What Size Exhaust?

[Jet Ski Puller]

It looks like I may have a clogged cat . . . if so, I'm going to have it replaced with a 3" high flow unit.

So, I thought at the same time I would have the performance shop fabricate and replace the rest of the system. They are recommending a Dynomax Turbo muffler. I know there are a lot of opinions out there as to which muffler is best. I've done a search and read many responses.

My question is . . . What size are all these aftermarket systems? I've found a Gibson on line and it is 2.5" and a generic on Exp Express and it is 2.25". Couldn't find anymore info.

My truck is basically stock, have an AMSOIL filter that flows more air than stock and at some point MAY change out the MAS and Throttle Body, but this is not for sure.

I do a lot of towing, so I need the torque.

What size tubing should I have them use?

Thanks.

 

[tbomb]

heres the deal with pipe size. large diameter = higher flow, more horsepower, less low end torque. small diameter = restricted flow, less horsepower, more torque (compared to the large diameter pipe.)

you said you do a lot of towing - if i were you, i would go with 2.25" diameter pipes. when i got mine installed about 6 weeks ago, i went with 2.5" pipes (i never tow anything), and i can slightly feel a loss of low end torque, nothing drastic, but if youre looking for it, youll notice it. i would think that if you tow a lot, youd notice the loss of torque even more.

just my thoughts. youre best bet is to take in some more opinions from people and let the guy at the exhaust shop know your situation and take his advice, then, MAKE UP YOUR OWN MIND. when i got mine installed, i went through 3 different exhaust systems in a week because i listened to what other people told me and i didnt like any of em until i tried my own idea.

i dont mean to come off with a negative connotation, but exhaust is a tough subject to ask advice on. i had to find that out the hard way and ~$500 later i got what i wanted. keep in mind, people have different tastes; what someone else likes you may hate, and vice versa. i only say this to help you save a little $$. if i didnt listen to anyone when i did my exhaust, i would have only spent ~180. im also really sorry this is so long, but i hope it helps.

 

[LukeDog3D]

If youre going to go with aftermarket tubing like Gibson, Borla, etc, I'd say to use 2 1/4". This tubing is mandrel bent and flows a pretty good deal of air. If you are going to use tubing from the exhaust shop, go with 2 1/2". Their tubing is most likely not mandrel bent, so it will end up being choked down to much less than 2 1/2" in the bends and twists of the pipe. I've got 2 1/2" exhaust shop pipe on mine and I've enjoyed it since they installed it.

 

[espnfreak]

go with the aftermarket borla exhaust. you can get one for 330 from truckperformance.com . its a deeper sounding exhaust, but not too deep. you can also notice MAJOR mpg gains along with a somewhat increase in hp. its all worth it. i'm pullin in 420 miles per tank with my light foot now because of my borla, k&N, coasting in straightaways, and hitting green lights whenever possible

 

[tbomb]

well, youre going to notice mpg gains with almost any system you get, not just borla.

as far as sound goes, like i said before, i went through 3 systems before i got a sound i like. example: i installed dynomax and a lot people say its really quiet, so i put it on and its way too loud for me - extremely annoying on the highway. what one person thinks sounds cool, might be too loud or soft for you.

and heres the deal with mandrel bends. waste of money. all it does is reduce the turbulence of the fluid flow through the pipes. everyone, remember, we drive explorers, i would be very surprised if anyone felt a mjor difference because of mandrel bends. also, keep in mind that not all aftermarket systems (i.e.: gibson, flowmaster, etc.) are mandrel bent. and like i said before, large diameter = higher flow, more horsepower, less low end torque. small diameter = restricted flow, less horsepower, more torque (compared to the large diameter pipe.) the way your pipes are bent shouldnt have any effect on what size you get.

i like the custom systems because you can pick whatever muffler you want and the shop can give you whatever you want (i.e.: duals, 3" pipes, etc.) no matter what you get, youll increase mpg, itll sound cooler than stock (whether its loud or just a slight rumble), and it will eventually rot off your truck and you get the chance to go through the hell of picking a new exhaust system again

but its all up to you.

 

[yob_yeknom]

Mr. Exhaust Guru is here

I strongly suggest 2.25" pipes and mandrel bends. If you go with an aftermarket cat-back, I suggest Borla.

Do a search with my user name and exhaust. You'll come up with a lot of stuff. I did a kind of in depth explanation on how the exhuast system actually works and why you should choose certain size piping. If that doesn't answer all of your questions, just ask and I'll be glad to help.