GuesDog

I'll tell you what, sitting at a stop light my eyes start burning, but then again the car runs pig rich until I get it tuned.

MeentSS02

iTrader: (11)

Hey. I have an idea. Let's do a poll on a really subjective topic

I voted duals simply because that's what I have, and it is the only exhaust I haven't grown tired of (out of the 4 or 5 setups I've had). Dyno numbers went from 331/347 before to 340/356 after (RWHP/RWTQ), and that was on a very shitty tune (Diablo canned tune with KR damn near every WOT run). I've since fixed the tuning issues (with an open loop Speed Density tune that I run full time), and it is a LOT stronger now.

Many people talk about flow numbers this, flow numbers that...to me, it is all about velocity. You need to keep the exhaust velocity up, and you need to scavenge well (which a well designed dual system will do wonderfully).

I wanted a great sound, and didn't expect any additional power. I was pleasantly surprised.

300bhp/ton

I agree with all your comments excpet velcoity.

Yes keeping velocity is good, but assuming you are not exceeding a Y setup I think it will have greater velocity. This is because you only have one 3" pipe containing gases from all eight cylinders. So as long as the tubing itself isn't too small the gases will move a lot quicker than the gases from only 4 cylinders in 2.5" pipe.

It's like if you have a hose pipe (garden hose!!!!) and squeeze the end of it, it is still flowing the same amount of water, but the velocity has increased.

A Y pipe is the same, a lot of gas in a more restricted and comparitivly narrower pipe (remeber there's double the amount of gases in a Y pipe as opposed to duals). Where as a dual setup has a low quantity of gas in a relativly large pipe.

SouthFL.02.SS

With turn-downs under the car, before the axle, stink come back up through the side windows.
I then went catback again, with tips out the back, ponting straight out. No stink.
It's all in the tips. I've run a catback with turndowns after the axle, and stink creeps back in.
It could be, also, that you've become immune to the smell.

MeentSS02

iTrader: (11)

Well, you would have to assume that the exhaust gases aren't fighting each other to get into that one pipe. A nice train of pulses perfectly synchronized from each bank would be wonderful, but I'm pretty sure that ain't ever gonna happen.

And I don't know about you, but I can sure as hell squeeze the end of a hose with my thumb and drastically cut down on the flow of the water while increasing its velocity...

300bhp/ton

Love that last line

Yeah I guess the tips could have an affect on it.

300bhp/ton

Well a Y pipe acts the same as an X pipe, in a dual setup with an X the two exhaust streams cross over and become intertwined. So I doubt this would really be much of a problem. But I dunno, never studied it.

Well yes once you reduce the size so that it becomes a restriction it will limit the flow. But there is a certain point where a smaller tube can still flow the same level of water but at a higher velocity, because flow is cfm (cubic feet per minute). This is provided the tube diameter isn't already a restriction. But velocity will still increase even if the flow rate diminishes.

GuesDog

Besides the sound difference, the horse power and torque that I wanted was achieved.

The other reason that I wanted to go with true duals is that this way with x pipe the pressures in the exhaust tubes would be identical, as well as having 2 2.5 inch pipes all of the way out, instead of 1, 3 inch pipe. Not too mention a restrictive y pipe before that.


2.5+2.5=5 (inches)


The exhaust is larger therfor the less restricting. I know I am already saying what you already know...but there are some others whom still think its a waste of money and time.

blkZ28spt

That is false.

You simply cannot measure/compare that way. You have to use cross sectional measurements. A single five inch pipe would absolutely dwarf dual two and a half inch pipes in CFM capacity.

GuesDog

I am just curious how that would come about? We are talking about ls1-lt1, not a diesel(sp?) truck, there are two headers, when y'ed together I see more restriction and less of an equal pressure.



If I am wrong then tell me differently, this is what I have learned, and been told, If there is something different I would like to know...

SouthFL.02.SS

This is all the merge you need to go fast .



If you ever get to look inside one, you'll see how smooth the transition is. The left and right pulses are not slammed together, they are truly merged together.

00SS4780

iTrader: (3)

I have that merge in my Mufflex Y. Now I'm wanting a dual exhaust but I have the sphon chasis mounted tq arm. So would I be just fine with dumping the Y-pipe with a 4" bullet? Or would a dual system be any better and a different tq arm? I do have a cutout before the axle now and it does help alot but the pipe reduced to 3" after the collector.

SouthFL.02.SS

You could get rid of the 4" to 3" reducer which attaches to the tail end of the merge collector, put a 4" cutout right after the collector, then reduce it after the cutout to 3" for a catback.

Redneck Z

iTrader: (3)

If duals really don't offer any hp/torque advantage over a good y-pipe setup, then why on earth is there a market for these loud, ground clearance stealing pipes? Why are there so many dyno's that suggest performance gains over a good single exhaust?

SouthFL.02.SS

I don't know. All I know is that a good Y-pipe and a good catback made lots of power on my old car. I'd rather have a 480rwhp car with good ground clearance, a good, tolerable exhaust note than a 490rwhp car that can't make it up my driveway, smells like a gas station and that I can't have a conversation in, yet sounds mean as hell. It's all in what you want. I just thing MANY people are quick to rule out a Y-pipe's potential.
And, as for the sound mean as hell factor, I ran dual elect. cutouts and still had better clearance than the duals.

300bhp/ton

That is a very good question. And I believe there are several answer. However one has to be this strange alure that people believe they are better, without knowing all the facts.

Also people are gulable. As a rule the mass populas are sheep and just follow what they have been told is good or the thing to do.

I'll admit duals do sound excerlent, and I may one day go custom duals myself. But to do it how I want it will cost a lot more than a catback and Y pipe off the shelf. If I supercharged my Z28 and had ~500rwhp then I would certainly be looking at 2.5" duals, but anything below that I just don't feel it justified.

But as always each to their own.

300bhp/ton

It's because you need to look at area (pie R squared).

Redneck Z

iTrader: (3)

Thats the exact reason I don't have duals myself. I wish there were more dyno's and definate answers to the dual vs. single debate. I tend to believe, from what I've seen, that they do offer some under the curve benefits, and probably fall into that "every little bit counts" category. I'm just not willing to sacrifice the hassle and ground clearance loss that the duals create. If my car was a track only car, then I run dumped duals without a doubt.

Z28*POWER*

guys !!! i received my TSP duals with ST today .... they look okay!!

my car is not lowered so am i going to face ground clearance problems?

spun03cobra

I ran hooker lt's in my 00' camaro cam only car with a hooker Y and a hooker cat back, car made 550rwhp on 150hp N20...Currently I have an 02' with a ls1 hot cam, stock exhaust, cats and stock cat back with a 3.5" welded in xr1, car sounds great and I can totally tell a diffrence from the flowmaster that was on the car. Plans are lt's with a flowmaster merge collector with 3-4" single exhaust to exist out the rear of the car.
If there was a real true dual exhaust set up that could be ran all the way out the rear of the car I would do it, I have looked into it but would rather do the single just due to laziness.