baq911

Hey everyone! a quick intro... cars make me happy; particularly Porsche.

Now that we've got the formalities out of the way, I've had my 02 996 C4S for a little over a year now and although it is completely stock, I adore it. The IMS, RMS AOS, plugs and coils have been addressed. Next I'll do tensioners etc..but thats not the point of this thread...

I've been dreaming up my "Perfect" 996 and thought about all of the things that matter a lot to me. I'm hoping this thread will document the journey.

Since my car is completely stock, lets start with the exhaust. I posted a question a while back here: https://rennlist.com/forums/996-foru...r-996-c4s.html

I looked into off-the-shelf exhaust setups that would save me headaches, money, guessing, and although they are nice with some gains? (with the exception of Cargraphic) it seemed like the systems changed the Porsche exhaust note. I didn't like that. I also didn't really want a system that followed the same linguine system that the 996 came with. Porsche, being evolutionary, went with a much more efficient setup with the 997 GT3's and 997.2 non-3 and other newer models.

So here's the idea: Upgrade the exhaust system to the newer design using lightweight HP parts from other / newer 911's with the "I know it doesn't, but lets make it fit" mentality.

I started calling around shops that I enjoy drooling over their builds: Sharkwerks, BBI etc. and was given great advice, and told that in theory it could work but basically...buy off the shelf.

I'm pretty persistent soooo....CHALLENGE ACCEPTED

and this project was born: muhahaha muuuuuhahaha



The Plan:
- Remove the entire stock exhaust setup
- Source and mount 997GT3 header / cats
- Source center mount muffler

The Problem:
The mezger 3.6 from the GT3 is a different engine than the 3.6 M96 and parts from the 997 3 will not fit.
Did more late-night Google-ing and found that its not that the header cut-out or holes (giggity) won't fit / line up, its the flange or bracket that is drilled for the mezger engine bolts.

The Solution:
Purchased a new M96 996 3.6 manifold gasket and took it to some friends with a CNC machine. Great news! they can CNC a flange in the 996 cut-out layout. All I have to do is find a set of header / cats and cut the flange at the seam and weld this new one. No pressure.

The Juicy Parts:
I'm a huge Akrapovic fan. They make things crackle, pop with a deep growl.
- One used (8k miles) center mount 997 GT2 Titanium Akrapovic slip-on exhaust
Disclaimer: I bought it damaged with one bent elbow (the one that the tip connects to) and had it cut out and replaced.
- Used set of 997 GT3 (7k miles) Fabspeed Sport headers with 200 cell HJS high flow catalytic converters

The Goal:
Light weight exhaust system + more efficient flow = Power
Akrapovic slip-on muffler = 10lbs
Fabspeed header / cat = 10lbs (roughly) x 2

Stock setup = 90lbs.

baq911

strathconaman

Just a thought from your photo: make sure your engine and transmission mounts are good before you start fabricating parts. From your photo, the engine mounts look shot.

baq911

Great point. Thank you.

jandackson

More power to you, man. I love when I am told "it can't be done". Looking forward to pics of the results.

Mike Murphy

Wow, 70lbs lighter - that's a good amount.

Longnose

OK - how can you tell that the engine mounts are shot from an exterior picture of the car? Just curious, because that is a trick I have never heard of before...

Oregoncoaststi

​​​​​​​The exhaust tips tend to sag down away from the body of the car indicating they are stretched out. The tips should be tucked up close to the body.

jcc0016

Very cool project! Can't wait to see and hear the results!!

Mike Murphy

I thought the same thing when someone said that about my car. But then I looked at the mounts and couldn't find anything wrong with them at all and they appeared to be in good condition. Is there a way to check the mounts via measurement instead to see if they are bad? My exhaust tips appear low, but not sure it's a motor mount problem.

rogazilla

When I bought the car, the motormount was shot and it was about 1.5-2 inch from the body.

Replaced with OEM mount and it is still 1 inch off. When I look at some other people's picture, mine still look sagging...

strathconaman

The only way to tell for sure is to pull one. This picture speaks for itself:

Mike Murphy

Thanks, I'll check mine out. I wonder if I might like semi-solid or solid better than stock. These stock 996s are very quiet and very luxurious (the suspension is more supple in my car than just about any other sports car I've owned).

baq911

I've been skeptical about my mounts for some time, I finalized an order on RS motor mounts. I'll get it installed before the exhaust - thank you strathconaman

Stock 996 C2, C4, C4S, GT3 exhaust layout:




New setup:

Capt. Obvious

I bet this is going to sound freakin' sweet.