Kenny H

I want to be able to make the car as quiet as possible, so an electric cut-out on the stock cat-back is my game plan. I know the after market cat-backs are bit lighter, but as far as performance goes am I losing anything? I plan to run pacesetters w/ cats into the stock cat-back w/ cut-out. It should be very quiet when its all capped up and thats what I want. Am I hurting performance at all in going with the cut-out on the stock cat-back?

blownws6_nc

iTrader: (10)

maybe someone will chime in on this, I don't kno, but if does not do what you want, I gotta a borla cb I'm gonna take off mine u might be interested in, and I'm not 2 far from you either. 20 mins. north of g-boro. L8ter Brian

c0ncEpT

iTrader: (4)

I run Pacesetter LT's, TSP ORY and a cutout in stock catback. I have never had the car on a dyno but I'm pretty sure with the cutout open you would make just as much power as someone with an after market catback with a cutout. When I have the cap on my set up its barely louder than stock. With the cap off the car screams.

WhosNXT

A cut-out will out flow any cat-back. Just make sure you put the cut-out before your cats. I have never ran a cut-out because I personally do not like the open exhaust sound, and do not mind loosing a few ponies for the added tone of mufflers.

BLACK2001SS

If you have cats then you want to put the cut out after your cats.
I have one just for that reason because it will out flow a catback and its a hell of alot cheeper and with and eletric valve you have the best of both worlds.

Medic/Z28

iTrader: (9)

You could also do the muffler mod. Add a bypass pipe between the inlet pipe and the outlet pipe coming off the same side. One of the first mods discovered in the early LS1 days.

CaliboyTA

iTrader: (2)

when my car was stock, i dynoed 5rwhp and lost 1rwhp with the cutout open through my factory cats.. now when im cammed, i've gained 18rwhp and 10rwtq with it open through tsp catted y-pipe

Pntbll309

iTrader: (33)

On my LT1 car I had just a flowmaster 80 series muffler and a Magnaflow 3'' uni cat, and with a cut out I only gained like 2rwhp.

teke184

iTrader: (5)

speaking in strict theory....NO

the stock catback is 2.75" in diameter, while aftermarket units are 3" (other than the big mufflex ones).
that equals to 16% more cross sectional area...a significant amount of flow potential.

but in real world applications....the variance will be so small...and variable between cars/dynos/days that you'll probably never notice a difference.


to make the most of your setup...and keep it quiet like you want...run some 3" tubing from the Ypipe back to the cutout. then have the stock 2.75" pipe welded behind the cutout.
that way you're getting the flow potential of the catback/cutout combo....but still retaining the sound of the stock unit when the c/o is closed.

3" tubing is cheap too...

ChocoTaco369

No, it won't. Not only is the stock catback smaller diameter tubing, but cutouts are not 100%. When the cutout is open, not all the exhaust goes out the cutout, so you're still using the muffler to an extent. You're still dealing with more restriction than a good flowing catback with a cutout. However, the difference won't be huge.

teke184

iTrader: (5)

that would be an interesting flow curve to see...

since the more restrictive the muffler...the more exhaust gets bled off through the c/o.

Snowman2K1

iTrader: (1)

i went with an aftermarket exhaust for a couple of reasons..first yeah i had a cutout but i didnt really like the sound of it..but most importantly..the look of the stock exhaust ..i hated it..i just wanted to lose the rust bucket..but if you dont have a problem with it than keep it i guess

chrs1313

iTrader: (24)

just get a cutout in the I pipe i have been rocking one there with my stock exhaust for over 2 years now..will gain you 20rwhp...i have dyno proof and track proof...definitely the best of both worlds...thats why i never got a catback...

BigKap94z

iTrader: (47)

I run the hooker catback which flows great, and sounds much better then the stock catback. A cutout only yielded me 2hp/3ftlbs at my power level. If I had to choose one or the other I would choose running the hooker catback rather then a cutout in the stock catback.

BLACK2001SS

Yes it would because even at an idle thier is still some exhaust comming out threw the muffler so at WOT I bet its alot more ,
But on a mustang dyno I had my exhaust taken down from the Y pipe so the I pipe was not on and I gaind like 5 hp or so it wasnt enugh for me to spend 500 bucks on a aftermarket exhaust, Thats why I got a cut out and it sounds realy cool to me too haha scares the **** out of all the poeple at Dairy Queen when I rap it up lol.

SOMbitch

iTrader: (8)

About what my dyno OP told me too. Apparently one of the best flowing systems out there. It's heavy though, I have one in my living room

BigKap94z

iTrader: (47)

You are right it is heavy, the aerochamber mufflers are definately built strong. After having the mufflex 4" catback with Spintech muffler...everything else seems light tho!

92SilverSHO

iTrader: (3)

Check the sig, i have headers, ORY, stock catback with a SLP OEM dual/dual muffler and its stocklike quiet. With the cutout open, its scary loud!. I wish i wouldve gotten a hookercatback or muffler just because its to quiet and with the cutout, its a bit loud.

socmguy

iTrader: (18)

you exhause will flow GREAT with that cutout in. Don't worry about the stock CB. Plenty of people with CME's do that.