Custom 3” Downpipes & Exhaust

[Breezyjr]

Hey, I'm out in Troy. I said the same thing when I grew out of my 400hp SRT-4 about 14 years ago, lol. Here I am throwing exhaust, springs, intercooler etc on the ST. Most exhaust shops should be able to put the cat back on for cheap. I'm a novice (my brother is a pro mechanic, luckily) and it's a really easy job. The DPs on the other hand....install could get expensive.

Well, if you ever have to call 911, I might be the one who shows up at your door.. lol. EMT, soon to be a medic... again.

lol

 

[Kruppa]

Piping to mid muffler done, now have to weld. Check out the pie cuts on the right, going to look awesome welded. Some examples post welding of others he’s done...

 

[Big Turk]

Hi,

I love the quality of the exhaust you are building and I definitely think bigger is better. I have what may be a stupid question. Why have a cross pipe (X) connection just up stream of the mid muffler and a cross connection in the muffler too?

Anyway, nice build.

Cheers,

Ron

 

[Kruppa]

Hi,

I love the quality of the exhaust you are building and I definitely think bigger is better. I have what may be a stupid question. Why have a cross pipe (X) connection just up stream of the mid muffler and a cross connection in the muffler too?

Anyway, nice build.

Cheers,

Ron

Honestly mostly to just be unique and experiment. Ideally an x is closer to the front but limited by the car setup and not wanting too sharp of an angle anywhere.

But X-pipes do help smooth the flow of air and clean up the sound and help scavenging effect for slightly more power.

X pipes also create a slightly higher pitch which I like for a v6. It’s not a deep glugging like a v8 muscle car. All just personal preference of course.

 

[UNBROKEN]

Dual X’s also help to cancel drone.

 

[Kirk ST]

Currently in the shop and can’t wait to get it back. Everything is 3”, stainless, mandrel bent, tig welded, back purged.

Custom catted downpipes to vibrant resonators to x pipe to large magnaflow mid muffler (x-pipe design) to two smaller rear vibrant mufflers to custom dual exhaust tips. G-sport cats. Rear mufflers painted in high temp black. Tips powder coated black.

Few pics of the progress so far, I’ll add more as I get them. This is ongoing work not completed I’m sharing...o2, defoulers etc. need to be added.

Really happy with the quality so far, even the interior welds are a work of art. I will feel bad putting it under the car.

Excited to get this on a dyno in the next month or so. So far have ZFG tune (93), Whipple IC, JLT catch can, K&N filter for performance. H&R springs and Steeda rear sway bar have greatly improved handling. Also got a slightly lighter (10lbs each corner) winter wheel tire setup in 20 inches. Hoping this rubber lets me grip the road a lot better than the stock 21 all seasons.

View attachment 3073 View attachment 3074 View attachment 3075 View attachment 3076 View attachment 3077 View attachment 3078 View attachment 3079 View attachment 3080 View attachment 3084

this looks great. I've never done any mods to a vehicle but am inspired by so much cool work that's been done to these STs. the exhaust work looks really good and I like the winter wheel setup.

 

[Kruppa]

this looks great. I've never done any mods to a vehicle but am inspired by so much cool work that's been done to these STs. the exhaust work looks really good and I like the winter wheel setup.

thank you!! I’ve been having a lot of fun with this ride.

 

[Kruppa]

Welding the pie cuts connecting to the mid muffler

 

[Kruppa]

Finished mid muffler welds and onto the rear mufflers and custom tips!!

 

[BigJ1982]

Finishing mid muffler welds and onto the rear mufflers and custom tips!!

View attachment 3137

Can't wait to hear this thing.

 

[Kruppa]

Can't wait to hear this thing.

Me and you both!! Obviously I wanted quite a bit of sound dampening with 2 resonators, a large mid muffler, and 2 rear mufflers as my intention is to have this be a daily driver and not be obnoxious/annoying for me to drive. Mainly I'm hoping for that difference in tone that sounds more like what I feel a V6 should sound like vs the ultra deep glugging typical of a v8 muscle car. We will see!

 

[UNBROKEN]

I can tell you this much...even with the 18” body Magnaflows out back mine is still a little loud when driving. I’m gonna try the same Vibrant 1136’s you have sometime next week. I’d pass on the tiny Magnaflows...I have a feeling it’ll be really loud when driving.

