turbo944s2

I seen on 968.net a turbocharged 968. how do u convert it the cam chain over to just a cam belt and timing gear? What are the parts need to do a 944s2 or 968 turbo conversion is there a cheaper route then powerhaus? thanks for your help

CBass

The factory cars used a 944 turbo head instead of the S2 or 968 head. It lowers the compression because of a larger combustion chamber I think. Most aftermarket jobs do this too, because although they're happily willing to charge 20-40 thousand, they won't get turbo pistons, I think.

CBass

I've been in contact with a few shops that have done these. Right now I'm in contact with one that has actually done 4V turbos, and they used a cylinder sleeve and custom pistons. I am told that Mahle did the OEM pistons, but they are quite costly. Like, $300 a piece.

Thom

Doesn't it give reliability issues?

Danno

I think the sleeving really only causes reliability & sealing issues on the 2.5ltr blocks. The cylinder walls were already thin enough and they usually try to bore them out to 2.8-2.9ltr. The 3.0ltr blocks have thicker cylinder walls as well as siamesed cylinders for strength.

The combustion chamber on the 951 head isn't that much larger than the S2/968 heads. The factory 968 Turbos actually had their own special head that's different from the 951 head because of the water-passage in front.

If you're looking at turbocharging your car, you pretty much have to follow the route that Porsche took in converting the 944 into the 951. That means using ALL of these parts:



If you don't upgrade your rods, pistons, heads, tranny, etc., those parts will become the weak link in your system and will definitely fail before you've reached your HP and reliability goals. There are no free lunches here. Plan on spending at least $10k minimun since there's going to be a lot of custom fabrication to make this work.

There's been SO many threads recently on turbocharging an S2/968 engine and while everyone's been focused on "will the parts fit" type of questions, no one has addressed the "how will it work" question after you get everything bolted together. One major sticking point is fuel & spark control. You can't you the S2/968 computers, and the 951 DME/KLR combo won't work either because of the extra displacement. You'll definitely need an aftermarket EFI system. That's a minimum of $2000 in parts and another $2000-3000 to install and tune it.

Check out the Oct. issue of European Car where Vision Motorsports turbocharged a 968 engine and stuffed it into a 951.

CBass

Yes, it can be quite expensive. It doesn't have to be, though. You can use the 968 ECU, but you have to have a custom chip burned, to control the increased need for fuel, and the extra output of the wastegate controls.

The tranny can take the power. The engine is good to around 500hp before things start to break, but you will want to upgrade to bigger injectors if you want more than around 350 hp.

Keep in mind, the factory 2V turbos made 369 ftlbs of torque. That's without the advantage of VVT, which should give you an extra 40 ftlbs or so. Thats a lot of torque.

You will need a new header. You can modify an existing header if you have skill at welding.