[SnowFox]

Looked to find a thread but didn't find one or my search words suck. Anyway...

I was thinking of just adding a high flow cat (200 cell) in place of the stock cat. I'm not looking for much if any gains from it. Maybe a little more noise to add to my cat back system.

Anybody done this before? Thoughts?

Sure I could just add a cated down pipe but I'm not going to right now. So there is that lol

 

[gatornek]

I've heard people "talk" about this on this forum, but to my knowledge no one has pulled it off and documented it here. I imagine you either have to be an excellent welder, or personally KNOW an excellent welder who will take the time to make sure the finished job "lines up".

 

[AnOunceOfPerception]

I've heard people "talk" about this on this forum, but to my knowledge no one has pulled it off and documented it here. I imagine you either have to be an excellent welder, or personally KNOW an excellent welder who will take the time to make sure the finished job "lines up".

Thank you! I am positive that I don't know anything about it but a bunch of questions popped into my head and you pretty much answered them.

 

[hiddenpants]

an exhaust shop could probaby get it done for you on the cheap. especially if you just brought them the parts.

 

[SnowFox]

I've heard people "talk" about this on this forum, but to my knowledge no one has pulled it off and documented it here. I imagine you either have to be an excellent welder, or personally KNOW an excellent welder who will take the time to make sure the finished job "lines up".

So back in the "day" we would cut them off (if accessable) and clamp the new one/s in. I'm over simplifying a bit there. Is that not an option any longer ? I Literally haven't messed with cats since the 80s on a 4 eyed fox. 🤣 So if my thinking is way off in this case I wouldnt be surprised. But would like to learn the why and why nots 😊

 

[Coyote Chaser]

Looked to find a thread but didn't find one or my search words suck. Anyway...

I was thinking of just adding a high flow cat (200 cell) in place of the stock cat. I'm not looking for much if any gains from it. Maybe a little more noise to add to my cat back system.

Anybody done this before? Thoughts?

Sure I could just add a cated down pipe but I'm not going to right now. So there is that lol

I added a high flow cat to my system. Purchased it from Summit Auto Parts. Mine was the 200 cell, 3" in/out unit. But, they sell several sizes. Your stock cat is 2.75" in and 2.5" out.

 

[zhent]

Something no-one has mentioned on this thread yet is:

To get the stock cat out, you're going to remove the stock down pipe. The cat is a part of that pipe. You have to put something in there. Now, because of the EPA crackdown on these things, it's tough to find a catless downpipe to then add an aftermarket cat to the end of like Coyote Chaser did. This is why most people just do an aftermarket catted downpipe.

And of course all of this is going to depend on how strict your state is on emissions laws...

 

[Coyote Chaser]

zhent is correct!
What is pictured in my post is system #3 for my Mustang. And I added the cat to the end of a $100 eBay catless 3" downpipe.
However, system #2 was a little different. I installed the cat in the stock location, using a 1/4" pipe reducer, ["Big mistake! In order to make it fit, I had to remove the mounting bracket"] and without proper support, I torn it off, loading and/or unloading my Mustang from it's trailer.

 

[SnowFox]

zhent is correct!
What is pictured in my post is system #3 for my Mustang. And I added the cat to the end of a $100 eBay catless 3" downpipe.
However, system #2 was a little different. I installed the cat in the stock location, using a 1/4" pipe reducer, ["Big mistake! In order to make it fit, I had to remove the mounting bracket"] and without proper support, I torn it off, loading and/or unloading my Mustang from it's trailer.

That is similar to what I WAS considering. But sounds like more hassle then it's worth at this point. So I'll just grab a catted down pipe from CVF in a week or or so.

I was originally thinking just grab a 200cell cat and swap it out in the stock location, making sure to get one with correct length and measurements in an effort to "slip" it on each end of the cut pipe. Then clamp her down and call it a day. I didnt have any expectations for better performance. But I was wanting to change the note of my current cat back system a little. I'm in no mood to drop Boral atak type money right now when mine sounds good, but maybe could be a little better (and no I don't think this modification would make it sound anything like an atak muffler)

Thanks for replying everyone I appreciate your input. Please add anything else you think is worth knowing 👍

 

[MrScharfenberger]

Looked to find a thread but didn't find one or my search words suck. Anyway...

