View Full Version : exhaust ideas for my 5s...

02-23-2011, 05:39 PM
i recently got a 4-1 header from a camry and i was wanting to get a whole new exhaust on my st184, but i had a couple questions....
Has any one ran split exhaust on a 5s? does it sound okay, or like crap since its a n/a 4cyl?
i was thinking 2.5" at most and mandrel bent of course, but does any one have any recomendations for a muffler, and can i get away with not getting a cat put on it since the header replaces my stock cat, and i would end up gutting it anyways....
any suggestions or insight would be greatly appreciated =D

02-23-2011, 05:44 PM
By split are you wanting to do Dual exhaust?

Wouldnt recomend that, but if you do i would run the piping at 1.75 or 2 inches.

If your doing single out, 2.25 is ideal, but 2.5 is an ok substitution.

If you go on youtube you can find what different mufflers sound like.

02-23-2011, 06:28 PM
Other than being a big waste of money, you might find it tricky properly routing two pipes under there while having proper clearance, and situating an additional muffler. If you do it, like Grot said, keep the diameters smaller which will help with the fitting and routing issues. Really though you'd be best off with a single mandrel bent pipe around 2.25 and a quiet muffler. You probably can't get away without a cat on the stock tune. A single aftermarket inline would suffice though (usually around $100), even if you gut the primary.

02-23-2011, 07:03 PM
i already gutted the cat on my cast exhaust manifold and i havent gotten any codes or anything... obd1 still...
but i figured dual exhaust wasnt gonna work, i just wanted to get a second opinion or two...
I live in florida so i dont have to worry about smog or anything really, which is why i was trying to just get around buying one and having the exhaust shop install it in the first place...

02-23-2011, 07:20 PM
Well if you don't have to pass emissions, you don't technically need a cat, then.

02-24-2011, 01:00 AM
Well if you don't have to pass emissions, you don't technically need a cat, then.

That may or may not be true - as here in N.C my cars are not subject to emissions testing - but they have a checkoff sheet for the required yearly inspection that includes two categories - "Safety Equipment" and "Tampering Inspection".

As I just got my inspection on my ST a few days ago I can read that list directly from the report I got:

Tampering Inspection:

Catalytic Converter - Pass
Air Injection System - N/A
PCV Valve - Pass
Unleaded Gas Restrictor - Pass
EGR - Pass
Thermostatic Air Control - N/A
Fuel Evaporative Control - Pass
Oxygen Sensor - Pass
Gasoline Tank Cap - Pass

So here - at least here is a little "visual" like California has (to the max).

My 1992 GT has a header, no CAT, and the Oxygen sensor in the header has cut wires. I have no CEL codes but I am sure this car would fail inspection here.

I go to a "friendly place" for inspection - a little hole-in-the-wall shop that work on imports - but there is no "free pass" there. I also have a "Russian friend in the inspection business" - but I hate to rely on that year after year.

I bought this car from a guy in Illinois where there is no requirement at all for inspection - and as it came from out of state I did not need to get it inspected till after the first year - which ends the 15th of next month.

I am going to go talk to those guys with some "hypothetical questions" - but I think if I get a full flow CAT downstream of the header and fake the wires to the oxygen sensor I'll be good to go.

A full flow CAT is a good idea anyway - because you do your part to keep the air clean - just like everybody else.

02-24-2011, 09:35 AM
If you're concerned about the loss in exhaust efficiency from having a catalytic converter I expect you also refuse to carry coins and empty your bladder before getting in the car -- the effect on performance is about the same. However, we also expect to be breathing long after the cars in our possession pass on to the great junkyard in the sky, and would like to breathe clean air. Or to put it another way, the enjoyment of clean air outweighs the enjoyment derived from a gutted cat. And that ignores the negative effect on exhaust efficiency of the turbulence created by a gutted cat.