yourhuckleberry

57 chevy with a ls3 out of a 2015 camaro. cams, fast ecm, . I am having 1 7/8 inch mid length headers made. Car will be cruiser. Looking to create hot rod deep bellow sounds with the exhaust. Question, should I run 2.5 inch or 3 inch duals from the headers all the way back and should have x-pipe or completely separate duals. Thanks

G Atsma

3" with X-pipe....

yourhuckleberry

Thanks, 3" over 2.5 to create the better sound?

G Atsma

The sound will be deeper, but also to let that LS3 breathe as it should.

Double06

Once you get to about 500 or so flywheel hp the 3 inch starts making sense and or you plan to modify and break that barrier later. The factory C6 Z06 has 505 hp and it uses 3 inch all the way out the back. What is also nice about 3 inch is it can be used up to 700 hp or more NA so it has a wide range of power it can accommodate. THese numbers are for NA the blower motors it is less sensitive as the exhaust is more pressurized.

RB04Av

For a "deep" sound, the muffler is more important than pipe size.

Generally the longer and larger a muffler is, the "deeper" of a tone will come from it.

All that of course, is apart from the question of restriction or whatever, that might result from a poor pipe size choice.

LS1 TJ

I did a LS2 stroked and sleeved to 427 cubes. 1 7/8" headers. 3" from the headers to the 3" mufflers. Then because space was a problem 2.5" from the mufflers back. It did almost 500 hp at the rear wheels. I used the longer case turbo mufflers to keep the sound down a bit. Mellow at idle sounded great with your foot in it.

themealonwheels

iTrader: (20)

As someone who's recently worked on a '57, you should look into pre-made long tubes. Muscle Rods has a mount and header kit with 1 7/8", and if you want to use a Unisteer PS rack and pinion, Hooker makes a 1 3/4" primaries long tube that fits like a dream with the Muscle Rods mounts. There are other swap options that fit for a long tube header, forget that mid length.

As for the size, go 3" as you have plenty of space... UNLESS IT'S A WAGON. You didn't specify, but just a heads up: if it's a wagon, you may want to have a cutout before the axle and run 2.5" out the back as you'll have to run it under the rail due to the unusual fuel tank in a wagon. Also, if you do pro touring and do some fancy rear suspension like a 4 link or IRS, you'll find space gets eaten up quickly. 3" would be nice, but 2.5" will work. Hope that makes sense...