3rd Radiator for Street Use?

[BruceP]

Have you checked both radiator fans to feel if they are moving about the same amount of air? Easy to tell if you stick you hands right in front of the front tires. (Turn on the AC or you'll have to wait until summer..) Could you have a weak motor, or part of the resistor is bad on one, and that it simply is not moving enough air? The fan runs at two speeds, but is dependent onte resistor to do that. You may only have one speed.

Perhaps you have a defective T-stat that's not opening all the way? I've never understood going with lower temp t-stat, as the stock one should be full open at well below 95C. Full open is full open. AFAIK, a lower temp T-stat does not open more than the stock one. Same thing if fans are already running. Running them sooner does not keep the top temp cooler. If fans are running, then the system will reach the same equilibrium temp, regardless of when they turn on. What you may gain, is less of an excursion before they reach equalibrium. This doesn't sound like Bruces problem. I assume you've done a coolant change, and the system was properly bled. You might try Water Wetter, or as Brad inferred, a larger or additional oil cooler. though the 3rd radiator might be less expensive than the oil cooler. It's certainly cooler looking.

As I mentioned in my original post, the cooling system is entirely working as designed. I'm pretty familiar with the car by now and comfortable with this stuff. Have actually been through a fan failure, so I know how that goes. They're both clean and working fine.

I share your view on the fan mod. It might work for some, but the coolant temperature rises and falls so quickly with this car that I don't see how prophylactic cooling is going to make much difference in the traffic I drive in, other than letting the engine run cooler for a minute or two longer.

A real fix doesn't exist, frankly, IMHO. If you look at how they deal with this stuff in police cars and taxis and military vehicles, the only variables you've got are surface area, air flow and system volume: More rad, more fluid, more air. We can add only a little volume and surface area, and can only control airflow with motion. The dream solution would be a fan design that moved more air, and fan motors that can deal with the load.

[SH-GT3]

Have you considered to find out the size of the stock fan and find a spal pusher the same size that moves more CFM?

[1999Porsche911]

Have you checked both radiator fans to feel if they are moving about the same amount of air? Easy to tell if you stick you hands right in front of the front tires. (Turn on the AC or you'll have to wait until summer..) Could you have a weak motor, or part of the resistor is bad on one, and that it simply is not moving enough air? The fan runs at two speeds, but is dependent onte resistor to do that. You may only have one speed.

Perhaps you have a defective T-stat that's not opening all the way? I've never understood going with lower temp t-stat, as the stock one should be full open at well below 95C. Full open is full open. AFAIK, a lower temp T-stat does not open more than the stock one. Same thing if fans are already running. Running them sooner does not keep the top temp cooler. If fans are running, then the system will reach the same equilibrium temp, regardless of when they turn on. What you may gain, is less of an excursion before they reach equalibrium. This doesn't sound like Bruces problem. I assume you've done a coolant change, and the system was properly bled. You might try Water Wetter, or as Brad inferred, a larger or additional oil cooler. though the 3rd radiator might be less expensive than the oil cooler. It's certainly cooler looking.

As I mentioned in my original post, the cooling system is entirely working as designed. I'm pretty familiar with the car by now and comfortable with this stuff. Have actually been through a fan failure, so I know how that goes. They're both clean and working fine.

I share your view on the fan mod. It might work for some, but the coolant temperature rises and falls so quickly with this car that I don't see how prophylactic cooling is going to make much difference in the traffic I drive in, other than letting the engine run cooler for a minute or two longer.

A real fix doesn't exist, frankly, IMHO. If you look at how they deal with this stuff in police cars and taxis and military vehicles, the only variables you've got are surface area, air flow and system volume: More rad, more fluid, more air. We can add only a little volume and surface area, and can only control airflow with motion. The dream solution would be a fan design that moved more air, and fan motors that can deal with the load.

Do you like making things more completcated than necessary? :o

It works for ALL. Street or track. It is not that the fans do not push enough air. It is the fact that they do not turn on soon enough to full speed.

Edited March 2, 2009 by 1999Porsche911

[BruceP]

Have you checked both radiator fans to feel if they are moving about the same amount of air? Easy to tell if you stick you hands right in front of the front tires. (Turn on the AC or you'll have to wait until summer..) Could you have a weak motor, or part of the resistor is bad on one, and that it simply is not moving enough air? The fan runs at two speeds, but is dependent onte resistor to do that. You may only have one speed.

