EXHAUST

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I know this has been covered before, but I wanted the current information. How much difference would I notice by going from a cat, muffled exhaust to a 3" and also to a 4". The truck is stock execpt for Scott's air induction system. I have noticed after running around in town for a while and then hook to my 5th wheel, it takes a while to blow the soot aout of it before she will pull good. I need some ideas please...

Thanks
Rick

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RICK
97 2500,CC,5 SPEED, 3. 54 Limited Slip,Psychotty System,K&N, ISSPRO 3" Pyrometer,Silencer Ring Removed
12,000 RBW 5th Wheel Hitch,25' Excel 5th Wheel,Rancho RSX17000 Shocks

[This message has been edited by RHARVEY (edited 08-14-2000). ]

 

[Archive]

I posted this again to bring it to the top. . I need some advise. I took a look at past post but they did not answer my questions. .

Thanks
Rick

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RICK
97 2500,CC,5 SPEED, 3. 54 Limited Slip,Psychotty System,K&N, ISSPRO 3" Pyrometer,Silencer Ring Removed
12,000 RBW 5th Wheel Hitch,25' Excel 5th Wheel,Rancho RSX17000 Shocks

 

[Archive]

RHARVEY, <font color=blue> Our truck sound about the same, except for my TST kits. I had the #12 230/605 and had the muffler elimination kit, when I took my cat off. My EGT, empty was getting hotter I was up at 800 deg running 70 MPH in 5th. (up from 600) I installed a Dynomax 4" bullet racing muffler where the cat was. This enable me to go with the TST #11 Plate 280/685 and now running empty @70 I only run 550 Deg.

Mine actually smoked more at full throttle with the cat than w/o. Blowing the soot out. I was always told that cats on diesels work different than on a gasser. That's not true. I do a bench test here in the shop and my old cat works exactly the way a gasser cat works. Diesels shouldn't have cats on them.

other than loosing the restriction of the cat I don't believe there is much of a gain in HP. But freeing up the exhaust allows you to add more fuel and make alot more power. TST it!!!</font>

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Dee'sel
97 2500 Club 4X4 3. 54, Forrest Green/Driftwood, LSD 5 speed, K&N Air filter RE0880 & Psychotty, TST #11 all the way forward, #12 for winter, AFC spring kit, Geno's Exhaust Blanket, TST EGT gauge & TST 0-60 boost gauge in A Pillar, Hypo clutch ass. , Cat-be-gone, 4" Dynomax Bullet muffler, Crome 4" turn down, AmsOil ser 2000 75W-90 in Trans, Geno's trans filter kit, AmsOil ATF In Transfer case, AmsOil 15W-40 Oil W/ Bypass system, AmsOil Ser 2000 75W-90 in front & Rear ends, Lund Winter front, Leer Cab Level Shell Driftwood , 235/85R16 Goodyears, Dyno'd 342 HP *NRA/USPSA member and proud of it*

 

[Archive]

Howdy Drawson---your benchtest illustrates the kind of 1/2-logic that the treehuggers subject us to... A "gas" cat has no chemicals to work with in a Diesel's exhaust mix--We've all suspected that some halfwit just put those on our trucks to satisfy a poorly written EPA reg. Now you've apparently proven it... . A "proper" cat for Diesel exhaust would be one capable of incinerating soot, and would only require 150-200*F as a "startup" temp... I personally suspect that it simply doesn't exist, and, therefore is not marketed to the "big 3"... Maybe a chemist, like Joe D. can devise one that can be painted onto the inner surface of the exhaust system (zero restriction, maximum heat distribution down length of pipe, keeping the gas expulsion/scavenging maximized)---We should all protest that our trucks cost about $900 extra for an ineffective piece of expensive equipment that only serves as "eyewash" for an ignorant public---rich--sorry for the rant&rave, but when ya gotta ya gotta

 

[Archive]

Drawson,

I thought that with removing all restrictions from the exhaust, it would make the EGT's go down not up. And why would adding a muffler back into the system drop the EGT's? This is a real head scratcher. .
Before I do any exhaust work I would like to find out more information... OK guys, I know some of you know the answer to this one. .

Rick


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RICK
97 2500,CC,5 SPEED, 3. 54 Limited Slip,Psychotty System,K&N, ISSPRO 3" Pyrometer,Silencer Ring Removed
12,000 RBW 5th Wheel Hitch,25' Excel 5th Wheel,Rancho RSX17000 Shocks

 

[Archive]

RHARVEY, I reread my post and I think I can finally see where you got this. My EGT went down by taking the cat off, this allowed me to gop with the next bigger TST torque Plate. By taking my cat off my EGT went down 250 DEG.

 

[Archive]

Thats what I wanted to hear. . Another question, how does the temp of the engine translate into EGT's. Example: Pulling a 6% grade with a 7000 lb trailer, same ambient temp,same speed,everything the same, with cat she runs about 190*. Would removing the cat and freeing up the exhaust cause it to run back around 180 where it runs on flat ground while pulling?

Thanks
Rick

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RICK
97 2500,CC,5 SPEED, 3. 54 Limited Slip,Psychotty System,K&N, ISSPRO 3" Pyrometer,Silencer Ring Removed
12,000 RBW 5th Wheel Hitch,25' Excel 5th Wheel,Rancho RSX17000 Shocks

 

[Archive]

My Engine coolant temp doesn't change even when I'mn playing around and pushing high EGTs. The coolant temp up to the 190 deg mark is regulated by the thermostat. But if EGTs drop so would engine coolant within what the thermostat would let it.

My trailer weighs in right at 6900 pounds loaded for camping and the only thing that really changes is the temp. stop cycling and stays steady at 190. I really don't think these OEM guages and sender are that repeatible truck to truck. Decat you'll luv it. but beware starting down the bombing road is addictive!!! #ad
#ad

 

[Archive]

Thanks for the information. . I can hear the muffler and cat making noises as we speak, it sounds like they could fall off at any time. I know about the bombing trail, and yes I am concerned someday I may find it. The big problem is that when I find a trail like this I don't normally walk down it, I RUN!!!!!! Thanks for the information, I'll keep you posted on how the truck acts when the kitty and its muffler goes for a walk. .

Thanks
Rick

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RICK
97 2500,CC,5 SPEED, 3. 54 Limited Slip,Psychotty System,K&N, ISSPRO 3" Pyrometer,Silencer Ring Removed
12,000 RBW 5th Wheel Hitch,25' Excel 5th Wheel,Rancho RSX17000 Shocks