kst8engineer

iTrader: (6)

I performed a little experiment yesterday on exhaust system layout. I've always been curious as to the effect that various factors such as length of tailpipe, muffler placement, and tube diameter have on exhaust sound. I've never before seen a good side-by-side comparison like this one. The only thing I wasn't able to compare here was different diameters of tailpipe. Hopefully this comparison will come in useful for other swappers beginning to lay out their exhaust system!

Let me know which one you like best (I've already picked my favorite)...

Hushpower exhaust layout experiment Part I

Hushpower exhaust layout experiment Part 2

Hushpower exhaust layout experiment Part 3

Hushpower exhaust layout experiment Part 4

In the interest of having something that sounds both muscular and maybe a little bit refined, my vote's on #1 (mufflers at the back). For the past 15 years, the Chevelle has had Flowmaster 40's dumping just in front of the rear axle, so refined is defintely something it hasn't experienced before. In order to make #1 work, I think I'll have to place the mufflers in the small open areas to the right and left sides of the trunk floor, just inboard of each 1/4-panel. I think I could cut some radius notches in the rear valance panel and have the exhaust exit through those notches.

pist0lpete

iTrader: (3)

First off let me commend you on having such a great side by side comparison. That sort of thing is hard to find in the hot rodding world. Personally I liked option #2 best with the mufflers up-stream a bit more. Sounded more throaty to me. I do agree that #1 sounds the most refined. I have the dumped 40 series on mine and it sounds good but its very loud as you know. One of these days I will likely have to tone it down as you have done.

P.S: Glad to see you got her running!

LS1MCSS

iTrader: (18)

I like #2 better.

RsSean

iTrader: (27)

4 and 2 get my thumbs up.

udlose99ta

iTrader: (18)

#2 also

2nd Gen Fl 'bird

iTrader: (13)

My vote goes to #1 also. Sounds mellow. Pipes start giving that cackle sound the longer the tailpipe.

kst8engineer

iTrader: (6)

Thanks, Pistol. I haven't been able to take it for a drive yet as I'm finalizing some floorpan work and getting the brake booster and pedals mounted up. I also still need to figure out what needs to be done to mount the 4th-gen F-body bucket seats in the Chevelle.

That's always been my thought as well -- that long tailpipes tend to contribute to the cackle / popping sound. I may be wrong, but I think smaller diameter pipes also contribute to that same effect.

Benner

iTrader: (2)

Personally #4 sounds the best to me but I'd say it's pretty loud in car as well and the cops may give you a couple looks, so if those are conditions for you I'd take #2.

kst8engineer

iTrader: (6)

Yeah, #4 would be a touch on the loud side. I just did that one for fun while I was recording the videos.

hookemdevils22

iTrader: (12)

i don't think the video does #3 justice. i know how the interior resonance is with the dumps that far up. i like #2, my g/f likes #4

ronniejames84

i love how number 4 is.. thanks for the pm.. yeah number 4 is a good chopppy sound

kst8engineer

iTrader: (6)

I just realized I hadn't explained the differences in the videos very well.

#1 - Edelbrock long-tube headers, 2.5" x-pipe, 4' intermediate pipes, 18" Hushpowers, no tailpipes, LS1 engine, 220/220 0.547"/0.547" 114 LSA cam. I did this one to emulate a late-model 'Vette exhaust where the mufflers are located very near the exhaust outlet.

#2 - Edelbrock long-tube headers, 2.5" x-pipe, 18" Hushpowers, 4' tailpipes, LS1 engine, 220/220 0.547"/0.547" 114 LSA cam

#3 - Edelbrock long-tube headers, 2.5" x-pipe, 18" Hushpowers, no tailpipes, LS1 engine, 220/220 0.547"/0.547" 114 LSA cam. This configuration was considerably louder inside the car in terms of interior resonance

$4 - Edelbrock long-tube headers, 2.5" x-pipe, no mufflers, 4' tailpipes, LS1 engine, 220/220 0.547"/0.547" 114 LSA cam. As you'd expect, this one was also very loud both inside and outside the car. If you're going to drive the car much, I wouldn't consider this a realistic option.