Gibson cat back installed

[Z71DieHard]

Well, finally got the system in. Installed this evening in a about an hour.

In the process of installing, I fired the Z up after just installing the dual header pipe...Man, talk about bad a$$! Didn't know that the 5.7 would sound so good with just cats...and the dual header pipe!

Put the rest together, a single swept side. Definitely quieter than flowmaster 70's. No rumble in the cab at 1500-2000 RPM's like flows...Going on long hwy ride tomorrow, so I'll give some feedback on the performance side.

If it don't measure up to the 70's I had on my 5.3, they're going back, and I told the guy at 4WP that too!

[99GMC]

Lol, good luck! I think you will like the setup, the trucks I have heard sound pretty good:D

[CKTA]

It may not sound as loud in the cab as the Flowmuster, but that is a good thing. Plus, Gibson will give you more performance.:head:

[Z71DieHard]

Well, I'm not sure if I went with the right system...

The Gibson does sound better than it did at stock, but I still did not achieve any better throttle response. As for performance issues, it seems from the seat that there's no apparent change:(

I was expecting a definite increase, kind of like "waking the truck up" and did not achieve this result. At low RPM I say it's weak, but mid to high is where you notice ....Could it be that since I opted for the single out the side vs. going with duals that it still restrictive?

I'm tempted to take it back and go back to Flows...I really want some thump! Any help or advice is welcome, Thanks.

[HENRY]

Its been argued that the single 3'' is probably the same as dual 2 1/2's.


What other mods do you have?
Its possible to still get more power from your exhaust as you make more mods to your engine.

For example:
Headers,
Intake, etc etc.

[Z71DieHard]

Thanks, Henry...

I already had a K+N filter, de-screened MAF, and then exhaust done. I just got back from 4WP's and they asked how it worked and I told them not too good. They said if it didn't do what was expected, bring it back for full refund!

While I was there, I went ahead and got a HPP3 for it and re-programmed the truck. On the way home I got into it only a few times. Did appear to provide some improvements, but not as dramatic as I had expected considering the mods...

During the re-program, I selected the 160 thermostat even though I think I have a 180 (gauge never over 180). Also, since I plan on putting on my 33's I adjusted for tire size although currently running 265's and selected firm shifts, higher rev limit, top speed etc.

Here's a couple of questions...

Does it make any difference on the temp setting?
I want to have normal shifts higher RPM, how can I do it?
What changes can I try to get better results?

[pullinpower]

Got ya a programmer huh? Must have got it cheap :read: ,If you will bring it by the house I have some notes wrote down on some of the tuning I had in my 2000 6.0 and well see if we cant wake it up.:naughty: