993GT

I agree the dash gauge is a bad comparison tool car to car, but for comparing one car to itself should be relatively accurate(as-in comparative numbers)...fresh temp. sensor and the fact the cores are cool to touch on the 'cold side' makes me more sure of my gauge reading...
I do need to get a Durametric or similar....
Of course will investigate more to make sure my findings are consistent day to day, hot/cold, etc.
Cheers,

cbracerx

I use an UltraGuage on my Land Rover to get the real coolant temp. It is an inexpensive ODBII device that can be suction mounted to the window and left on for extended periods (mine is permanently installed since older Land Rovers throw codes often...). Highly recommended and no affiliation.

993GT

thanks Chris, will look into that! My current OBD2 is freeze frame only

dprantl

While I have little experience with 996TT radiators specifically, I have lots of experience with other makes, including Porsche 928 Behr radiators that are now practically the price of gold. I don't believe the 996TT radiators are anything special in terms of heat exchanger design.

All it takes is one junior tech putting tap water into a coolant system because they don't really understand why it is very bad and the deposits start forming. After a few years, the efficiency of the system will definitely not be 100%. Also the ultimate joke of "lifetime" coolant that never requires changing will also begin to take its toll after a number of years. Of course one may not notice any cooling degradation for years since automotive cooling systems are designed for the most extreme environments and on top of that is some margin of safety. As an example, this margin is extremely small in later model 928's (some question whether there is any there at all, it is the same radiator size from a 4.5l 220hp engine to a 5.4l 345hp engine) and it is not uncommon for these cars to suffer from cooling problems in hot conditions with older radiators. If not overheating, you may see the rate of coolant temperature drop after a hard run decrease over time. The problem usually goes away with the installation of a new radiator. All-aluminum radiators are also available for 928's, and the same topic comes up over there.

Porsche doesn't specify anything about this since it is pretty self-explanatory. If the cooling system is not operating properly, diagnose and if it is the radiator(s), replace with new factory parts. Additionally, if pure distilled water is always used and no contaminant ever gets into the system (and the coolant's properties do not degrade too much), chances are the radiator(s) will not lose much efficiency even after a decade. The point here is that these are unknowns and if you really want to know if that new aluminum radiator cools better, you need to do an apples->apples comparison and the only way is comparing to new stock, not used stock.

Dan

TB993tt

Who is going to be bothered putting brand new stockers on to see if your theory is correct ? Actually I have a set of new stock side rads (they didn't go on because my shop had a look at my rads and said they were perfect and no "junior techs" have ever been near my car - obviously they didn't look inside for those nasty deposits)
I would be willing to wager (with someone who will bet enough to pay for the rigmarole of all the swapping rads and renting the airfield) that the difference between my 5 year old rads and the brand new factory ones on a test 0-300kph 5 times is less than 2 degreesC water temp.
On the other hand if installing the CSF rads results in a temp drop of more than 5DegC I will be endorsing them with confidence.
TBH this is what CSF should be doing but like all intercooler manufacturers they rely on theory mostly and no one ever wants to get their hands dirty

dprantl

Most probably the engine temp difference between your 5 year old rads and new stock ones will be 0 degrees, it just may be that the rate of temp drop will be slightly slower on the older ones. Or maybe not, especially if you are certain the cooling system has always been perfectly maintained, but I am not a gambler hence I like to be 100% sure of my results when possible . But how about a set of 13 year old radiators? You specifically are a sample size of '1'. I see that you are skeptical about this, maybe you have never seen a radiator blocked by sediment in person?

Dan

TB993tt

Dan, I take your point of course. If I can post pics up of my rads as soon as they are taken off will you be able to make an informed assessment on their likely state of efficiency ? I'd like any testing I do to be as meaningful as possible.

dprantl

I don't think I would be able to assess your radiator cooling efficiency based solely on pictures. Plus, you would have to remove your end tanks so we could look down the tubes. When you do that you can break the aluminum tabs that hold the plastic end tanks to the core, so I don't recommend that solely for this purpose, especially since it seems based on your descriptions your old radiators have a good deal of useful life left in them.

