I've been planning to open up my whole exhaust as I knew it was a restriction at the Air I was moving. Some of you may have seen that I went to a larger cam a couple months ago, upon doing so my single 3" exhaust started sounding like a big air leak at WO. I already upgraded my old headers earlier in the summer, I switched to Kooks 1 7/8 3" collectors. This got me curious so I put a back pressure gauge on it, at WO my pressure was 10psi in first gear and kept climbing when I hit second so I just said screw it and let out. Time to get this exhaust done.

I did dual 3" into a dual 3" in / single 4" out merge. I used a Flo Pro Dmax mid pipe into a Magnaflow SI/SO then a Magnaflow universal 4"tailpipe. All stainless and V band clamps used for easy of removal etc.

Some things to note, the big Magnaflow muffler is a 3.5" core, I couldn't find a good large case 4" muffler that wasn't a diesel style muffler. I knew 4" was gonna be hard to keep tolerable sound wise so figured I would try the 3.5". Many forget the fact that a 3.5" core muffler is really 3.5" where as a 4" pipe is more like 3.75-3.8 as its measured in OD not ID like a muffler. So I figured I would try it and check back pressure and go from there. Much to my suprise there wasn't any. I lost about 1.5 psi boost and was a bit lean on topend.

It was also loud, so that started the next project. Adding in a resonator. Pics to follow.

Magnaflow 4" tail, had to modify it as my Dana 60 rear and QSteer requires more clearance then a standard axle.





Tail modified

 

It was pretty loud, it sounded great but a bit to much for my tastes. It also had a pretty good drone. I only had about 12 of pipe to work with where I wanted it placed so it was time to modify something. I got a 4" Magnaflow muffler, it's a 14" case. So we shortened it.

 

The resonator is now 10" long, we took 2" off each end, kept the Magnaflow logo centered. Best of all it removed the drone and it sounds great! I need to get a WO video. I dropped down to a 2.9" pulley now to get boost back to 15ish

I couldn't have done it without the help of my buddy Mark ( Mark Buck)

 

Launch, let out once second hits. Cruising down highway it is silent in the cab.

 

Sounds good!

 

It's got a nice tone to it! What's the part number on the 4" MF muffler?

 

Looks like Mark Buck does high quality work

 

4" part # is 14153

Mark and I consumed many Red Bulls and Beers in the process. He redid his TBSS exhaust prior to us doing mine.

 

Truck sounds great Pat!!

 

Did you have to make the dual 3 inch merge to single 4 out? I plan on running 4 inch on my cammed lq4 when I get it in,I really like how you did this and it looks very well put together, I will be running something a little more on the loud side tho, thinking a small borla xr1