Well, It's time for me to start looking for exhaust options. (7afe) I have a ebay header and plans to go 2.5 pipe and High flow cat. I am looking for a deep sound as possible. No high pitched ricer racer sound. Any suggestions?

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Well you ruined that with the header. Magnaflow or Flowmaster. If you don't have emissions(I'm assuming you don't since you put on a header and removed the first cat) don't even bother with a high flow cat, just remove the other one and call it a day. I was going to put a 30" Magnapack where the second cat is and run straight pipe from there. Then if it was still too much I was just going to throw another muffler on at the end. Being you want a deeper sound you'll want a muffler with baffles. Magnaflow has the XL series which is baffled, and anything from Flowmaster is.

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I didn't touch from the cat to the engine, I was just going for a nice pur from the engine...

I think mine is 2.5" from the cat to the muffler, and I can't remember the muffler brand (Its an australian local brand though...). If you watch Mighty Car Mods 'McM', they went to a shop called Kirrawee Mufflers and that's where mine was done

Mine has a nice purr to her when she is at idle, and also has a nice purr when driving I've been complemented a few times about the sound of my car...

Basically for my car at least, the tip made the biggest difference, my mate has the EXACT same setup on his car, with a different tip (dual-single pipe tip) and his sound like crap...

Here it's only a safety inspection on 95 and older. But they will look to see if the cat is there. May just take it off and open it up. Then just mount the shell.

2.5" piping is too big for a stock or mildly modified ST. 2" or 2.25" would be much better. I can't remember what size most guys go with.

I was going to go with 2" myself. In regards to the cat the best thing to do in that case then would be to hollow it out and insert and weld in a pipe into it, that way there's not a bulge in the exhaust stream.

The restriction created by a clean catalytic converter is, in terms of effect on performance, far less than that of carrying a spare tire or incorrectly adjusting tire inflation. Particularly on a 7AFE.

If you want to avoid the buzzy cheap sound of a poorly-done exhaust, make sure to include a resonator. Note, a round body muffler is NOT a resonator. Very few of the items sold by aftermarket manufacturers as resonators are actually resonators.

A resonator is a hollow echo chamber in which sound waves are bounced into each other, transforming the sound energy into heat. There's almost no effect on exhaust efficiency, but it smoothes out the tone of the exhaust. A less irritating tone is perceived to be of lower volume -- a smooth exhaust will seem quieter than a buzzy one, even at the same decibel measurement.

Magnapacks are straight-through mufflers, where insulation absorbs sound waves. They're good for reducing the volume, but not so much for smoothing the tone.

Two easy ways to tell the difference between a resonator and a muffler. One is to tap on the item in question; a resonator will ring like a bell, while a muffler will produced a muffled, dull response. The other is to check the price; resonators aren't sexy, so they're readily available at your local exhaust shop and cost $50-70.

A final aside: MagnaFlow makes a universal cat with a resonated core, combining the two functions into one piece. You get a smooth exhaust note, and leave the air a little cleaner for everyone.

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I had a look at mine and its 2.25"

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True, but invariably we're talking about a catalytic converter with hundreds of thousands of miles on it. It's going to be fairly clogged. If he lives in a state he can get away with it he'd be better off removing it, save some money. I'm all for saving the environment, but a de-catted car is no worse than the slew of lawn and off-road equipment being sold today. If he wants to spend the money for a new high flow cat, then more power to him and that's what I advise. It could be worse, he could decide he wants to drive a 60's V8 powered behemoth that runs on leaded fuel.

Ok, so magnaflow has a 18in Resonator or the combo Res/Cat for about $90.00 and I was looking at apeix N1 any good?

Apexi=rice on a stick.

I wanted mandrel bent, not crushed. but no one in the area does that type of work. Guess it's 2.25 crush for now. Magnaflow and Resonator/cat.

I do have a question.. want to make sure the ecu works properly. They have one model with a place for the O2 sensor but it is before the cat. so I would have one O2 at the header and one before the cat? or after the cat?

On the stock setup there's an O2 sensor, then a cat at the bottom of the manifold followed by another O2 sensor on the down-pipe, with another cat behind that. The last cat can be removed without any problems. Being you have a header you have the one O2 sensor in it. Then you'll want to find space for the new cat and then put your other O2 sensor behind it. You can remove the larger un-monitored one without problems. You could even get past visuals since you could point out "Here's the first O2 sensor, the cat, and the second O2 sensor." The only people that'd know about the second cat would be someone who's owned or worked on the Celica.

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You could order mandrel bend stainless steel pieces from Summit Racing or Jegs. Vibrant Performance is a good brand for stainless steel tubing

This post has been edited by Tigawoods: May 8, 2013 - 2:20 PM