Custom Exaust; 2 Cutouts & a Catback??

**camaroluvr447** · 02-01-2010, 02:57 PM

Right now I have a 3" magnaflow catback on my z28 with stock exaust from the cat to the engine. In order to get the power of true duals without scrapping my catback I want to place 2 electric cutouts at my headers and replace the cat with 3" tube connected to my catback through a Y pipe. Any Input on this idea?

**Mr. Luos** · 02-01-2010, 03:01 PM

It will most likely be down on power with the cutouts open.

**camaroluvr447** · 02-01-2010, 03:06 PM

Originally Posted by Mr. Luos

It will most likely be down on power with the cutouts open.

why do you say that? would having the cutouts open give me the most power?

**Mr. Luos** · 02-01-2010, 03:14 PM

Originally Posted by camaroluvr447

why do you say that? would having the cutouts open give me the most power?

Too free flowing for most stock and near stock motors.

Cutouts open will likely be lower on power and actually ADD time to your ET's.

**camaroluvr447** · 02-01-2010, 03:18 PM

Originally Posted by Mr. Luos

Too free flowing for most stock and near stock motors.

Cutouts open will likely be lower on power and actually ADD time to your ET's.

I have k&n intake, ls6 manifold, and MSD, is that still too close to stock? thanks for the tips!

**Too Fast** · 02-01-2010, 03:23 PM

Originally Posted by Mr. Luos

Too free flowing for most stock and near stock motors.

Cutouts open will likely be lower on power and actually ADD time to your ET's.

Didn't you have some dyno proof for your claims? I thought maybe you did on some other thread. Can you back that up, about less power with open headers? Or maybe a link to an article some mag has done to dispell or prove this claim.

**blue02Z** · 02-01-2010, 03:28 PM

i have the exact system you are talking about except mine arent electric. and yes it takes away torque you can definately feel the loss but maybe its just me i think once i get into the rpms it pulls pretty damn good

**Too Fast** · 02-01-2010, 03:32 PM

Originally Posted by blue02Z

i have the exact system you are talking about except mine arent electric. and yes it takes away torque you can definately feel the loss but maybe its just me i think once i get into the rpms it pulls pretty damn good

Have you been to a dyno, and tried it open cutouts and shut, to see the power curve?

**camaroluvr447** · 02-01-2010, 03:42 PM

I have heard that cutouts will decrease torque but increase horsepower at higher rpms... I would like to find oput as much as possible before I go and buy a setup and expect more power. Anyone done a dyno with cutouts open/closed?

**Too Fast** · 02-01-2010, 03:55 PM

Allright, first article I've found, but this is no stock engine, but it lost around 35 HP with mufflers. However, as the article states, this is only a very small amount from a 1300+ HP engine.

http://www.hotrod.com/techarticles/b...ler/index.html

**Too Fast** · 02-01-2010, 04:00 PM

Here's another, from a You Tube poster, he says he ran 3 open and 3 shut dyno pulls. Doesn't say what car or engine, tho:

You are absolutely correct., After 6 pulls on a dyno, 3 open, 3 closed, the findings in fact DO decrease HP/TQ at the low end, but not anywhere near a 20% loss. Maybe 5% then picks up 6-7 Hp above 4000 RPM. Nonetheless they are more for intemidation and they are Very loud! Close and it's quiet - best of both worlds. The RaceReady and Pypes are all but identical.. And contrary to your smart ass response. The RR's have not had a single issue at all.

**Mr. Luos** · 02-01-2010, 04:56 PM

Originally Posted by Too Fast

Didn't you have some dyno proof for your claims? I thought maybe you did on some other thread. Can you back that up, about less power with open headers? Or maybe a link to an article some mag has done to dispell or prove this claim.

My car gains a little with the cutouts open....but not until 4200.
But I also do not have a near stock motor.