kdurg

Always enjoy your pictorial DIY write ups Mike. Used the front bumper R&R when installing my aerokit nose. Worked like a charm.

Keep up the good work !

utkinpol

it was exactly same question I asked - rate of oil temperature increase is much higher than rate of water temperature increase so I was wondering if additional sq. ft of water cooling helps in any way to control oil temperature increase rate or only solution there is to use oil intercooler or other more complicated methods.

Carrera Mike

pls see pictures above where Im showing the splines. They are quick disconnect types. just push them in straight into the key/spline and secure with lock rings.

jacks stands were on the hard points aft of the suspension linkages and were back ups, jacks were on the main jack points.

Thanks Alex. Surely will

Thanks

Thanks Keith! Have not seen you in a loooooong time.. hope all is well. Keep that black beauty running.

We(at least the 997s) have dummy water temp gages.. see ... https://rennlist.com/forums/997-foru...tter-what.html
so we are not really getting the real-time variations of the water temps.

ADias

I read that older thread and I do not agree with the premise that the coolant temp gauge is dumb. My coolant temp stabilizes at 175F but can (and has) go higher. People who track their 997s tell me that their coolant temp goes up. In normal conditions the temp is stable at 175F because the cooling system controls, with thermostat and fans, its working point, that is all.

A third radiator may be needed in extreme track temp cases, but I do not agree that is needed (or desirable - extra weight) in all cases. Like insurance, there's no point in being over-insured.

Carrera Mike

I agree 110%. Porsche would have installed it if its needed in "all cases".
Though, I dont think there's any mention of "that its needed in all cases" anywhere in this post.

Edgy01

These gauges are dumbed down. Unfortunately, they have been dumbed down to the point that they are useless for warning you that you are getting into damage territory. By the time they move up to the top part of the gauge the heat is already there and been there. Too late to react.

MichaelL

The temperatures indicated by the water gauge don't always make sense. Here are my observations on a 997 2S:
-Third radiator installed. No apparent temperature changes from the usual 175 degrees in any operational mode. Oil temperatures unchanged.
-Hit a road alligator & busted up the air duct plastic on the left side of the car. In 90+ degree temps, had gauge readings up to 195 degrees. Fixed it & back to normal.
-Had an LN Engineering 160 degree thermostat assembly put in. Coolant temperatures stayed at the 175 degree mark under all conditions.
-Oil temperatures decreased from 220-230 to 210-220 degrees. Generally 10 to 15 degrees.
-The car warmed up slower under all conditions, according to the water temperature gauge.

Lower oil temperatures with a thermostat retrofit are a real benefit, but it sure doesn't make sense from the car's instruments. But, low cost and no downside.

ADias

The behavior you describe makes perfect sense to me, as I understand how a thermostatically close-loop control system works. The sensor/fan closed loop will try to maintain the coolant temp constant.

Using a low temp thermostat never made sense to me either.

Carrera Mike

Thansk! good info.

gpjli2

"Slower warmup under all conditions" IS the downside. You have decreased oil efficiency and increased emissions as a result.

Gibbo

Hi there

I've added the X51 radiator to my car.

No changes in water temperature at all.

However oil temperature on a spirited drive is much improved.

Previously a spirited drive on a hot day could see oil temperature in the 115c region.

Now same kind of drive after the 3rd radiator added the temp struggles to pass 105c and once you return to driving normal the car cools faster.

So the centre radiator is a very worthwhile addition, it has no effect on the normal 92c operating temperature in normal conditions, but it drops peak temperatures vastly when you having a spirited drive. Making it ideal for anyone who is doing track days etc.

Also regarding lower temp thermostat, there is a free and easy mod where you can just set your cooling flow to maximum at all times which again helps to lower peak temperatures.

pissedpuppy

very well done/documented

gpjli2

My understanding of the LN thermostat is that the main purpose is not to lower average running temps (hard to see how it could) but to make the cooling system more responsive to temp spikes and possible cylinder failure caused by sudden large throttle openings at low rpms.

simsgw

We do not have a 'dummy' water temperature gauge; it is not desirable to lower peak temperatures; and if it were the thermostat isn't what would achieve that. Instal... never mind. Not in the mood for a design seminar. But if it were desirable and the thermostat helped, the original designers or the production engineering team would have fitted a different thermostat themselves. Are we supposed to believe they were stunned into foolish choices by the different cost roll-up for some other thermostat? Gimme a break.

I'm not opposed to mods for their own sake, and I'm considering some on my own car, but they will be personalization, not a misguided attempt to out-think the guys who designed this lovely piece of machinery.

Just for the record, my car never gets the coolant more than half a needle width above 175 degrees either. But it ain't painted on or faked in some silly way. That's obviously the target for the feedback control loop and the feedback works. The oil temperature rises and falls with engine workload, which is what it should do. (In fact, that's what it must do.) Usually, here in the desert with a brisk driver, my oil temp is 200 degrees. On a track day after the longest session, I saw 230 I think it was. I would be comfortable up to at least 275 though a reading like that certainly would get my attention. I don't know what I'd need to do to get it up that high. Pull a house trailer up "The Grapevine" probably.

On a 997 engine, the fuel system alone takes into account outside temperature, temperature of the flow control valve, operating duration, load point, tank filling level, and idle period prior to vehicle start. And some people think they don't know how to pick a thermostat?

It's my car. I'm going to have fun with it and mod it as I please, but I'm not kidding myself that I'm improving on the design efforts of Zuffenhausen. I just do it because my taste is my own taste, and it's my car.

Gary

gpjli2

[QUOTE=simsgw;8772088]We do not have a 'dummy' water temperature gauge;

No, it is not a dummy gauge. It functions, however, more like an idiot light than an accurate gauge. It will register temps over a preset threshhold in the same way that a light would go on to tell you that you have a problem. If you think that your coolant temps stay rock steady as indicated I have a bridge in germany for you to buy I do not understand why you think it is not desirable to lower "peak" tempreatures if peak is defined as a sharp spike in temperature caused by a sudden application of throttle when the thermostat is less than fully open. if you are referring to average temps of 200-250 I agree with you. I am surprised that you find temps stay at 200 during "brisk driving' in such a hot clime but that sounds great. Nice dog.