Adding after market ECV to my Borla cat back.

[Sham12738]

So a little back story, I recently put in some catless primaries and on top of that I have the ark secondaries as well as a Borla cat back on my 2020 GT2. I was getting a nasty tin can sound around 2500-3k rpm so I went ahead and got some resonators which will be installed in 2 days.

I want to add some ECV's to my borla to make it quiet at start up (has a ridiculous cold start ahah) and to keep it low key when I'm driving downtown. (I've had complaints but I love the loudness). I'd like to avoid getting a new cat back that has the system pre-installed if possible.

I found some ECV's online that would work (pic below), im thinking about getting them welded in but im unsure of where exactly to put them. I dont think I have space to add them to the tip of exhaust as I'd have to fit 4 of them (2 per side), so I was thinking of adding them after my resonators just before the borla muffler. Is that an okay place to put them or would it cause issues?

 

[GennyGuy]

So a little back story, I recently put in some catless primaries and on top of that I have the ark secondaries as well as a Borla cat back on my 2020 GT2. I was getting a nasty tin can sound around 2500-3k rpm so I went ahead and got some resonators which will be installed in 2 days.

I want to add some ECV's to my borla to make it quiet at start up (has a ridiculous cold start ahah) and to keep it low key when I'm driving downtown. (I've had complaints but I love the loudness). I'd like to avoid getting a new cat back that has the system pre-installed if possible.

I found some ECV's online that would work (pic below), im thinking about getting them welded in but im unsure of where exactly to put them. I dont think I have space to add them to the tip of exhaust as I'd have to fit 4 of them (2 per side), so I was thinking of adding them after my resonators just before the borla muffler. Is that an okay place to put them or would it cause issues?

View attachment 76727

Running a full catless system as what you described will have oil leaking into your turbos. I advise putting back in either the stock primaries or stock secondary DPs.

 

[Sham12738]

Running a full catless system as what you described will have oil leaking into your turbos. I advise putting back in either the stock primaries or stock secondary DPs.

Oh why would that occur?

 

[Sham12738]

Running a full catless system as what you described will have oil leaking into your turbos. I advise putting back in either the stock primaries or stock secondary DPs.

Would that have anything to do with running dual catch cans?

 

[oddball]

Exhaust cutouts make the exhaust louder, not quieter. it's just such that you can temporarily run an open exhaust, or have the exhaust run through an alternate path. The kits with the valves built in essentially have two paths through the muffler: one path is a typical windy path that suppresses noise, while the other path is more direct straight-thought which is louder. So the valve switches between those two paths.

When adding a valve to an existing system you don't have this option. There's a couple of aftermarket mufflers that have dual paths in them (I've seen some made by Holley). Note that a 2-in-2-out muffler probably does not have this feature - fittings and shape are about fitment and routing, not about the internal construction.
Adding valves after the muffler would do nothing. Well, closing the valves such that the engine couldn't actually exhaust would literally kill the engine. Or you, as the exhaust would find some other path out, likely into the cabin.


Oil control in the turbo is pretty delicate. The center rod that holds the turbines is suspended in oil in a bushing. They can't really use an oil seal because of how hot things are and how fast it spins. They rely on the close tolerances and the air pressures to keep the oil in place. Once you remove the primary cats you've changed how the exhaust works. Now there's less pressure in the exhaust track which means oil will tend to leak out that side of the turbo shaft.
The ECU tuners can make some modifications to help. But if you're that intent on performance then this kind of thing should just be a part of the gig. You need ECU tune or EWG wires with a JB4 to manage overboost faults anyway.

Catch cans manage oil mist in the intake track, not the exhaust.

 

[Sham12738]

Exhaust cutouts make the exhaust louder, not quieter. it's just such that you can temporarily run an open exhaust, or have the exhaust run through an alternate path. The kits with the valves built in essentially have two paths through the muffler: one path is a typical windy path that suppresses noise, while the other path is more direct straight-thought which is louder. So the valve switches between those two paths.

When adding a valve to an existing system you don't have this option. There's a couple of aftermarket mufflers that have dual paths in them (I've seen some made by Holley). Note that a 2-in-2-out muffler probably does not have this feature - fittings and shape are about fitment and routing, not about the internal construction.
Adding valves after the muffler would do nothing. Well, closing the valves such that the engine couldn't actually exhaust would literally kill the engine. Or you, as the exhaust would find some other path out, likely into the cabin.


