LS6427

iTrader: (2)

So, I'm planning my new stuff for when my 441ci goes in. Expecting 600 RWHP N/A.
2" headers going back to custom Y, into a flowmaster merge (3" inlets), then 4" outlet back to Magnaflow muffler.

Just wondering if these things are worth it.

Dual cut-outs after each collector.

OR

A 4" single right after the merge.

Car does highway pulls only. 100% fun street car. Is it gonna really make a difference using dual cut-outs or a big single cut-out????

Thanks.

.

98 White T/A

iTrader: (5)

Single cutout should be fine. Seems like with your setup the exhaust will flowing well already. 2 cutouts will just make it louder, but then again, every1 has their own opinion and has seen different outputs on different setups.

LS6427

iTrader: (2)

Is it really gonna be noticeable though.......seat of the pants feel a little bit?

Just wondering with close to or hopefully right at 600 RWHP....is it worth doing.

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98 White T/A

iTrader: (5)

With that much horsepower your not going to feel the difference, it will only be seen on a dyno. With cut-outs installed at the stock level cars, I dont feel the difference, yet on they put out some more power on the dyno. I have a e-cutout so i can open it while im driving.

Stippy17

iTrader: (5)

Patrik G had a thread about making 500whp out of an LS1 a few years ago. In the thread he goes into detail about the exhaust setup he decided to run. He had a custom Y-Pipe fabbed up like you plan on doing w/ a Dual 3" to Single 4" merge, then a 4" cutout, and I believe reduced back down to 3" for the catback.

On the dyno he gained 10whp between opening up the cutout in comparison to running through the tips. He also stated that with the design of his Y-Pipe he only lost 1whp in comparison to running 20" straight extensions off LT Headers.

With that evidence, Id run a 4" Cutout after the merge. Thats what I plan on doing this fall.

LS6427

iTrader: (2)

Thats what I figured........not worth it.

Stippy,
10 HP certainly isn't worth the hassle.



Thanks for the info......................

Stippy17

iTrader: (5)

So I dont steer you in the wrong direction or confuse you Ill make what I said easier to understand lol, because 10whp is a good bit to gain.

Imagine this is the same setup on a car. Easy comparison:

490whp - Thru the exhaust tips.
500whp - Single 4" cutout open after merge.
501whp - 20" extensions off headers. (Equivalent to dual cutouts)


For the cost to run two cutouts, its not really worth gaining AT MOST 1whp. So, Id run a single 4" after the merge.

senicalj4579

iTrader: (41)

I would even waste my time with a cutout. You already have a 4" merge.

LS6427

iTrader: (2)

We'll see when it gets closer to exhaust day........can't hurt to have it there I guess.

I do plan to spray it maybe 6 months after its in......so really might not be worth it. Whats 10 HP when its making 800 RWHP.

I think I'm gonna do a 200 DP dual stage (100/100)...........with the ability to pick either a 100 shot or use both and spray 200...on the fly.

.

Stippy17

iTrader: (5)

What size pipe do you plan on running for the catback?

omarrakeen

iTrader: (2)

one cut out for sure, why bother with 2? a 4" merge will help alot. as LS6427 said: whats 10 hp when its making 500+ lol