Hi, I'm looking to replace my stock exhaust with a switchable one. A bit of a history, I made exhaust bypass hole in the OEM exhaust which made Porsche should like a sport car - very aggressive, very loud. Men turn to look at the car when I drive, but grandmothers do not run away when they hear me coming - great combo Unfortunately, the car is loud all the time and it drones (a lot and very loudly). I also noticed a very significant increase in responsiveness - they car just flies now.

the problem is that I leave up a large hill and have to push the car to get up - no problem at all, but... it screams when it's going up and drones. I wouldn't mind, but I have to leave quite early - around 6:30 am so to be a decent neighbor, I try to stay away from making very loud noises this early in the morning.

So I don't want to lose the power I gained, but I need the car quieter at times.

The only solution for that, if I understand correctly, is switchable (valvetronic) exhaust. That way I can have muffler bypass when I need and silent operation during other times. I can't stand drone either - I measured, it gets to 104 dB inside the car when it drones!!!

Any recommendations on how to solve my dilemma? There are quite a few switchable exhausts out there, but paying $6,000-7,000 is just crazy.

I found this exhaust, but not sure if it's any good:
http://www.ebay.com/itm/201344836675

Thanks,
Nick

 

Undercover Performance fabricates a really cool switchable exhaust. Goes from mild to wild when you stomp on it -- Could email them for more info: Sales@undercoverperformancenj.com

 

I'm sure this can be easily modified to fit your 997.1 exhaust; it is the cheapest and simplest option out there. Other options are Ipe and Armytrix however they are highly priced and don't seem like what you want to spend. The link above is for the Top Gear exhaust made out of the UK; looks decent to me but I have yet to hear a single review of any of the Top Gear exhausts. The Undercover Performance/Fabworx exhaust would be ideal but I can't imagine it being that cheap either. This way you can retain your oem muffler to keep quiet when needed, have the power gains from being catless, and have the volume when you're WOT or when you want to be loud. Hope this is helpful.

http://www.ebay.com/itm/AGENCY-POWER...xVQaEz&vxp=mtr

 

The big issue I see with TopGear, after looking it over more carefully, is that two mufflers are not connected - I believe that connection is necessary to create a resonance chamber of OEM exhaust and eliminate resonance at around 2,000-2,700 Hz frequency.

AP route is easy one to take, but the car is going to stink as it does with exhaust bypass and cold cats.

I'm OK with spending around $3,500 on that kind of exhaust, but it looks like there are very limited options there.

 

What about this http://www.fi-exhaust.com/product/po...997_turbo.html

 

Here's a video of the Undercover exhaust

 

Someone posted they had an exhaust that was switchable and the servos/valves kept melting. After the second set IIRC the MFG said they are to close to the cats and no more warranty. The MFG was the ones who designed the exhaust system. So, they are the ones that put them to close. I think he went back to an X pipe. I believe this was on rennlist.

 

i have a switchable path exhaust that opens into straight pipes at 10psi of boost. however it was over your desired budget of $3.5k by quiet a bit. i really do not think you can get a quality system with actively changing path for that money. heck the sound performance cutouts and valves used in my system were almost $1k just for them.

 

When switching from one mode (open & loud) to the other mode (closed & quiet), I'm assuming 2 different ECU tunes are necessary? Or can the 997tt run in either mode with the 1 same tune?

Apologies, if this is a silly question. Logic tells me 2 different tunes will be needed.

 

And folks.. that right there is how you do it. Thanks for the pics Prod. 3" to 3.25" tips?

 

well that depends on how much power you are making and if the open path is actually freeing up any power. up until a certain point all it is, is noise.

 

.. or go with proEFI and use an exahust back pressure sensor to tune for BP vs VE

 

Curious.. did you dyno or 60-130 the difference between closed and open?

 

Not sure how much power I'm making - I have COBB Stage 2 map on it. I did notice a significant difference with bypass - the car accelerates from 60 to 100 in a blink of an eye now, where before it was taking a bit of time to get there. No dyno results to prove it though - but I'm happy.

the sound of the car with the bypass is glorious - it's just the drone that's not good.

It's easy to weld the plug back since it came out cleanly, but I don't have any desire to do that

I think I found a solution to my problem though - instead of trying to buy a mega expensive exhaust, I will just buy a second car for the short trips that I take in the mornings It's cheaper and will reduce amortization on my TT.

 

I meant prod