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YOUR RESEARCH996 C4S - Project BLACK MAMBA
Leading reported evidence
Install before the exhaust - thank you strathconaman
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Performed · outcome unconfirmed · Original poster
I'll get it installed before the exhaust - thank you strathconaman
Leading evidence: 'Install before the exhaust - thank you strathconaman' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check mounts via measurement instead' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
(with the exception of Cargraphic) it seemed like the systems changed the Porsche exhaust note.
Use set of 997 gt3 (7k miles) fabspeed sport headers
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Performed · outcome unconfirmed · Original poster
- Used set of 997 GT3 (7k miles) Fabspeed Sport headers with 200 cell HJS high flow catalytic converters
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Suggestion
Is there a way to check the mounts via measurement instead to see if they are bad?
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Suggestion · Original poster
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.
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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.
[Image-only post; no author-written text. Original image references:]
https://cimg8.ibsrv.net/gimg/rennlist.com-vbulletin/1080x1080/img_9185_db16e55a353662e0a7bc400547397f95f28f1aa2.png
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.
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...
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.
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.
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...
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).
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:
Parts update:
The nice mailman dropped off more goodies! This, ladies and gent's, is what we're going to use to fab the side elbow pipes connecting the cats to the muffler. One 3" & one 2.5" mandrel bent U-pipe + 2 V-band clamp flange kits
We're using manifold gaskets as a template and cutting from the top down to allow for curvature that will follow the design of the Fabspeed headers.
- Not sure if I answered your question
I've got the muffler mounted as low as possible to have the tips clear the bumper holes. I may adjust it higher once I get the bumper on? I don't want the muffler to scrape...
A+ for effort so far. Was there a "before" dyno pull, or is this a sound-first kinda mod? Based on the "juicy parts" part of the OP, I'm assuming not, but it would be interesting to know.
The sound should be insane!
Regrettably, I did not do a before dyno pull. This build is about achieving (hopefully) incredible sound through the high performance parts from the high performance versions of the 911... but equally as important, its also about losing weight and improving the efficiency of the stock exhaust setup. I am fairly certain I will make power.
To quote Sharkwerks when they did a similar project but with a 996GT3 "The 30hp power increase from the 6GT3 to 7GT3 can be attributed to a few key areas - higher compression as well as some to the better exhaust/header flow/design and tuning"
[Image-only post; no author-written text. Original image references:]
https://cimg9.ibsrv.net/gimg/rennlist.com-vbulletin/1280x960/thumbnail_fbe0bf47_4afd_4714_b0ad_4a430c4a44d1_aacdd4cace67423b7d44a8889c93b1d6bc87dc27.jpg
