cat delete question

[JamesStevens]

WWomack

There will be no problem removing the cat and towing, there may be a little less engine braking but I doubt U would notice any difference. If U leave the stock muffler on U are kind of defeating the purpose of taking the cat off. The stock muffler is more restrictive then the cat. Each to his own though.

 

[WWomack]

You mean that the exhaust moving thru that little honeycomb in the Cat is less restrictive than muffler?? Also what gives with the drone noise when some are removing the Cat. I was planning to install an exhaust brake so I guess the engine braking is a non problem. Thanks for the help.

 

[jshumate]

Muffler Delete Kit

I just installed the MEK from Geno's and took off on a 2 week trip towing my 5ver (mostly uphill). I was really concerned that it would be too loud with the 15K lb. trailer. Instead it turned out to be no problem. The only time it was noticably loud was climbing uphill on a switchback road in 3rd gear. Inside the cab with the windows up, it wasn't really noticable.

What surprised me was that it was a deeper, throatier sound than I expected.

 

[DWakefield]

I to installed muffler delete on an 07 5. 9 and I love the sound!!! Under normal conditions it doesn,t even seem to be noticeable. Maybe I have hearing problems also. ?Thinking of punching out the cat but that may be to loud. NOT!!

 

[DogramTD]

I finally towed for the first time after removing my cat. Drone is only bad when it begins to lug a bit in a slight incline, not too bad when RPM 's are up tho. Definately not as comfortable in the cab as before the delete. But here is my issue, the purpose of me deleting it was to decrease EGT's while pulling my 10K trailer. Even w/ the Edge set to stock, there are some grades where I am pushing 1450-1500 on EGT. I never saw those temps before, seems as if the end result is opposite of what I was looking for.

 

[Tinman]

Don't cats have a finite life? Is the end user responsible to replace it once it is trashed?

 

[MVenditti]

Muffler delete sounds good, and I'm a 47 year old kid. A diesel is not a diesel unless it sounds like a diesel. IMO

 

[WWomack]

DogramTD, Who high were the EGT before you deleted the Cat? Seems odd that the EGT's should be higher w/o the Cat?? I tow heavy like you, but I dont want the EGT's getting that high. Now I'm concerned, better install a guage.

 

[HBarlow]

I finally towed for the first time after removing my cat. Drone is only bad when it begins to lug a bit in a slight incline, not too bad when RPM 's are up tho. Definately not as comfortable in the cab as before the delete. But here is my issue, the purpose of me deleting it was to decrease EGT's while pulling my 10K trailer. Even w/ the Edge set to stock, there are some grades where I am pushing 1450-1500 on EGT. I never saw those temps before, seems as if the end result is opposite of what I was looking for.

Something else changed to cause a higher EGT reading after catalytic converter removal. A slight reduction in back pressure could not cause higher exhaust temps.

I never paid any attention so can't comment about exhaust temp reduction but my '06 did have gauges and certainly never displayed higher EGT after the muffler was removed. Some claim temp reductions but I simply enjoyed the sound of power.

 

[DogramTD]

Yes, definately like the sound better, especially when driving through tunnels/canyons! Just dont like the change in EGT's. I did change to a different model AFE filter, I went from the old original one to the new AFE 7 gold. Also Edge sent me an updated version programmer but the mapping shouldnt have changed. Decrease in power and higher EGT is never desireable!

I do agree tho, cat delete shouldnt have increased EGT.



Sorry, dont mean to hijack this thread!

 

[DogramTD]

DogramTD, Who high were the EGT before you deleted the Cat? Seems odd that the EGT's should be higher w/o the Cat?? I tow heavy like you, but I dont want the EGT's getting that high. Now I'm concerned, better install a guage.

I never saw temps higher than 1300 even with the edge set a 2 "tow" mode while pulling an 8% grade at 55-60. Now i easily see that up to almost 1500. Something else had to have changed, I cant see the absence of a cat causing the increase. It is advisable to install a guage if you are towing heavy even if you have no mods.



Basically, unless you are looking for the "sound factor" the labor/$$ to benefit ratio doesnt add up. IMO

 

[HBarlow]

I agree with your cost/result analysis. The only "gain" I realized was the sound which I enjoyed.

