I installed my exhaust on Friday afternoon. Got the system to bolt on from the cat back. My question is with the sound. To be honest it is not much louder than stock. Should it be? Is the cat causing it to be still to quiet. I have a CA truck and am afraid to remove the cat for fear of setting emissions codes. Did I mess up the install? It just doesnt seem to be "loud" enough for an after market performance exhaust.http://www.dieselplace.com/forum/smileys/smiley5.gif


Eric

it's the kitty

Trust me, it's the Cat. I did what you did at first, not much
louder, but noticeable. Then got rid if the Cat, and it is much
louder. I probably drove around for three weeks or so before I
got rid of the Cat. Sounds great now. If you are worried
about codes, make up a circuit like Fingers did (EGR Disconnect thread)
and get a blocker plate. NO codes, everything is good.



Dennis

Thanks for the replies. I was just thinking maybe I did something wrong being I am mechanically challenged. I will look into your suggestion Dennis as always you guys are a wealth of knowledge.http://www.dieselplace.com/forum/smileys/smiley4.gif


Eric

1SAST,


The other memebrs are correct, if you leave the cat in place it will be very near stock sound wise. Then again we have a lot of folks that want it that way too so to each their own I guess. We have the front pipes to test the cat if you want to see how the sound will be, give us a call and we will try to help you out. If you don't have any rattles or such then you got it installed correctly it's just Mrs. Kitty doing her thing!


We have recently even gotten an resonator to quiet things down for those that want to remove the cat and still have a quiet system.


Mark @ DPPI

Is the truck an LB7 or LLY?

Mark, does the MBRP dual system quiet down with the resonator? Close to stock, no drone?

1sick57,


Yes it will quiet down any system out there, I just got a call late yesterday from a 2004 Dodge owner (noted for the drone much more than the Diuramax) that had a brand "X" exhaust system that he was ready to remove and go back to stock, he added our resonator and said it's not stock but close and he's really happy with the system now.


Mark @ DPPI

The truck is an LLYhttp://www.dieselplace.com/forum/smileys/smiley32.gif


Eric

If you've got an LLY, then there's 2 thiungs to remember:





1) The LLY is quieter and actually "hisses" like an air leak at idle.





2) From what I hear, the majority of the LLY "catless" in CA set SES lights.





Removing the cat is the "in thing", but remember when the SES light illuminates that the cat removal is the likely cause.

If you remove the cat, and then go into the dealer for warranty service, will it void the warranty?

My LLY with MBRP exhaust is not much louder that stock..???

If you remove the cat, and then go into the dealer for warranty service, will it void the warranty?





That will depend on the dealer, but my guess is at a minimum, MANY will not do any driveability troubleshooting if it is removed...

I have had mine in SEVERAL times without the cat. They never said a word. When I asked about the cat and EGR they had blank looks on their faces. They didnt even know about either of them! I think it all depends on the dealership and their knowledge (or lack thereof) of the Dmax.

How much pressure drop occurs across the cat, IOW is there a real performance advantage in removing it?

All of the test I've seen yeilded 0 HP and Torque, only sight egt reduction and a faster turbo spool, which in some cases can be interputed differently from one person to the next. The second two not being measureable on paper "not any paper I'm privy too, anyway" only leaves interputation. Bottom line for me is, on some trucks the cat removal just isn't worth the call backs, i.e. Ford for turbo whine and ses light, GM for ses light and air hiss. These being the case, only if the customer isn't aware of the possible issues already. And Kennedy is right about the servicing issue, if they suspect and air flow problem in anyway and they see the cat gone, you will be putting it back on.

John

Thanks John,



Now if I can find a dual exhaust that will clear my spare I would be happy. I have a 315 that just touches the factory hangar. Do the new exhausts use the same hangar location?

I am getting my Dmax in Mid Feb. I am looking at the Predator, 4" exhaust and gauges. I have been following the exhaust issues daily. I want a 4" exhaust to help lower EGTs but I do not want the drone and loud pipes. I have one of those now with my CTD & Banks Exhaust.

Does doing a CAT back system lower EGTs enough for guys that tow heavy(13K) in 100 degree days?

If a turbo back exhaust system is the answer does the resosnator add back EGTs?

I have read a post or two that the resonator did not lower the dbs much at all.

:confused:

Hey JK and Eric, don't wreck me for asking another crazy question. An exhaust that lowers EGT is moving more combustion gas, correct? Or is it just lowering pressure (therefore temp)?

