I want to get a more in-depth look at exhaust systems here.

I currently have edelbrock TES shorty headers with 1 5/8th and a Y-Pipe. I have a stock Cat for now, but I'm having a custom made pipe to replace it since I believe mine is clogged. I also have Edelbrock 3 In. cat-back exhaust.

My first question is, will I acquire any power by switching to maybe a better brand of cat-back, like maybe the Applied Technologies at www.ls1speed.com ? or am I better off just staying with what I have.

Another question, are any benefits to be gained by moving up to a 3.5 in. or 4 in. exhaust? I notice I can get a Mufflex/Spintech setup in 3.5 in or 4 in. My headers are 1 5/8th, so they flow for Torque. A larger exhaust, like 3.5 in. and 4 in. have power in the mid-range and top end. So if I have torque oriented headers, would a top end oriented exhaust be logical? I'd appreciate any help, thoughts, or ideas. thanx all

 

Headers make power. Cat-back makes noise.
On your car switching the cat-back isn't going to make a bit of difference. Don't change it unless you want to change the sound.
Going to a bigger diameter exhaust won't change anything either. If you want to buy some exhaust parts, get some good longtubes and a y-pipe. Probably Hookers or Jet-Hots.

 

the only thing that would cause you to gain power from switching cat back brands (but staying with 3") would be due to the muffler and how restrictive it is. since the edelbrock is 3" and mandrel bent you could just install reall free flowing muffler. one way would be to put a bullet on it and run a single tip.

with a hotcam kit you may benefit from the 3.5", but i doubt the 4" would do much. one thing you'll have to look into is having the collector on your Ypipe enlarged to 3.5" if you go with that.

i would just install a cutout and see how that works...

 

Unless you are making upwards of 400rwhp there won't be any noticable difference from a 3" to a 4" exhaust. If you want more power from your exhaust ditch the edelbrocks and get some LT's.

 

Any other ideas?

How much could I really be losing from a clogged cat? I'm running 14.1s right now (without 3200 stall TC) and my car should be in the 12.8-13.1 range. Could my exhaust be causing any problems? I checked almost all the other possible areas where problems could exist.

 

cut the cat off or get an offroad pipe, run it at the track and see if it makes a difference.

a clogged cat could be causing some serious pwer lose. i know a buddy who melted the cat on a rental truck with a 318 V8...and it felt like a 4 cylinder.