Are RT and SRT8 Cats Bigger then 3.5?

[DannyC]

I know a lot of the hemi guys have replaced their stock CCs with aftermarket high flow converters. This might be a good mod for our V6s if the stock hemi cats are bigger than ours and will bolt up. Anyone thought of this before?

[shadowvox01]

I have a set of Hemi cats do install when I do my manifold retrofit project.
The inlets for the converters are LARGE

[DannyC]

Let us know how much trouble it is. I'm pretty sure the mid pipe on a hemi is larger than our V6 but should be easy to fix that. Maybe run the stock hemi cats and mid pipe and then a set of FM with inlet the right size and outlet the stock V6 size so everything else works together.

[Magnum375 Jr]

Well, there are universal Magnaflow high flow cats, the only place i know that sells them are A&A auto parts, and I think they are 2.5 in/out diameter.

[ekaz]

The stock exhaust size on an SRT is 2.75, so should be doable.

[MooNDoGGie]

As I understand it, the hemi CC's are exactly the same as our 3.5L CC's.

[Samoan Tsunami]

I know a lot of the hemi guys have replaced their stock CCs with aftermarket high flow converters. This might be a good mod for our V6s if the stock hemi cats are bigger than ours and will bolt up. Anyone thought of this before?

just a question, but outside of extra weight from a larger part, what exactly are you looking to gain?

the catalytic converter installed in stock form, will be rated for most all the mods boltons and mild internals will allow. thats just the way parts are made.

aftermarket stuff is usually lighter.

would seem to be more beneficial to follow suit and upgrade to something lighter than something used and heavier, with no performance advantage....

if i am missing something, please let me know. i'm new to this forum, but i am not seeing the reason to use them...

[NC-SXT]

As I understand it, the hemi CC's are exactly the same as our 3.5L CC's.

Different part numbers. The 3.5 and 2.7 are the same . 5.7 and 6.1 are also 2 different part numbers

[Hemi RT]

I know a lot of the hemi guys have replaced their stock CCs with aftermarket high flow converters. This might be a good mod for our V6s if the stock hemi cats are bigger than ours and will bolt up. Anyone thought of this before?

You have to remember that getting things to flow better is good up to a point. Unless you build your heads up to run with little or no back pressure you may run into a problem with a larger exhaust system. Also if it too free flowing you may throw codes.

Your best bet is to get a system designed for your car.

[Samoan Tsunami]

You have to remember that getting things to flow better is good up to a point. Unless you build your heads up to run with little or no back pressure you may run into a problem with a larger exhaust system. Also if it too free flowing you may throw codes.

Your best bet is to get a system designed for your car.

if you dont want to get a system for the car.... this article will help.... its written in conjunction with magnaflow, but gives the basics on building an exhaust. its been passed around through many forums.

http://magnaflow.com/05news/magazine/05sportc.asp

[ZMagnum]

You have to remember that getting things to flow better is good up to a point. Unless you build your heads up to run with little or no back pressure you may run into a problem with a larger exhaust system. Also if it too free flowing you may throw codes.

Your best bet is to get a system designed for your car.

There is no such thing as good back pressure on a 4 stroke engine. Each exhaust pulse produces negative pressure behind it. Just the opposite of back pressure. On a 2 stroke engine you need back pressure.

Our engines are like a big air pump. The more air you can get in and out of it the better (as long as the air/fuel mix is good).

[MikeEast]

It's all about flow, but it's also about the timing and velocity of that flow too, that's a pretty decent article.

How else can I explain the 25 ftlbs of torque I gained on the dyno from going to a full Zoomers catback? My pipe diameter went down 1/4" in a few places, yet it performs better? Interesting concepts..

Mike

[Samoan Tsunami]

It's all about flow, but it's also about the timing and velocity of that flow too, that's a pretty decent article.

How else can I explain the 25 ftlbs of torque I gained on the dyno from going to a full Zoomers catback? My pipe diameter went down 1/4" in a few places, yet it performs better? Interesting concepts..

Mike

the velocity is a major "kine" with exhaust. many times people use too large of an exhaust pipe, thinking bigger is better, but they actually LOSE low end power. using an RT exhaust for looks would be fine, but if i am not mistaken, its still restrictive being stock...

unless a car is highly modded, nitrous, boost, heavy N/A internals, i've personally never really seen the need for excessively large piping. maybe 1/4 inch more in pipe size, but when you take a single pipe and make two from there, sometimes you may have to go down a size (i.e. 2.5 single stock, broke down to a 2.25 dual aftermarket). thats just my experience. definately open to other experiences.

[DannyC]

I have duel exhaust on my SXT. I was just thinking that the RT or SRT cats may allow a little more flow if they are larger diameter but still able to bolt on.

If the hemi guys are gaining HP with high flow cats maybe worth trying on our V6s.

[MikeEast]

I have duel exhaust on my SXT. I was just thinking that the RT or SRT cats may allow a little more flow if they are larger diameter but still able to bolt on.

If the hemi guys are gaining HP with high flow cats maybe worth trying on our V6s.

It's most certainly worth a try - if someone wants to come on over and get 'em, you can have my stock cats - they are just taking up space that I could use for storing other obscure stuff I don't need..

Mike