350 Chev Hilux Exhaust size

[Dannz71]

I know its probly been discused before but i cant find any threads on it.

So i have a 350 cubic inch small block chev thats just been run in,
its got high compresion heads
a mild 4x4 torque plus cam
block hugger headers
a holley 650
and an edlebrock manifold.

so its a bit more than stock,
im planing on running a two into 1 style set up exiting out in front of the LR Wheel

What exhaust set ups are other people running behind chevs?
Trying to get the right balance between flow and back pressure.

All input is appreciated

[mudlva]

1 1/2 either side into a 2 1/2 main pipe. Any larger and you will end up losing torque

[callum007]

I run 2.25" from each manifold thru boy racer muffler and out.
Each side is separate.

[oldyella]

I've gone 2.25" after collector and 2.5" for a Rover 3.9L V8 injected with high torque cam with coby and hi-flo muffler in 2.5" section.

I would consider going 2.5" and 3" for 350 chev with those specs and install a single hi-flo muffler (not coby) in the 3" section.

I don't think you will loose F all torque (even noticeable?) compared to installing that camshaft and would let it rev.

Not quite the same but used to run 2 x 3" on the 350cu chev jetboat. However, the water cooling was injected after the manifold into these 3" pipes so reduced the cross-section and provided muffling and back-pressure. Would be equivalent to a 2 x 2.5" with hi-flo mufflers I reckon. Went bloody well.

There are calculators for this sort of carry on. Plug your specs into a few different ones and see what they come up with.

http://dairally.net/daihard/chas/MiscCa ... iPipes.htm

http://www.wallaceracing.com/header_length.php

[Dannz71]

Yea I think 1.5 is waaaay to restricting.
I was thinkn 2.25 or 2.5 just not sure which. I want tge torque but stil want it to rev out wen I need it

[mudlva]

Juess dont follow me ah...
With all the extra comments i had to go out and measure them up and.....
1.5 header tube into 2.5 link tube into 3.0 main pipe.
There you go i knew there was 1 1/2 in there some where

[Dannz71]

haha thanks mudluva i had to wonder for a bit, but yea that makes a lot more sense, sounds like what i need, what sort of mufflers are you running

[mudlva]

A single bullet shaped unit 100dia x 400 long
Quite enough when cruising along the trails but roared good and loud when i had me boot hard up it