Exhaust Cut-Outs

[cnard]

Has anyone installed Cut-Outs on there exhaust. I been looking at the electrical cut-outs sold by Qtec.( see link below) If so I was wondering where in the exhaust they were installed and how do they sound. Does the CATS interfere with the sound.

http://www.quicktimeperformance.com/QTEC/index.htm l

[Old Goat]

Has anyone installed Cut-Outs on there exhaust. I been looking at the electrical cut-outs sold by Qtec.( see link below) If so I was wondering where in the exhaust they were installed and how do they sound. Does the CATS interfere with the sound.

http://www.quicktimeperformance.com/QTEC/index.htm l

They're freaking LOUD! Sounds like the starting line at the Strip. :D

[Adam4356]

It's gonna be loud. Cats will actually make it bearable. The sound is gonna be straight pipe and not very "tuned". The electric cutouts are a nice idea but if you are gonna be running them open all the time then consider a cheaper catback. If you want to look OE, sound OE to the cops, and then unless the gates of hell then electric cutouts are pimp.

[Dbluegoat]

so essentially you can leave those closed for as longs as you like and it will not change the stock sound? and then when your feeling like a bad@ss you can open them up and get the roar?

[Dbluegoat]

Ok was it me or was the bolt on the top of the cut-out in the WRX video turning by itself? I promise I have not been drinking

[Dbluegoat]

I think I am really going to have to get those electric cutouts. I watched all the videos on that site and now they are calling my name. Who would install them? A muffler shop? Is there any cutting or welding involved?

[FLORIT]

"I will not spend more money. I will not spend more money. I will not spend more money."

Sorry, I was meditating. Anyway, this looks like a mod I may install when I install the long tube headers. Having the electric switch probably makes the mod "street legal" because you can run with them closed most of the time and just open them up when you want to run "straight pipes".

One concern, though. Wouldn't the PCM need to be re-tuned to change the AFR (and other parameters) if you switched from "closed" to "open"? The O2 sensors would have a panic attack if they were switched out of the loop. My "gut instinct" tells me the two running modes ("cutouts closed" and "cutouts open") would require two very different PCM tunes. I would definitely verify this before installing this mod.

[cnard]

I think I am really going to have to get those electric cutouts. I watched all the videos on that site and now they are calling my name. Who would install them? A muffler shop? Is there any cutting or welding involved?

Dbluegoat, Any muffler shop can install the cut-outs but I am not sure if they would insatll the wiring and the switch. They will have to cut a hole in the pipe and then weld on the cut-out. Its a easy install. I had them on my 67 GTO and they sounded great when opened. Only back then I had to remove 3 bolts and remove the cap for each one. With the electric one you partially open them for the sound you like or open all the way.

[cnard]

"I will not spend more money. I will not spend more money. I will not spend more money."

Sorry, I was meditating. Anyway, this looks like a mod I may install when I install the long tube headers. Having the electric switch probably makes the mod "street legal" because you can run with them closed most of the time and just open them up when you want to run "straight pipes".

One concern, though. Wouldn't the PCM need to be re-tuned to change the AFR (and other parameters) if you switched from "closed" to "open"? The O2 sensors would have a panic attack if they were switched out of the loop. My "gut instinct" tells me the two running modes ("cutouts closed" and "cutouts open") would require two very different PCM tunes. I would definitely verify this before installing this mod.

Florit, Depending on where they install the cut-outs befor or after the sensor. These are things I am trying to find out befor I install them. But my gut feeling is it will work either way.

[Tails]

This is a mod I am definitely going to do. I am anxiously waiting for someone to be the first guinea pig!!!
:drink: :drink:

[DANSLS1]

I stopped in at one of the local speed shops and asked that exact question to the guy who does the LS1 tunes Florit. His response was he would recommend just spending the money to have a decent flowing full exhaust system and tune for that. Unless you are going to have separate tunes for open or closed and some sort of method to switch them, yes there will be some potential loss of efficiency either open or closed depending on how you tune.
Dan

[Old Goat]

I stopped in at one of the local speed shops and asked that exact question to the guy who does the LS1 tunes Florit. His response was he would recommend just spending the money to have a decent flowing full exhaust system and tune for that. Unless you are going to have separate tunes for open or closed and some sort of method to switch them, yes there will be some potential loss of efficiency either open or closed depending on how you tune.
Dan

Agree Dan, and personally believe a nice way to go would be to do a nice set of 4into1 Long Tubes, and keep the 2.5 pound backpressure stock system by just compressing (shortening the distance between components) after the headers, and maybe locating the first set of O2 sensors in bungs on the collectors ahead of the cats.

[gto_in_nc]

Agree Dan, and personally believe a nice way to go would be to do a nice set of 4into1 Long Tubes, and keep the 2.5 pound backpressure stock system by just compressing (shortening the distance between components) after the headers, and maybe locating the first set of O2 sensors in bungs on the collectors ahead of the cats.

Do we have any numbers yet that definitively indicate there is a significant choke in the stock manifolds? I'd love a cat-forward LT solution but only if it means more than a few HP. Know what I mean?

[Old Goat]

Do we have any numbers yet that definitively indicate there is a significant choke in the stock manifolds? I'd love a cat-forward LT solution but only if it means more than a few HP. Know what I mean?

The shop manuals give pressure readings measured at the sensor bungs and sets a standard measurement of 2.5 PSI indicated on the backpressure gauge at those points ahead and after the cats. Anything higher is considered restricted, and requires repair/replacement. I'd say that's a pretty free flowing system. Anything restrictive after that (mufflers) would drive up those readings. The stock system is going to be a very hard act to follow. It indicates to me that other than Headers, there may be no need to mess with anything else. My Grandpa used to say "If it ain't broke, don't fix it!"

I am also led to believe that if there is anything to be gained here it would be in Long Tubes. The scavenging effect of a properly designed set can only help. I am not getting into Tri-Y's, as I can't imagine any need for more low end torque without a lot of flywheel/flexplate back drivetrain beefing first and having to balloon the rear fenders to get enough tire to handle it.

[Thanatos]

Why do all of the people making car videos for the internet decide it is necessary to put music into the damn things? The point of this video was for you to hear the car with the free flowing exhaust, but it was half drowned out by the stupid music.

[Old Goat]

Why do all of the people making car videos for the internet decide it is necessary to put music into the damn things? The point of this video was for you to hear the car with the free flowing exhaust, but it was half drowned out by the stupid music.

Or record them in a garage where the blending echoes, reverbaration, and engine noise make them sound like a combine? :D

[Ude-Lose]

im surprised that no-one here has mentioned that the 70-71 GTO had an option that was called the - "TIGER BUTTON" , guess what it was ? and exhaust cut-out (cable actuated) , it even shows it in the "HUMBLER" commercial - SEE HERE 2mb (http://mypage.bluewin.ch/Pontiac/Download/Commerc ials/TheHumbler70Gto.wmv)

im definately getting cutouts.

[AmesGTO]

The 04 needs a commercial like that. This is the way it's going to be baby!

[HAHA I 1]

I have put cutouts on both LT1 and LS1 cars that I have owned. The LT1 car gained 12rwhp and 13rwtq. The LS1 car (2001 Z28 with an A4) gained 14rwhp and 15rwtq. Neither one lost hp or tq anywhere on the rpm curve. Both hp and tq were always higher. I have also seen this on several other LS1 cars. I am lucky to have a dyno shop a few minutes from my house, so I hang out there a little. The cutouts are actually a very good bang-for-the-buck. The electric ones are even nicer because you can open and close them very easily.

They are loud, though. Especially with LTs and no cats.