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C4S uses Turbo radiators so the hose must be correct, if it is actually a C4S part. Have you got the part#? I believe that it does not go from the aluminum pipe to the radiator. It goes from one aluminum pipe to another aluminum pipe and the branch gets yet another aluminum pipe.
Those fittings on the Turbo radiators are called Henn connectors. The Turbo center radiator also uses Henn connectors, just smaller ones.
I have to take the front bumper off my Turbo tomorrow to clean out the radiators so I can take some pictures then.
I hope you're still interested in this because it is complicated. Also I don't know the configuration of the 40th cars. Obviously you have a Turbo bumper, so I am assuming you have Turbo left and right radiators. I believe the 40th is an awd car so you should have similar front to rear aluminum pipes.
So what happens is the aluminum pipes from the engine split into a Y shape in the space behind the steering rack. This is the passenger's side, easier to see.
The aluminum pipe from the engine is just visible and the yellow line is that splitter hose you linked above. The left radiator has a hose that crosses under the car with the red L arrow. The splitter hose dumps into two aluminum pipes. The one labeled red R goes to the right radiator, the one labeled red C follows along the inside of the frame rail and gets a short hose to attach to the center radiator. The blue R aluminum pipe crosses under the car.
The driver's side is harder to see.
The aluminum pipe from the right radiator has a short joiner hose above the steering rack and connects to the inboard leg of the Y, the blue R. The yellow squiggle is another of those splitter hoses which dump out into two aluminum pipes - the blue L goes to the left radiator and the center radiator can't be seen behind the frame rail. The center radiator aluminum pipe here also has a short hose on the end to attach to the center radiator. The red L pipe comes under the car in front of the steering rack.
So to duplicate the Turbo setup you'll need to see what hose is installed in place of the splitter hoses and if it could be replaced with the turbo/C4S hoses. The you'll need to source both center radiator aluminum pipes and short hoses.
I sort of doubt that's going to be practical or cost effective. Here's the parts list:
Right side splitter Y hose: 996-106-728-72
Right side aluminum pipe to center rad: 996-106-730-71
Right side short hose to center rad: 996-106-638-73
Left side splitter Y hose: 996-106-724-72
Left side aluminum pipe to center rad: 996-106-725-71
Left side short hose to center rad: 996-106-639-73
Additionally some O-rings and clamps, etc for hoses.
Assorted clips to hold pipes to the frame rails.
If you don't have the brackets etc. those are:
Exhaust air duct: 996-575-151-01
Intake air duct: 996-575-141-30
Intake air duct attachment strip: 996-575-761-00
Pop rivet for attachment strip: 999-190-419-30 (need 6, I used stainless M3 bolts and nylock nuts instead)
Lower radiator bracket 996-504-493-00
Upper radiator bracket: 996-504-495-00
Speed nuts attachment to car: 999-591-869-02 (need 4)
Bolts attachment to car: 900-378-074-09 (need 4)
Speed nuts bracket assembly: 999-507-550-02 (need 2)
Bolts bracket assembly: 900-378-036-09 (need 2)
Grommet for radiator: 930-113-430-00 (need 4)
In reply to my note above, all I can say is that the parts list diagrams appear to be incomplete or incorrect. The same part# pipe is used on the Turbo and the C4S to cross under the car and it's shown bent differently in each diagram. I am not at all sure what parts are used on the NA cars that use the Turbo radiators. I can say that if the situation looks like the pictures I posted the parts list will work.
@theprf - Thanks so much for taking the time to look into this and document it! Always appreciate your technical "know how" on these cars.
Few things to clarify here.... The 40AE cars are a bit of an odd ball and sometimes feel like a parts bin special (not necessarily a bad thing) so things get confusing. I can confirm that the side radiators are the same as Turbo as I cross referenced the part numbers previously. Having said that, they are NOT AWD like Turbo or C4S cars so that's where the differences will come from. It's essentially a narrow body C2 with Turbo front bumper and radiators. Their logic behind it seemed to be to provide additional cooling along the side of the X51 package that bumped the HP to 345. I'll pull the front wheels tomorrow when I wash it to better document this - pictures speak a thousand words. I do have a potential game plan in mind that I'll share soon but it may require some customization. I did purchase the 2 hoses that come with the pelican kit that I may be able to use - 996-106-666-56-M100 & 996-106-665-58-OEM.