Perhaps you have a defective T-stat that's not opening all the way? I've never understood going with lower temp t-stat, as the stock one should be full open at well below 95C. Full open is full open. AFAIK, a lower temp T-stat does not open more than the stock one. Same thing if fans are already running. Running them sooner does not keep the top temp cooler. If fans are running, then the system will reach the same equilibrium temp, regardless of when they turn on. What you may gain, is less of an excursion before they reach equalibrium. This doesn't sound like Bruces problem. I assume you've done a coolant change, and the system was properly bled. You might try Water Wetter, or as Brad inferred, a larger or additional oil cooler. though the 3rd radiator might be less expensive than the oil cooler. It's certainly cooler looking.

As I mentioned in my original post, the cooling system is entirely working as designed. I'm pretty familiar with the car by now and comfortable with this stuff. Have actually been through a fan failure, so I know how that goes. They're both clean and working fine.

I share your view on the fan mod. It might work for some, but the coolant temperature rises and falls so quickly with this car that I don't see how prophylactic cooling is going to make much difference in the traffic I drive in, other than letting the engine run cooler for a minute or two longer.

A real fix doesn't exist, frankly, IMHO. If you look at how they deal with this stuff in police cars and taxis and military vehicles, the only variables you've got are surface area, air flow and system volume: More rad, more fluid, more air. We can add only a little volume and surface area, and can only control airflow with motion. The dream solution would be a fan design that moved more air, and fan motors that can deal with the load.

Do you like make things more completcated than necessary? :o

It works for ALL. Street or track. It is not that the fans do not push enough air. It is the fact that they do not turn on soon enough to full speed.

I disagree with you. That's my right. My own experience tells me that your suggestion will not work for my needs, and your aggressiveness does nothing for your credibility.

[Loren]

Here is another (but more expensive thought).

You could put a C4S or Turbo front bumper on the car. Add in the larger radiators (from either C4S or Turbo) and the ducting and you should have more surface area to cool under both standing and driving conditions.

You might be able to find those parts reasonable at a salvage yard like Oklahoma Foreign or Silver Star Recycling.

[1999Porsche911]

Have you checked both radiator fans to feel if they are moving about the same amount of air? Easy to tell if you stick you hands right in front of the front tires. (Turn on the AC or you'll have to wait until summer..) Could you have a weak motor, or part of the resistor is bad on one, and that it simply is not moving enough air? The fan runs at two speeds, but is dependent onte resistor to do that. You may only have one speed.

Perhaps you have a defective T-stat that's not opening all the way? I've never understood going with lower temp t-stat, as the stock one should be full open at well below 95C. Full open is full open. AFAIK, a lower temp T-stat does not open more than the stock one. Same thing if fans are already running. Running them sooner does not keep the top temp cooler. If fans are running, then the system will reach the same equilibrium temp, regardless of when they turn on. What you may gain, is less of an excursion before they reach equalibrium. This doesn't sound like Bruces problem. I assume you've done a coolant change, and the system was properly bled. You might try Water Wetter, or as Brad inferred, a larger or additional oil cooler. though the 3rd radiator might be less expensive than the oil cooler. It's certainly cooler looking.

As I mentioned in my original post, the cooling system is entirely working as designed. I'm pretty familiar with the car by now and comfortable with this stuff. Have actually been through a fan failure, so I know how that goes. They're both clean and working fine.

I share your view on the fan mod. It might work for some, but the coolant temperature rises and falls so quickly with this car that I don't see how prophylactic cooling is going to make much difference in the traffic I drive in, other than letting the engine run cooler for a minute or two longer.

A real fix doesn't exist, frankly, IMHO. If you look at how they deal with this stuff in police cars and taxis and military vehicles, the only variables you've got are surface area, air flow and system volume: More rad, more fluid, more air. We can add only a little volume and surface area, and can only control airflow with motion. The dream solution would be a fan design that moved more air, and fan motors that can deal with the load.

Do you like make things more completcated than necessary? :o

It works for ALL. Street or track. It is not that the fans do not push enough air. It is the fact that they do not turn on soon enough to full speed.

I disagree with you. That's my right. My own experience tells me that your suggestion will not work for my needs, and your aggressiveness does nothing for your credibility.

If your water pump is working within spec and your radiators are not blocked with debris or damaged, it will work without doubt. I can't tell you how many trackers keep the fans running and maintain engine temperatures well below what you are getting.

My aggressiveness is to put an emphasis on what WILL and DOES work, contrary to what your opinion is so others know there is a real world work around to high engine temperature.

