15 years in one place, it'll be heat-welded into position. 
The bends in the CM system are pretty precise, the pipe should fit even for being 1/2" bigger. There isn't much room under a Z31, so you can't go much bigger unless you completely change the pipe routing.


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## hondakillerZX (Aug 16, 2004)

that sounds like a problem i think ill probably just go catback and go back and do the rest some other time. is there really that much of a performance difference with catback and turbo back


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## Zen31ZR (Mar 24, 2004)

hondakillerZX said:


> that sounds like a problem i think ill probably just go catback and go back and do the rest some other time. is there really that much of a performance difference with catback and turbo back


Yeah, there is. If there wasn't, they wouldn't bother selling turbo-back systems. Better spool up time , more flow capacity. See, when you force a turbo to push higher boost out through a stock sized downpipe, the downpipe heats up quite a bit. Since the downpipe and it's outlet from the turbo housing is present in the engine compartment, it heats up the engine compartment quite a bit as well. The intakes pipes run right over that hot turbo housing. Running a larger downpipe takes some of that heat away from the under the hood, which means your engine and your intake air runs a bit cooler. That frees up more available Hp. Also creates less heat strain on the turbo, which already runs red hot. The more heat you can move out from the engine bay, the better. I wish I had done a downpipe before I ran over 10 psi, I think it's worth it.


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## hondakillerZX (Aug 16, 2004)

oh, im having a shop do it anyway because i know this muffler shop that my friend works at and they can do a full exhaust for 1 to 2 hundred bucks but i dont want to blow all my money at once so i wasn't thinking of getting the high flow just yet. can i just get the catback first and go back and do the rest of the pipe and the high flow later. oh and do you have any suggestions on what muffler i should get. i want a low growl not like those ricer fart cannons that sound like crap.


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## Zen31ZR (Mar 24, 2004)

You want to stay fairly close to the size of the pipe as far as a muffler goes. Dramatic size changes result in the exhaust sounding more hollow and tinny, such as ricer pipes give. They have like a 1 1/2" pipe going into a 5" cannon, which for the most part is why they sound so crappy. Catbacks or full systems with appropriate sized mufflers sound much better.
The CM exhaust system is piece-together, meaning you can buy the catback part first and finish the exhaust off later. It's all designed to bolt together no matter when each part is installed. I tend to not care for local muffler shops too much, because they insist on welding everything together. Not good if you want to go to the track and ditch the catback for a few runs.....


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## hondakillerZX (Aug 16, 2004)

ya im having them put flanges on so i can just unbolt . i thought about that too. do you think a flowmaster would sound good on a 300zx turbo.


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## Darkstar (May 31, 2005)

i know you already said a turbo back makes a huge difference but what about headers back on a non turbo? is that worth it or should i pass and go cat back (it's way in the future anyway)


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## asleepz (Feb 24, 2004)

Or go like me and get a DMH electric cut out


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## Zen31ZR (Mar 24, 2004)

hondakillerZX said:


> ya im having them put flanges on so i can just unbolt . i thought about that too. do you think a flowmaster would sound good on a 300zx turbo.


Never had Flowmasters on anything, so I couldn't tell you. Seems to me ******* domestic lovers put Flowmasters on everything because they're cheap, not because they're actually any good. A muffler can make or break your exhaust systems flow ability and sound quality, so choose carefully.


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## Zen31ZR (Mar 24, 2004)

Darkstar said:


> i know you already said a turbo back makes a huge difference but what about headers back on a non turbo? is that worth it or should i pass and go cat back (it's way in the future anyway)


 Things work a bit differently on a nonturbo engine, exhaust flow rate rise is pretty linear across the rpm band, unlike a turbo engine where flow rate spikes and fades according to boost levels. Nonturbo engines don't need the exhaust flow capacity that turbo engines do. Go too large on the pipe size too close to the engine and you'll kill low end and midrange torque and have only top end. I'd worry about a header-back system after you get cams and better intake piping and maybe get the intake manifold ported. Til, then, a catback system should be plenty.


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## hondakillerZX (Aug 16, 2004)

Zen31ZR said:


> Never had Flowmasters on anything, so I couldn't tell you. Seems to me ******* domestic lovers put Flowmasters on everything because they're cheap, not because they're actually any good. A muffler can make or break your exhaust systems flow ability and sound quality, so choose carefully.


are their any mufflers i should look for.


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