Center Radiator Retrofit - Base to S Hoses, Thoughts on Best Solution?

[rick3000]

Hi Everyone,

I am going to be adding a center radiator to my '99 base 986. I have most of the parts, but am trying to determine the best (and most reliable) way to hookup the center radiator hoses. Unfortunately, they no longer sell the kits with the hose sized for a base 986, and I just spoke with Precision Chassis Works, and they no longer sell their adapter (link).

I am hoping to get some opinions on what everyone thinks is the best, most robust way to hook everything up.

Option 1: Use a copper step adapter to connect the 'S' hose to a base. It looks like Pelican Parts does this behind the hard hoses, but I see no reason why this couldn't be done in front of the hard hoses. Thoughts?

Option 2: Use a 'Y' adapter and splice into the existing base hoses.

Option 3: Buy a set of 'S' hard lines and find someone to weld them together with the base hard lines, like the Precision Chassis product.

Option 4: ???

Thanks,
-Rick


EDIT/Solved: Problem solved, Precision Chassis Works responded to me again, and while they no longer sell the modified lines outright, they still offer the modification service.

[Eric523]

If you don't want to fully update to the S hoses, then option 3 is probably best.

The full S hose update is expensive with all of the parts you'll need, and it doesn't appear you need the extra diameter for your application.

[BoxsterSteve]

Check this thread:
Install 3rd Radiator & Coolant System Bleeding Instructions
Pedro fabbed up his own fittings from copper pipe to make up Y adapters.

[jsceash]

Here is what I ended up doing. I purchased the radiator, brackets, mount clips, fasteners, 2 Y hoses, 2 extra original spring hose clamps for the hard pipe to the side radiator hose, and the clamps for the new radiator hoses. Where the Y hoses connected to the old hard pipe I used 2 original wire hose clamps and some high temp silicon on the hard pipe. You will have to work to get the original clamp on the new hose but I have never had a problem or leak. Three years on the clock never a drip.

[rick3000]

Thanks to everyone for the input.

jsceash, what would you say the difference in diameter between the base and S hose is? I would think clamping the bigger hose down would leak, but you are proof to the contrary.

I am leaning toward having the pipes welded, because it seems like the most robust and least likely to leak option. I originally wanted to ask because I have read about both the Pelican step adapter and the Pedro Y adapter leaking or bursting, but having the pipes welded is a pricey alternative (probably $150-ish, still waiting to get quotes). Leaks do not seem common with the hose fittings, but I am getting tired of having to buy coolant, so anything to avoid any possible leaks.

I wonder what the dealer does when someone comes in with one of the old retrofit kits installed that had the y hose sized for the base hard lines?!

[spendy]

I used these guys to modify my existing pipes. Very clean solution. Tried making my own copper Y pipes but didn't like how it went together.


Boxster cooling line modification - PRECISION CHASSIS**** WORKS

[jsceash]

Originally Posted by rick3000

Thanks to everyone for the input.

jsceash, what would you say the difference in diameter between the base and S hose is? I would think clamping the bigger hose down would leak, but you are proof to the contrary.

I wonder what the dealer does when someone comes in with one of the old retrofit kits installed that had the y hose sized for the base hard lines?!

There was about 1/8" (3MM) difference.

In answer to your second question if it's not a Porsche part they won't want to touch it (Mine is all Porsche part numbers). With a "Y" metal adaptor your probably on your own they won't have a hose to fit and won't want to be responsible to cut one.

[jsceash]

You never did say why you were doing this, and your comment to replacing antifreeze is puzzling. I don't believe before the motor swap I ever had a heat issue, after only in continuous stop go traffic. I never had a fluid loss problem.

If you have a 2.7 that is just running hot, you probably have some other problem that needs fixed and this isn't going to stop that other problem.

Most people who have done this have bigger motors in base cars (my case) or some sort of racing or DE purposed car (also my case 21 day this year).

[rick3000]

jsceach, thanks again for the reply/information. My dealer question, was more rhetorical, because Porsche used to sell OEM center radiator Y hoses that fit on the base car with no modification, and I am curious what they do when someone with one of the OEM kit's comes in for a repair and the Y hose sized for the base car is no longer available.

I have a 2.5L base and have been having an overheating issue, which I am fairly confident is either a bad thermostat or water pump. I am about to change the water pump, and install a low temp thermostat, and decided while I have the coolant drained from the car I would also like to install the center radiator to keep everything running as cool as possible.

I track the car a few days a year, but I am primarily interested in keeping the coolant (and in turn oil) as cool as possible to help keep my engine healthy over the long term.