As far as your statement that the cooling system is working as designed....isn't that your problem? As designed the high speed fans do not turn on until engine temperature reaches 215F.

Edited March 2, 2009 by 1999Porsche911

[perryinva]

Well, I'm a little confused here. From the first post I thought that your fans were running continuously, but the temp still stayed above 215F which is about 102C, in stop and go traffic. (It doesn't specifically say that, but that is what I thought.) In which case MR 1999s fix will not work, even he has to agree with that.

(And for the record, there is no way that turning the fans on sooner or constantly will yield a lower final coolant temperature any lower than if the fans kicked on at 215F and stayed on. Period. That is Thermo101. It WILL prevent the temperature from ever reaching 215F, or even exceeding whatever that final temperature is, but it will be the same pre or post mod. I run under the reasonable assumption that 215F max is no big deal, and there is nothing really to gain keeping the coolant constantly at 180F, at the expense of more wear & tear on the fans and the parasitic loss of the load. Using your logic, why not just hard wire the fans and keep them running all the time the engine runs?)

But when you say that the cooling system is running normal, do you mean that the fans are cycling on and off all the time in traffic? In that case, Mr 1999s fix will work exactly as he has stated, the coolant will be a more constant lower temp on average, as it will do what you stated works, move more air through the radiators. I have a 2002, and they don't seem to have the same cooling issue, as the fans infrequently turn on even in stop and go city traffic in 105F air temps. And as you stated, when the fans kick in, the temp drops very quickly, which is why I didn't suggest a higher rate fan. The ones you have work. On an aside, I had done the clutched fan delete on my BMW a few years back to "gain" a bit of HP back, as I really didn't think that the apparant small amount of air did much. I shortly re-installed it as it made a huge difference in the number of times the electric fans came on and their duration. The clutched one is much quieter and suffices for normal use. It doesn't take much air make a difference. It almost seems like the 996 with this cooling "issue" could benefit from an additional lower (quiet, less load) speed on the fans.

[RFM]

I could be wrong, but in hot conditions with the air condition on and the system in good shape, the fans should be run all of the time, fans kicking on and off is out of the question in this 996 case.

[KevinMac]

Whether you agree with changing out the thermo as offered by L&N is not for debate here since L&N has a pretty good reputation on Porscghe rebuilds and fixes for Porsche engineering foo pahs! So based on my discussion L&N has stated there are no issues running the 160 thermo and recommendds it for hot climates and stop and go traffic. The 160 thermo just lowers the baseline of when it opens therefore giving one more time to reach the higher temps then with a 180 thermo. One has to remember Porsche has designed their engines to run in a very large variety of climates, as obvious by their recommended oil list. So to just dismiss this suggestion made by a very reputable aftermarket engineering firm is just opinion with no fact to back it up! I for one living on SE florida plan to make the thermo change. If not satsfied, just put the old one back! IIt's niot only easy to change but it will not put a huge dent in your wallet. In this case I have every bit of confidence in L&N

Edited March 4, 2009 by KevinMac

[1999Porsche911]

Whether you agree with changing out the thermo as offered by L&N is not for debate here since L&N has a pretty good reputation on Porscghe rebuilds and fixes for Porsche engineering foo pahs! So based on my discussion L&N has stated there are no issues running the 160 thermo and recommendds it for hot climates and stop and go traffic. The 160 thermo just lowers the baseline of when it opens therefore giving one more time to reach the higher temps then with a 180 thermo. One has to remember Porsche has designed their engines to run in a very large variety of climates, as obvious by their recommended oil list. So to just dismiss this suggestion made by a very reputable aftermarket engineering firm is just opinion with no fact to back it up! I for one living on SE florida plan to make the thermo change. If not satsfied, just put the old one back! IIt's niot only easy to change but it will not put a huge dent in your wallet. In this case I have every bit of confidence in L&N

The 160F thermostat will not keep your engine any cooler. That has been tested many times. You can actually remove the thermostat and you will still see 215F+ in similar conditions, although running with a removed thermostat does help the engine cool down faster when airflow is applied due to do an increase in the volume and reduced pressure of coolant flow. The water pump does not have the flow it needs and airflow past the small radiators at slow speed is not sufficient.

Don't waste your time with a lower opening thermostat. You engine cannot run much lower than 190F anyway.

Increase air flow and your problem is solved.

