what do you guys think of them???

my original plan was to just delete that cats all together when i did headers but someone mentioned high flow cats. i'd just like to know everyones opinions on them....

 

It is mostly if you are worried about emissions. If you aren't I would delete them. It gives your a truck a MUCH more clean crisp sound while the cat muffles it a fair bit. I wouldn't even believe the difference when I gutted mine. And to keep the codes from coming use o2 sims or you can try the old frame rail tie trick.

 

I am completely for them.To get the best performance out of your exhaust,you need a certain amount of back pressure.So when you lose that back pressure you are actually hurting your low end.Sure it will make it louder,and give you slightly more top end,but is that what you want? Yes a gutted cat will make the vehicle run better than a "CLOGGED" cat not better than an operating cat,especially a high flow one.Thats where the mix up comes in.People hear about a guy that had a clogged cat and his vehicle ran like crap until he gutted it,and then it ran great,so they think thats the way to go.It would have run better with a good cat on it as well.

The advantages are 1..Its legal....2...You will still get the performance and sound you want and not sacrifice your low end.

 

ok, now i have conflicting opinions.... so the score is 1 to 1. all others chime in any time now please.....

 

i agree with meinekeman, i lost enough low end when i got my high flow cat on which i got on after the exhaust was on so i would say just go with a hi flow about the only thing that no cat will do is make it louder and possibly sound better. my truck is a real dog untill it hits like 2500-3000 rpm's. mines also not an r/t but i dont think it would be that much different. and in no way am i a tree hugger but go with a hi flow to save the environment a little so unless its a track only car i'd say dont delete.

 

OR, my buddy ran this idea past me and it sounds pretty good: if i delete the cats and lose some low end, i could just put in a small converter (say 2400) and i wouldnt even notice..... hmmmm. what do you guys think about that???

 

I don't know why people keep saying these magnum motors need back pressure. If you haven't noticed the amount of torque created by these beasts your low end torque/power will not be noticeable. The muffler alone is good enough or a x pipe or y pipe, cats don't help except to keep the air clean.

I say go cat free, a free flowing exhuaust is fine. There is a reason why a car overseas can get 50mpg but then when it reaches US territeory and they slap a emmisions **** on it it only gets 30mpg on the same car.

Deleting the cat will actually help the power of the truck and probably increase your mpg a bit, but i feel sorry for the people behind you smelling your nasty *** exhaust.. So get turn downs lol... hehe

Right now i have Gibson headers with stock ypipe and a flo pro cat back exahust with a dump before the muffler, still have the cat its loud and gets the job done.

but i need a better exhaust for my intake and mods i have.

I have PPhs getting coated right now, and when i save the money im getting a single 3" Exhaust made with no Cats and a Spin tech muffler with side exit tips, and an elecric dump before the muffler for the track.

The OBDII emissions test dont sniff the exhaust it goes by the computer codes, so if you don't though codes it will pass.. and on the Dakota zip tie the o2s to the rail and you will be fine, and lower the truck so they cant do visuals.. lol..

 

I noticed a huge difference when I removed my cat. It just had more power. If you have a high flow enough to flow the same as the exhaust it will give you the same as if you had none, of course that isn't possible. But I do say I noticed more low end when removing my cat. The 5.9 puts out so much air it won't even matter as long as you aren't running straight headers you should be fine. Back pressure is still created as long as you have some pipe running. I hope to put my magnaflow on my truck tomorrow without the cat I think it will have a nice sound now. (You can always gut the cat if you want to keep the look of it. )

 

Sorry,but I disagree.Have you ever tested your vehicle with both a high flow cat and none?I have with many of my customers and they have always stuck with the high flow cat.One guy had his own programmer and actually noticed a huge difference after removing it.Another guy,I did a 3 inch dual exhaust on his truck(per his request) and he came back and lost his quart mile time from that alone.All I had to do was switch his tubing size to 2 1/2 and he got it back.

Guys,I know this is a strong motor,but you're not putting out that much exhaust pressure that a high flow cat would hurt it.It's just not so.For those that have said they have gotten their power back after removing/gutting it,if your cats were clogging up in the first place,yes you will get power back,but that doesn't mean it's better than a performing cat.

Like I said,think of the plumbing cenario,the bigger the pipe,the less the flow of the water will be,the smaller you go with the pipe,the higher the water pressure will be.No different than exhaust.You need "VELOCITY" of exhaust.The bigger a path it has to travel through,the less force it will need and hence not travel as fast.

 

Okay user this may be a stupid question but it will deffinately solve the problem that i have between the v8's and v6's. arent they pretty much the same just the v6 has two cylinders taken away. that is nor my questino but if you take the cats off wouldnt it hurt the v6 engines. just a quick question becasue you guys have v8's and i have a v6