First of all thanks for all of your help with my questions on upgrades for my truck. The info you guys gave me has really helped me go in the right direction in upgrading my truck the right way the first time. one of my last questions is Exhaust I have been asking around and some people are telling me that i should go turbo back 5" and others say 4'' mandrel bent and that 5'' turbo back will not give give me the back pressure my motor needs I am going do a smarty programer first and tst pmcr if ever available for my truck. tranny upgrades( billet torque converter billet input shaft and mabye different valve body) afe stage 2 intake arc flow and two piece exhaust manifold I mainly drive on the street do a little towing and am mostly trying to blow away sports cars
This is up for debate. There's a big technical article about it in Diesel World this month. They are saying going 5" doesn't hurt you. Many guys are saying 5" hurts your low end and throttle response. I say bigger is better esp. for towing. You could probably do fine with 4" around town. The choice is yours.
Diesel World magazine is an excellent place to gather technical information on these subjects! The magazine is well worth the reading. It is my opinion that you should always only do a modification one time. If you are planning on doing a bunch of work, as you suggested in your last post and plan on using the truck like it was intended for, then by all means go with the five inch exhaust. It will be more supportive of more horsepower, cooler exhaust temps, and some would argue that it sounds better. With the price of the exhaust kits as high as they are I would only offer that you make sure of not only the best quality but see if there is a way you can take a look at the kit installed and also if there is a way to listen to the kit you are wanting. There are a few web sites that have sound clips of different exhausts on different trucks. Hope this helps. LT.
Not that I'm the expert here but me and a friend both have the '05 Dodge he has the 4" and I have the 5" he is quicker off the line as his turbo seems to spool a little faster than mine but he quickly maxs out his egt's and then defuels (less power) I have to have the 35' goose neck stock trailer on my truck to get my egt's up near max (1250*) with a load and his truck does not seem to pull as hard in the 2000 to 3000 rpm range as mine does. As stated I think that it is all a matter of what you want to do with your truck, he wants to get a 5" kit like mine because he says it has a deeper tone to it I can't tell the difference though hope this helps a little bit.opcorn:
First of all, the turbo supplies all the backpressure you need to keep from sucking a valve. No worries there. You can hood stack it if you wanted, it would be fine. The loss of bottom end is minimal and can be attributed to the larger diameter, but not for the reason you are thinking. See, the larger pipe will have less velocity at low CFM. Less velocity than a 4" pipe with the same CFM. So, the exhaust gases cool inside the pipe more and therefore are harder to push out the end that a hotter gas in the smaller pipe that flows faster. Follow? Now, go to midrange to high rpm performance, AKA towing, racing, ect. The 5" will be better due to its ability to move more CFM more effectively out of the engine with less restrictions. Your truck has 4" on it stock, so unless you want to patch together a cat delete and muffler delete, then the 5" turbo back is the way to go. Also, get a kit with a muffler. Just about every single 5" kit we have installed without muffler the customer has come back wanting us to install one. With a muffler they are deeper and cleaner in tone, and less drone on the highway.
Can I get away with punching out the cat on my truck until i get 5'' to lower egt and get more power or do i need to put in a straight pipe will it cause problems having a big empty space in my exhaust I already put on a more free flowing muffler(aero)
Definately get the muffler the drone will drive you nuts. The one that I got has been a good system and was fairly cheap, here's the link for it http://www.rpmoutlet.com/dodgecdd5.htm Granted it is not one of the fancy ones but it is well priced and I had no problems on install and no problems since.
