Exhaust opinions - MAGNAFLOW DECIDED

linewarbr · **Posted:** Mon Jul 20, 2009 3:44 pm

I think my next upgrade will be changing out the exhaust, so I wanted to start a thread to get some input.

What exhaust are you running?

Have you experienced any mileage/ performance gains?

DIY job or did you have it done?

I'm looking for a Saturday install, something I can do in the driveway, with a price max of about $400. (That rules out the Magnaflow full catback kit)

I am not sold yet on straight-piping it, plus I don't have the fabrication skills to weld in a straight pipe. (or the welding machine, for that matter) I have followed some threads on here, and seen RTStabler's MBRP install (which looked great) and another member's side-exit Magnaflow install. I do want to wheel it, so a side exit is not feasible without trim modification.

Please share your thoughts.

DarbyWalters · **Posted:** Mon Jul 20, 2009 4:52 pm

Two recent threads

http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=44951

http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=44669

linewarbr · **Posted:** Mon Jul 20, 2009 5:52 pm

I'm familiar with both of those, and am considering the MBRP because of the price and the DIY nature. I just want to consolidate the opinions into this thread.

stoutdog · **Posted:** Mon Jul 20, 2009 11:04 pm

Save your money and just replace the muffler. A catback is pretty, but not really worth the extra $2-300.... Unless, of course, you care about having a pretty muffler.

The stock pipes, when 2.5", will work just fine.

CRD Joe · **Posted:** Mon Jul 20, 2009 11:33 pm

I just paid 155.00 for a 2.5" cat back no muffler! I LOVE the sound. Now Im going to see whether I get any better mileage out of the deal.

stoutdog · **Posted:** Mon Jul 20, 2009 11:52 pm

CRD Joe wrote:

I just paid 155.00 for a 2.5" cat back no muffler! I LOVE the sound. Now Im going to see whether I get any better mileage out of the deal.

Nice, that's not a bad price! I'm just going to put on a Magnaflow (for legality issues, plus I like the throaty sound). It'll be 2.5" straight through though!

RTStabler51 · **Posted:** Tue Jul 21, 2009 7:00 am

stoutdog wrote:

Save your money and just replace the muffler. A catback is pretty, but not really worth the extra $2-300.... Unless, of course, you care about having a pretty muffler.

The stock pipes, when 2.5", will work just fine.

Actually most of the cat backs have a straighter flow as well, so with the better muffler and less bends it will improve flow even more of the stock set up. Granted gains are minimal, but we care about minimal gains.

linewarbr · **Posted:** Tue Jul 21, 2009 7:39 am

How did you guys do the straight pipe? Did you weld in a new piece, or can you do it in the driveway with clamps?

Stabler, have you noticed any performance/ mpg gain with the MBRP? I'm kind of leaning toward that right now, but some of the issues Turbo Tim and gmctd brought up in your install thread concern me.

RTStabler51 · **Posted:** Tue Jul 21, 2009 8:04 am

linewarbr wrote:

Stabler, have you noticed any performance/ mpg gain with the MBRP? I'm kind of leaning toward that right now, but some of the issues Turbo Tim and gmctd brought up in your install thread concern me.

I can't say as I put in the GDE tune at the same time. MBRP makes exhaust for the 'big' trucks as well. If the muffler is that big of an issue, I'm sure an email to them and they could modify it as the only 'unique' part of the muffler is probably the length. They could probably substitute a 'real' diesel muffler if requested. To be honest, I'm not that really concerned about the few potential HP that may be lost. If their dyno graphs are accurate, the gasser version (patooie - for gmctd) made something like an additional 7hp/13ftlbs over stock. I figure the diesel using the same catback will benefit a bit more than that since we flow a bit more.

that's just my uneducated opinion.

stoutdog · **Posted:** Tue Jul 21, 2009 8:17 am

RTStabler51 wrote:

stoutdog wrote:

Save your money and just replace the muffler. A catback is pretty, but not really worth the extra $2-300.... Unless, of course, you care about having a pretty muffler.

The stock pipes, when 2.5", will work just fine.

Actually most of the cat backs have a straighter flow as well, so with the better muffler and less bends it will improve flow even more of the stock set up. Granted gains are minimal, but we care about minimal gains.

Well, okay. Hope you enjoy that extra 1 ft/lb and .001 mpg

.

I looked into the catback and, as I'm really only seeking mods that will improve my mpg to a degree that I will make it back financially, it wasn't really an option....

ribbon · **Posted:** Tue Jul 21, 2009 9:18 am

stoutdog wrote:

RTStabler51 wrote:

stoutdog wrote:

Save your money and just replace the muffler. A catback is pretty, but not really worth the extra $2-300.... Unless, of course, you care about having a pretty muffler.

The stock pipes, when 2.5", will work just fine.

Actually most of the cat backs have a straighter flow as well, so with the better muffler and less bends it will improve flow even more of the stock set up. Granted gains are minimal, but we care about minimal gains.

Well, okay. Hope you enjoy that extra 1 ft/lb and .001 mpg

.

I looked into the catback and, as I'm really only seeking mods that will improve my mpg to a degree that I will make it back financially, it wasn't really an option....

