Aftermarket exhaust

jws84_02 · **Posted:** Sat Dec 31, 2011 1:51 pm

Do these crd's benefit from a aftermarket exhaust. I have looked on here but really haven't had much luck.

What have u guys done, and If there are any threads could u post links

nickademus · **Joined:** Mon May 09, 2011 2:15 pm **Posts:** 54

i personally just replaced the muffler with a high flow version

the turbo acts as a muffler, you can just straight pipe after it.

papaindigo · **Posted:** Sat Dec 31, 2011 2:07 pm

Fair amount of chat on the topic but you have to search the CRD forum for "muffler" to find much of it. Several have done and some have undone a straight pipe rig, apparently rather noisey to some ears. Some have remove the cat but that causes problems if you are in or move to an emissions inspection state/area. A number have replaced the existing muffller with a good 2.5" muffler like a Magnaflow Muffler #12226 and added a bit of pipe to remove the nearby choke point.

My son has done the swap but I have not. He "thought" it coasted a bit better with the larger muffler but that was before we both got the GDE TCM tune that holds lockup at lower speed.

Several have reported lower back pressure but how much that matters on a diesel I just don't know.

Bottom line is it's an under $100 mode that might help a bit and certainly won't hurt. I'll consider it when I drop in the GDE turbo and better flow might mean something.

audiboy86 · **Posted:** Sat Dec 31, 2011 5:02 pm

Cherry bomb makes a full set up that eliminates the reduction in the exhaustand gives you all new 2.5" pipe all the way back from the cat. It is about 200 and easily installed in under and hour.

irollgen4s · **Posted:** Sat Dec 31, 2011 7:19 pm

straight pipe it. Diesels don't need back pressure, and it sounds better with it straight piped IMO.

Roostre · **Joined:** Sun Oct 24, 2010 3:57 pm **Posts:** 195

I put an 3" Aeroturbine muffler on (It was $20) and did a full mandrel bent 3" cat-back by ordering the parts from Summit Racing and copying the factory tail pipe.

This thread was helpful:
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=13549&highlight=custom

I started mine with no exhaust after the cat just to see how it sounded; surprisingly quiet. We are required to have a muffler here for inspections or I would not hesitate to straight pipe it as many recommend.

2mopar_diesels · **Posted:** Sat Dec 31, 2011 11:43 pm

Strait pipe it, and never look back!!!

Hoosier CRD · **Posted:** Sun Jan 01, 2012 6:04 am

The Magnaflow # 15870 is a cat-back muffler & tailpipe set that has a 2.5 inch mandrel bent tailpipe. This, along with addtional 14 inches of piping up front :wink:

will give you the best possible set up that is reversible for the future, i.e selling. Be sure to keep what comes off in front of the muffler. Amazon sells for about $430 currently plus any shipping.

Any larger piping will not help you. The turbine housing outlet is 2.5 inches. Exhaust will not flow any greater past that point with larger piping, it will only change the sound (I think that it gives it a deeper rumble) FWIW

Hoosier CRD

CIMARRON13 · **Posted:** Sun Jan 01, 2012 2:10 pm

Straight pipe here as well. The extra noise is only noticeable at idle. Most people will not notice you did anything to it unless you tell them. I didnt notice any MPG gain but did notice the turbo seems to spool up faster.

CRDMiller · **Posted:** Sun Jan 01, 2012 7:40 pm

Straight pipe it.

mikey1273 · **Posted:** Mon Jan 02, 2012 12:14 pm

if it came with a muffler PA requires one to pass the basic annal safety/visual inspections. that and the presence of the cat would be checked but all diesels are exempt from emissions testing. so I and other in places with those laws would need to keep some kind of muffler and tailpipe.

jws84_02 · **Posted:** Mon Jan 02, 2012 2:52 pm

Thanks guys for the info. I'm leaning toward straight piping. I don't have inspection and it is def the cheapest route.

Hopefully I can get some time this week and I can say bye bye to my cat and muffler

papaindigo · **Posted:** Mon Jan 02, 2012 3:43 pm

I'll stay out of the straight pipe vs. less restriction debate, although I have my own opinion, and simply note that it would be prudent to at least keep the cat on the shelf so to speak. If you move to an emissions state/location or your state/location starts emissions testing or you trade/sell the vehicle to someone who has to deal with emissions replacing the cat can be expensive. I recall at least one member who fell into that trap. Muffler is another matter, if circumstances change and a muffler is needed that's a rather cheap and easy install.

Food for thought.

jws84_02 · **Posted:** Mon Jan 02, 2012 4:34 pm

Well considering I'm a farmer, i don't see myself ever moving to a different state. It would be hard to move 2000 acres somewhere.

As for selling it. I guess I will cross that road when it comes. I might keep the cat for this reason

CIMARRON13 · **Posted:** Mon Jan 02, 2012 8:49 pm

Doesn't the turbo count as a muffler on diesels?

Roostre · **Joined:** Sun Oct 24, 2010 3:57 pm **Posts:** 195

CIMARRON13 wrote:

Doesn't the turbo count as a muffler on diesels?

Depends on how your local jurisdiction defines things; add the hassle of having to convince your local inspection guy and it just seems easier to keep it on.

warp2diesel · **Posted:** Mon Jan 02, 2012 9:34 pm

jws84_02 wrote:

Well considering I'm a farmer, i don't see myself ever moving to a different state. It would be hard to move 2000 acres somewhere.

As for selling it. I guess I will cross that road when it comes. I might keep the cat for this reason

The cat provides no restriction other than the 2 1/8" choke point on the back. With out the crap stock muffler and choke point, you will have 5 PSI of back pressure with a stock tune. Get rid of the two the back pressure will be ZERO, ZIP, NADA, 0.0PSI.
One of the simple Laws of Physics that applies to turbochargers is that back pressure decreases performance. Get rid of the back pressure and you can increase the pressure difference across the turbine and the turbo will spool up faster until the VRT fins move to drop it back to the max allowed pressure setting. Since you move more air through the engine with out the added restriction, the EGT will drop.
Been there done that.

nursecosmo · **Posted:** Mon Jan 02, 2012 11:20 pm

papaindigo wrote:

If you move to an emissions state/location or your state/location starts emissions testing or you trade/sell the vehicle to someone who has to deal with emissions replacing the cat can be expensive. I

Having moved to where I am now in Wisconsin from Chattanooga Tennessee where they do emission inspections, I can attest that gutting the CAT will make no difference in an emissions inspection. These engines run clean enough even without the cat to pass the opacity test and no state does NOx sniffing on diesels. They were put on at the factory simply to comply with federal rules. I did not gut my cat because of restriction concerns but simply because biodiesel exhaust stinks when it passes through a CAT.

papaindigo · **Posted:** Tue Jan 03, 2012 7:54 am

My point on the Cat was not related to gutting it which certainly may be worth while. I was just weighing in to the effect that if you remove it from the system you might want to save it just in case circumstances change to emission inspection required in which case the inspector's at least look to see if the Cat housing is in the system. One member already had to find a Cat cause he no longer had his.

nursecosmo · **Posted:** Tue Jan 03, 2012 8:53 am

papaindigo wrote:

My point on the Cat was not related to gutting it which certainly may be worth while. I was just weighing in to the effect that if you remove it from the system you might want to save it just in case circumstances change to emission inspection required in which case the inspector's at least look to see if the Cat housing is in the system. One member already had to find a Cat cause he no longer had his.

So true.

Aftermarket exhaust

Who is online