[tholyoak]

Well you answered your own question didn't you. The lower temp. thermostat does nothing to lower the operating temperature of the engine, it simply increases the warm up period. Obviously once the thermostat is open in either case the system reaches the same equilibrium point and the engine will run at exactly the same temperature. That temperature is dictated by the effectiveness of the cooling system. In order to lower that equilibrium temperature you need to increase the radiator size/effectiveness (larger radiators or more air flow, or the ability of the cooling liquid to transfer heat (ie running water wetter or straight water)).

If you are familiar with Porsche history you will remember that the old lower temp thermostat was the 'solution' for warm running 944's back in the day. Turned out not to be the case as one would expect, they just took forever to warm up. The trick that did help was a lower temp thermofan switch that activated the fans at lower temp keeping the motor cooler.

Ultimately it is your money, so if you want to stick a lower temp thermostat in the car go ahead.

-Todd

Whether you agree with changing out the thermo as offered by L&N is not for debate here since L&N has a pretty good reputation on Porscghe rebuilds and fixes for Porsche engineering foo pahs! So based on my discussion L&N has stated there are no issues running the 160 thermo and recommendds it for hot climates and stop and go traffic. The 160 thermo just lowers the baseline of when it opens therefore giving one more time to reach the higher temps then with a 180 thermo. One has to remember Porsche has designed their engines to run in a very large variety of climates, as obvious by their recommended oil list. So to just dismiss this suggestion made by a very reputable aftermarket engineering firm is just opinion with no fact to back it up! I for one living on SE florida plan to make the thermo change. If not satsfied, just put the old one back! IIt's niot only easy to change but it will not put a huge dent in your wallet. In this case I have every bit of confidence in L&N

Edited March 4, 2009 by tholyoak

[SH-GT3]

One point of clarification: the t-stat chosen by the factory is not done so to run in a 'very large variety of climates' – its set at that temp for the engine to operate at optimal efficiency.

If you are already overheating, a lower t-stat doesn’t increase the cooling capacity of the system; it simply delays the overheating process.

[1999Porsche911]

The temperature of your coolant is determined by several factors. Volume of flow, line pressure, the speed of flow through radiators, efficiency of radiators, and volume and temperature of air flow through the radiators. There are several other factors, including the density of the fluid, etc.

Changing to a thermostat that simply opens at a lower temperature does nothing to change any of these variables.

[perryinva]

Yeah, what he & I said.

Good point RFM, the fans WOULD be on all the time with AC, as you would expect in the summer, which makes Bruces problem even more confusing, and also eliminates 1999s fan switch solution, as well. I can't recall, but is the AC fan speed the high or low one? If low, then it could be explained, if high, it can not.

I was not poo-pooing L&N. I simply stated thermodynamic facts and said I never understood the use of the lower T-stat solution. I'm an ME with 30years experience, that majored in thermofluids, but I am smart enough to not claim to know it all. If I know for a fact that something is true, I'll state it, but I rarely state that I know something is false unless I have first hand experience with it. There are always missing pieces to a puzzle that too many people ignore and base assumptions on an incomplete picture. Unless the lower temp T-stat allows more flow at full temp (entirely possible, if it includes a new housing) then it does nothing. Period. It just can't. Saying that it is based on my opinion is like saying that drinking gasoline won't make you sick because I've never done it. Anders is exactly correct, the T-stat design point is for efficiency and emissions. 1999 brought up a very good point, though. In BMW straight 6s, a very effective upgrade is to install a Stewart SS pump. I've compared them side by side, and there is NO comparison. The Stewart is so much better designed and built, it's a no brainer to use it, and always yields a more constant, often lower temperature, due to increased efficiency and higher flow rate. Is there a similar aftermarket water pump for the 996? Is the 997 or S one any better?

Edited March 4, 2009 by perryinva

[Loren]

Fans go to stage 2 (high speed) all the time the AC is on.

[RFM]

997 MY05> use a new water pump with greater flow, the propeller is 3 mm. greater in diameter. The seal is slightly adapted to the new propeller, it can help if the pump will fit.

[phillipj]

Does anyone know if the 997 MY05 water pump will fit on earlier 996 3.6's?

Edited March 4, 2009 by phillipj

[BruceP]

Fans go to stage 2 (high speed) all the time the AC is on.

I know, and this is why I'm skeptical about the value of the 'fan mod'. Under the conditions I'm talking about, the fans are running on high most of the time anyway.

