HellNBack

This might or might not be a performance issue now, but it definitely will be an issue when boost comes into play.

The first catalytic converter is attached to the exhaust manifold directly in front of the engine, the second one is under the passenger compartment in the typical location.

I guess it really isn't an issue if you plan on going turbo since you will be replacing the stock exhaust manifold anyways, but how about performance now and when the supercharger is in place?

The tC service manual states its a ultra thin wall, BUT high-density for the 1st catalytic converter. I am going to assume the 2nd is the same.

That can't be the best for exhaust air flow.

_________

tcwannab

no stock exhaust has the best airflow

aftermarket>stock

HellNBack

No ____

Except I'm not talking about an aftermarket system.

DemonEyez

ehh the 2003 tib v6's have 3 cat converters.. and a ____y stock catback.. : (

why else do u think the right combo of headers + exhaust nets around 30whp.

GotSVXWannaTc

The Tib cannot have a ____ty stock catback, since there is no such thing as a stock catback, its an oximoron. A catback is in reference to an aftermarket exhaust system that replaces from the 'cat' back as opposed to an 'axle' back system. The TRD exhaust is an 'axle' back. A 30hp increase from just headers and exhaust can only be seen on a few turbo-charged or supercharged vehicles and in Gran Turismo.

maybeillcatchfire

now now its a known fact there is a big hp loss from the stock exhaust on those tibs ...they did that on purpose for insurance purposes

one of my uncles owns a hyundai dealership

DemonEyez

Like the next guy said. the Tibs are KNOWN to have a very restrictive engine back exhaust/header whatever you wanna call it. and a very restrictive stock air box.

And yes we do net that kinda power.

GotSVXWannaTc

I just look up the specifics, and the Tibs exhaust goes down to 1.25" near the end. :o

DemonEyes, I thought you were a tC owner trying to prove that Tibs suck , now I understand. I'm sure upgrading from such a small exhaust has a chance to net 30hp. Sorry for doubting you :oops:

DemonEyez

its aight man. no im a tib owner. i just really like the tc's as well.

but yeah. even taking alook at the stock exhaust manifold... its tiny..

and yes right at the y split that looks more like a stepped on lizard, the diamater of the pipe goes to almost nothing.

EDIT:

P.S im here to learn about the TC's. so im sure in the process some people here may learn something about the tib. cus me owning the tib, the best i can do is compare it to my own car.

GotSVXWannaTc

Thanks for the info, I appreciate it. The Tib is number 3 on my list of possibles trailing right behind the Mazda 3 5-door and the tC. If I get the Tib it looks like I'll be changing the exhaust ASAP :D

DemonEyez

honestly i wouldnt get the mazda 3. i am not impressed with them at all. having ridden in them, drive them, and raced them.

I'd keep it to the Tc and Tib and then letting your factor be mostly what you want out of your car. If its the most performance potential the tib has it.

gadgets/accesories the TC.

handling = tib

resale value = tc

their both awesome to look at.
both appear equaly spacey inside to me.

if i were to consider a mazda 3, i'd get the srt-4 instead *i like performance if you cannot tell*

meder

are you sure its a second cat? ive never heard of that before, i know toyota usually puts a resonator between the cat and the muffler just to dampen exhaust noise a little more, most resonators are straight through tubes with fiberglass around the outside, so it wouldnt be restrictive at all. Im not sure if thats what it is, but it seems more likely than a second cat.

Mudd

Welcome to 10 years ago. Almost every new car nowadays will have at least 2 cats (or a main cat and a pre-cat , which reduces emmissions on cold starts).

zoltiz

What he said. Plus this first cat is something that costs us probably around 10whp, or will cost us at least 10whp on low end when we get the SC. But oh well - anything to save the planet.

komik

If you're that concerned about a second cat, just cut it off. My '93 T-Bird had three cats on it. I had the insides busted out of them so it would still look legal.

rumblee

The problem with removing cats is that there is gonna be an o2 sensor in front of and behind each converter. It looks at the differences in o2 between the two to make sure the cat is doing its job and also to base a/f ratios off of. When you remove the cats you need to put in some o2 sims or something or it will run like ____ and throw all sorts of codes causing a cel.

GrungeFactory

O2 sensors aren't that big of a deal, remove them and plug resistors into the socket. Tricks the ECU into thinking everything is running like it should.

Did this on my WRX, both O2 sensors pulled and resistored. Even passed emissions with no cats :D

blitzcat

B.S.

EFI doesn't function without being able to adjust fuel to air ratios in respones to air temperature and engine conditions. The exception is when you first start a car and it runs its 'warm up' program until the exhaust reaches temperature, however your hp is reduced and MPG is very low.

So you either have a working O2 sensor and don't know it, or you are wasting a lot of money on gas.

komik

Never messed with the sensors on my T-Bird. It runs just the same as always. (It purrs a little nicer now though).

Draxas_VP

There are only two O2 sensors in the exhaust system. One before the first cat built into the exhaust manifold and one after it. There are no O2 sensors installed to monitor the second cat, so the computer has no way of knowing if you removed or modified the second cat.

Our Race Header that we will soon be developing for the 2.4L engine will of course not have a pre-cat installed. I hope to begin prototyping the tC header the first weekend in September.

Nikolas