Oil control in the turbo is pretty delicate. The center rod that holds the turbines is suspended in oil in a bushing. They can't really use an oil seal because of how hot things are and how fast it spins. They rely on the close tolerances and the air pressures to keep the oil in place. Once you remove the primary cats you've changed how the exhaust works. Now there's less pressure in the exhaust track which means oil will tend to leak out that side of the turbo shaft.
The ECU tuners can make some modifications to help. But if you're that intent on performance then this kind of thing should just be a part of the gig. You need ECU tune or EWG wires with a JB4 to manage overboost faults anyway.

Catch cans manage oil mist in the intake track, not the exhaust.

Thanks for the in depth info! Looks like ill have to maybe get a different catback at this point. Thank you!

As for the turbo oil leak, whats the best way to see if its occurring? I haven't seen any blueish smoke coming out of my exhaust or a smell of oil. If it is happening, what do I have to do to remedy it? Should I throw on the stock primary or stock secondary back on like GennyGuy suggested, switch to a HFC, or do I just need to top up oil every now and again? What kind of problems would I be looking at if it is leaking?

I do currently have a JB4 installed with the EWG wires to manage the over boost (getting a custom map done this weekend after i throw resonators in as well), would this be a remedy to prevent the turbo leak?

 

[AlphaNav]

Exhaust cutouts make the exhaust louder, not quieter. it's just such that you can temporarily run an open exhaust, or have the exhaust run through an alternate path. The kits with the valves built in essentially have two paths through the muffler: one path is a typical windy path that suppresses noise, while the other path is more direct straight-thought which is louder. So the valve switches between those two paths.

When adding a valve to an existing system you don't have this option. There's a couple of aftermarket mufflers that have dual paths in them (I've seen some made by Holley). Note that a 2-in-2-out muffler probably does not have this feature - fittings and shape are about fitment and routing, not about the internal construction.
Adding valves after the muffler would do nothing. Well, closing the valves such that the engine couldn't actually exhaust would literally kill the engine. Or you, as the exhaust would find some other path out, likely into the cabin.


Oil control in the turbo is pretty delicate. The center rod that holds the turbines is suspended in oil in a bushing. They can't really use an oil seal because of how hot things are and how fast it spins. They rely on the close tolerances and the air pressures to keep the oil in place. Once you remove the primary cats you've changed how the exhaust works. Now there's less pressure in the exhaust track which means oil will tend to leak out that side of the turbo shaft.
The ECU tuners can make some modifications to help. But if you're that intent on performance then this kind of thing should just be a part of the gig. You need ECU tune or EWG wires with a JB4 to manage overboost faults anyway.

Catch cans manage oil mist in the intake track, not the exhaust.

Would the oil control be an issue if you delete the primaries but keep the stock secondaries? I heard about this and wondered if deleting primaries and maintaining secondaries would do the trick for power/response.

 

[GennyGuy]

Oh why would that occur?

Not enough backpressure iirc.

 

[TheBeastwBorla]

So a little back story, I recently put in some catless primaries and on top of that I have the ark secondaries as well as a Borla cat back on my 2020 GT2. I was getting a nasty tin can sound around 2500-3k rpm so I went ahead and got some resonators which will be installed in 2 days.

I want to add some ECV's to my borla to make it quiet at start up (has a ridiculous cold start ahah) and to keep it low key when I'm driving downtown. (I've had complaints but I love the loudness). I'd like to avoid getting a new cat back that has the system pre-installed if possible.

I found some ECV's online that would work (pic below), im thinking about getting them welded in but im unsure of where exactly to put them. I dont think I have space to add them to the tip of exhaust as I'd have to fit 4 of them (2 per side), so I was thinking of adding them after my resonators just before the borla muffler. Is that an okay place to put them or would it cause issues?

View attachment 76727

Hi! Did you manage to find a way and implement ECV for the Borla Catbacks? I have just the catback Borla installed and after a long while now feel the same - would like an option to muffle out cold start sound in the mornings and be able to go low key at times.

BR
Kert from Estonia