Masterp2, the exhaust moves more air because it is larger and free flowing therefore lowering pressure and EGT's at the same time. And yes, most of all the new exhaust systems use the existing hangers. I don't know of any system that will fit that tire, not without a blow torch and a pair of Juicegrips):h

Seawizard, the duramax systems don't drone at all, give me a call and I can give you more details. The dodge's react differently to the exhaust systems. Some have needed a resonator and some haven't to remain quiet. The resonators don't add egt's, they are just a mini muffler that is straight through.

John

Trust me, it's the Cat. I did what you did at first, not much
louder, but noticeable. Then got rid if the Cat, and it is much
louder. I probably drove around for three weeks or so before I
got rid of the Cat. Sounds great now. If you are worried
about codes, make up a circuit like Fingers did (EGR Disconnect thread)
and get a blocker plate. NO codes, everything is good.
DennisInstead of removing the Cat, could we just drill a four inch hole through the honeycomb inside the cat, leaving the remanding outside honeycomb to offer a small amount of back pressure and some catalyze effect?

I'm scheduled to take my truck in today to a muffler shop to have the MBRP 4" cool duals with the LB7 downpipe installed. The guys at the shop won't touch the CAT, Federal crap! From what I've read so far there doesn't appear to be any documented benefit to removing the CAT in terms of EGT's and HP, rather the 4" exhaust and higher flowing muffler appear to provide the most benefit. :rolleyes:

I'm thinking if there isn't any noticeable or real benefit to removing the CAT WTF? Mama JJ drives the truck a lot on the road, she is not going to do any exhaust mods before any unscheduled trips to a dealer should the need arise. Looks like I may have an LB7 downpipe for sale. :o:

Anyone out there have any documented testimony contrary to the above, say dyno or EGT gauge numbers before/after CAT removal? JJ :)

I'm scheduled to take my truck in today to a muffler shop to have the MBRP 4" cool duals with the LB7 downpipe installed. The guys at the shop won't touch the CAT, Federal crap! From what I've read so far there doesn't appear to be any documented benefit to removing the CAT in terms of EGT's and HP, rather the 4" exhaust and higher flowing muffler appear to provide the most benefit. :rolleyes:

I'm thinking if there isn't any noticeable or real benefit to removing the CAT WTF? Mama JJ drives the truck a lot on the road, she is not going to do any exhaust mods before any unscheduled trips to a dealer should the need arise. Looks like I may have an LB7 downpipe for sale. :o:

Anyone out there have any documented testimony contrary to the above, say dyno or EGT gauge numbers before/after CAT removal? JJ :)Hi JJ,

I think it is just for the exhaust notes out the tailpipe. I have the MBRP 4" cool duals, that I installed myself, and did not remove my cat.

So far, all I have achieved is the looks of two mean looking dual pipes with sassy looking tips exiting the rear bumper with a slight heavy rumble at idle. Other than that it sounds almost like the stock system.

However, sound and sassy good looks are very important to us young 64 yrs old kids.
:lol:

OBTW JJ, save that money you are going to pay a muffler shop. If I, (at 64 )could install my duals. I am sure that you, (a mere youngster) can also, if not I bet mama JJ could.
I know my Peety-pie would have if I had not done ours. She is heavy footed and the reason for me buying the Predator. Hopeful that will satisfy and keep her quiet for a while.



:lol:

Regards,

MH, thanks for that vote of confidence but putting a wrench in ol' JJ's hands is a disaster just waiting to happen! Even Mama JJ just shakes her head when she sees me heading out to perform meck-a-nickel stuff. At least my 6lb Yorkie doesn't laugh, or does she? ):h

Well worth the $100-$125 they are charging to get er' in the air, pull the right rear tires (dually), remove the old OEM without torching, and install cool duals. The price he quote me was for removing the CAT to, but I have a funny feeling they may balk at this once I get there. :o:

I've been doing some reading, most guys that didn't remove the kitty initially that did later on like the CAT gone. Doesn't sound like there is too much noise either. I'm leaving at 12:30 to :grd: , any final thoughts out there? JJ :)

Here kitty, kitty, kitty! Yeah Baby, yeah! :muahaha:

To say the least the new sound is going to take some getting used to! I have never had a performance exhaust system before so imagine my surprise when we fired the Dumax up minus the kitty and the cool duals. Sounds like a big air pump, the VVT just singing away! The guys in the muffler shop were thrilled with the sound. Evidently that sound is what they live for! ):h

I am so glad I didn't take this job on myself. :rolleyes: Turns out they had to cut a small section of one of the straightpipes, the hangers had to be heated up and modified to accommodate the system, took them about 3 hours to get it in the way they liked it. The guy that runs the shop is a freakin' perfectionist, took them a good 15-20 minutes to get the tips exactly the way he wanted them. :ro)

