600s running hot
Yes, it's generally excepted that the 600s runner hotter than previous models. I've owned both and I'd say it's probably 200*. But when you consider all the improvments that were made to the 600 to handle heat then IMO it is much better to handle the heat than previous models, and the net affect is on the side of the 600. I had the '04 and went to the '04. 5 because of all the upgrades. You got a larger intercooler, stellite valves and seats, improved cooling pistons, larger, better cooling turbo and I'm sure I forgot other things, but since DCX knew the result of things like adding a cat and three injection fueling, ETC. , then they took the appropriate precautions to handle it since they expect you to tow and tow heavy with these trucks. Cummins has an unparalled rep in the Lt. truck application and you don't really think they'd jeopardise that by building a engine that couldn't take it? No one is coming clean on whether the old threshold of 1250* holds true on this engine. I've called Cummins Hot Line and also spoken to the DCX Area Serv. Mgr. , and neither know or or saying if that threshold has changed with the advent of all the upgrades to this engine. The party line is the 1250*, but when you get them passed the standard answer then they don't know or aren't saying since why would they want you to push the limit. So I say don't,... ... and have and use the gauge. A brief encounter with say 1400* is one thing but what many of us are talking about is sustained abuse of EGTs. That's where the shark infested water comes in. Having said that and what I've seen on an EGT gauge under different applications and having towed in excess of 4k lbs over CGVW successfully then I think anyone who doesn't pop for the security of a EGT gauge is foolish and taking unneeded chances. When you look at it, that gauge is the only thing between you and sitting on the side of the road scratching your head and asking "what the heck just happened". My $. 02.
Attention: TDR Forum Junkies 
. Then I have about a 2 1/2 foot piece of 4" stainless to my 26" Donaldson. I opted for the the shorter 26" since I can't get past my drag/street racing days which won't let me believe a 40" to 50" muffler provides the best sound and performance. Everyone to their own however. Out of the Donaldson I have an adapter which is 4" and it has two twin 4" outlets set at the appropriate angle for the two stainless tailpipes and they have 5" tips which are maybe 15" long on either side and set at an angle at the back of each quarter panel. IMO it is a very cool look expecially with the Mag-Tech rear cover. For the exhaust and a view of how the tail pipes sit check out dieselpowerproducts.com. I got the straight stainless pipe, the tail pipes and the tips from them. Dave Meheen was great to deal with. I have had 3 or 4 other exhaust variable setups which were a mix and match because I didn't like anyones total setup and I had these on my truck in the 1st 3 months I had it so exhaust and just the right exhaust for look/sound and performance was an issue for me. This is what I came up with and I'm quite happy. I also added two extra factory-type hangers welded to the exhaust pipe which are both located further up on the exhaust pipe. When I laid under the truck I wasn't happy with what I perceived to be too much weight on the turbo end and I had at the time a bad droan which drove me nuts. My two extra hangers which are mounted in rubber hold downs combined with the setup I described above have eliminated the droan completely. I can't honestly say which particular item did it since it all went on at the same time. Hope that helps you. Oo.
