302 EFI Engine, Will going from a 1 5/8" header collector to 2 1/2" Pipes have negati

Janeails22x · 03-11-2007

I hope this is the right department to post my question. I have a 92 5.0 EFI Engine in my 1966 Mustang and I have the JBA shorties (1650-1) headers with the 1 5/8" collectors. I wanted to put in a 2 1/2" piping system behind them with flowmaster deltaflow 40 mufflers. My question is, will going from a 1 5/8" header collector to 2 1/2" Pipes have terribly negative effects such as sound turbulence and/or performance due to the increased flow area? I realize the 1 5/8" collector will be my bottle neck which will always restrict my flow at that point, so I am wondering if it is even worth it to go with the 2 1/2" pipes if no other reason to look cooler coming out of the valence

. I have heard 5.0's with the bigger pipes and it sounds awesome! That is the sound I want. No idea what 1 5/8" would sound like.

Any help, comments, suggestions? Anything will be appreciated. Thank you.

830hp · 03-11-2007

i have never seen 1 5/8 collectors the tubs coming off the heads is 1 5/8 the collectors should be 21/2. the engine would barely run with 1 5/8 collectors.

Janeails22x · 03-11-2007

Oh gosh. I am a complete idiot.

I read the description wrong. I went out to the garage and you are completely right. 2 1/2" collector. I feel like a moron. I guess I had one of those moments where I wasn't thinking....at all. Thanks, man. Lessons learned.

meangreen92 · 03-12-2007

1&5/8ths describes the primary tubes.