I want the JCW Kit for my auto but it is starting to look like it will never come. I came from a heavily modified 05 Steeda Mustang and I do not like auto cars with to much exhaust noise. This time around I swore I would not void my warranty or drive a car that is loud inside. Here are my questions.

How much louder is the Alta Cat Back VS Stock Inside the car. If it were up to me I would like the horsepower and no interior noise but 5 to 10 percent would be OK.

Is it realistic to expect the claimed 10 HP from this exhaust

Is a catback exhaust and a drop in K&N filter the only HP mods that would be fully compliant with the warranty

 

To piggy back on this thread - If anybody does have an interior sound clip of the Alta exhaust I sure would love to hear it!

 

Derosi don't get downhearted about waiting for the JCW Tuning kit for the auto, I got it on good authority this very morning that it's coming very soon.

 

That is encouraging I think the JCW Kit is really what I am looking for.

 

I have the ALTA intake, turbo inlet hose, and catback exhaust, and the only thing I hear inside the car is the turbo "whooshing" because of the intake.

Now roll the windows down or pop the sunroof, and it's a whole 'nother story, but I don't hear the exhaust AT ALL inside the car when it's all sealed up.

I can also say I believe the claimed 10HP increase. I had the intake and turbo inlet hose installed for a day before the exhaust, and didn't really notice any extra power. As soon as the exhaust went on, it was like night and day! VERY noticeable increase in power, and the turbo spools up so fast now, it's hard to drive the car without the turbo kicking in. Makes it a little tricky on cold mornings when you want to let the engine warm up a bit before laying into the boost, but well worth it IMO.