HuggerOrange

is there a significant advantage or any at all over a y pipe when using a true dual exhaust on an ls1? just wondering thanks.

93octane

Without cats and large mufflers, you will loose backpressure, which will cut some out of your torque on the bottom end. However, you gain what you lost on the bottom end, on the top end as horsepower. You also get rid of "rasp" which you get with a high flow y-pipe and no cats.

So the advantages would be sound, and horsepower. Disadvantages would be legality (if you don't have cats, or if you dump it at the axle), and loss of low end torque since you don't have as much backpressure.

WILWAXU

iTrader: (6)

Most of the advantage is in weight.

Many of us are going fast with an ordinary y-pipe

Lane

iTrader: (1)

I picked up 24 rwhp at 5000-5500 rpms with duals, over a custom 3" open Y. Stock internal, with Mac headers. 2.5" system with a Dr. Gas X crossover.

So YES would be my answer. Peak numbers may be similar, but mid-range power and torque should be greatly increased.

Z28Venom

iTrader: (13)

All ya had to do is search..

5POINT7

SOTP is waaaaaay better w/ duals. But you can go fast w/ either setup, like mentioned above. I got duals b/c I wanted my car to scream on the top end after my cam install.

And btw, any "loss" in torque (which is a misconception anyways) can be made up with steeper gears.

ZR2877

The power up top of true duals is great but the sound alone is worth it.

HuggerOrange

cool sounds like i will like it then, cause i have enough gear for the torque issue and i think the t-rex cam will like it!

zchgla

I choose mine for sound, and price.

Z-286speed

Its cheaper, sounds better and gives you more power, what else do you need!

5POINT7

Get the duals, bro. You'll love em.

Mr.BigE

go duals!!!!

dug

iTrader: (10)

Thats true with cars with big converters. I think it would be different with m6 cars. From dynos Ive seen most of the gains from duals happen below 5k. With a big stall, engine rpms dont fall much below 6k during shift extension. So you wont see much benefit with duals.

I think with a stick car youd notice some benefit with duals cuz the engine sees a wider range of rpms.

Mooobunnny

iTrader: (1)

actually it is basically the opposite as long as you use an x-pipe....

MeentSS02

iTrader: (11)

Well, I can certainly say I lost no backpressure when I went to duals with no cats (my previous setup was a Kooks 3" catted-y into a Hooker). The low end is still there with my car. I made gains all across the power band on my car.

As for cheaper Not necessarily...

BottleRocket

why do people actually want backpressure? you DO NOT WANT backpressure, you want better scavenging from the combustion chambers. what good is backpressure? that keep the burnt up hot air in the cylinders. why would anyone want that. now yes, if you put 2'' primaries on our 346, it wont like it. why? because the collectors cant do their job. the exhaust gas doesnt have enough velocity to pull the air out of the other ports.

MeentSS02

iTrader: (11)

Because a lot of us use these cars as daily drivers and spend most of our time cruising around in the 1-2k RPM range where the engine isn't making a lot of torque. More backpressure makes the car much more responsive around town.

Mooobunnny

iTrader: (1)

Only if your exhaust setup was improperly designed to begin with.....

Scavenging is what people need to talk about....backpressure is just a crutch

You can decrease backpressure by A LOT and still increase hp and torque from idle up.......

If you run stock exhaust manifolds or shorty headers into a 4 inch exhaust or something along those lines backpressure will definately help, because you are loosing way to much exhaust velocity, which kills scavenging....

BACKPRESSURE sucks though....period....

Sorry for the rant......

MeentSS02

iTrader: (11)

Well, I think we need to be realistic here. There aren't many people out there with these cars that could afford to have a custom made exhaust fabbed up, and most can't even afford some of the better designed off-the-shelf systems. Most folks want an easy, bolt in solution for a few more ponies around town, which usually involves a compromise of sorts. I had custom true duals fabbed up, but I still don't think my car is as responsive down low as it was when it was stock. Sure sounds a lot better and is much more fun to drive though.

BottleRocket

no it doesnt. velocity is the key at any RPM range. just like turbos, you can get one that spools early and makes good power down low, but its not going to do it's best at 7000rpm. same with headers, you can have some that are meant for all out racing and make great power up top, or you can get some smaller headers that are better for daily driving? all that does is make the ideal flow velocity for those headers come lower in the revvs. backpressure is the enemy.