 

[Kruppa]

I can tell you this much...even with the 18” body Magnaflows out back mine is still a little loud when driving. I’m gonna try the same Vibrant 1136’s you have sometime next week. I’d pass on the tiny Magnaflows...I have a feeling it’ll be really loud when driving.

Yeah we are going with the vibrant I think for that reason but still need to hear them. How large is your mid muffler? You have vibrant resonators?

I wish everyone with a custom set up could get together and we could all hear them in person, based on prior experience it’s impossible to compare clips online and everybody’s opinion of what is loud is so different. It could be based on tone vs drone etc. At the end of the day I am more concerned about the tone versus the volume however I do not want it overly loud

 

[UNBROKEN]

We’re virtually identical aside from your second x. SPD downpipes, Vibrant 1794 resonators, Magnaflow 12599 mid muffler and after I swap we’ll have the same Vibrant 1136’s...all 3” mandrel bent stainless. Mine sounds fantastic...I have no doubt yours will too. Very deep at idle and not loud at all. The only thing I’ve been fighting is the volume while driving. Having four 4” tips just outside the cabin doesn’t help but some sound treatments on the rear floor and hatch helped it a lot.

 

[Kruppa]

We’re virtually identical aside from your second x. SPD downpipes, Vibrant 1794 resonators, Magnaflow 12599 mid muffler and after I swap we’ll have the same Vibrant 1136’s...all 3” mandrel bent stainless. Mine sounds fantastic...I have no doubt yours will too. Very deep at idle and not loud at all. The only thing I’ve been fighting is the volume while driving. Having four 4” tips just outside the cabin doesn’t help but some sound treatments on the rear floor and hatch helped it a lot.

Awesome and yes I can’t wait to hear it. No idea what, if any, difference my custom catted downpipes vs SPD and the extra x pipe will have. I was planning on trying to put some sound deadening under the spare tire and maybe few other places in back. Do you think that’s worth it? My only other comparisons are relatively unfair as they’re more expensive vehicles but the explorer definitely has more road noise than I’m used to to start with.

 

[UNBROKEN]

Depends on the cell count in the converters you used. SPD uses a larger diameter 400 cell cat. If you used something like a 200 cell from GESI it may be a hair louder but I wouldn’t think too much. For the deadener I did full coverage CLD on the floor, tire well and hatch with Dynapad CCF/MLV in the same areas. It made a noticeable difference. I’m also in the middle of treating the entire cabin. I just got all 4 doors finished yesterday. Interior side panels are next.

 

[Kruppa]

Depends on the cell count in the converters you used. SPD uses a larger diameter 400 cell cat. If you used something like a 200 cell from GESI it may be a hair louder but I wouldn’t think too much. For the deadener I did full coverage CLD on the floor, tire well and hatch with Dynapad CCF/MLV in the same areas. It made a noticeable difference. I’m also in the middle of treating the entire cabin. I just got all 4 doors finished yesterday. Interior side panels are next.

You’re going all out, I love it! My wife and I also have a X7 M50i and that thing is whisper quiet inside with absolutely zero squeaks rattles etc. I may mess around with some sound deadening on the explorer. Which model magnaflow do you have now for rears? The vibrants are bigger I assume since you’re trying them?

 

[UNBROKEN]

They’re actually about 3” longer. They’re the 12298’s. I like the way Vibrant packs their mufflers so I just wanna try them to compare. If they’re louder or drone I’ll swap the Magnaflows back in.

 

[Kruppa]

They’re actually about 3” longer. They’re the 12298’s. I like the way Vibrant packs their mufflers so I just wanna try them to compare. If they’re louder or drone I’ll swap the Magnaflows back in.

The vibrant muffler part is 5x9x15 and magnaflow is 5x8x18 so volume wise only about 7% difference. I’ve only heard MF vs Vibrant on the same platform once and they were similar - maybe Vibrant was slightly smoother but that was years ago and I’m sure the technology has improved. Your MF has also broken in so it will be hard to compare until you drive a bit. Your sounds clips from what I could tell sounded great and not loud at all - you could hear the engine plenty from outside but like you said perhaps the issue is just interior cabin noise.

Also just looked, my downpipes have G-Sport 300 CSPI (4” body, 7” overall)

 

[UNBROKEN]

The way Vibrant does their packing they claim they don’t burn in and have the sound change. Magnaflow definitely changes over the first 1000 miles or so. Mine got deeper and maybe a touch louder.
GESI makes your cats...I wouldn’t expect to notice any difference at all between a 300 and 400 cell cat with an exhaust this long.