Secondary Cat Delete on 3.3T

[nimasis]

Hey people, I've recently did a secondary cat delete on my G70. Overall Im pretty happy with the results, its noticeably louder during accelerations and thankfully no drone and maybe its in my head but I feel like the car has a better low end.

Here's a small sound clip I recorded for anyone interested:

 

[Beefer]

Does sound better!

Did you do it yourself? As in hollow them out? Or did you replace them with straight pipes?

 

[nimasis]

Does sound better!

Did you do it yourself? As in hollow them out? Or did you replace them with straight pipes?

I took it to my local exhaust shop and they replaced the cats with straight pipes. That being said I looked under the car and the factory exhaust is really restricted, I would say some parts of it can go as low as 1.5inch in diameter...

 

[joschneider]

I took it to my local exhaust shop and they replaced the cats with straight pipes. That being said I looked under the car and the factory exhaust is really restricted, I would say some parts of it can go as low as 1.5inch in diameter...

My turbo genesis coupe had the same thing, a crimp in the exhaust where it went down to about 1.5. I replaced it with a catback and found that i lost low end torque but gained some top end, at least on that car. So it makes me wonder if they crimped it for a reason on this car. I know turbo cars benefit from unrestricted exhaust, but just something to think about when cat backs start becoming available or switching to a different mid pipe. Dyno results would be fun, but damn that time is expensive

 

[joschneider]

Hey people, I've recently did a secondary cat delete on my G70. Overall Im pretty happy with the results, its noticeably louder during accelerations and thankfully no drone and maybe its in my head but I feel like the car has a better low end.

Here's a small sound clip I recorded for anyone interested:

Secondary cat delete didn’t throw any CEL?

 

[nimasis]

My turbo genesis coupe had the same thing, a crimp in the exhaust where it went down to about 1.5. I replaced it with a catback and found that i lost low end torque but gained some top end, at least on that car. So it makes me wonder if they crimped it for a reason on this car. I know turbo cars benefit from unrestricted exhaust, but just something to think about when cat backs start becoming available or switching to a different mid pipe. Dyno results would be fun, but damn that time is expensive

Yeah I had a gen coupe as well i know exactly what your talking about haha, but i saw 2 or 3 spots in the exhaust system on the G70 unlike the gen coupe. SSR performance has a downpipe which basically removes the 2nd cats with straight pipes for the stinger and the gains are pretty nice and they have a dyno sheet posted. Of course my way was way cheaper and smaller part of the exhaust was replaced so I shouldnt be getting those numbers.

 

[nimasis]

Secondary cat delete didn’t throw any CEL?

No there is no sensor on the 2nd cats so no CEL

 

[Electrode]

Are warranty and emissions an issue doing this?

 

[nimasis]

Are warranty and emissions an issue doing this?

Emissions definitely not at least here in Canada since there is no CEL and also still having the primary cats in. Warranty honestly depends on the dealer same as any other exhaust systems but most of time there is no problem! Although i dont think they would even see it unless they are looking for it

 

[CoconutRob]

Yeah I had a gen coupe as well i know exactly what your talking about haha, but i saw 2 or 3 spots in the exhaust system on the G70 unlike the gen coupe. SSR performance has a downpipe which basically removes the 2nd cats with straight pipes for the stinger and the gains are pretty nice and they have a dyno sheet posted. Of course my way was way cheaper and smaller part of the exhaust was replaced so I shouldnt be getting those numbers.

Does the ssr same dimension for stinger and g70. The only vendor that sells downpipes for g70 as of now is jun.bl

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[CoconutRob]

Hey people, I've recently did a secondary cat delete on my G70. Overall Im pretty happy with the results, its noticeably louder during accelerations and thankfully no drone and maybe its in my head but I feel like the car has a better low end.

Here's a small sound clip I recorded for anyone interested:

I took it to my local exhaust shop and they replaced the cats with straight pipes. That being said I looked under the car and the factory exhaust is really restricted, I would say some parts of it can go as low as 1.5inch in diameter...

Do you plan to get a cat back ? Also did the local shop do it in 1 piece and can the old section still be put back on. Sounds good!

 

[nimasis]

Does the ssr same dimension for stinger and g70. The only vendor that sells downpipes for g70 as of now is jun.bl

Im not sure tbh but most likely not since g70 has a shorter wheel base

 

[nimasis]

Do you plan to get a cat back ? Also did the local shop do it in 1 piece and can the old section still be put back on. Sounds good!

No not getting a cat back just gonna leave it. And yes they did in one piece and the cats can be welded back on the car.

 

[Gianttama]

No not getting a cat back just gonna leave it. And yes they did in one piece and the cats can be welded back on the car.

Where r u located? If u r in Vancouver, where did u go?

 

[Dpaulc]

Does this affect your mpg?

 

[nimasis]

Where r u located? If u r in Vancouver, where did u go?

No Im in Toronto

 

[nimasis]

Does this affect your mpg?

Not sure but I've been driving it in sport since

 

[Beefer]

I am interested in doing this...but something that can easily be put back to stock since I have a lease car.

Is it possible to simply replace the 2ndary Cat (I assume it is a fairly short piece) with a straight pipe? No welding...just undo screws/clamps on either side of the Cat...and replace with new.

That way...very easy to put them back. No welding, etc, etc.

 

[joschneider]

Im also really close to doing this. seems to cheap and easy to do and its reversible...Im looking up videos right now on some other cars that had it done to make sure its not weirdly raspy or anything I would consider a negative

This seems like the perfect mod to increase the volume slightly without changing the tone, and without needing to spend over 1k on a new exhaust

 

[joschneider]

@nimasis Would it be too much to ask for a full throttle example/outside the car drive by? just so we can see what it sounds like at around 5-6k rpm. I know this might be a pain in the ass so no worries if you cant, especially since its cold as balls out haha