[KevinMac]

U guys misread my post what I did say was with 160 thermo and housing, the baseline changes. Therefore when under highway speeds It is possible the car will run at less than 180 or somewhere cooler then when the 180 is in.! When in stop and go, the temp will go up, but when under way should cool down to a possibly less than then 215. Meaning the aggregate is less than when the 180 is in. I never said the 160 will overall keep it from going to 215 or so! My car with the 180 thermo in it with ambient temps at 50 degrees and on the hwy my car runs slightly above 180 nothing like the temps at more than 190! I agree airflow and flow determine the actuall effeciancy of the system.

[BruceP]

Well, I'm a little confused here. From the first post I thought that your fans were running continuously, but the temp still stayed above 215F which is about 102C, in stop and go traffic. (It doesn't specifically say that, but that is what I thought.) In which case MR 1999s fix will not work, even he has to agree with that.

(And for the record, there is no way that turning the fans on sooner or constantly will yield a lower final coolant temperature any lower than if the fans kicked on at 215F and stayed on. Period. That is Thermo101. It WILL prevent the temperature from ever reaching 215F, or even exceeding whatever that final temperature is, but it will be the same pre or post mod. I run under the reasonable assumption that 215F max is no big deal, and there is nothing really to gain keeping the coolant constantly at 180F, at the expense of more wear & tear on the fans and the parasitic loss of the load. Using your logic, why not just hard wire the fans and keep them running all the time the engine runs?)

But when you say that the cooling system is running normal, do you mean that the fans are cycling on and off all the time in traffic? In that case, Mr 1999s fix will work exactly as he has stated, the coolant will be a more constant lower temp on average, as it will do what you stated works, move more air through the radiators. I have a 2002, and they don't seem to have the same cooling issue, as the fans infrequently turn on even in stop and go city traffic in 105F air temps. And as you stated, when the fans kick in, the temp drops very quickly, which is why I didn't suggest a higher rate fan. The ones you have work. On an aside, I had done the clutched fan delete on my BMW a few years back to "gain" a bit of HP back, as I really didn't think that the apparant small amount of air did much. I shortly re-installed it as it made a huge difference in the number of times the electric fans came on and their duration. The clutched one is much quieter and suffices for normal use. It doesn't take much air make a difference. It almost seems like the 996 with this cooling "issue" could benefit from an additional lower (quiet, less load) speed on the fans.

Hey, Perry, let me be really clear. Sorry if it seems terse, but there's a lot of broken telephone on this thread:

In high ambient temps, sitting in very slow or stationary urban traffic, the temp as displayed by the OBD can exceed 105C. This is within Porsche's parameters. But I worry about it anyway, hence the original question.

When I say the system operates as designed, I mean: The rads are clear. The coolant is less than two years old. The coolant level is correct. The coolant type is correct. The expansion tank cap is new. The fan relays turn the fans on, and switch to high speed when they are supposed to do so (102C or AC on).

This means that in the conditions described above, the fans are already on high speed at all times, but I'm still operating at 105 to 108C.

When I say that the temperature drops quickly with air flow, I mean that it does so when the car starts moving again.

Realizing that I can't manipulate too many variables in the system, I wondered whether the increased surface area and system capacity offered by the GT3 center rad made any difference at all.

That's my story. To me, the three reasonable answers would be: Yes, it will help. No, it won't make any difference. Or, stop worrying and trust Stuttgart. ;)

Thanks,

Bruce.

[1999Porsche911]

U guys misread my post what I did say was with 160 thermo and housing, the baseline changes. Therefore when under highway speeds It is possible the car will run at less than 180 or somewhere cooler then when the 180 is in.! When in stop and go, the temp will go up, but when under way should cool down to a possibly less than then 215. Meaning the aggregate is less than when the 180 is in. I never said the 160 will overall keep it from going to 215 or so! My car with the 180 thermo in it with ambient temps at 50 degrees and on the hwy my car runs slightly above 180 nothing like the temps at more than 190! I agree airflow and flow determine the actuall effeciancy of the system.

No it won't. And your car will not run with a coolant temperature <180F even WITHOUT a thermostat unless you are coasting at speed downhill in cold weather.

[1999Porsche911]

Well, I'm a little confused here. From the first post I thought that your fans were running continuously, but the temp still stayed above 215F which is about 102C, in stop and go traffic. (It doesn't specifically say that, but that is what I thought.) In which case MR 1999s fix will not work, even he has to agree with that.

(And for the record, there is no way that turning the fans on sooner or constantly will yield a lower final coolant temperature any lower than if the fans kicked on at 215F and stayed on. Period. That is Thermo101. It WILL prevent the temperature from ever reaching 215F, or even exceeding whatever that final temperature is, but it will be the same pre or post mod. I run under the reasonable assumption that 215F max is no big deal, and there is nothing really to gain keeping the coolant constantly at 180F, at the expense of more wear & tear on the fans and the parasitic loss of the load. Using your logic, why not just hard wire the fans and keep them running all the time the engine runs?)

