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YOUR RESEARCHQuestion? Can a 996 GT3 engine fit in a '99 C2
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Basically you would need a complete parts car to get it to run correctly.
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It is the only way for those of use who love the MkI GT3, to have one here that we can drive.
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Short answer: Yes, it's more or less "bolt in"
Longer answer: While it will technically "bolt right in", you will need a complete engine, transmission, wire harness, gauges, along with a slew of other assorted random parts. Basically you would need a complete parts car to get it to run correctly.
For the same, or less, time and money you could send you car to Flat6 or another specialist shop and have your 3.4 "enhanced" to a 3.8 with proportional HP and torque increase. FWIW that's what I'm doing with my 2002--its transformation has already started.
You would need to bump out the rear bulkhead/firewall to accommodate the oil tank, and getting the electronics to play nice together could be tricky.
I think you would need the GT3 tranny also.
Engine and transmission yes, other parts possibly not. A '99 without PSM would match quite nicely with a GT3 engine while both have a conventional TB and plain Variocam (not VC+). Wiring loom needs few alterations, mainly you'd need to check sensor's pins and ignition outputs (They are not the same).
But a very good programmer would be needed to get Motronic right.
Engine rear bracket must be modified, it's easier to modify it instead of chassis' points. New transmission carrier is required.
Some mods to fuel and cooling lines are required too.
Mostly DIY for someone not technically challenged with proper tools. But is it worth it?
IMO yes if your original engine is toast (or not toast and you can sell it away...) and you can get GT3's engine and trans affordably.
Extra bonus is solving IMS bearing and RMS problems for good.
Or, you can sell your good engine for a decent chunk of cash and put the money towards an LSx swap. 400hp+, similar fuel mileage, insanely reliable, limitless aftermarket support...
I thought many time about installing the Metzger motor and trans into my 99' race car. Not that difficult in a stripped down race car, but as others have noted, you will need the complete GT3 wiring harness and ECU and then you get to integrate all the existing components and talk them into playing nice with each other. For a street car I don't think it's worth the effort....
You're still in custom built Raby engine territory for that price methinks.
What about a turbo or supercharger? The M96 seems to take nicely to boost if you do it smart.
A guy over on 6speed did it to a 99 996 with a donor gt3 from Europe. It was before the mkII GT3 came to America. It is the only way for those of use who love the MkI GT3, to have one here that we can drive. There was an Iris Blue 99 GT3 for sale in Tahoe a few years back, but it could only be driven a few miles per year...(Show exemption?) It would be a fun project with a wrecked GT3 as a donor car. Here is the place to find the donor car....
https://www.iaai.com/
I have bought and rebuilt several salvaged cars from this site. It is fun, but I seem to have a problem parting with them.
Pete, in my opinion, has done one better by putting the 996tt engine in his car. Way to go Pete.
