3 1/2" Muffler - FYI

[moondoggie]

Good Day!

I installed (actually, John installed) a JK 3 1/2" exhaust system on our Sub two or three years ago. I am COMPLETELY happy with the exhaust system, but am one of the very few for which it's too loud. I finally installed a different muffler; now I am 100% happy with this exhaust system.

From the local Fleet Farm, I purchased a muffler labelled "Stanley Muffler Co. Inc., IH-26, replaces INTERNATIONAL 534546R3." It's oval; the body is ~ 23 1/4" long. (I could not find a website for Stanley, although I didn't look real hard. It's probably the company at 3000 W. Highway 80, East Prairie, MO 63845, but I don't know for sure.)

I then purchased two Walker Mega-Clamp Heavy Duty Muffler Clamps; the label says "33279 268-2935 3.50" BUTT CLAMP STAINLESS." I'm pretty sure I got these from one of the street rod vendors - I don't think it was Jegs, but the other biggie in this market (can't remember the name).

The clamps are 3" wide; I cut the pipes off the muffler ~ 2" from the body on each end. I only had to slip the rear pipe hanger a little (< 1/2") from where JK had clamped it on the pipe.

Now I LOVE my Sub again, well as much as I can until I get the A/C fixed. With the windows up, you can't hear the exhaust at all; with both right-side windows down, it has a tiny little rap to it, suggesting it might not be as restrictive as a factory-type muffler. I had hoped to tap the exhaust right after the turbo & measure backpressure before & after installing this muffler; I was happy just to finally have time to get it installed. I virtually never pull with this Sub anyway, so even though I've increased exhaust backpressure some unknown amount, it probably doesn't affect it where I'd notice anyway.

It looks like the Page has 15,000 or 20,000 members now; I figured there's a chance two or three might want a JK exhaust without the volume.

BTW, John smeared dielectric grease all over every joint on this exhaust system when he installed it. When I installed this muffler, the joints I needed apart came apart like they'd been installed yesterday. I hate exhaust work, & this job was a breeze.

Blessings!

[DaveNY]

Moondoggie,I need an assesment of the exhuast upgrade am contemplating next move, Im' all stock except for TM and Remote PMD. Truck runs fine and does 16-17 mpg on hwy but always a touch anemic.Got a guy here local with mandrel setup.
Thanks DAVE

[moondoggie]

Good Day!

"...I need an assesment..." I'm not sure what you mean. I'm far from an expert on any of this stuff - most of my posts are simply parrotting what I've read over the years. I started this thread/topic so the few folks like me might be able to easily do the same thing as I did.

Search on exhaust & similar - there's been TONS of stuff written on the subject. I put JK's exhaust on because my exhaust needed replacing anyway, & this way I'm ready for future power upgrades. I can't quantify any increase in power or mpg from this mod - it would take collecting data I can't collect to determine any improvements. From what other folks have said, it's almost certain my boost comes up a little quicker & goes a little higher, & EGT's are likely lower.

From my reading, 3" might be a tad too small if one's going for max power later on, 3 1/2" is probably as big as anyone needs to go, but some folks swear by their 4" systems. I guessed that 3 1/2" was adequate for anything I'd ever do. I also base this on the fact that I've not been able to find JK wrong about anything when it comes to these engines.

It's also worth remembering that virtually all of these systems are 3" when they come off the turbo - that's the size of the turbo outlet, & there really isn't room for a bigger pipe until you get past the frame & fenderwell. JK's opens to 3 1/2" as soon as it's practical to do so.

"Got a guy here local with mandrel setup." If he's real good, & his price is considerably better than JK's, go for it; otherwise I'd get JK's or whatever you might find that's similar.

Blessings!

(signature in previous post)

[DaveNY]

Thanks for the reply I guess I was just looking for a seat of the pants feel in the truck and maybe a little fuel milage #s. From your response I am going to assume that there is no real significant changes to either,and the benefits are realized with some more substantial performance upgrades.
My exhaust sytem is healthy and I will leave it alone until more mods are completed or the current system gives up. thanks again Dave

[ronniejoe]

Check out Kennedy's website for dyno results before and after his exhaust.

[moondoggie]

Good Day!

"From your response I am going to assume that there is no real significant changes to either, and the benefits are realized with some more substantial performance upgrades." I can see where you might conclude that from what I wrote, but it's not the whole truth. I don't feel a seat-of-the-pants improvement in power, but the seat of my pants is dead - I doubt I'd notice less than a 20% or 50% improvement. As far as mpg, I simply haven't taken enough data to have any idea how much if any it improved. It's almost certain both have improved, I just don't know how much.

I'd look at the dyno charts RJ refers to. I couldn't find them in a quick look-see, but I know they're there somewhere. That's why John calls his dyno his lie detector - his numbers talk & anything else walks.

It's important to keep in mind: a freer-flowing exhaust is about the only modification safe enough to be done on a 6.5 without gauges. Based on all I've read here over the years, you'd have to be out of your mind to do any mod other than exhaust without installing at least boost & EGT gauges.

I never intended this to be about JK's exhaust, which I happen to think was worth every penny I paid for it. I just wanted the very few who, like me, want things a bit quieter, to know there's an option out there. When I was looking for this muffer a couple years ago (yeah, it's been laying around waiting to be installed for awhile) I could not find a 3 1/2" muffler at all. Hence the Fleet Farm purchase.

Blessings!

(signature in previous post)

[ronniejoe]

Look here (http://www.kennedydiesel.com/photogal/images/1997-GM-65-kdexhaust.gif).