I know exhaust gets gone over and over all the time, but heck.. whats one more? Its not so much what exhaust to choose, or what muffers to choose, but rather an exhasut flow question. I have an 01 ram 1500 5.2L that we will call stock for this exercise. I was considering putting a high flow cat on and re-doing the cat back exhaust down the road. My question to you is... "how free is too free" in terms of exhaust flow. I know there are people that run right out of a gutted cat. There are so many different configurations, but again how free is too free? Some will argue for backpressure, some against it. Since my cat is on its way out, im swapping that with the high flow, but I am also not installing a muffler. There is going to be a y-pipe where the muffler would be and dual out the rear exhaust @ 2.5" / pipe. I remember the discussion on how if you are doing duals, you should put 2 1/4 pipes. The kit I plan to getonly comes as2.5" pipes. I have 3.55 gears right now so low end is not so hot. I want to retain what low end I do have, but also have a louder exhaust. I currently have 2.5" duals on my truck now with a super 44, but again im swaping the cat and the mufflers getting removed. If backpressure is going to be a problem, could I create a bottleneck in my exhaust? reduce the size of the exhaust and bring it back up to the correct size after the cat. Then I didn't know if that would affect scavenging etc... I'm just asking someone with experience what would happen, or someone who has been here before and pretty much saw what was wrong with there setup and knows what they would do differently if they did it again. lol im not asking much, but there are people that run glass packs which is.... basically no muffler, so I guess it isnt so much of a big deal, but as far as flow and my torque in the end is kinda the question. What are your throughts? and no I'm not going to gut my cat before that question arrises. I need to retain emissions.

Thanks,
pcfixerpro


- - - - EDIT
Heres a link to the exhaust I was looking at
http://www.lmctruck.com/icatalog/de/0046.asp

 

Personally I think if you want some bottem end power you should consider switching back to 2 into 1. You've lost bottom end running dual 2.5's and I want to say you're not going to lose anymore with a high flow cat/no muffler combo, or at least you wouldn't notice it.

 

Please do not waste your time running 2.25" piping[8D]. If your running a nice high flow cat, and a y-pipe from that, then you'll be quite alright. It will sound good too I am sure. I just think it is so ignorant waisting your time with 2.25". Maybe if it's a true dual then yeah sure, 2.25". But these are fake duals as Cereal says, so it's quite ok. And you can find better tips to match with 2.50" piping.

 

I read an article, which I will try to find, that talked about what size exhaust pipe to use, and it was based mostly on hp output. This article said that if you are not pushing over 300hp, you should not be using more than 2.5" pipefor a single pipe exit.

 

Keep it simple, 2.5", Single outlet, unless extremely modded

 

No offense, but I don't think you're really the one who should be calling people ignorant when it comes to exhaust systems. The majority of your knowledge of Ram exhausts has come just in the last 10 days while you were getting your fubar'ed exhaust installed. I don't think you can definitively say what will be a waste of time and what will be alright or not because the setup you run is very different then what he is talking about, and your truck isn't even the same. For starters, his truck is a 5.2.

I think 2.25" duals is the right size on a 5.2, or else 2.5" single, but that is just my opinion. I'm changing my single exhaust to 2.5" from the 3" I currently have, so I can't imagine running dual 2.5" pipes on a 5.2 unless it is built. Just my opinion.

 

Not trying to jack the thread, but I was wondering if that article was talking crank or wheel hp?

I just happened to be talking with my mechanic again today about exhaust and he was telling me that dual 2.5's would be "o k" (depending on mods) on a 5.9 but would be too much for a 5.2 unless it was laying down some serious power. Pretty much right on track with what Silver is sayn'. Let us know what you do, I'd like to hear how things turn out.

 

Not sure...probably crank...but don't quote me on that. Yeah, I don't want to jack the thread, but I'll try to find that article.

EDIT: I was a little foggy on this, but here is the article:

http://www.magnaflow.com/07techtips/faq/question10.asp

 

Silver, c'mon...cut that out man. This is where all the lame bickering starts, there are better ways to address an issue you have with what somebody says. And for whatever reason, you put yourself on the defensive end of what I said, when I never attacked anybody.There is no need to call me out like that, that just unecessary and immature, especially coming from you...A moderator. My deal is completely different with the exhaust. I'm pretty sure I know what I'm doing, I loved what the exhaust has done to my truck, I jsimply ust got shafted from the mechanic who did the work, and I'm having him fix it and it is in the shop as we speak. Once those nit picky things are addressed, the headers have been an overall success. When I get the intake and tb, everything will be restored, PERIOD.

It isn't like he is proposing running a true dual 2.50" system. Running a 2.50" y-pipe from the cat is not going to affect ANYTHING. 5.2 or 5.9, they are both big trucks. You don't think a big dodge ram 5.2L can handle a small piece of the exhaust being 2.50"? Please. His truck would very aduaquatly handle that. In fact, I'm betting he will hardly feel a differance in power at all, any catback exhaust is only going to be freeing up minimal power anyways, we all know that. 2.25" and you are just getting too literal. Like I said, if it was a true dual or something of that nature, then yeah, that'd probably be where it should be, but if it's just from the cat, that's not a big deal.

P/S: That is a nice looking kit as well, I think it's going to look really sharp all mandrel bent with those nice stainless steel tips, it will be nice and loud.

 

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grrrrrrrr

1st no such thing as to free flowing. End of story.

2nd The most impotant thing to remeber is exhaust velocity. If your exhaust is sized to big then the exhaust slows down and cools wich means it is harder to get out of the exhaust pipt meaning less engine power. Ideally the entire exhaust would be heat wrapped to avoid any heat loss.

3rd 20DodgeNeon has a sick sounding truck and I'll be running a system almost exactly like his minus the cat. However technically 2.5 duals are a tad to big for the 5.9. They are way to big for a 5.2. Again end of story don't argue with me 20DodgeNeon I'm not starting a fight I think you know what your doing and your truck sounds great but, the fact is 2.5 is to big for the 5.9. I went with 2.5 because I'll be getting into heads, cams and possibly stroking the motor. Just because it sounds cool dosen't mean it's doing a good job.

4th 2.25" pipes will be perfect for the 5.2 and will leave you plenty of room to grow. If you want to run one pipe then go 2.5". If your going to run true duals you might be able to get away with 2.25 but, you would have a ton or room to grow and would have to do a ton of mods so you might want to go one size down.

5th This is extremly important if you want to gut the cat then you need to put a pipe in place of it and wrap that pipe with the cat so that it looks like it is still there. While gutting the cat does add power putting a pipe in place of it will definetly add power.

6th this is the last one. for all of you who think backpressure is real try this. Install a system that is to big so that you can feel the loss. Now kink like he asked about and let me know how much more power you loose. Thats about as dumb as running the exhaust into your intake.