2004 996 GT3 3.6L ENGINE - INTO A - 1998 996 C2 3.4L BODY SHELL

2004 996 GT3 3.6L ENGINE - INTO A - 1998 996 C2 3.4L BODY SHELL Was really hoping I could rack brains re this - seems not many have done it before! We have been looking at the body shells & PET diagrams. - Understand the GT3 engine/box is longer & heavier (?) The 2 key parts that seem different are on: PET "REAR END" DIAGRAM - 801-35 A - TERMINAL PIECE - item 1 - this is VERY different. C2: - 996 551 973 00 GT3: - 996 551 173 90 B - REAR WALL - item 9 - large piece - but seems quite similar? C2: - 996 502 911 00 GT3: - 996 502 191 91 Would most appreciate any advice re: - Are these the relevant different body parts? - any other different parts people can think of? - Can we use the existing C2 REAR WALL to mount engine on to etc? - as guessing its a big job to swap in a GT3 REAR WALL!! many thanks JB

All I can say is consult Uncle!

I don't have the answer but I am very interested in the subject. After I've had my fun with the turbo SC this on my list of interesting projects.

Gt3's are built on C4 platforms which have strengthened bulkheads (where the front diffs sit), the carrera (c2) front chassis is shared with the Boxster) so in theory you'll never have a proper GT3 geometry suspension set up on a carerra 2 chassis. Mechanically the engine will fit in the back with a few mods, (wet sump v dry sump ) gearbox same size but differs in weight.. One thing you need to keep in mind also is not just the mechanicals fitting, you need to consider things like early 996 3.4 throttle is cable driven whilst the later engine (Post 01) is fly-by-wire etc Good luck with the project.and keep us posted...

TO ALL - THANKS GREATLY!! PS - should have clarified: A- we are also swapping in my GT3 Cup Transaxle/Gearbox B- also fitting my GT3 engine wiring harness to manage GT3 engine.  The GT3 engine wiring harness looks like it will "plug & play" into the existing C2 harness - @ just behind the seats - hopefully! ANY THOUGHTS RE: 1 - do you think this will still cause issues with the WIRING for the GT3 engine e-throttle? (As the Carrera 2 did not have e-throttle back in 1998) 2 - the GT3 box is longer I think - true? fitting issues? thanks again!

if the GT3 engine/gearbox combo is heavier, I assume you'll be using the mounts from a GT3?

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thanks - but really dont know whay you mean ??!!  cheers

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THANKS HEAPS! RE C4 VS C2 CHASSIS Yes, aware of this - but C4 shells very hard to find! To deal with this, we plan to: - front strut brace - bolt in roll-cage - ex factory issued GT3 CS 2004 - seam welding:  -  small spot welds along major points. The bulk of the work is on the side sills RE ENGINE/BOX MOUNTING - this is scaring all of us - including workshop! - can you clarify re: "the engine will fit in the back with a few mods"  ?? - nb understand the Mezger engine is quite a bit bigger than the M96. The crank case alone is over 4" longer? RE - ENGINE ELECTRICAL - GT3 rear engine harness/ECU (we removed it) SHOULD just “plug & play” into C2 main harness @ just behind the seats hopefully - Big job to try to match up all individual wires if it doesn’t - Alternative: off-shelf engine management system - $1k - but big labour $ to install. cheers JB nb - advice received from UK panelbeater re fitting in GT3 larger engine: the difference is the rear hanger that is shaped like an arch at the rear of the car and the engine mounts. These can be modified, or by using parts off your old shell This modification has been done over here many times when required more by the guys who race these cars. So if you look from the back of the car with engine and gearbox out, you will see a cross member, this is different either by thickness or the cut outs. There is also difference in engine mounts brackets which have to be altered, this is easier if you have your old shell.

another thought! is the 3RD RADIATOR really REQUIRED? - AS PER GT3 996 (IN CENTRE) - vs just the 2 Radiators on sides in 996 C2 - Does it have its own piping, circuits etc? - or just plug into the existing piping?

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thanks - havnt made any plans there - but guess that makes total sense - we have the GT3 engine mounts. Most worried about fitting of the larger GT3 engine - ie mods required to REAR WALL? - or we do have to replace the entire rear wall panel? - a huuuuge job!

if a chevy LS3 V8 can fit with no rear wall modification, i'm sure a GT3 engine will fit

May I ask why? If its a track car, there was a 996 Cup roller for $35k (blown motor) on one of the Porsche club classifieds.

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Do you have the cross member that came with the GT3...? The gearbox differs from a standard one in weight due to a dedicated oil pump and external oil/water cooler, the GT3 gearbox is also an evolutionary step from the 993 TT whilst the Carrera is a completely different unit. I'd be thinking that a Motec tune would be much easier than trying to patch into the old carrera harness.. Just out of interest there was a GT3 roller chassis on ebay the other day that had suffered some track damage... might be worthwhile looking into..as much easier to put on a car-o-liner and jig it back into place then mucking around with a shell ??

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thanks - but road registered is our end game. Have a registered C2...plus a complete set of GT3 2004 drivetrain/suspension/brakes/interior/harness/cage/seats etc to swap in.

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Thanks again YES - have the entire GT3 body shell - not sure just what you mean re the "cross-member"? is this part of the rear wall - or engine hanger/mounts? ps - the black 2004 GT3 shell that was on ebay last week is mine!

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IMHO Yes. I added a 3rd radiator to my C2 because excess heat is never a good thing and 996's run pretty hot from the factory, hence the availability of lower temp thermostats these days. Adding a 3rd rad was not difficult. It requires using some different coolant lines at the front of the car. I documented the mods I made to my coolant system here http://www.oz951.com/public/emmy.htm#Cooling

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AWESOME ADVICE! - thanks Kelly - great website too

THANKS FOR ALL THE ADVICE! PROJECT UNDERWAY - PARTS REQUIRED FROM 996 GT3 BODY SHELL HAVE BEEN CUT OUT INCLUDING THE "BULGE" IN THE REAR WALL - AS REQUIRED FOR THE GT3 DRY SUMP ENGINE'S OIL TANK CHEERS

Start posting pics as you go mate. Keen to see it happen.

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Thanks for the interest! project is in full swing - new rear cross member to accommodate GT3 engine en-route ex UK Martin - what is the best way to post updates...onto this story line etc - or some easier way? cheers