Red3.slow

MudHippy

Actually, I do sometimes. But, I haven't noticed any loss of low end torque at all by doing either. Removing just the muffler or removing the cat too.

I know 2 people that run open headers behind their 22REs and both swear by it.

Just so people get what I'm saying. It's the pipe being there at all that will effect the flow. So if you run nothing behind your headers/exhaust manifold, ie. open exhaust, nothing can effect the flow. Leaving the scavenging up to the exhaust manifold(creates an excess of backpressure on it's own so no scavenging possible)or the header(why you bought a header in the first place, it's designed for optimum flow on it's own, supposedly, notice they are a certain size themselves).
So what size pipe can = no pipe. If you want to talk REAL performance gains. Talking about increasing the heat or rate of flow of the exhaust once it's left the header/exhaust manifold no longer is needed or relevant, it's already flowed to it's destination. Instead of talking least resistence, I'm talking about shortening the path. You see. Engines make noise, hence the term "muffler" and it's function. Engines exhuast harmful gasses, hence the need for a "catalytic converter" to convert theses gasses into less harmful substances. Neither is a performance enhancing component.

Zealot

Does someone want to sticky this tread so in the future we dont have another crazy backpressure thread. I believe that would be most helpful for everyone.

elripster

I wanna see some dyno results proving/disproving this. My experience has been consistent over many vehicles; less back pressure produces more torque at higher RPM's at the expense of lower which doesn't matter on a stick shift because you just instinctively change your shift points.

That's all I have to add. In Ca you have to have the catalytic converter, etc... so it's a moot point. We are going to have back pressure.

Frank

AH64ID

Actually you have to have one in all 50 states...

kcrunner

I sincerely apologize for asking this question.

Now,

can we get on to the biggest size tire I can fit on my 4Runner w/o rubbing.

Totally kidding.

ozziesironmanoffroad

"actually, you need them in all 50 states..."

not in utah or most parts of nevada.. i got unlucky enough to move to vegas, where you have to get your car smogged... only 2 or 3 counties smog.. and clark is one of them... . i know a guy at work who lives here but got a P.O. box in Pahrump, NV and also knows people in pahrump, so his address is in pahrump, so he doesnt have to smog. he has a 1987 yota with a supra V6 Turbo with only a header and nothing behind it. cops cant say sh.... uh... stuff.

stormin94

I'd like to see someone get pulled over in Alaska for not having a cat...

AH64ID

Just because you dont somg doesnt mean your not required to have one...

And alaska is a different beast, the town where I spent many summers working didn't get unleaded until well after the rest of the US so you had to remove cats when the rigs got there, by plane or sea only.

ovrrdrive

Best post in this entire thread...

I have no idea why though, but I got a kick out of that comment.

ozziesironmanoffroad

if you dont have to smog, whats the point of having a cat? what r they gonna do, oh theres gonna be a 500 dollar no smog fee and you are required to do a smog? uh.. cop, there aint no smog in this county. alaska i can understand.

AH64ID

The point is to keep the air clean, all smog checks mean is you air is already crappy so they test your equipment....

And IIRC no cat fines are like 25K, not 500....

ozziesironmanoffroad

i know i know. but if your county doesnt smog, then everyones runnin around with dirty, polluting vehicles. why should yours be any different? you get what i mean? like, ok. out here, anything 68 or older (cali 75 or older) doesnt have to get smogged. whats the point of THAT? those cars produce WAAAY more pollution than newer cars do. ive never got a no cat fine, so i dunno what it is. ive known people in utah and pahrump and certain parts of cali that dont smog that keep their cat, but hollow it out. so a cop cant say you dont have a cat. im not trying to start an argument on here, just statin some ideas, ya know?

AH64ID

What benefit do you get from it??? I had no cat for a while on my 22RE and it ran much better with it...

And why not set an example to follow, and not be the problem?

ozziesironmanoffroad

in other places that would work. in pahrump, i dont think that would work. most of the cars and trucks out there with no cat are old chevys and fords that have HUGE engines, im not sure about no cat on the 22re. it just makes sense that a straight pipe would run better than with a cat... i guess its a general misconception

stormin94

Cats are good for the air, and not so good for performance, plain and simple. Different cars have different results, I'm just speaking generally.

fork

I used to run open headers on my 3.0. it was horrible. after 2.25" and a slowmaster muffler it's much better now. my 4runner's exhaust is rotted behind the headers and it is also horrible. the only place it flows now is into the cab via the giant holes in the floor

stormin94

Mmmmmm.....Carbon Monoxide....