Flowmaster 40 Installed

oldnavy · **Posted:** Sat Dec 17, 2005 11:54 am

Installed a 40 series Flowmaster this morning ($95 installed) and I was supprised how quite the CRD still is at any speed or power range. I probably could have done a 30 series install and had a really mellow sounding CRD. But I was afraid I might get it to loud or flat note to exhaust for the wife. There is no drone what so ever at any speed, the exhaust is loudest at about 65 mph then at any speed and even then it a deeper tone and really sound nice sound. At 75 mph I would say it might be quiter then stock, at least it sounds like it inside the Jeep. All in all I was pleasently supprised and pleased.

I was going to do the AT muffler but the Flowmaster was half the price with install and I was too much a penny pincher to not try the Flowmaster. :roll:

Now to go install the custom lettering on the back window between the two hinges, it says "Yes! It'a diesel!" in two inch high vinal letters and cost me $6 to have them made at local shop.

retmil46 · **Posted:** Sat Dec 17, 2005 9:20 pm

Did you notice any difference in the amount of throttle you have to give it, to get your usual "normal" acceleration rate?

When I went to the store tonight, it took noticeably less throttle to get that beast up and rolling with the AT installed.

Good thing I didn't have a vehicle with this much oomph when I was 20 years old, I would have gotten myself into SO much trouble! :twisted:

oldnavy · **Posted:** Sat Dec 17, 2005 10:26 pm

When I was 20 I was on the other side of the world.

I don't really drive the Jeep much as I prefer to drive the Magnum, the Jeep is the wife's sit high and see the world vehicle. But it did seem to me to spool up quicker and excelerate harder, but then it has always seemed pretty fast for a SUV.

retmil46 · **Posted:** Sun Dec 18, 2005 1:19 pm

oldnavy wrote:

When I was 20 I was on the other side of the world.

I don't really drive the Jeep much as I prefer to drive the Magnum, the Jeep is the wife's sit high and see the world vehicle. But it did seem to me to spool up quicker and excelerate harder, but then it has always seemed pretty fast for a SUV.

Yep, know the feeling. When I was 20, was a couple hundred feet underwater giving some SLBM's a joyride off the coast of a certain evil empire.

Did you get a good look at the stock muffler when it came out? I did on mine, since I was helping the installer with fitup and measuring. The inlet and outlet are necked down to 2". I had my Maglite with me, and looked down the inlet and outlet of it. The only engine that muffler would give decent flow on would be a 5 HP go kart. After 3800 miles, that thing was caked with soot. I wouldn't be surprised to learn they use the same muffler on the 3.7 V6, especially since one of DC's big pushes right now is trying to get 60% commonality between models for running gear. IMHO, the stock muffler was NOT made to go on a turbo vehicle, gas or diesel, just there to reduce noise and to heck with flow.

From the sound of it, you're getting good results with your Flowmaster as well. Good to hear, it'll give people a middle of the road option, other than dropping most of a paycheck on getting an AT installed.

I think that's going to become a standard mod for the CRD, replacing the stock muffler with one that gives better flow. You choices will be dictated by how much money you want to spend. As the racing guys say, speed costs money, how fast do you want to go?

I can even tell the difference on mine at idle, as soon as I put it in gear. I don't even have to push the go pedal, it has enough oomph now to back itself up out of it's parking spot and out the circle drive at something less than 5 mph. It would move on it's own, to varying degrees and much slower, depending on conditions before the AT, but now I REALLY have to keep my foot on the brake if I don't want it to move.

oldnavy · **Posted:** Sun Dec 18, 2005 2:31 pm

Yes Mitch I'll looked at mine also and had the same thought about it being the same muffler used on the V6, VW did the same thing with it's diesel cars. Don't know if MB did that, but dollar wise it would make sense. One other thing VW did was to use the same fuel tank for diesel cars and gas cars, which was nice in a way as you could press (I removed mine) the little button for venting vapors on a gas car (it was not connected to anything on the diesel because they don't need the evap expansioon like a gas car) and that would allow you to fill the tank compleatly. This allows VW TDI's to pump approxemently extra 3 gallons of diesel into the tank, then instead of 14.5 gal tank you had 17 to 17 1/2 gals of fuel. That habit of venting has caused me couple of times to overflow, so the tank on the CRD doesn't seem to be set up like the VW's.

