X51

Has anyone added a 3rd radiator to their 991S ? If so, which brand and any negative results (CEL or other)? My oil temp at a recent DE went to 278 in sport plus mode. It was not in the "red" zone, but it still got my attention.

Jabs1542

I'm interested in this as well, my highest temp (on track) was also 278 (running in sports+ mode)...

X51

Jabs1542 - looks like you and I are the only two interested in this. Here is the one which came recommended from a tech I know: http://www.rennline.com/991-Third-Ra...tinfo/R-21091/

Free shipping from them through August 30. I'm going to pick one up. It's about a 2-3 hour install by a tech.

STG

I did it like 2yrs ago as has mdrobc1213.

http://www.suncoastparts.com/product/9913RD.html

The Rennline one looks like the same OEM parts obviously at a lower $$.

Pretty basic install by a tech. Looks better aesthetically and better cooling. Standard issue on the GTS and all 991's in the Middle East countries.

Since the bumper is coming off, good time to do Rennline grills too.

http://www.rennline.com/Bumper-Parts/products/1018/

Jabs1542

My plan is to do this install in the fall once my track season ends. Though I really need it now in the hot summer I don't want the car to be down and I certainly don't want to be THAT GUY that shut down the track because I spewed coolant everywhere due to a brand new install where I didn't have enough time to properly wring it out.

STG: Where did you route the air? Do you leave it free flowing into the front box? Route it down under the car? I'm considering routing it up over the bumper similar to the GT3.

GTS owners: Does your center radiator route the air anywhere? Really interested in what Porsche did for its implementation.

STG

The trim pieces that come with it are designed for proper air flow. There isn't massive air being channeled behind the bumper. It's confined to the center boxed in center radiator. This is the same for either bumper. Remember, the X51 has been available on early 991.1 models before the GTS.

This is the exact same set up as the GTS model. From my take on it, the airflow is directed downwards under the bumper. Porsche already has done the work for you. Get the complete kit and its install and drive ready. Don't overthink it.

bittrl1000

I live in the Atlanta area, and even with only 2 radiators, my 991 C2S hasn't exceeded 210 degrees in the 9 months I've owned it. Even when I'm driving enthusiastically in the north GA mountains.

I will say that I much prefer the look of the GTS front, with the different bumper and 3rd radiator.

Larry Cable

+1

Jnosol

Don't forget to add mesh grill once you have the 3rd radiator. Much easier to install once the bumper is out. 278 would scare me, that's way too hot for comfort.

https://rennlist.com/forums/991/9383...ar-grills.html

Jabs1542

Yes I plan to do the grills at the same time.

STG: Thanks, any less thinking I have to do the better

210 degrees street driving all Summer long, no problem. Top of the tach for 25 minutes on the track in 100+ heat and 270+ is not uncommon. Of course I change my oil more often while cycling the engine this hot - currently running Motul 5W-40.

Chris C.

I have it as well, for 3 months now - bought the X51 kit minus the motor :0 (thanks STG for the tip!)

Temps didn't move from 200 degrees in 104 degree napa heat and spirited sports mode driving. No track time yet

Captscrub

I live in SW Fl. and track Sebring. I am interested to see if anyone has installed one and if they ran into any problems. Suncoast recomends dealer install. I wonder if there is a trick way to burp the cooling system to nget out air pockets. Thank in advance.

X51

Thanks for the replies. I have the rennline grills for my bumper already, so I would add the center one too if I do the third radiator. I likely will, just for the piece of mind for the additional cooling. I was not close to the red zone (plus Porsche is always conservative on these measurements), but the 278 did concern me. I have a 997.1 and I've never come close to that temp, though I have a 6 spd in that car vs. the PDK in this one - huge diff in operating temp. What's amazing to me is my wife's '09 Boxster S has the third radiator for the PDK already. Why not the 991s, and particularly the S?

Larry Cable

note that engine cooling is distinct from PDK transmission cooling, if I were tracking a PDK car a lot, I would add a larger transmission cooler such as the one that TPC-racing has.

Note that the GT3 and RS have larger PDK oil coolers for just this eventuality.

chuckbdc

The 991.1 S has an oil-water intercooler (radiator) mounted above the engine that opens when in Sport or Sport+ mode. It drops oil temps ~20 degrees almost instantly.