o/r midpipe vs. catted midpipe vs. stock midpipe

[dstang01]

I think its time Mr. restrictive stock 4-cat and I go our separate ways, but Im undecided on an aftermarket offroad pipe or catted pipe I live in british columbia, and we have something called "aircare" (aka sniffer test ) every few years, so if I went o/r I would have to keep the stocker and swap it in for smog... this combined with the dreaded "gas smelling clothes" stories I hear is making me consider a catted midpipe instead of an offroad (also, I think an offroad and my flows might be a bit too much sound wise for my daily)

The question: Will I notice SOTP and a real power increase from an aftermarket catted midpipe compared to the stocker? And, does and offroad midpipe yield a lot more power than a performance catted one? Since catted midpipes are quite expensive (compared to offroads) I want to justify my purchase.

 

[bloopbloob]

i think for the $$$ difference, it's totally worth it to go with the o/r pipe. first, it's much cheaper. second, you'll see a slight hp gain also... ! i didn't notice a SOTP difference, but i'm sure i picked up a couple hp. so why not? just keep the stocker around for the tests! my car was also quieter after my o/r x pipe (but it happened with the LT's at the same time, which probably made the biggest difference).

 

[GTA_V6_Mustang]

I personally went the catted X way just because I prefer the sound of a catted exhaust (Which everyone gives me compliments about on my exhaust) and I dread the gas smelling clothes and near passouts from fumes sitting at traffic lights. And I really wanted to stay emmissions legal in case it came back. Mine is very good quality and sounds great and has a great crossover design. I bought it for $280 and it had free shipping. Definite difference in how the car feels up top and I have no regrets.

 

[ga94gt]

Keep the stock one and by you a MAC or BBK o/r.

 

[final5-0]

Exhaust threads ... they can really get out of hand
if
You don't be specific :Word:
cause
They ALWAYS get around to the ... SOUND ... of things
which
We all have to agree ... That is a subjective kind of thing

Now ... I went back and read the original post several times
and
His focus of concern is on a performance gain or making more power

His ONLY mention of sound is a concern of ...Too much of it

Soooooooo ... Having said all that

I won't address ANY of my reply in this post about
How Good or Bad this pipe or that pipe sounds
and
I won't even get involved with using a H pipe or X pipe

First ... The OEM 4 cat mid pipe

It is restrictive and on a stocker ...........
the most restrictive part of the entire exhaust system

You can have various degrees of restriction simply because the amount
of miles on it can make it ... more or less ... of a restriction

Second ... A true high flow catted mid pipe

There have just been too many articles using a dyno or the 1/4 mile track
to show the cats make very little difference.

True ... they do offer some restriction but I've seen dyno articles that show
typical NA street car combos will give up 5 rwhp or less with their use.

Common sense would tell us they offer more restriction on PA combos

Third and lastly ... Off Road mid pipes

Most amount of flow
but
Way over rated performance gain by most I've seen on these various boards

Now ... before we see a ton of peeps post up in this thread and say ........

"I notice a BIG gain with my off road mid pipe!"

We need to remember this fact :Word:

Most of those peeps went from the OEM 4 cat pipe to the OR pipe
and
If the truth be told .............

I'd bet a bunch of those 4 cat pipes were clogged up to some degree

So ........ We need to stay focused on the Q here of ........
The comparison of catted to non catted pipes

The OR pipe issues of ..........
smell
increased db level
etc

They've all been talked about

OR pipes also can cause emissions issues such as ............
Having to swap it out to pass testing
Having to be concerned about being ticketed for their use

I have to tried to stay non biased with any of the three choices
or
I did try to ... not give .... my opinion

My attempt was to ... try to share ... what I've learned about each

Grady

 

[95five-oh]

go with an o/r and keep the stocker around for emissions. I went with a $300 catted x and while its an improvement over stock, everytime i hear a catless 5.0 i wish i had just saved the money and went o/r.

 

[Black95GTS]

i think for the $$$ difference, it's totally worth it to go with the o/r pipe. first, it's much cheaper. second, you'll see a slight hp gain also... ! i didn't notice a SOTP difference, but i'm sure i picked up a couple hp. so why not? just keep the stocker around for the tests! my car was also quieter after my o/r x pipe (but it happened with the LT's at the same time, which probably made the biggest difference).

