RA40

iTrader: (6)

I was wondering what your thoughts were about a single exhaust over the dual's that the LS has?

I was thinking that the Y split at the silencers is one of the bottlenecks in the exhaust. If I were to run 2.50" from the first Y merge all the way back to a single muffler if this would be a viable alternative? Slight cost and weight savings too.

??

Jasoneo5

iTrader: (4)

I have also thought about that in the past. I don't know anything about that stuff though Look forward to the responses!

-Jason

JBrady

Mike, yes, that would work. I would also replace the front Y pipe with a proper racing merge Y-pipe. I can get those if you want just PM me. I can also advise on the rest of the parts if you wish.

Jasoneo5

iTrader: (4)

but would this be better than dual?

RA40

iTrader: (6)

Not necessarily "better", theoretically if there is optimal flow, the single or dual should perform similarly.

Not all exhaust shops are great at tuning so the I'm thinking of the KISS method. Also plumbing dual mufflers is a challenge and I've seen enough that are not mounted symmetrical. With a single, there is no reference so if it is slightly off, it isn't a problem. This may be a savings of about $75-$100.

JBrady

Jason, if you are asking if a Y setup is better than full duals... yes.

On a multi-cylinder engine, you can improve single direction velocity/energy by merging the exhaust pipes together. This works in both the primary and secondary pipes. Merging the duals into a single will create a velocity and energy zone greater than the dual pipes can on their own. From there back either a single or dual system will work fine and would perform relatively equal. The benefit of a dual from the Y pipe allow cleaner routing with smaller pipes and better muffling at the expense of more weight, complexity and cost.

Shmee

iTrader: (3)

I searched,I found and now I'm kicking this almost 9y/o thread back up...

I have been thinking about doing a single for the reasons JBrady just mentioned, and I was wondering if anyone had actually done this. I found this video: but it doesn't really have any details nor does it sound very good... Because of a hack-job? Who knows?

My idea was to build new downpipes from the cats, with 2-1/4 tube into a Burns Stainless y-merge that necks down to 2.5 and with a long transition back up to a 3" tail ring and 3" all the way back. I'd run a long straight through resonator down the tunnel, mufflers in the stock positions along the driver side into a hidden tip and tuck everything up as tight to the underside of the car as possible. If clearance will be an issue around the diff carrier, I will probably just run 2 oval transitions together ( ==><== ) under the carrier back to 3" sort of like this: (excuse the crude representation)
-------\__/-------
-------------------
Where the dip in the middle would also expand laterally to maintain (to a point) the internal volume of the 3" tube.

The performance is a byproduct of what I'm actually after, which is a specific sound. If I cannot get the sound I'm after, I'll go back to the drawing board.
Not that it's going to cost me a lot to build a dual exhaust, but this should save me about 50%


thoughts?
comments?
concerns?
Ideas?

Cheers

RA010623

iTrader: (1)

i think if you run a front pipes to Y collector to a single exit exhaust and if you use the correct piping size it should not be much different from dual
essentially the stock exhaust is 2 into 1 back to 2..

Shmee

iTrader: (3)

I am aware of that, but looking for an answer of a more technical nature though...

Thanks though

PureDrifter

iTrader: (10)

should change the crap Y-pipe to an X-pipe and redo the piping from there back.

cobalt91

Whats the best location for the x pipe as far as distance from the manifolds?

Shmee

iTrader: (3)

I am curious about the single exhaust setup as I outlined above. Dual setups with an X or and H are fairly simple and I've built lots of v8 duals. I wanted to know about running a single 3" and if anyone has done it and how it turned out.



Cobalt,
that comes down to a bunch of different variables. Realistically, on these cars -- or any basic NA street car for that matter -- it's not going to show any sort of discernible gains if its biased towards the manifolds or if its centered or baised to the rear where the first factory mufflers. Most of the time you'll see them positioned where they end up simply due to packaging constraints or the laziness of the guy installing/building the exhaust!

JPratt

here's another single setup

cobalt91

Thanks for the reply shmee. The reason I was curious about placement. Thought I read something a few years back about location helping maintain low end torqe. Somthing along the lines of balancing the exhaust pulses and scavinging between the cylinder banks.

Shmee

iTrader: (3)

Jpratt,
Thanks!


Cobalt,
With dual exhaust you want equal length and positions to everything.
So you wnt to try and position the X and all additional parts(mufflers and resonators) in a symmetric fashion between sides with equal lengths and diameters of tube between each item.

So length, number of bends and shape of bends of the tube between the cats and X should be even between each side. And same for the tube from the x to the mufflers.

If you we're to draw an imaginary line down the center line(driveshaft) of the car, theoretically, if you folded the car in half along that line the right and left sides should be perfectly matching... In a perfect world, that is.
Because you are not building the car from scratch, you are limited to the space constraints of the car so the theoretical perfect my not be possible so just do what works best without being overly costly or complicated!