cayenneturbo

Yes I have been reading through the search engine and it confused me more than enlightened. Some of the posts went back for years with no activity since etc.

I have just purchased an 04 Turbo with very low miles. We bought in Denver and drove back to Phoenix. I enjoyed every mile! I have been online looking over accessories, mods etc for past two days. Aside from Navi CD missing for our region I have no complaints. According to history the coils were replaced less than a year ago, front brakes pads replaced, Body computer/module checked and Engine cleaned (Don't know why) and all interval maintenance performed.

The three immediate things I have planned are rear entertainment for kids, updating nav, and possible cat bypass,

From what I understand for the NA it is great: sound and performance.

But what is the answer for Turbos? I dont want to sacrifice HP or performance for sound. So basically I have seen it broken down into three categories and which one is true?

1. Great sound loss of HP/Performance

2. Great sound - No increase of HP/Performance

3. Great sound - Increase in HP/Performance

If someone with them actually installed or had them installed and removed could shed some light that would be great. I just don't want to spend $$$$$$ to put my cats back on because I lost performance.

pdxjim

I assume you are talking about replacing the rear cats, which are not plugged into anything. I replaced mine with the bypass pipes about 30,000 miles ago and noticed at idle, at the rear of the truck it sounds like a V-8 inboard. I would think outside there is a nice loud noise created when the turbos kick in, but nothing objectionable is noticed inside. I drove about 600 miles this weekend in the truck and it is still a joy to drive. Averaged about 19 MPG with average speed of 65 in and out of the mountains.

cayenneturbo

After spending a good part of the day between commercials searching for answers I founda thread on another site that states:
Good for NA, but bad for Turbos,

I guess I will be sticking with stock unless new data has been found,

OCNYPORSCHE

That is a very old thread. I do not think they affect turbos, since there are alot of dyno results of turbos that shows an increase in HP and torque.

alex911s

Dont know where you heard that... link? many of CTT owners have them for years..

It actually gives a higher pitch sound in NA's .. on the Turbos it gives is a better growl..

the head

I have them on my 04 turbo and they don't raise the noise level that much, but it sounds better in my opinion. My wife likes the sound as well and there's no droning. I knocked 0.1 off my 1/4 mile time with them and no other mods. And I passed emissions as well here in TX (no sniffer, just visual and OBD). So a bit more power but nothing drastic.