All 2004. 5 and later OEM stock B5. 9 engines produced maxiumum exhaust temps under load of 1400-1425*. Not long after they were on the highways back in 2005 a TDR member/RV transporter posted a story of a failed engine due to high EGTs. I exchanged e-mails with a Cummins engineer I knew at the time. He sent me back a message stating that under carefully monitored testing the then new engines ran at 1425* under Cummins test conditions and that was expected, safe, and routine.

My '06 always produced 1450* egt under heavy load and I ran it 230k miles w/o failure before I sold it.

Perhaps your pyro or gauge suddenly began producing accurate readings simultaneously with your exhaust system modifications.

 

[HBarlow]

This is the original email I received back in December 2004 from a Cummins engineer who will remain anonymous.

Harvey

+++++++++++++++++++++++++++++++++++++++++++++++++++++

"Re: Cummins ISB Acceptable Maximum Exhaust Gas Temperature??
<HR style="BACKGROUND-COLOR: #a3a4a6; COLOR: #a3a4a6" SIZE=1><!-- / icon and title --><!-- message -->Harvey,

Happy holidays! EGT's are always a touchy subject due to differences in measurement locations and differences in the devices used. It's difficult to say what a true upper limit is on EGT for the ISB engine because we don't test it above the "stock" settings. However, I can tell you what we have measured on the latest 2004. 5 and 2005 engine configurations.

MY04. 5/ 325 exhaust temps can be as high as:

Sea Level: 1375 Deg F pre turbo, 1125 Deg F after turbo.
Altitude: 1450 Deg F Pre turbo, 1200 Deg F After turbo.

The above are typical temperatures from development trips. The MY04. 5 product was developed to operate at these temperatures. I have no idea what would happen at temps above these, because they haven't been tested.

I don't mind you sharing these numbers as long as the source remains anonymous. We don't want someone thinking "Cummins approves this temp on my engine because . . . " . This really isn't a guideline or approval or anything, just some results from tests we've conducted on stock engines.

I hope this help answer you question. If you need anything else, let me know!


xxxxxxxxxxxxxxxx"

 

[DogramTD]

Harvey, thats excellent info. I appreciate that input. Although Cummins doesnt "approve this temp on my engine" I feel a bit more at ease when i see those temps. And maybe you are right, with the cat delete and a version update on my edge, maybe, just maybe, I am reading more accurately than before!

 

[RonD]

Harvey, 1450 under load, where was your prob located?, mine is in the post turbo PacBrake elbo, I have never gone over 1225 .

 

[HBarlow]

RonD,

My probe was in the exhaust manifold.

The writer stated in the line where he listed the measured temps that egt was measured "after turbo" which I can only assume means in the exhaust manifold.

My three Rams have had a hole drilled and tapped in the center of the exhaust manifold for the pyro probe. That's where most TDR members install them and where the most responsive and true temp reading can be found.

Few TDR members install the pyro probe downstream because it provides an inaccurate reading that has to be "adjusted" by adding 300*.

 

[Dieselnut59]

Removal of the cat sure won't hurt anything, and as others have stated, may actually help a little. My '03 never came with a cat ('04s built before Jan 1, 2004 do not either). I tried a 4" straight pipe and it sounded like absolute crap. I ended up putting in a straight through Rip Rook's muffler. I still prefer the sound of the 12 valve with straight pipe, especially the first generation. No drone like yall mention. That seems to be most noticeable on the 24 valve engines and is disgusting on the common rail! My big ole truck sounded like a wet fart with a whistle. I have heard others with straight pipes and they sound similar. I have heard some with straight stacks and they sound good. Got a friend with a '08 with the DPF/cat mess. He removed it all and swears he gets 5 mpg better.

 

[WWomack]

I didn't know that the 03 and early 04 didn't have a Cat on them?? I had a 1998 12 valve and I had the exhaust off it and I remember that it had a Cat on it. I remember looking into the end of the Cat to see if it was plugged up but all looked good. I just assumed that all later years than my old 98 would have a Cat on them. My 98 was not a California model either, Good to know.

 

[Dieselnut59]

89-93 calender year, no cat, '94-98 calendar year, cat, 99-03 calendar year, no cat (cat replaced by a "resonator" same configuration as cat), 04-07 calendar year, cat, 08-current calendar year, cat + DPF

California models have just about all had cats since '04, I believe.