Mib44

I'm doing some work on my 4S and I asked my mechanic about center radiator and low temp thermostat. The latter he said is fine but as for center radiator he says it might not give much, since you're adding more pipes with coolant but the pump is still the same and now it would need to pump more coolant to cool effectively. Did I miss something and I need to upgrade the pump too or my mechanic is not correct?

Just FYI he is not Porsche-only mechanic, more like German cars specialist

Thank you.

808Bill

I'd trust someone that has done it vs a mechanic that has no experience in this area. Are you having cooling issues?

dporto

In my experience, the center rad did nothing to lower overall temps in general, but it does increase cooling when driving do to the increased radiator surface area (duh, right?). In hindsight this seems obvious as there’s no fan on the center rad, but I think some people get fooled and just assume that overall temps will be lower - they won’t! So the short of it is, when you’re sitting in traffic your temps will be what they always were (regardless of having an extra quart of coolant in there), but when driving they’ll drop below where they used to be...

rotorite

With a center rad and a low temp thermostat in my 4S what I noticed is much what dporto described.

• In stop and go traffic it rises a bit above the 80 mark (Canadian car)
• Once I start moving it drops right to the 80 mark. This was not the case before the center radiator on really hot days in my case. Before the center radiator, it ran a bit past the 80 mark similar to where it would be stuck in traffic. However, I cannot recall though if it was this way before the increased displacement from the engine rebuild or not.

Sula

This is clearly wrong: if you maintain the same coolant flow rate but increase radiator surface area, you'll dissipate more thermal energy.

Mib44

No I Don't have cooling issues, yet. I just recently bought the car and plan to track it from time to time and I've see people here suggesting to install center radiator as one of the options to help with cooling.

De Jeeper

I just replaced the factory rads with csf racing direct replacements. They do have more cooling capacity for a lot less work. I paid $400 shipped for each. I will probably end up with a center rad eventually but i will make the gt3 mod with the ducting and slot the front bumper to add the down force to the front end.