Since I just rolled over 105k miles it was also time for an oil change. Since I had some extra time and felt a bit frisky I decided to pull the UIDS as it's been 11 months and 10k miles since I installed it. I thought I'd also play around with the borescope. I love the fact that I didn't have to screw around with a sealant when putting it back together and then spiking future UOA numbers.
Didn't find anything in the sump ¯\_(ツ)_/¯ Everything looked good to my eyes.
The scoring marks on the wheels looked concerning at first but upon closer inspection, the surface underneath looks perfect with no marks and looking at the photos I took during the install the marks were also there. Seems like they were there from production and felt smooth to the touch.
Nothing in the screens either.
Nothing to see here. I've been using the LN magnetic plug which had just a thin layer of some "dirt". Didn't seem abnormal from what I've seen before.
The rubber gasket did a great job keeping things sealed and I did not experience any leaks. It has flattened out slightly but no leaks this morning.
Went out for a brief drive to get some gas after. Ran into a nice guy named Rob with his 87 Carrera cab. Next thing you know we're talking about valve adjustments and oiling systems and 30 minutes has gone buy. Porsche owners are a different breed.
@theprf - Thanks so much for taking the time to look into this and document it! Always appreciate your technical "know how" on these cars.
Few things to clarify here.... The 40AE cars are a bit of an odd ball and sometimes feel like a parts bin special (not necessarily a bad thing) so things get confusing. I can confirm that the side radiators are the same as Turbo as I cross referenced the part numbers previously. Having said that, they are NOT AWD like Turbo or C4S cars so that's where the differences will come from. It's essentially a narrow body C2 with Turbo front bumper and radiators. Their logic behind it seemed to be to provide additional cooling along the side of the X51 package that bumped the HP to 345.
It is interesting that the parts catalog specifies a center radiator for either the X51 or the M249 Tiptronic cars. Yet the 40th doesn't have a center radiator. I suppose with the Turbo radiators, which are 50% bigger than the Carerra radiators the factory did not feel it was needed. I would think that you will have no problems with the side radiators only. I see this is going to be a tricky install. I think it could be done with 997 hoses; without the car here to try them out I cannot be sure of that.
It is interesting that the parts catalog specifies a center radiator for either the X51 or the M249 Tiptronic cars. Yet the 40th doesn't have a center radiator. I suppose with the Turbo radiators, which are 50% bigger than the Carerra radiators the factory did not feel it was needed. I would think that you will have no problems with the side radiators only. I see this is going to be a tricky install. I think it could be done with 997 hoses; without the car here to try them out I cannot be sure of that.
I agree that some of the info out there is inconsistent. It's possible that standard Carreras with X51 could have the center radiator added on but after discussing this topic a good deal with folks in our 40AE registry the consensus seems to be that our cars did not come with the center radiator from factory.
For the 997 Porsche made some changes, one of them with the hoses. Both ends have the Henn connectors you've mentioned so it wouldn't work here. Another thing I noticed is that on the Turbo radiators, the hoses connect on the side that is closer to the wheel, while the standard smaller radiators have the connecting point on the other end. After doing some more digging here is what I found:
For reference, here is how things would typically connect on a regular C2:
Below are photos of my passenger side wheel well and coolant lines:
You can see that the hard lines are essentially the same and the main difference is that Henn connectors are used on the radiator side and are situated on the opposite side of the radiator body in comparison to a standard one. In order to make this work I should be able to replicate what the hoses for a standard C2 accomplish by cutting the lower hose (on the passenger side in this illustration, upper hose on driver side) and inserting a coolant compatible T fitting that will then connect to the center radiator via a skinnier hose. This should work with a T fitting like below. I'd just need to make sure that the diameter is correct and the hose will fit tightly so it can be secured with a clamp.
I think that's the most straight forward approach that should work here. I'm essentially routing the coolant to an additional location via correct lines and there are no additional switches or sensors that are in play here. As long as I can have it all nice and tight with no chance for leaks we should be in business. Let me know your thoughts but I think this seems like a good plan. I haven't seen this done before on a 40AE car so all for being the guinee pig. Someone's got to try it first! We did have one guy in the registry convert his front end to the GT3 bumper and while adding a center radiator, however, he replaced the stock side ones with smaller C2 radiators.
