Radiator sizes

[speedysprocket]

Are the turbo and S2/968 radiators in fact larger than the NA/S radiators? I see turbo and S2/968 radiators have different part numbers, too. Any one know the differences and if either can be fit into a NA body? I know the bottom support is different, anything else...?

[v2rocket_aka944]

Yes, the 951/S2/968 radiator (they are essentially the same radiator, but the 16v version has a port capped off) is about 1.5" taller than the 944NA/S radiator.

I believe it might be a slightly thicker core too. You would need the 951 lower rad frame to make it fit, but the little mounts are the same.

[speedysprocket]

So get the lower frame rail and the bigger radiator will fit?
Thanks!

[MB968]

Originally Posted by v2rocket_aka944

. . . but the 16v version has a port capped off

When I wanted to replace the ageing cap mentioned above on my 92 968, I could not find it in the 968 parts list. If you are looking for it, you need to look at the parts list for the S2. Not sure why it wasn't shown on the 968 list, unless the later 968s didn't have this feature on the radiator?

[v2rocket_aka944]

On the S2/968s I've worked on, IIRC it wasn't so much an actual cap, so much as the upper water port on the pass side of the radiator has undrilled plastic. The port has been there but the water can't come out.

So you could probably use a 951 radiator in a pinch and come up with some sort of rubber plug/cap.

[Volhv]

One more thing. Due to the rad being bigger, the frame for the fans is also bigger on the Turbo. Brackets can be made to extend the NA fan frame, to fit the Turbo rad.

[djnolan]

Can anyone elaborate on the cooling capacity differences between the two radiators?

[v2rocket_aka944]

I'll be seeing how well the NA radiator works very shortly with my supercharger, but it has been doing fine for over a year now with an AC condenser, 3" intercooler and 2 oil coolers mounted in front of it. Water temperature has not even gotten to the middle mark since then, even in 110* stop-and-go traffic.

If you think you are starting to run hot, consider an oil cooler upgrade first, it really makes a big difference.

[speedysprocket]

Running the stock 968 oil cooler with the 968 in my S. Should officially start driving it Friday, so see how temps go, though it's freezing here now...

[v2rocket_aka944]

Gotcha.
If temps start to get worrisome, which I would doubt with that setup in anywhere but a desert region in the summer, then I would add still add oil cooling capacity first. A second cooler plumbed in series to the 968 piece, or a single larger unit will go a long way.