I was out and about this morning about 6 am and had a chance to run the CRD through it's paces and yes it does seem to spool up lot quicker then before. I did a full throttle standing start and it roared past 75 mph without any hesitation, stumble or flat spots. I would like to take it out next Sunday (should be quite at that time on Christmas morning) morning about same time to see if the topend power and speed has inproved. I have had it to 107 mph where it just didn't have any more left in it, I didn't look at the RPM's and would like to know what it pulls at top end. :wink:

LibertyCRD · **Posted:** Sun Dec 18, 2005 4:57 pm

I checked the part # stamped on my wife's 3.7L V6 Liberty and yes it is indeed the exact same muffler used on the CRD. So obviously the muffler you get with the CRD is not truly designed for a diesel engine.

Glad to hear you are having success with the flowmaster. I will be switching my muffler out again at my earliest convenience now that I know how much of a difference it makes.

oldnavy · **Posted:** Mon Dec 19, 2005 7:41 am

If you use a Flowmaster 40 the sound will be almost stock, wife stated she would not have noticed if I had not told her. If you want to mellow it up some do a Flowmaster 30 series, that should make a little more of a rumble.

Reggie · **Posted:** Mon Dec 19, 2005 9:53 am

oldnavy wrote:

If you use a Flowmaster 40 the sound will be almost stock, wife stated she would not have noticed if I had not told her. If you want to mellow it up some do a Flowmaster 30 series, that should make a little more of a rumble.

Just out of idle curiousity, did your warm up times increase with the new free flowing muffler? I know it is too soon to see if there was a MPG increase.

LibertyCRD · **Posted:** Mon Dec 19, 2005 10:29 am

I have an appointment tomorrow afternoon with the muffler shop. Not sure what I'm going to do right now, but I'm leaning toward trying the straight-pipe again. One of the things that concerns me is that these CRDs blow so much soot through the exhaust, any muffler would surely get coated real good over time. The Flowmaster, etc. would be MUCH better than some other mufflers because it's more of a straight-through design and it's all steel internally. So if I don't do the straight-pipe, I'll probably try a Flowmaster on here.

In my experience, the 40 series is the loudest muffler they make when used on gas engines. So if you say it's not very loud at all on the CRD...then how could the 30 series be louder? Just curious...

oldnavy · **Posted:** Mon Dec 19, 2005 10:56 am

You be correct dude I got my terms mixed up, senior moment I guess. What you might want to try is Hushpower II for straight through shot.

The thing with a straight through pipe in a diesel is the mid range drone that most find very annoying. I have heard a few big bore diesel PU trucks with the straight pipe and the sound was real flat and they had what I call mid range drone. Meaning they had this droning sound starting about 2300 rpm to 3000 rpm in the diesels I have heard the staight pipe on.

They way the Flowmaster is chambered would not lead to any real soot build up as there are no real chambers, just a series of of baffels that are shaped like this <<<< with the exhuast flow going toward the pointed end then out and around to each chamber like that then out the exit. THis will never have much of a soot build up and with a once a tank hard 0 to 60 run it will self clean the system.

retmil46 · **Posted:** Mon Dec 19, 2005 10:59 am

LibertyCRD wrote:

I have an appointment tomorrow afternoon with the muffler shop. Not sure what I'm going to do right now, but I'm leaning toward trying the straight-pipe again. One of the things that concerns me is that these CRDs blow so much soot through the exhaust, any muffler would surely get coated real good over time. The Flowmaster, etc. would be MUCH better than some other mufflers because it's more of a straight-through design and it's all steel internally. So if I don't do the straight-pipe, I'll probably try a Flowmaster on here.

In my experience, the 40 series is the loudest muffler they make when used on gas engines. So if you say it's not very loud at all on the CRD...then how could the 30 series be louder? Just curious...

My advice on how to decide -

First, tell the guy it's a TURBO DIESEL! Then say, OK, to get the best bang for my buck, what would be my options as far as getting a muffler with the best possible flowrate, for performance and fuel economy, AND keep noise levels close to stock?

If he knows his business and is halfway honest, he should be able to give you the pros and cons of each different style of muffler, particularly if you're sticking with one brand such as Flowmaster. It's when you start asking them if Brand X is better than Brand Y when things get sticky. Word of moouth does get around, and in that case he stands the chance of irritating one of his suppliers. Gee, like I haven't been involved in THAT situation lately! :roll:

retmil46 · **Posted:** Mon Dec 19, 2005 11:07 am

Reggie wrote:

oldnavy wrote:

If you use a Flowmaster 40 the sound will be almost stock, wife stated she would not have noticed if I had not told her. If you want to mellow it up some do a Flowmaster 30 series, that should make a little more of a rumble.