I was thinking of just adding a high flow cat (200 cell) in place of the stock cat. I'm not looking for much if any gains from it. Maybe a little more noise to add to my cat back system.

Anybody done this before? Thoughts?

Sure I could just add a cated down pipe but I'm not going to right now. So there is that lol

My thoughts: It's a neat idea but I think you would spend a fair pile of money for a little more noise and not much performance gain. ...and... If all you want to do is make noise have a muffler shop weld in a Doug's Electric Exhaust cutout at least 18 inches after the last oxygen sensor. Then you could have normal noise, a little noise or a lot of noise!

And I'm not just suggesting it. I have one welded in under my car already.

Doug's Headers DEC300AKS Doug's Headers Electric Exhaust Cutout Kits | Summit Racing

Free Shipping - Doug's Headers Electric Exhaust Cutout Kits with qualifying orders of $99. Shop Exhaust Cutouts at Summit Racing.

www.summitracing.com

 

[MD18EcoStang]

My thoughts: It's a neat idea but I think you would spend a fair pile of money for a little more noise and not much performance gain. ...and... If all you want to do is make noise have a muffler shop weld in a Doug's Electric Exhaust cutout at least 18 inches after the last oxygen sensor. Then you could have normal noise, a little noise or a lot of noise!

And I'm not just suggesting it. I have one welded in under my car already.

Doug's Headers DEC300AKS Doug's Headers Electric Exhaust Cutout Kits | Summit Racing

Free Shipping - Doug's Headers Electric Exhaust Cutout Kits with qualifying orders of $99. Shop Exhaust Cutouts at Summit Racing.

www.summitracing.com

Requesting a video comparison (with sound) of open/closed please!! 😁

 

[MrScharfenberger]

Requesting a video comparison (with sound) of open/closed please!! 😁

I'll get one for you but it won't be until this weekend.

 

[SnowFox]

My thoughts: It's a neat idea but I think you would spend a fair pile of money for a little more noise and not much performance gain. ...and... If all you want to do is make noise have a muffler shop weld in a Doug's Electric Exhaust cutout at least 18 inches after the last oxygen sensor. Then you could have normal noise, a little noise or a lot of noise!

And I'm not just suggesting it. I have one welded in under my car already.

Doug's Headers DEC300AKS Doug's Headers Electric Exhaust Cutout Kits | Summit Racing

Free Shipping - Doug's Headers Electric Exhaust Cutout Kits with qualifying orders of $99. Shop Exhaust Cutouts at Summit Racing.

www.summitracing.com

"Doug's Electric Exhaust cutout"


Ok I'm game for something like this. never done or even looked at cut outs before. After looking at it I know it's something I could easily do. But could you explain to me exactly what it does? Is it basically just venting exhaust early if I want it to? And thus generating more noise?

 

[MrScharfenberger]

"Doug's Electric Exhaust cutout"


Ok I'm game for something like this. never done or even looked at cut outs before. After looking at it I know it's something I could easily do. But could you explain to me exactly what it does? Is it basically just venting exhaust early if I want it to? And thus generating more noise?

Yes. It opens a big hole in the exhaust system thus bypassing the rest of your exhaust system in the back. When fully open it makes for very little back pressure in the exhaust system and one heck of a lot of noise. I have a rocker switch mounted low on my dash. If I tap it for a second I can barely crack it open. If I hold down on the switch it will open all the way. Then of course push the switch the other way and it closes.

You will find cheaper exhaust cut outs on the market but they all leak. Doug's are by far the best. Most have butterfly valves that leak easy. Doug's has a solid metal plate with a knife edge that slides down and when closed....is actually closed. They are very well built. Don't buy cheap ones.

I'll still get a video of my car this weekend with it shut, cracked & wide open.

 

[SnowFox]

Yes. It opens a big hole in the exhaust system thus bypassing the rest of your exhaust system in the back. When fully open it makes for very little back pressure in the exhaust system and one heck of a lot of noise. I have a rocker switch mounted low on my dash. If I tap it for a second I can barely crack it open. If I hold down on the switch it will open all the way. Then of course push the switch the other way and it closes.