I ran the same off road X that you did and my car was about 3 times louder then stock with it. I can't believe that your exhaust actually quieted down by removing the cats.

Mufflers get louder with the more air that goes through them. Less cats, less restriction, more air, more volume.

I wouldn't worry about smelling fumes. Maybe if you are stopped at a red light for 4-5 minutes you'll catch a whiff, but its not like you have to roll down your windows because your eyes water. People that have this problem most likely did not install exhaust components correctly and have a nasty leak underneath the cabin or their tune is off and they are running too rich.

I did the whole "swap on the stocker" thing. If I could do it all over again I would have saved up the extra cake and gone with some high flowing Bassani catted X pipes. My .02.

Adam

 

[dstang01]

Exhaust threads ... they can really get out of hand
if
You don't be specific :Word:
cause
They ALWAYS get around to the ... SOUND ... of things
which
We all have to agree ... That is a subjective kind of thing

Now ... I went back and read the original post several times
and
His focus of concern is on a performance gain or making more power

His ONLY mention of sound is a concern of ...Too much of it

Soooooooo ... Having said all that

I won't address ANY of my reply in this post about
How Good or Bad this pipe or that pipe sounds
and
I won't even get involved with using a H pipe or X pipe

First ... The OEM 4 cat mid pipe

It is restrictive and on a stocker ...........
the most restrictive part of the entire exhaust system

You can have various degrees of restriction simply because the amount
of miles on it can make it ... more or less ... of a restriction

Second ... A true high flow catted mid pipe

There have just been too many articles using a dyno or the 1/4 mile track
to show the cats make very little difference.

True ... they do offer some restriction but I've seen dyno articles that show
typical NA street car combos will give up 5 rwhp or less with their use.

Common sense would tell us they offer more restriction on PA combos

Third and lastly ... Off Road mid pipes

Most amount of flow
but
Way over rated performance gain by most I've seen on these various boards

Now ... before we see a ton of peeps post up in this thread and say ........

"I notice a BIG gain with my off road mid pipe!"

We need to remember this fact :Word:

Most of those peeps went from the OEM 4 cat pipe to the OR pipe
and
If the truth be told .............

I'd bet a bunch of those 4 cat pipes were clogged up to some degree

So ........ We need to stay focused on the Q here of ........
The comparison of catted to non catted pipes

The OR pipe issues of ..........
smell
increased db level
etc

They've all been talked about

OR pipes also can cause emissions issues such as ............
Having to swap it out to pass testing
Having to be concerned about being ticketed for their use

I have to tried to stay non biased with any of the three choices
or
I did try to ... not give .... my opinion

My attempt was to ... try to share ... what I've learned about each

Grady

Just the confirmation I was looking for, thanks once again Grady

My main concern was that I would spend MORE on the catted pipe, and loose SIGNIFICANT performance over the cheaper offroad one (lets be honest, that would be a big screw. .) Also, I wouldnt want to spend a few hundred bucks, and then not have a noticeable improvement over the stock pipe either

Thanks for all your imput everyone

 

[final5-0]

One more thing about running cats

There is the issue about running an air supply to them from the air pump

I'm really not sure
about all that as in my experience ............

I've run a Shorty and LT catted mid pipe and in both cases .........
I hooked up the air tube from my air pump to them

Now ... If you have done away with your air pump

anyway

Seems like I heard someone say some cats needed the air
and
Others do not need it

I just wanted to bring it up and hopefully someone who knows
what they are talking about can enlighten us all on this subject

Grady

 

[dstang01]

Grady, you must be a mind reader or something I was actually going to bring up that subject afterwards. I read somewhere that borla highflows (I think it was borla) do not need an air supply. I also read that doing away with the air pump will cause some cats to clog (the stockers at least) thus creating a huge restriction. If anyone can enlighten us on this, that would be much appreciated

I havent done away with my pump yet, but it was something I was planning to do during my head/intake install, so Id like to get an answer before I bite the bullet. I want to kill the pump to reduce clutter, free up some weight (marginal, but whatever), free up some power (again, marginal), get rid of the whining pump sound, and stop exhaust popping (the air pump introduces oxygen, thus causing backfires on deccel) Overall, Id just rather not have it in my engine bay, but if my cats are going to foul without it then it can stick around.