Resonated Borla ATAK exhaust

[GordonM]

After driving the TT RS for a while with the Borla ATAK exhaust. I found that the raw cold start sound was really starting to bother me, my neighbors and bystanders in parking lots that made negative comments on how loud and raw it was. Then came the new down pipe and increase in sound volume. Too much like a race car! This system needed resonators now for sure.

After taking some measurements and resonator research I came across a pair of Vibrant Performance #1792 resonators 9.5" case length, 4" diameter that could be modified and welded in behind the X Pipe with out rebending any of the pipes. The resonators on the OEM sport exhaust are pretty much the same size as the Vibrant ones and seem to cut the harshness of the cold start down on the OEM system. The reason I am doing this is I really like the Borla, the way the borla looks and the use of the X Pipe and twin pipes down to twin mufflers does something to accent the sound of the 5 cylinder motor.

Also got the bung welded in on the down pipe for the wide band O2 sensor for tuning purposes.

Hope to get this reinstalled next week and see what changes were made to the sound.

Gordon

[nzt]

Jealous neighbors!!


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[JohnLZ7W]

Will be looking forward to your thoughts on this post install. I'm going to reinstall my secondary cats to see what it does to the sound. Haven't gotten any noise complaints and I really don't think it's that loud, just looking to get back some of the air-raid siren

[Marty]

Your neighbors thank you!

[hightechrdn]

Will be looking forward to your thoughts on this post install. I'm going to reinstall my secondary cats to see what it does to the sound. Haven't gotten any noise complaints and I really don't think it's that loud, just looking to get back some of the air-raid siren

What do you mean about getting back the air raid siren?

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[hightechrdn]

Difference in opinion is interesting... I would love to have the full on race car sound with my TT-RS :-)

Just have to recover from sending my son off to college for the first time.

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[JohnLZ7W]

What do you mean about getting back the air raid siren?

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Hmm, you know the noise the car makes at 4k rpm and maybe part throttle? It's a warbling tone, almost like an air raid siren winding up. From inside the car there's much less of that with the Borla. You still get it in 1st and a bit in 2nd. From outside the car it still has that distinct sound but from inside it's a bit more raw.
It's different than I expected it to be and I think it's because all of the Borla videos were with the secondary cats in and I've got mine replaced with the Milltek pipes. I'm a bit torn at this point because I absolutely love the noises the car makes with this setup, will give it a shot with the cats back in place just for comparison sake.

[GordonM]

It is all installed now. I put the OEM down pipe back on with cats to do some tests. Hope to have a video clip soon. The resonators did not change the sound or pitch of the Borla, just lowered the volume down 15 to 20% at the lower RPMs. Stomp on the throttle and it barks just like it did without the resonators. No drone on the freeways either. So far I like em!

I would give this set up a higher rating than the flappered OEM Sport exhaust. The Sport exhaust droned on the freeway for me and has a lower pitch to it, the Borla is higher pitched, and sounds more exotic.

Gordon

[GordonM]

Here is a cold start to idle clip. As you can hear it is still pretty Borla sounding. Just a little turned down volume.



Here is just a quick run up to 4K. I will add some more when I get some more time.

[R5T]

I really like the two way run across the rear diff.
It means there is less restriction in that part of the exhaust.
Most systems are a single pipe along the diff.

[Marty]

I really like the two way run across the rear diff.
It means there is less restriction in that part of the exhaust.
Most systems are a single pipe along the diff.

Right... because you're well-trained in the field of fluid mechanics and gas dynamics, I'm sure.

[R5T]

Right... because you're well-trained in the field of fluid mechanics and gas dynamics, I'm sure.

2x60 is always better then 1x80, for example.

[Black BeauTTy]

I'm no expert by any stretch on this stuff, but my understanding is that larger volume isn't always better when it comes to exhausts on a relatively small displacement turbo charged engine. IIRC it has something to do with needing to push against a larger volume of gas and even though there is technically less of a flow restriction, the increase in volume can overcome the benefits and become detrimental. I have no idea where those curves cross or if this is entirely accurate. IIRC it is less of an issue with larger displacement NA engines. Maybe someone with more knowledge of this can weigh in...I'm happy to be educated!

[crackkills]

You had downpipe with the exhaust with secondary cats in place? Now you have stock downpipe with stock secondary cats with the exhaust and resonators now?

Or did you have secondary cat deletes with the exhaust and now you added the resonators and secondary cats?

I know, I know I am dumb and stupid.

[GordonM]

You had downpipe with the exhaust with secondary cats in place? Now you have stock downpipe with stock secondary cats with the exhaust and resonators now?

I returned the car to stock OEM down pipe and OEM cats with the resonated Borla system. I decided that I was not going to utilize the new down pipe and High flow cat and post pone the move up to stage 2 this year.