Mike818

The warranty is where Porsche puts their money where their mouth is. I already quoted from that so I won't do it again but I can provid a link to the full thing if that helps.

blackland

I noticed that Suncoast sells a 3d radiator for installation. Why does Porsche have this option if it is not needed?

TheOtherDave

Maybe it's just to fleece money from people like me!

It's always interesting that they don't post the actual Porsche part numbers.

And I am saying this as a person who has given them multiple orders (mostly because their shipping is cheaper).

detansinn

For track use in hot climates.

phefner

@TheOtherDave Hey mate. I did this on my C4S and no regrets. Have a GTS incoming and it’s one of the first mods I’ll do.

You’ll see the coolant temp temporarily drop when the third radiator is opened, and it takes a bit of flogging to get there. What you’re after is to limit the oil temp spikes, and with additional coolant capacity you’ll achieve that. The max coolant temp will likely not change over time. Because it’s a closed system, it will get there at some point. Your just trying to give the oil cooling mechanism some additional capacity to exchange that heat.

I sourced the parts from SunCoast, and had the dealer do the work. I was all-in on this for $2500-$3000.

Waste of money or not…🤷‍♂️.

TheOtherDave

Sorry I was referring to using a different intercooler in the stock location, not a relocated (i.e. in front and below
the radiator) change. Most of those types of intercoolers (replacement ones in the stock location) are way heavier than the stock one so they hold a lot more heat energy to cool off when you start moving.

Certainly moving the intercooler so it isn't over the turbo is a better heat soak solution.
On my stock location intercooler STI when I start from a sitting for a while I always monitor
the intake air temps to know when I can start pushing it. Supposedly the ECU compensates
for this but I have seen IAT temps in the 150 deg F range so I don't take any chances.

By the turbo working harder I think the person who posted that is referring to
that at altitude the turbo has to spin faster to generate the same amount of boost pressure
because the ambient pressure starts lower. I have no idea if this makes the turbo run hotter
or not than at lower altitudes.

Ultimately the turbo will stall, where there is not enough energy coming from the exhaust
to spin the turbo fast enough to increase the boost pressure any more.
At least that's the way I a was referring to it as.

An 80K STI....that must be a real runner...or it had a really really good stereo.

TheOtherDave

I am not sure I would let my local Pcar dealer do this....the image of monkeys trying to screw a football comes to mind.
But there are 2 local indi shops I would trust with it.

OK if the temp drops when the 3rd rad opens then it must be a parallel circuit rather than inline with the other 2 correct?

If so this might alleviate one of my fears. It already takes nearly my entire trip to work to get the thing to completely warmed up
from my 50 deg garage. When I head home from work and it is cold outside.....well lets just say I worry about not getting the oil hot enough to boil off the crap because it doesn't make it past 180 deg or so. Most days I take a longer way home to make sure it gets to a stable temp for
the coolant and oil.

My work run is very variable. Some days I spend most of the time sitting in traffic....some days I get to work without
ever coming to a complete stop (except for 1 stop sign).

Does the 3rd rad contain an additional oil cooler? And if so is it temp operated (only flows after a set temp is reached)?

Do you have a list of additional parts you needed to buy besides the radiator itself? I saw a 991.1 (I think it was a .1)
where they did it themselves (what I would plan on doing) and ended up having to use some scrounged parts.

Thanks, Dave

phefner

I have no issues with my P-Car service department. Guess I’m lucky but they are very capable and have always delivered for me.

Yes.. it’s a parallel circuit…you clearly passed basic EE 👍..

There is no separate cooler for the oil or coolant reservoir for the 3rd radiator.

No I don’t have any additional parts list. The people I worked with at SunCoast provided everything. Tell them this is a DIY and I’m sure they will kick up the support some.

Who ever does this, see if they have done one before.

F8Driver

Good write up by The Other Dave. Third rad is doable, it'll need plumbing bits and a new front fascia. Is it necessary? Because the water temp is buffered (a trick the Germans discovered in the 90's to avoid customer complaints about varying temps), it's not a particularly good indicator of temp stress on the engine. Oil temp is better, and accurately reported in the 992. Given synthetic oil, normal temps should be 240-260 fully warmed up, but the oil can handle higher temps ... I'd start to worry if it exceeded 300 under track conditions, but opinions vary ... never-the-less hot oil indicates a hot engine, even if the water temp is stuck at 194.

My recommendation. Monitor the oil temp under track conditions. If it climbs above recommended temps (do your own research here), perhaps the 3rd rad is a solution. You might ask those who regularly track their cars. I'm unaware of any overheating issues on our cars. OTOH, relatively few people track at 5,000' MSL+ on 100+ days.

Flat6Motorsports

Water temps stay pretty solid from our testing, really the oil temps on the base model seem to get hot quick on the track (likely do to their sizing) and the catalyst chocking off the exhaust flow.

TheOtherDave

And I don't believe the 3rd radiator (if you install it) has an oil cooler in it so installing one might not help the oil temps.
Maybe an additional air-air oil cooler is needed.