So far, I like <img src="gr_grin.gif" border="0"> . I took the Walker off because my mpg has taken a dump with it, gone from always gettng about 15.5 to getting 14.. Putting on the Walker is the only thing I've done to account for the drop in mileage <img src="images/icons/confused.gif" border="0"> . I went with Magnaflow pn-12278, it's a 3" in and dual 2.25" out. I started over, I replaced the 2.5" pipes with 2.25" ones and ran them all the way back. The ends are out next to the fenders and I had turn down tips installed, you can barely see them poking out, stealth style <img src="gr_tounge.gif" border="0"> . The Magnaflow has a low DEEP rumble, nice tone under load and a little growl on the freeway to let you know it's there, but not loud by my standards. We'll have to see about the mpg, I'll let you know after I put a couple tanks through it.
Jim <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />

 

Sounds good, I am planning on dropping my Dynomax and addind Magnaflo's. How do you like that PV Venturi? Notice any of the claims they make on it?

 

[quote] <hr></blockquote>How do you like that PV Venturi? Notice any of the claims they make on it? [quote] <hr></blockquote>

I like the Venturi just fine, it does add some low end torque. I had a 70 Series dual 2.25" out Flowmaster on my truck when I installed it. Before the install, I truck to do a brake stand burnout in my truck, wouldn't do it. A week after the install, I went back to the exact same spot I had tried before and the truck left a two tire burnout 65' long (I actually stepped it off). I don't really know if the truck actually got quicker but the low end definitly got more responsive.
Jim <img src="gr_grin.gif" border="0">

 

Sounds like you have a nice exhaust set up..


What is a Power vault venturi? Is that Like a cut out or something?

 

[quote] <hr></blockquote>What is a Power vault venturi? Is that Like a cut out or something? [quote] <hr></blockquote>

A PV (Power Vault) Venturi is a device John Finnel at PV designed to enhance low end torque. It's designed to bring back lost low end normally found when a catback is installed on the new Vortec engines. It looks kind of like a flower vase, it's large one end and reduces down to a smaller opening. You install it before the muffler, it does something to the exhaust gases. There is a write up about it on the www.pvmufflers.com website. If you pull up a picture of the cat-back system, it's the flower vase looking thing on one end of the muffler. They use to come on the cat-back but I don't think they do any more, now he sells them seperatly.
Jim <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />

 

They use to come on the cat-back but I don't think they do any more, now he sells them seperatly.

They are built inside of the muffler. I just bought one from him a couple of weeks ago.

 

[quote] <hr></blockquote>They are built inside of the muffler. I just bought one from him a couple of weeks ago.
[quote] <hr></blockquote>

The inside of the muffler does have the same design as the Venturi, but you can still get the Venturi.
Jim <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />

 

Anyone tried to dyno before and after with one of these venturi things?


I know when I open my duel cut-outs on my truck , I picked up power and torque but I have a 6 litre. The small cid 5.3`s may not like the extra flow... My cut-outs by pass the muffler completly.. My 99 ls1 firehawk picked up 12 rwhp and 11 ft. lbs of torque with open cut outs.. Never lost torque but it also was a 5.7 litre.. Both of those motors loved the extra exhaust flow..

 

I'm not sure but I think it's Speeder in the PA forum is going to dyno them when he puts true duals on his truck. John at PV is real straight forward when it comes to his products, no <img src="graemlins/gr_bs.gif" border="0" alt="[bullshit]" /> . I believe he claims about 5 rwhp and 5 lbft. All I do know is the 5.3L in my truck is no torque monster, that's for sure, and the Venturi I put on definitely helped.
Jim <img src="gr_tounge.gif" border="0">