Cost me $150 labor, plus $30 for welding the sections of pipe together versus clamps. Since I didn't know what they were doing I was concerned when they started welding. When they took me under the truck to check the install I really appreciated the quality work. I guess the only reason they come in pieces is for ease of shipping. You can't tell it is a bolt on system. They didn't weld the driver's side exhaust feed behind the muffler, just clamped it so I could remove the system myself if the need arises. :)

They removed the CAT without blinking an eye. I just left the straight pipe in the back of the truck and the boyz knew what to do with it. No rattles, vibration, drone, just a healthy rumble when ol' JJ puts the pedal down. I'm curious to see what the new exhaust does for my EGT's and MPG's. Will advise. :rolleyes:

I expected Mama JJ to complain about the noise level. She was fine, and insisted on driving the LLY home and threw my a$$ in the Ranger. I'm beginning to think she likes that truck! ):h She groans a bit when I'm shopping, but hasn't stopped me yet from modifying her, err our truck! ;) Later. JJ :)

Good morning JJ & mama JJ,

How's y'all truck running, now that it is kitty-less? I am sure the exhaust notes are sweet especially with the addition of the cool duals.

Please don't get rid of the kitty that you removed just in case you have to take mama's truck back to the dealer for some warranty work.

From what I am told removing and replacing the kitty is a piece of cake.

I am still working on gutting my spare kitty that I plan on installing sometime after the weather warms up and get caught up peetie-pie's "Honey-do list. :)

Ok, you guys take it easy and keep us posted on mama's truck.

Regards,

Me & Peetie-pie,

MH,

Day 2 1/2 with new exhaust. I was following Mama JJ this morning and finally got to hear what the new exhaust sounds like from behind. Under normal acceleration you hear more of the turbo spooling up. She romped on it for a short stretch and the VVT opened up and pushed a lot more air with a throaty rumble: AWESOME! :ro)
So far Mama JJ seems happy with the sound, that surprised me. SOTP feeling is it gets the power to the wheels a bit faster, I was going more for EGT reduction. JJ :)

JJs DuMax,

If mama's happy everybodies gonna be happy!!!!!!

Mark @ DPPI

JJs DuMax,

If mama's happy everybodies gonna be happy!!!!!!

Mark @ DPPI
That is one reason that I have to get busy and continue the surgery on my cat and load the 65 hp setting from the Predator.

:grd:

I know that will keep my peetie sweet!

Just wondering here, trying to figure out what to do.

Looking to install the edge juice/attitude soon.
1) do I need a different exhaust? (not planning on using levels 3 and up, I think)
but I will be towing a 40ft enclosed with a heavy foot (75-80mph)

2) if I should replace the exhaust , should I do it cat back or turbo back??
I read if you do turbo back, you will get codes and other fun stuff.

How much louder is cat back in the cab itself. (do not want to drive 16hours an loud noise)

please let me know what you guys thing

Just wondering here, trying to figure out what to do.

Looking to install the edge juice/attitude soon.
1) do I need a different exhaust? (not planning on using levels 3 and up, I think)
but I will be towing a 40ft enclosed with a heavy foot (75-80mph)

2) if I should replace the exhaust , should I do it cat back or turbo back??
I read if you do turbo back, you will get codes and other fun stuff.

How much louder is cat back in the cab itself. (do not want to drive 16hours an loud noise)

please let me know what you guys thing
My LLY has MBRP cool duals, from the cat back and it is not objectionably louder to me or my peetie-pie, inside the cab or out the tailpipes.

Good morning JJ & mama JJ,

How's y'all truck running, now that it is kitty-less? I am sure the exhaust notes are sweet especially with the addition of the cool duals.

Please don't get rid of the kitty that you removed just in case you have to take mama's truck back to the dealer for some warranty work.

From what I am told removing and replacing the kitty is a piece of cake.

I am still working on gutting my spare kitty that I plan on installing sometime after the weather warms up and get caught up peetie-pie's "Honey-do list. http://www.dieselplace.com/forum/images/smilies/smile.gif

Ok, you guys take it easy and keep us posted on mama's truck.

Regards,

Me & Peetie-pie,

Melvin,
Could you put me in touch with whoever told you that removing and replacing the front pipe is a piece of cake? I tried and failed to remove mine two days ago. I may have fat fingers or a left handed wrench. I could not remove the hanger bracket which is bolted to the transmission case. One of the bolts (there are two) is in a very tight spot. I could only get an open end wrench on it and had almost no room to turn it. If I ever did get it out I can't see how I'd ever get it threaded again. Of course I could support the transmission somehow and remove the crossmember. If anyone has the right mojo I'd sure appreciate the help!!!
Thanks,