My stock 2001 Cab (6sp) does not have the 3rd radiator. I wanted your thoughts on installing it as I have the temp creep up in the Southern California traffic.

AND.... Can the "wetter" additives be put into the Porsche factory coolant without issues?

 

the fan mod is best for traffic.... better than the 3rd rad.

 

+1. For reference according to the climate readout: Running DE track sessions with the fan on keeps the temp at or below 94 C. When I did not have the fan on, the temp is around 100 C or higher.

 

Do it for the looks...and bragging rights...hehehe

 

so you guys are saying the 3rd radiator is pretty much ... useless ? at least unless you track the car on rather lengthy racetracks.

 

^ you got it. The engine temp is all relative to speed(moving air through the radiators) and engine RPM at the end of the day. Every time you slow down on corners, speed is lower(moving less air through the radiators) but you are also in a lower gear and keeping the high revs.

You can brag all you want with a 3rd radiator but if your engine temp runs high, I am willing to bet the engine's durability is also compromised.

 

What about the "wetting" additives??

 

I would not mess with the Porsche coolant mixture at all.

FWIW, I installed the 3rd radiator a few weeks ago. The car does run slightly cooler under street driving conditions (I don't track). I think it's worth it based on the price to acquire but only if you do the install yourself (fairly easy (but messy) DYI). If you were to pay for install that could cost more than radiator itself which makes it a much less attractive proposition.

Now, did I mention the cool-look factor???

 

Msark, do a search on cleaning out the radiators... And also make sure that both fans are working at both low and high speed. Likely addressing both of those issues will solve your problem.

 

I would clean the radiators, and wash them with hot water first (to remove salt deposits). This should make for a very big improvement if it wasn't done recently.

As for track driving, my experience on the MK1 showed that one fan functioning as factory and the 2nd fan/shroud completely removed actually ran colder on track, though warmer on the street. I also run A/C on track. On the street both fans as factory was just fine. I've owned 2 MK1 996s, and saw several friends', all of which at least one speed of one fan did not work properly. My current MK2 had one bad fan also. I would double check that everything works as intended... Current MK2 with both fans as factory runs cooler on/off track than any of the MK1s I've driven/instructed in, suggesting that it's mostly an airflow issue so if cleaning radiators/water wetter doesn't have it running as cool as you'd like, you could consider a fan mod for the street or go for the 3rd radiator for the track, though like I said it's not necessary from my experience.

Also, water wetter is widely used across many different makes/models. Some racing series run exclusively water wetter +water (good idea for those that track their cars and live in warmer climates, coolant is VERY slippery in case of cooling system failures).

 

Oh yea,--there's a LOT of "salt deposits" on cars in SoCal. Nuts!

 

I know you're trying to be funny but consider that one trip somewhere (beach even) would be enough to hinder cooling, not to mention that a lot of these cars change regions when they change owners.

As a data point my last 996 was sold and registered in Florida since new. Had zero rust or corrosion anywhere but tons of sand and salt in the radiators -along with cigarette remains, towels, rocks, rags, you name it.

 

Maybe you're racing on the salt flats, too.