How many catalytic converter's do I have?

[bigcoltrick]

If my flowmaster has a 2 1/4" inlet should I still do 2 1/2" cat back or should i get a new muffler?

 

[storlied]

I would get your choice of muffler, and get 2 1/2 out.. that's what I'm planning on doing.
BTW: My 98 XLT 5.0L V8 has 4 cats.

 

[bigcoltrick]

What is the purpose of have so many cats, is that really necessary?

 

[storlied]

Less emissions....

 

[manaen]

LEV certification, it gets Ford some credit with the EPA requirements for vehicle production.

 

[storlied]

Could they still pass IM with 2 cats? (5.0L)

 

[Rogers-Explorer]

Don't know about that, but mine has one.

I'm in Canada, and I haven't screwed with the original config...But of course, it's different for the calif. folks and maybe the States?

This is what I can remember about the exhouat on my Ex, and of course, I am open to any comments.

And, it is way to friggin' cold (-29C) to go out and take pics ... so, wait until it warms up and I'll check it out agian

Cheers, Roger

 

[Rogers-Explorer]

Don't know about that, but mine has one.

I'm in Canada, and I haven't screwed with the original config...But of course, it's different for the calif. folks and maybe the States?

This is what I can remember about the exhuast on my Ex, and of course, I am open to any comments.

And, it is way to friggin' cold (-29C) to go out and take pics ... so, wait until it warms up and I'll check it out again

Cheers, Roger

 

[storlied]

I know how you feel man, it's been around -35 here.. Hopefully it gets warmer out, maybe like 10 or something..

 

[Regulator_XLS]

i just ran straight pipes from the cats today, mine was 2 pipes going into two cats going into one muffler and one resinator and one tailpipe.
i cut the pipe ater the cat but before the muffler and ran straight pipes, sounds great,
my question is what the hell, does a resinator pipe do? had anyone straight piped their x's from cat back like i did?

 

[storlied]

Resonators are used to cut down noise, if you have interior highway drone.. I suggest putting one in. It shouldn't affect your outside noise tone too much at all.

 

[Regulator_XLS]

Resonators are used to cut down noise, if you have interior highway drone.. I suggest putting one in. It shouldn't affect your outside noise tone too much at all.

whats interior highway drone, i live in canada and we only have to have an inspection every 2 years, and i gte mine hot regardless, my question is can i do any damage to my vehicle by running a straight pipe from the cats

 

[storlied]

No damage, you might lose too much back pressure though. Highway drone.. hm.. a very annoying constant noise from your exhaust while you're on the highway.

 

[mounty71]

The droning is just the noise/vibrations inside from the exhaust.

 

[storlied]

Yeah... lol

 

[bigcoltrick]

I don't understand the whole concept and importance of back pressure wouldn't you gain horse power by having the exhaust come straight from the manifold. Isn't back pressure just more restriction?

 

[storlied]

Your engine has to keep Some backpressure or you'll Lose power.. it's a balance I guess.. I think you get a lot of your torque from the backpressure.. I'm not too sure though.. but I do know the engine needs back pressure.. Someone who knows more will chime in..

 

[storlied]

Should a 5.0 setup be 2 1/2 from the cats back, or only from the muffler? Would it make a difference?

 

[manaen]

With no backpressure you will gain HP (well to a certain extent) however you will also loose low end torque which is what gets you moving. it has to do with how the air flows through an engine when the valves overlap. Overlap is the time when both intake and exaust valves are open. (BTW I am not an expert here, just an enthusiast, there are much more knowledgable engine designers here that know more)


the optimal design in theory would be a variable back pressure design like used on some Honda CBR motorcycles. This varies the exhaust to give good backpressure at the low end for torque, and then opens for the upper RPM range for HP increasing flow. But those systems are expensive and rarely work properly.

 

[Regulator_XLS]

i left my cats on so id have some backpressure, no muffler or resonator though