But when you say that the cooling system is running normal, do you mean that the fans are cycling on and off all the time in traffic? In that case, Mr 1999s fix will work exactly as he has stated, the coolant will be a more constant lower temp on average, as it will do what you stated works, move more air through the radiators. I have a 2002, and they don't seem to have the same cooling issue, as the fans infrequently turn on even in stop and go city traffic in 105F air temps. And as you stated, when the fans kick in, the temp drops very quickly, which is why I didn't suggest a higher rate fan. The ones you have work. On an aside, I had done the clutched fan delete on my BMW a few years back to "gain" a bit of HP back, as I really didn't think that the apparant small amount of air did much. I shortly re-installed it as it made a huge difference in the number of times the electric fans came on and their duration. The clutched one is much quieter and suffices for normal use. It doesn't take much air make a difference. It almost seems like the 996 with this cooling "issue" could benefit from an additional lower (quiet, less load) speed on the fans.

Hey, Perry, let me be really clear. Sorry if it seems terse, but there's a lot of broken telephone on this thread:

In high ambient temps, sitting in very slow or stationary urban traffic, the temp as displayed by the OBD can exceed 105C. This is within Porsche's parameters. But I worry about it anyway, hence the original question.

When I say the system operates as designed, I mean: The rads are clear. The coolant is less than two years old. The coolant level is correct. The coolant type is correct. The expansion tank cap is new. The fan relays turn the fans on, and switch to high speed when they are supposed to do so (102C or AC on).

This means that in the conditions described above, the fans are already on high speed at all times, but I'm still operating at 105 to 108C.

When I say that the temperature drops quickly with air flow, I mean that it does so when the car starts moving again.

Realizing that I can't manipulate too many variables in the system, I wondered whether the increased surface area and system capacity offered by the GT3 center rad made any difference at all.

That's my story. To me, the three reasonable answers would be: Yes, it will help. No, it won't make any difference. Or, stop worrying and trust Stuttgart. ;)

Thanks,

Bruce.

Well, if in fact your fans are running full speed at all times, (double check them individually) then you have a problem elsewhere. I run with AC on and fans running in 100+ stop and go traffic and coolant temperature remains below 200F, as do all the cars I know that have the fan mod. Even climbing Pike's Peak in 85f, my coolant temp never got above 205f.

You don't have to do the mod, just ground the 2 high speed relays and run that way for awhile.

[911dark]

I believe the 160 degree thermostat is recommended because there is an assumption that there is enough cooling capacity for the system to keep the water temp below 180 degrees. If that assumption is true (given specific conditions, speed ambient air temp, ...) then the lower thermostat would translate into a lower maximum operating temperature.

I too see 218 degrees (c6 display) while driving in traffic and we've only just started to hit 90 degrees ambient here in Phoenix. I've used the car for my daily commute for the past three years but was until recently unaware of the c6 ODS display. 118 degree ambient is not at all abnormal around here...

I think before the garage gets any warmer I'll pull my bumper skin and check for the debris around the radiators. I would love to do the third radiator as my next mod regardless.

'99 996

88K+ miles

Bounced off the rev limiter daily

[perryinva]

Not terse at all Bruce..perfectly clear, thanks. It takes a WHOLE lot to offend me... Yes, the 3rd radiator will help. Just don't think it's worth $600 to do the fix, unless you track. Since I've read about this issue other times, I can only assume it's common. But on my car, with the AC on, in 105F stop and go, I've never exceeded 195F. Now, I did experiment with my Autoenginuity software (temp control easter egg doesn't work on 02 or newer) and monitored coolant temp while I roasted with the AC off last summer, and consistently hit 210F, then fans would kick in and drag it down to 195F pretty quick. But, dang those are small radiators for 320 HP... I'm going to see what I can find out about the '05 water pump. Maybe Jake Raby can help.

Edited March 5, 2009 by perryinva

[flyingpenguin]

Or you can keep your coolant temperature below 200F at all times by doing my simple fan mod. Cost is virtually nothing.

Got the OMRON MY2K relay in (finally), and I am at a loss how to wire it properly. Previously posted diagrams seem to have vanished (yes I searched).

Does anyone have a complete diagram with the Porsche toggle switch, the OMRON relay and the wiring to the fan relays?

Joost