Thanks again for the replies!

[911monty]

hey rick3000; I also have a base 2.5 and can understand your concern. With temps 100+deg and climbing hills in the twists I see my temps occasionally touching the right edge of the 0 in 180. I have a freshly serviced cooling system, LN low temp, New OEM WP and cleaned radiators. My temp in same ambient conditions when driving on freeway are on the left edge of the 180 hash mark. Not to steal the thread but do you currently have or have you considered the S oil cooler? This would be much simpler and perhaps cheaper than the radiator mod and since would have a direct effect on oil temps, may provide the additional cooling needed. I am considering installing one on my car.

[rick3000]

911monty, even before I suspected my thermostat and/or water pump where bad and even when my radiators had just been cleaned, I was often sitting on the right edge of the 0 in 180 or just past the 0. This is why I would like to get my 986 running as cool as possible.

I am actually adding the 'S' oil cooler as well (forgot to mention it above). Perhaps, the low temp thermostat, and 'S' oil cooler, plus the center radiator is overkill?

I already purchased the center radiator (I got a really good deal on it), but maybe I will hold off and see how what kind of temperatures I get with the low temp thermostat and 'S' oil cooler. If I where to hold off on the center radiator, can anyone comment on installing the center radiator without fully draining the coolant system? Would I need to be concerned with clamping off 16 year old coolant hoses?

Thanks!

[911monty]

Rick3000; As others have said and my observations also support, the Low temp thermostat has no effect on the real world temperature the engine will run at. It appears the cooling system is in balance with the heat output of the engine. My engine gets to the same temps it did before Low temp thermostat install. Now when ambient temps are less than 65deg then yes the engine will also be at lower temps but, Since we are looking for cooler oil in high ambient temps then my thought is that even if my water temp is actually 215 deg, 215 would be a lot better oil temp than the 230 deg+ range without the S cooler. (These temps are clearly best guess since as JFP has made clear the temp gauges are less than accurate). While it may seem putting additional heat in the cooling water would defeat the purpose, I believe the cooler oil returning to the oil cooler would ultimately lessen the BTUs into the water system. All opinions welcome.
As far as 16 year old hoses I replaced all my engine end hoses when I did the cooling system and they were actually in very good condition. still very soft and pliable. SO except for some abrasion on one I think they would have been fine. However if a hose fails when you clamp, it needed changing anyway!

edit; Sorry for rambling. Reread your text. I am considering the mods you bring up. I will say that I like to change one thing at a time and evaluate. This way I know what had what effect. Makes troubleshooting a lot simpler if problems arise. Too many changes at once is hard to determine. So that being said I will do the S cooler first then center rad if necessary. May not to have to do the complex stuff.

[mikesz]

you might want to check and make sure your fans are working. I had a overheating problem and one fan was completely dead and the other only worked on high speed. I also changed the thermostat and waterpump and care was much more stable. I do have the S third radiator i want to put in but havent had the time to do it.

[rick3000]

Thanks, the fans where the first thing I checked via the relay click test and jumping them to make sure they came on.

[mikesz]

I had called precision and at the time they said they will still do the mod but you have to send them your hard lines. they dont do the exchange anymore. Some of the guys on the forum have just attached the Y pipes to the exisiting lines with 2 clamps and clamped them down good and it worked. FYI. Keep us posted I want to do this but I like you trying to figure out how to do it.

[rick3000]

Mikesz, see the edit I made to the first post.

I called them back, and I guess I wasn't very clear when I spoke to them the first time. They will still do the modification, but they do not do the exchange. The price is also higher, $100 plus shipping both ways. I am sending my pipes in later this week, once I get some time to remove them from the car. I will let you know how it goes.

[itsnotanova]

Did someone suggest replacing the whole system with S water lines/brackets, and I missed it? That's what some spec guys are doing. That's what I had planned to do to a base boxster I was going to fix up. But then I found an S instead. I have the whole kit for $150+shipping. Getting the water hoses in-between the fuel tank and the body is a major PIA though.

[mikesz]

Finally completed this project! Been over a year. I had Precision do their adapter welding mod. It was the path of least resistance. I thought of the other options but the thought of being 2 hours away from home and loosing coolant all over the highway didn't appeal to me. Total cost to add the S center radiator to my 99 Boxster was about $275 including Precision's cost. Recouped some of my cost sold some left over coolant pipes on ebay. Took me about a day to do with frequent breaks.

[Deadeye]

I am parting a low mileage '01 S and have all pipes hoses etc. PM for pricing etc.