The left and right Turbo radiators fit exactly as yours do. For the 997 Turbo Porsche flipped the side radiators and the connections are closer to the center of the car. The side radiators are symmetrical which is why I though that perhaps flipping your radiators and using 997 Turbo hoses would work. The 997 front radiator hose configuration is far simpler than the 996.
Of course that would require the Turbo center radiator with Henn connections as well.
If you could figure out the part#'s of the hoses that attach to your radiators perhaps I could do some more research. The part# should be printed on your hoses somewhere.
I am closely watching this as I think it may have some real pertinence to my upcoming problem of getting the turbo radiators working on my car. Thanks to both of you guys for so thoroughly covering the work here.
The left and right Turbo radiators fit exactly as yours do. For the 997 Turbo Porsche flipped the side radiators and the connections are closer to the center of the car. The side radiators are symmetrical which is why I though that perhaps flipping your radiators and using 997 Turbo hoses would work. The 997 front radiator hose configuration is far simpler than the 996.
Of course that would require the Turbo center radiator with Henn connections as well.
If you could figure out the part#'s of the hoses that attach to your radiators perhaps I could do some more research. The part# should be printed on your hoses somewhere.
Those are good points! Since I already went through the motions of getting the 996 center radiator kit with hoses (here is a link with all part numbers https://www.pelicanparts.com/cgi-bin...ator-parts.htm), I don't think I want to try to get the 997 center radiator route as for it to work nicely without any modifications I'd still need the 997 side radiators. That's additional cost and complication. They have separate plugged ports to feed the center radiator. It's a much better design and makes the install super easy. It's also much cheaper than the 996 one but I was able to source my parts individually and save a lot of cash.
I went ahead and got some measurements of the 996 hoses and coolant pipes to figure out what size T fitting I'd need to make it all work.
The coolant pipe to which the radiator hose attaches is ~32.31mm in width. The pipe is the same size on both ends so I just measured where I had easy access.
The outside of the stock hose that attaches to that pipe is ~40.63mm
By comparison, the hose that is part of the 996 kit has an outer width of 41.63mm, which is essentially the same. 1mm difference which is normal due to one being 20yo and other new. The inside of that hose is 32.72mm which is inline with the diameter of the coolant hard pipe at 32.31mm. What this tells me is that the T fitting that will work must be able to accept a hose of that size.
Finally, the skinnier hose that leads from the T fitting to the connecting point on the center radiator has an inner width of 21.13mm, so the T fitting must be able to accept that size. The connection to the 996 center radiator is secured by normal worm style clamps and not a Henn connector like on the 996.
After a quick search, I think the Dorman Coolant connector part 627-006 will work here. It's an Audi / WV part, so kind of in the family! The larger connectors are 1.35in or 34.29mm, which is very close to 32.72mm of a new hose and I think should fit just fine. The smaller exit port is .87in or 22.1mm, again right in line with the 21.13mm on the new hose.
The game plan would be to buy 2 of those T fittings and insert them into the current hoses that feed the center radiators (1 for each radiator) and then feed the center radiator from there.
Those look rather suspiciously like the coolant T's that are behind the engine on my Cayenne Turbo - and which seem to shrink, crack, and blow apart after a few years. Perhaps keeping it away from engine heat will help them survive longer.
Most Cayenne guys replace them with aluminum T's sourced from a place called "Jags that run" in England. Although the aluminum T's that I got leaked at the side fitting so perhaps not a perfect solution.
Those look rather suspiciously like the coolant T's that are behind the engine on my Cayenne Turbo - and which seem to shrink, crack, and blow apart after a few years. Perhaps keeping it away from engine heat will help them survive longer.
Most Cayenne guys replace them with aluminum T's sourced from a place called "Jags that run" in England. Although the aluminum T's that I got leaked at the side fitting so perhaps not a perfect solution.
Thanks for pointing that out! I'll keep an eye on them but since they will be upfront I'm not as concerned. There is other plastic there that's been fine. It will be nestled in the hose mostly which is right behind a radiator fan and a vented wheel liner so the temps should not be as high as near the engine. I'll order 2x and continue to update as I make progress.
