Right then. Ive already installed Carnewal cat bypass pipes but want to hear a bit more of a rumble inside the cabin on light throttle but dont want any loud drowning resonance.

Contacted Tubi but they told me fitting bypass pipes and their rear muffler was "very loud"

Is it likely to be too loud for regular use?

Its my wifes daily drive and she hates obnoxious sounding cars (like my Maser ) but loved her old V8 Audi S6 with Milltek fitted.

 

Why not add a miltek exhaust they are not the loudest but give a nice tone to the exhaust.... since she liked it on the S6 she may like it on this car too...

 

Just wondering what the increase in volume would be like 'cos the few dealers Ive spoken to gave the impression that bypass pipes and the rear muffler together may be too loud for most.

Last thing I want to do is spend loads on a muffler only to have to take it off again in a week due to earache (on 2 fronts )

Is there anyone on here that is running this combo who can offer any experiences?

 

Not too loud but hey at least its addicting, I have the Fabspeed Bypass pipes and Mufflers on mine and I am loving it. Sounds very sportive and quiet loud at full throttle but normaly city driving is okay not loud what so ever.

 

I did make a change in my exhaust. There is a specialty exhaust shop nearby that I've used for some of my other cars (and my kids' Audis) that I trust. They are good pipe-benders and welders and understand exhaust flow very well. They understand that you can't mess with the Cats and that you still need enough back-pressure so you don't burble on throttle lift & sound like a rice-rocket going pop-pop-pop. I took the CTT there on the 3rd morning and we removed the stock muffler and replaced it with two small Magnaflow mufflers, then piped them so that we could retain the existng bolt-on dual tips (which look great, by the way). Because you can still see the mufflers through the ports in the rear valance, we used the highly-polished stainless steel version of the Magnaflows.

I did not install the cat bypass pipes and won't.

I'm very pleased with the improved sound. No raspiness. Much deeper, richer baritone note. In Sport with WOT, the car growls and you can hear the turbos spool up ..... they were silent before the change to the smaller mufflers. At idle and in parking lot maneuvers, the sound is great, sounds like the big V8 that it is.

Probably a small HP increase due to more efficient throughput.... 5-10 HP, most likely.

At first, I was a little concerned that it was almost too loud. But I've run it easy and hard through an empty parking garage with the top open and all the windows down and I am comfortable that it's just right. Plus, the acid test, my wife hasn't mentioned anything about it. She was going to the market the other day and I asked her to take it so I could hear it drive away (in non-Sport, I'm sure). It was awesome. Also, when driving it in non-Sport .... you won't hear the turbos spool up.

I don't have any sound clips, probably don't have the time to make any (sorry) but I highly recommend the exhaust mod. It was $525 at my local exhaust magician. You want to find the place in your city that does exhaust mods for the local Corvette club guys, I would think.

Saturday night at dinner with some friends, my wife was commenting on my latest toy .... and the fact that I hardly had it home for 2 days before I took it to the exhaust shop to make it sound better. She said that it actually sounds more aggressive than the Ferrari 430 across the street. Now, I'm sure that the proximity of my CTT in our driveway and garage vs. the 430 all the way across the street has a lot to do with it. But I thought it was an interesting observation on her part.

Photos:

 

How much did you pay for the exhaust system? Where did you get it? How much to install? Thanks!!

 

I did make a change in my exhaust. There is a specialty exhaust shop nearby that I've used for some of my other cars (and my kids' Audis) that I trust. They are good pipe-benders and welders and understand exhaust flow very well. They understand that you can't mess with the Cats and that you still need enough back-pressure so you don't burble on throttle lift & sound like a rice-rocket going pop-pop-pop. I took the CTT there on the 3rd morning and we removed the stock muffler and replaced it with two small Magnaflow mufflers, then piped them so that we could retain the existing bolt-on dual tips (which look great, by the way). Because you can still see the mufflers through the ports in the rear valance, we used the highly-polished stainless steel version of the Magnaflows.

I did not install the cat bypass pipes and won't.

I'm very pleased with the improved sound. No raspiness. Much deeper, richer baritone note. In Sport with WOT, the car growls and you can hear the turbos spool up ..... they were silent before the change to the smaller mufflers. At idle and in parking lot maneuvers, the sound is great, sounds like the big V8 that it is.

Probably a small HP increase due to more efficient throughput.... 5-10 HP, most likely.

At first, I was a little concerned that it was almost too loud. But I've run it easy and hard through an empty parking garage with the top open and all the windows down and I am comfortable that it's just right. Plus, the acid test, my wife hasn't mentioned anything about it. She was going to the market the other day and I asked her to take it so I could hear it drive away (in non-Sport, I'm sure). It was awesome. Also, when driving it in non-Sport .... you won't hear the turbos spool up.

I don't have any sound clips, probably don't have the time to make any (sorry) but I highly recommend the exhaust mod. It was $525 at my local exhaust magician. You want to find the place in your city that does exhaust mods for the local Corvette club guys, I would think.

 

I think I may go down this route too.

At least this way I can experiment with different mufflers.

The Custom Chrome mufflers my local exhaust guru uses are reversible apparently, put them in one way they're quiet, rotate them through 180 deg and they're loud. If I can get away with at least the quiet option I'll be happy

 

TT,

You seem to be unaware of the fact that the CTT has 4 cats....2 are totally unecessary (unless your priority is quiteness) and should be removed to improve performance.

 

I'm very aware. Thanks.

Are you aware that there are states in the US that have more restrictive emissions requirements than others?

The 2nd set of Cats is not unnecessary in every jurisdiction. You're not saying that in all of Porsche's expertise that the only way they know how to keep the CTT's sound below worldwide noise limits is to use a 2nd set of catalytic converters, are you? Small, intermediate baffles in the exhaust system woul do this at a fraction of the cost if all they were trying to do is meet a noise requirement.

Go ahead, price a new set of cats for your CTT. Think unnecessarily adding a 2nd set of cats would be a smart way to have record profits at Porsche AG when you could otherwise fix the sound issue for about $29?

I suppose I could've taken the 2nd Cats out and replaced them with expensive bypass pipes and then paid the same exhaust shop 3 or 5 hundred to install them.

Instead, I spent $525 to install twin high-grade Magnaflow mufflers, tuned to B Flat. The sound is intoxicating.

 

TT,

Removing the cats/replacing them w/ delete pipes (I get for cost) and a GIAC flash is the cheapest way (2.5K) to get an extra 70 hp at the crank.
And yes, being born in California and educated in New York (almost 40 years combined in those two states) I am very familiar w/the differences in state laws.

However, age has wisened me, and I now live in Texas and understand that your state is more inclined to redistribute a large portion of the money you earn to welfare recipients. Thus I sympathize with your need to be cost concious.

 

this is getting interesting lets play nice now....

 

Kerry should chime in here...his CTT sounded/performed AMAZING...i think he had Fabspeed bypass & exhaust but im not 100% sure.....sickest CTT i have ever riden in/heard though

 

Hey TTCarrera,
Thanks for the info on the Magnaflow exhaust. I just went to my local shop & they reccommended the same thing. Is there a way to tune them to B flat or is that just an expression? How can you change the exhaust sound for $29 as stated above? I just have the "S" version, not the turbo. Have you heard any back pressure noise, kind of like a back fire or spitting noises? Thanks again for the last reply. Any info will help! - COpepper