Getting the 833 in the truck and am still figuring exhaust.

The truck came with a single exhaust, probably 1 7/8" haha. Then we upgraded to dual 2" stock style round POS mufflers. I recently replaced those with 24" glass packs because the other mufflers were falling apart and were welded together to make them last just a bit longer.

I noticed I picked up a tad bit more power, by the butt dyno, but they were noticeably louder. I actually loved the sound

In hopes of putting the 360 in later, I have the chance to upgrade now. The glass packs didn't have an h pipe or x pipe.

The 360 would be making under 400 horse, and the 318 is probably only making 100 haha with a 4bbl, headers and dual exhaust.

I guess what I'm asking is, H or X? I have 2 1/2" dynomax's already that sounded ok on a 360 with an H. I'm after a sleeper sound, with a bit of rumble grumble, but not glass pack sound haha


Last question. What would the HP boost be from stock single, to 2" dual 24" glass packs, to a 2 1/2" x or h dynomax?

I think the "X" pipe may sound a bit quieter than the "H", not sure if there is any power difference?

multiple users report that an X pipe quiets it more than an H pipe which that then lets you run a higher flowing (louder) muff while still staying under your noise tolerance (& has a differnt tone than an H). Good thing about a truck you have alot of room to work with & just me with a truck I'd want straight back duals (no H or X) & resonator muffs in the rear in addition to regular Dynomax muffs up front to quiet it. Mandrel bends always

FWIW, my 56 Plymouth, 277 poly with 2" duals and cherry bombs is a heckuva lot quieter than my 67 Barracuda, 360 with TTI headers, 2.5" X-pipe exhaust. The 56 has a nice tone to it with the glasspacks, but isn't noisy at all.

The Barracuda is not only a lot louder than the 56, but it is quite a bit noisier now (albeit a LOT faster) than it was with cast iron exhaust manifolds, 2.25" muffler shop bent pipes with stock 340 mufflers. It's also louder than my Hemi Charger with 2.5" TTI H-pipe exhaust and what are supposed to be the same mufflers. Not to say the Barracuda is annoying; I think it sounds good, but it's not the quietest exhaust system I have for sure.

I have a few other V-8's, some with H-pipe, some with no crossover at all, some mandrel bent, some not, and based on how they all sound, I'd guess that compared to pipe size, horsepower and muffler selection, the noise difference between H-pipe vs X-pipe is pretty small.

Here is a clip of my 63 leaving on cruise night. It has a TTI 3" system with an X-pipe and Ultra-Flow mufflers out to the rear of the car. Its not bad at all as I listen to the radio while driving all the time. But it is much louder when I get on it. Ron

http://www.youtube.com/watch?v=bYIM2HLaOI4&feature=related

If you can afford it and if there is room the X is probably better. Having said that, an H is really easy to fabricate and usually easier to find room for, under the vehicle.
Or, you could go to one 3" pipe. That has the same flow area as two 2 1/8" pipes.

Back in the day I "converted" a single exhaust to duals by tapping into the crossover pipe that ran from the drivers side exhaust manifold, and running a second pipe back on that side of the car. Voila! Instant H-pipe, easy duals.
Keep in mind that this was a college student's hack job and I pieced the rest of the second line together out of scrap pipe. I had more time than money.

R.

Yep, X flows slightly better with the downside being increased cost and a little more fitment/space issues. Either one is fine on a street 360 and I doubt you'd be able to tell any difference, other than perhaps sound.

As far as the HP increase with the various systems you've outlined, it depends on the HP your engine is making....probably little difference on your 318 between the 2" and 2.5" duals.

A decent 2.5" mandrel bent system with low restriction mufflers, using an H pipe is all you'll need for your current and future plan IMO.


Dave

Yes it on a pontiac. But an engine is just an air pump after all.
http://www.pontiacstreetperformance.com/psp/exhaust.html

Ok, I decided on X pipe. Just got done installing it. I picked up a universal x pipe system. 2.5". Went to the dynomax 17748's I got for a steal. Ran that to a turndown 1.5' after the muffler. Total investment into the 2.5" x pipe system, with dual dynomax's, is just a hair above $100. I wish I could do some MORE horse trading like this.

So far sounds AWESOME. Only ran for a few minutes because I didn't have my belts on from doing the radiator/belt swap.

I can't WAIT to actually drive her on the road. Just need that cross member, and I'm golden