You will find cheaper exhaust cut outs on the market but they all leak. Doug's are by far the best. Most have butterfly valves that leak easy. Doug's has a solid metal plate with a knife edge that slides down and when closed....is actually closed. They are very well built. Don't buy cheap ones.

I'll still get a video of my car this weekend with it shut, cracked & wide open.

I'll order it up this week, thanks.

 

[Elamcup]

Something elase to concider is you should get a tune. The 200 cell cat flows more than the factory cat and that could put you into an overboost condition.

 

[SnowFox]

Something elase to concider is you should get a tune. The 200 cell cat flows more than the factory cat and that could put you into an overboost condition.

I ended up changing my mind and I'm instead ordering the CVF catted down pipe. A tune will happen shortly after installing. However, I do wanna see how the stage 3 Cobb tune performs before I get a tune (I'll get one anyway)

Thanks for the input all. I'm sure I'll start a thread WHEN I hit a snag putting in the pipe later this week 😂

 

[MD18EcoStang]

I ended up changing my mind and I'm instead ordering the CVF catted down pipe. A tune will happen shortly after installing. However, I do wanna see how the stage 3 Cobb tune performs before I get a tune (I'll get one anyway)

Thanks for the input all. I'm sure I'll start a thread WHEN I hit a snag putting in the pipe later this week 😂

Heads up... Do you already have a Cobb AccessPort with stage 3 downloaded? If not, you're out of luck with a canned tune that's appropriate for a car with an aftermarket downpipe, since Cobb is no longer offering stage 3.

 

[Elamcup]

I ended up changing my mind and I'm instead ordering the CVF catted down pipe. A tune will happen shortly after installing. However, I do wanna see how the stage 3 Cobb tune performs before I get a tune (I'll get one anyway)

Thanks for the input all. I'm sure I'll start a thread WHEN I hit a snag putting in the pipe later this week 😂

Snowfox
MD18 Eco Stang is correct, I bought a new Accessport a few months ago through PD Tuning and it only has Stages 1 & 2. I would bet that you can find a used accessport with Stage 3 tune on it. However you should plan on a professional tune from a tuner like Ryan Martin at PD Tuning. I highly recommend it and this is why. I installed the K&N ait filter panel, a Garrett intercooler and burn only 93 octane gasoline. Those 3 things are required for Cobb Stage 2 so I loaded the program into the car. I ran the car up to 6,000 in third gear, the engine was stronger than stock and made 2 more psi of boost, SWEET! When I let off the gas pedel there was a extreamply loud POP. That startled me and for a split second I thought I blew the engine but I realized it was probaly the compressor bypass valve snapping open. I don't like that so I stopped driving the car hard. I recieved a tune from Ryan via email a few days later, loaded it into the car and ran it up to 6,000 to data log. This time there was no POP when I let off the gas and the car hasn't done it since. I assume Cobb is making it POP because they think it's cool, I can live without that. Anyway I have 3 or 4 different tune updates in the car, and I have much more power than stock but the engine operates smoothly like I need for a daily driver, it's not a tempermentel beast. I have seen on these forums that Cobb Stage 3 =ECOBOOM!, I don't know how true that is but I don't want to find out.

I'm not telling you what to do, I am just sharing my experiance. Ryan told me to get the tune prior to installing an aftermarket downpipe or I could experance an overboost condition. Mishimoto has this disclaimer in the notes at the bottom of the page for the catted downpipe they sell:

This downpipe cannot be used with the stock ECU programming. The customer must retune the vehicle's ECU after installing the downpipe. Power gains will vary depending on the type of ECU tune that is applied to the vehicle, and other supporting modifications that are installed.The Mishimoto downpipe is for track and off-road use only. The customer must have a professional engine tune/calibration after installing the downpipe.CATALYTIC CONVERTER OUTER MATERIAL 304 Stainless SteelCATALYTIC CONVERTER INTERIOR MATERIAL 200 Cell Spun Metallic Core

Ryan told me that all 200 cell downpipes are about the same, so it really doesn't matter which downpipe you use this applies to all of them.
Happy motoring my friend,
Tom