Dan

993GT

I found a small but critical flaw yesterday/today in the rads, issue involves the vent line connections on all three rads. Main line connections are not affected.

Have been on the phone/email all day with Ravi@CSF, I have provided the specs/created a simple but effective repair for the radiators, and more importantly ensured all future 996 rads will be correct from day one.

CSF has been great to deal with the whole way through and will be making it right for anyone who purchased the radiators; they will be in contact with all involved, doing things the right way.

For the record, I have repaired mine(and not taking CSF's very generous/proper offer of replacement) and will continue testing, I am told I am the first person with a complete set installed.

Will keep all updated,
Cheers,
Rob

PAULUNM

Can you elaborate on the connection issue? Any pictures?

993GT

the neck/receptacle of the vent tube was machine to same tension clip-end of neck specs as the main lines, approx. 1mm too long not allowing the tension clip to fully engage, works for a bit...
Shaving the end of the neck down with a file allows the clip to function properly, and is a very simple quick(20mins each when off car) fix, this will be an 'approved' method for those who do not wish to wait for replacements.
I have done 2 of 3 rads so far and will try to take some better DIY-friendly pictures tomorrow on the 3rd rad.

CSF Cooling

We've been informed by Rob (993GT), and have been working with him all day to find a quick and 100% reliable solution for these radiators.

The 3 CSF Porsche racing radiators that are effected by this slight 1mm variance are CSF #7053 #7055, #7056. This issue is that they may not be seating correctly and may possibly pop off when driving.

Thankfully this is a very easy fix and I can offer you several solutions:

Solution 1 - The variance is off by only 1mm. You can easily grind/file/sand down the top of the vent line to make sure that the pipe inserts and locks correctly. You can double check that the tension clip is indeed locked into place by giving the hose a nice tug before going any further. *see pictures attached for correction instructions*
- This grinding job can be done within 10 minutes each. If done, please make sure to block pipe from debris with a cotton ball when grinding.

Solution 2 - You can return the units, at CSF's expense, to our headquarters, we can fix the radiators for you, then send it back

Solution 3 - You can wait for a newly revised unit with proper vent pipe to be delivered. Estimated delivery time will be about 1 month to 6 weeks.

Please let me know if you have any questions or would like to discuss anything.

All current stock is being fixed, and new production units are being built as well. We have informed all current customers about this issue. Any new orders will not be affected by this.

To all the customers who have pursched CSF cooling systems, Thank you for the opportunity you have given CSF to supply cooling systems for your vehicle. I hope that we can work through this small pipe tolerance issue. I look forward to your feedback and decision.

Rob has been a great help with this issue, and has helped us address the problem before any other units have been installed. His thorough reporting and feedback to the community has been excellent, and he is a great example of why we have forums! Thanks Rob!

- Ravi

CSF Cooling

All radiators have been fixed, inspected, tested, and approved for shipment.

We have a few sets left.

We also weighed the stock units versus ours. The side radaitors are equal weight to stock, and both weight 8 lbs.

Ck986

Has anyone installed these yet? Im waiting on my set.

993GT

I have the first installed whole set.
Mine have been installed for almost a month now, have put 1000kms on them including time at the drag strip doing 'hot-laps'...since solving the initial incident regarding the vent-line necks(which have ALL been fixed/replaced), these rads have been great IMO, temperature as read on the gauge is lower and more consistent, never see above ~185F even during WOT passes and then sitting in staging lanes or traffic. Plan on getting on the roadcourse in the next week or two and using the car where it belongs, and will update then as well.
Again, I will say that the beauty of these rads is the peace of mind knowing that there is no plastic is fail/spray coolant.
If you have any questions I'm happy to help.
Cheers,
Rob