cat back exhaust? little info and usefulness.

[Decoy]

Hey,

I just bought a 91 Celica GT-S in almost excellent condition with 156,000km. 5spd of course Now to get it safetied i have to fix a hole on the exhaust piping. But the guy i'm buying it from said he has a cat back exhaust that he bought and should arrive in a few days and he said he'll sell it to me. Will it benefit me any or should i just stick with the regular? And what does a cat back exactly do?

Thanks

[Thourun]

First of all the street racing section is not the place for this, the celica peopole should be able to help you more than us since few of the regulars to this forum know about celicas.

If the hole is after the cat it will help. I have a hole in my downpipe (before the main cat) on my VR4 so a cat-back exhaust would not help fix that. You'll want to find out what kind of cat back it is and how it sounds, looks, how much it is at online retailers, and how much he wants for it. If it turns out to be somthing you want and he is selling it for signifigantly less than the online retailers you might consider buying it. Cat back systems are mostly for sound with some performance gains, the celica guys will be able to tell you how much HP you can expect and how much weight you might save.

[Polygon]

I agree that the Celica forums would be a better place for you to ask this. Just let me know if you want me to move it there. However, like Thourun said, if the hole is after the cat then it will help. If it is before the cat you will have to replace other pipe anyhow.

A cat back exhaust is a replacement of the pipes and the muffler after the catalytic converter. This is more of an aesthetic modification that a real performance mod. You can expect to gain about 5-10HP at the most from a good cat back system. People buy them mostly for sound.

If you want real performance you will want to replace the exhaust from the exhaust manifold all the way back. If you're rally interested look at the system he is trying to sell you. Is the muffler any good? Does the muffler exhibit a lot of back pressure? Are the pipes crush bent or mandrel bent? What kind of metal are the pipes made of?

These are all things you need to look at. If it is a good system then I would go for it if the price is right. However, I would replace the rest of the exhaust later on if you're looking for real performance.