Center radiator update. Cliff notes = got it working! In depth info = read on.
After some more planning and few parts collected I took advantage of no work on monday to get this all hooked up. The goal was to DIY your own hoses to plumb up the center radiator as the OEM hoses for a regular 996 would not work for a 40AE car.
I started by pulling the front pumper and front wheel liners. The cool thing about the ones on the 40AE is that they have exhaust vents which aid in cooling. I've seen some people make cut out on theirs to help with it. I got the center radiator back off (I had it attached in it's place for fitment and planning) and test fitted the hose that will run from the radiator to the T fitting. I was able to get the hose from my local AutoZone and the fitment was tight but right kind of tight. This will be secured with a worm clamp. The hose also fit in the same way onto my T fitting so success on both ends so far.
Next I started to remove the stock hoses from the radiators that will need to be modified and drained some coolant. Probably a little over a gallon total came out.
The T fitting was the perfect size for the oem hose connecting the aluminum pipe to the radiator.
Next I marked up the hose to figure out where I'll need to cut it to insert the T fitting into. Did this on both sides. The adage of measure twice cut once applies here as I didn't want to goof up the good and probably expensive hoses. They have some curvature in places so it was important to install the T fittings in a straight area and avoid potential leaks.
Next step was to attach both hoses to the center radiator and do a soft install to route the hoses and estimate the location of the T fittings. I did need to slightly bend the horn bracket to create some extra room and not have anything touching.
On the passenger side, the radiator connects to the lower side radiator hose. It routes nice and clean on that side with no binding or excessive bends. Coolant flow is not affected there.
The driver side demands a bit more attention as the side radiator hose to which I'll be connecting is the top one. There is a nice opening in the plastic panel to route the hose through but I knew it will require some modification as it seemed like it will create too much bend in that smaller hose and potentially compromise flow. Extending that opening will allow the hose to have a smoother path and prevent this from happening.
Because I'm apparently glutton for punishment and work on my car is 90+ degree weather I had a beer brake or two before cutting up my hoses because that order seemed right to me.
From there I starting cutting hoses after measuring everything twice and began to test fit things before fully connecting everything. The goal was to have the hoses not bind up and run through a clear path that wouldn't contact anything they shouldn't.
Passenger side fit great.
Driver side came out well too. Could have been slightly closer to the right but it still looked good. Once splitting the hoses you do need to cut out a tad more of each one to compensate for the T fitting. If you don't do this then the hose will be too long and won't fit well.
Those old oem side radiator hoses looked perfect inside after 20 years fwiw. After the test fit on both sides I started to connect everything with clamps and cleaned up the hoses. Below is the passenger side.
Driver side.
Here you can see the enlarged cut out I did to ensure the hose has a smooth path and does not bind up. I cleaned up the edges with a dremel after. It's all plastic so went like butter.
View from below before the bumper went on. There is ample space where the center radiator will vent to under the car. With the bumper on, this is still wide open.
The center radiator I used is the OEM Porsche part that I picked up cheap second hand. It was in great condition and included the plastic shroud and all mounting brackets.
View from the front once everything was connected.
From there on, I lowered the car, started it up and began to add coolant and bleed it via the bleeder valve. After a few minutes of idling and a few light revs to get things going, the coolant started to get sucked into the new larger system. I ended up adding about a gallon and half back in as the car idled. After a bit of time I shut things down and checked for leaks but there were none. From there on I buttoned things back up and got the car ready for a test drive. I grabbed another gallon of coolant and went on a 40ish mile drive. I left the bleeder valve open to get rid of any residual air in the system. Bleeding via the valve was super easy and I had zero issues. During the drive the temps stayed in check with zero leaks of any kind. I wasn't expecting any dramatic changes but this modification will definitely add cooling capacity for hot track days and other spirited driving during summer. Also, modding cars is fun! I'm also curious to see what oil temps will look like when stuck in city traffic. I noticed that the temps can go up a tad and heat soak when coming to a stop in the summer while in traffic. Overall, this wasn't too difficult but it did take some planning to get things right. Now I have 2 center radiator hoses for a regular 996 that I need to return or sell so let me know if you want them.
05-30-2023, 04:08 PM
