4.0L Exhaust Question???

[JRanger23]

I'm looking at having a si/do Flowmaster super 44 put on my truck and I've got a couple of questions. First, the guy who'll be installing it for me said he was planning on installing 3" dual pipes bent behind the rear wheels...is this too wide of a diameter? Secondly, I like straight pipes but thought I should go with bent pipes to maintain some back pressure...are there any differences performance wise between the two (MPG, torque, power)? Thanks.

 

[blh0007]

hey man,
i think that the best way to maintain your back pressure in this situation is gonna be your pipe size. you may want to tell the guy to go smaller on the pipe if you are concerned about losing too much back pressure. you are probably going to not notice a lick of difference between the pipes going straight out or bent. have a good one man

 

[Downey]

dude no bigger than 2.25 pipe you will loss a ton of low end. the muffler will probably be a 3 inch in a dual 2.5 out but down size the out to 2.25. it will be prefect. your not running a huge compression motor that doesnt need back pressure. you need back pressure.


who are you having do it?

 

[JRanger23]

So I had him use 2.5" pipes instead of 3" and had him bend them behind the rear wheels. I'm really happy with it, sounds good and not obnoxiously loud. A buddy of mine from work recommended a mechanic who does this type of stuff out of his house. I was a little skeptical at first but he exceeded my expectations.

 

[JRanger23]

Just a few pics of the new exhaust...