2.5' pipe will make a gain r not

[Smalldogg/03mm]

Hey thinking about today going to change my exhaust piping.. I cut the cats,the back two, added 40 flows,want to no if changing the old piping and up grade to 2.5 like some of guys did will I hear and feel a difference. Not ready to add the x -pipe system are the aro- system yet.. Respect...

[Rockettman]

Coming out of the 1st cats (the ones you left in), is 2.5" pipe. The original mid-pipe set-up is 1 7/8" (if you left that in). That's a "clog" in the system.

Moving up to all 2.5"? Well it depends where you want your power to be. Changing to 2.5" pipe all the way through will increase top-end power. Immediately you will feel loss of low end torque. I kept mine 2.25" throughout for that reason, and still can feel a small loss in low end.
Now if you race the car on the track or drive "balls-out" allot, the 2.5" may be what you're after.
Just a side note. Changing to a 4.10 gear in the rear-end (as many have done), gets your car up into the higher rpm range quickly. As noted above, that's where 2.5" piping puts your best performance...so "1 + 1 = 2" !

Will you feel and hear a difference? Feel: I've noted above. Hear: yes. I had 40s on for one afternoon and evening. Too loud for me. Removing the 2nd cats as you did, brings up the volume too. It's all personal.
Hope I've helped.

[Smalldogg/03mm]

Man u guys no ur stuff. I have 4:10 already so that one plus.. Now I'm a average driver until the bottle get turned up.. Lol.. As for as racing I whenever there is a op..

[ctrlraven]

Any upgrade of the exhaust will help increase performance, now wheither it's all around or more towards the top end is a different question. When I did my full 2.5" exhaust I noticed a little less low end torque on the take off but the car pulls much harder in the mid to high rpm range.

An engine is basically a big air breathing machine, the more air you can move in and out of the engine the better.

[fastblackmerc]

Any upgrade of the exhaust will help increase performance, now wheither it's all around or more towards the top end is a different question. When I did my full 2.5" exhaust I noticed a little less low end torque on the take off but the car pulls much harder in the mid to high rpm range.

An engine is basically a big air breathing machine, the more air you can move in and out of the engine the better.

+1...

I noticed the same when I had a custom 2.5" mandrel-bent SS system installed to replace the stock system.

[ctrlraven]

If the engine was push-rod then might fair better to the same exhaust but with it being a mod motor and already known for not having jack on the low end being NA, just have to add 4.10 gears to help balance it out.

[Rockettman]

An engine is basically a big air breathing machine, the more air you can move in and out of the engine the better.
100% true!!...but putting together a plan on "where that power is going to happen" is almost a science in itself.

[Rockettman]

As I mentioned in our PM's "smalldogg",
with the tons, and tons, and tons of advice and help I got on this site; along with help from family that are engineers; if I were to do it all again, I'd have had the mid-pipes redone with 2" pipe (up from 1 7/8"), and change the mufflers (only for sound) to the Flowmaster 50's that I have now.

[Smalldogg/03mm]

Ol I forgot" rockettman" u want a more quieter sound... Don't u love how those cobra's sound, like a panther n heat..:) lmao