Getting rid of the restriction will gain you more than that. Much easier to coast... more mpg.
I agree with just replacing the muffler. If you want the bling weld on a tip

sentry · **Posted:** Tue Jul 21, 2009 12:31 pm

I had the muffler cut out and a 2 1/2 pipe welded in it's place at the local pro fit muffler shop. Cost me $60.00 and took 30 minutes. I can hardly notice a difference in sound. Just a little more bass especially when under load. Not sure about MPG as I also cleaned my MAF sensor and max inflated my tires for running the interstate. That being said, my hand calculated MPG while running at 80 MPH for 383 miles is now 25.61 MPG. That's about 4 MPG better than last trip without the changes.

stoutdog · **Posted:** Tue Jul 21, 2009 12:52 pm

ribbon wrote:

stoutdog wrote:

RTStabler51 wrote:

stoutdog wrote:

Save your money and just replace the muffler. A catback is pretty, but not really worth the extra $2-300.... Unless, of course, you care about having a pretty muffler.

The stock pipes, when 2.5", will work just fine.

Actually most of the cat backs have a straighter flow as well, so with the better muffler and less bends it will improve flow even more of the stock set up. Granted gains are minimal, but we care about minimal gains.

Well, okay. Hope you enjoy that extra 1 ft/lb and .001 mpg

.

I looked into the catback and, as I'm really only seeking mods that will improve my mpg to a degree that I will make it back financially, it wasn't really an option....

Getting rid of the restriction will gain you more than that. Much easier to coast... more mpg.
I agree with just replacing the muffler. If you want the bling weld on a tip

Ribbon, wait, I'm confused. Did you just disagree and agree with me at the same time? :shock:

I'm all for replacing the muffler/exhaust brake (I'm doing it to my CRD in two weeks). My comment re: minor gains is intended for those who also replace the stock 2.5" piping with shiny new parts. Maybe it is a hair straighter, but - to me - the very slim gains that such a mod would provide do not outweigh the extra $2-300 in cost.

linewarbr · **Posted:** Tue Jul 21, 2009 1:00 pm

Ok, I'll come clean here - I've never replaced a muffler before. How big of a job is it?

I was under the impression that a muffler replacement required welding, and since I'm not sure of the legalities of a straight-pipe setup in my state/ parish (county) I didn't think I could just go down to Joe's muffler shop and have them weld in a straight pipe.

One of the reasons I want a DIY (and one of the reasons I became a lifetime member on this site) is that I really look forward to doing my next mod, and doing it myself.

dgeist · **Posted:** Tue Jul 21, 2009 2:32 pm

sentry wrote:

I had the muffler cut out and a 2 1/2 pipe welded in it's place at the local pro fit muffler shop. Cost me $60.00 and took 30 minutes. I can hardly notice a difference in sound. Just a little more bass especially when under load. Not sure about MPG as I also cleaned my MAF sensor and max inflated my tires for running the interstate. That being said, my hand calculated MPG while running at 80 MPH for 383 miles is now 25.61 MPG. That's about 4 MPG better than last trip without the changes.

I had the same thing done (2.5" straight pipe welded in place of the muffler back to where it makes the sharp up-bend over the axle). About 100 bucks at Meineke (would have been less but the guy accidentially spot welded it in backwards and had to go back and re-do it).

Noticeable changes are as listed above: slightly faster spool on turbo, a little more bass in the exhaust note, better coasting downhill and on highway, and about 1-2 mpg gain (based on my numbers).

Dan

ribbon · **Posted:** Tue Jul 21, 2009 2:40 pm

Hey, I'm working on 3 hours of sleep here

(D@mn deadliest catch dvd's)
I thought you were saying you would only see .001 mpg change from getting rid of the exhaust brake.

stoutdog · **Posted:** Tue Jul 21, 2009 3:51 pm

ribbon wrote:

Hey, I'm working on 3 hours of sleep here

(D@mn deadliest catch dvd's)
I thought you were saying you would only see .001 mpg change from getting rid of the exhaust brake.

I forgive you

linewarbr, a new muffler can be do-it-yourself. You will need a saws-all and the appropriate clamps or welding equipment. I will be having a shop do this (I don't have the tools or the $$$ to buy them), but from what I understand you can simply hack off the old muffler and clamp on the new one (along with a piece of extension 2.5" pipe to make up the difference).

I believe three clamps and a few beers is all that's needed :wink:

Check out eurekaboy's website. I think he has instructions on there.

linewarbr · **Posted:** Tue Jul 21, 2009 3:54 pm

Yeah, I've seen eurekaboy's install. I like the side exit, except for the loss of ground clearance.

tulsa · **Posted:** Tue Jul 21, 2009 4:49 pm

linewarbr wrote:

Ok, I'll come clean here - I've never replaced a muffler before. How big of a job is it?

I was under the impression that a muffler replacement required welding, and since I'm not sure of the legalities of a straight-pipe setup in my state/ parish (county) I didn't think I could just go down to Joe's muffler shop and have them weld in a straight pipe.

One of the reasons I want a DIY (and one of the reasons I became a lifetime member on this site) is that I really look forward to doing my next mod, and doing it myself.

A local shop should know if a muffler is required in your state. I have an Aero 2525, would use straight pipe if I did it again.
Lewis

stoutdog · **Posted:** Tue Jul 21, 2009 5:42 pm

linewarbr wrote:

Yeah, I've seen eurekaboy's install. I like the side exit, except for the loss of ground clearance.

Yea, well, if you leave the stock piping alone and just replace the muffler you can do his install and still have the rear exit.

Exhaust opinions - MAGNAFLOW DECIDED

Who is online