Just out of idle curiousity, did your warm up times increase with the new free flowing muffler? I know it is too soon to see if there was a MPG increase.

With the AT, didn't notice any real difference in warmup times as far as coolant temp yesterday. While we are talking about a probable significant reduction in EGT's, based on oldnavy's experience with TDI's, you're still talking about exhaust gas at several hundred degrees going thru that EGR cooler.

oldnavy · **Posted:** Mon Dec 19, 2005 11:12 am

Mitch is right about that, unless like me you are in the sticks 150 miles from any metro area and the muffler shop has only done a couple of diesels and they were OEM style mufflers, then like me your on your own. Turbo diesels don't have the same sound or pitch range a gasser has, so the shop I was at didn't really know what to expect. They thought the 40 series would be real load, total off the mark they were. But that's just here, some place else with a larger customer base would most likely have some diesel experience and know how to get what you are look for in the exhaust system.

LibertyCRD · **Posted:** Mon Dec 19, 2005 2:57 pm

Well I called Flowmaster myself on their 800 number, and I also called some local exhaust shops in the nearest large cities. No one had a clue what muffler to really recommend for the Jeep CRD, and some still didn't even know the Jeep could be bought with a diesel.

I think for $35 I can get the muffler removed completely. Seems like that's what I paid back in the Spring when I tried it the first time. I will straight-pipe this puppy again tomorrow and see how it goes for a long-term period. I'll check my fuel economy and power to see if there are any differences and I'll let you guys know how it goes.

If I get more CELs after straight-piping, then I will try a Flowmaster muffler and that should end all issues.

&JUSTICE4ALL · **Posted:** Mon Dec 19, 2005 7:28 pm

oldnavy, which 40 series Flowmaster did you get? I'm thinking the Super 40, "GEN II Delta Flow" ( their words). After reading these posts I'm having it done Wed of this week. Work takes me from the "sticks" to the city some 140 miles. I noticed on flowmasters web page that the 30 has been replaced with the super 40 as of Nov 1. What do you think of the 50 series?Thanks all for the R&D.

oldnavy · **Posted:** Mon Dec 19, 2005 11:25 pm

I don't know which one for sure, but it was one they had in stock and probably the standard 40 was probably used.

As for as the 50 goes the only experience I have with it is the one I have on my Magnum and it has a deep rumbling growl and gets loud under hard excelleration but levels off when you get off the throttle and doesn't have the annoying drone without a resinator.

&JUSTICE4ALL · **Posted:** Wed Dec 21, 2005 6:27 pm

I had the super series 40 installed today. Sounds stock to me. I'm very happy with it although I've only driven it a few miles. Tomorrow 140 miles to home then Friday another 150 to get to my steelhead fishing. (oldnavy, don't ask if you don't know :roll:

I was IdahoTDI on fred's page and purchased one of your milled CCV filters for my 01 NB that's why I think I know you some my friend.) I'll report back on the 26th or 27th. Merry Christmas everyone :!:

oldnavy · **Posted:** Wed Dec 21, 2005 6:54 pm

Eat some fish for me and have a Merry Christmas.

&JUSTICE4ALL · **Posted:** Wed Dec 28, 2005 12:05 pm

It has gotten so warm in the mts of Idaho it feels like spring. I still caught fish, however. The the CRD does seem to spool up faster with the flowmaster. After putting some 400 miles on it there is no droning sound while driving. Outside at idle there is a litte more of a rumble from the exhaust. All in all I'm lovin it and think everyone should mod the muffler. Happy New Year to all.

jinstall · **Posted:** Thu Dec 29, 2005 5:58 am

Hmm this is one of the things I have been looking for. I run a SuperTrapp on my race cars. It allows me to adjust the backpressure of the exaust as well as adjust the loudness. This is very interesting. Does anyone havs a Particle Filter on their CRD or is that a europe only option? How many mufflers/resonators are there on the CRD? Ihave not gotten mine yet but I hope to have it in a few weeks. Does opening ut the exaust help any like maybe to 3"?

Flowmaster 40 Installed

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