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914World.com _ 914World Garage _ Rear Mounted Auxiliary Oil Cooler
Posted by: earossi Oct 31 2016, 08:34 PM
I can't locate the post; but someone was asking about mounting the front auxiliary cooler for a 6/ conversion project. I had responded about an alternative that involves mounting a cooler and cooling fan in the engine bay of a 914. I have attached several pictures of such an installation. This was not my car; however, my installation was essentially the same as depicted in the attached photos.
The cooler and fan carried a price tag of less than $400. To install the cooler, you have to fabricate some brackets as shown in the pictures. You'll need to route 12 volts to the cooler which incorporates a thermostatic temperature switch to actuate the booster cooling fan when oil temperatures reach a predetermined point. You'll also have to fabricate two short jumper hoses to take suction from the engine mounted oil cooler.
There are a number of these installations out there, including the one in my car. Several are running down in Dallas and work well.
Installing this rear mounted cooler deletes the need for hoses to be routed to the front of the car, and for body modifications needed to mount an oil cooler in the front trunk. The cooler is available from Savage, or from any number of suppliers.
Posted by: Mark Henry Oct 31 2016, 09:30 PM
I posted this set-up a while back done by Henry Schmidt of Supertec Performance .
He stated it brought temps down and didn't affect the cooling of the engine.
It was in an original /6 that the owner put a bigger engine in, but didn't want to cut up the car for a front mount cooler.
It's a modified RX-7 cooler.
Posted by: Perry Kiehl Nov 1 2016, 06:06 AM
I've done three coolers under the rear trunk, sold two kits for the engine lid mount, and did one with the cooler in the right rear 1/4 panel below the sail panel.
I don't like the idea of pre-heating air going into the engine compartment, or oil lines going up to the lid.
The cooler in the 1/4 was the cleanest, but most difficult. It did require a stone shield for the cooler/fan sandwich.
For ease and least amount of trouble, I'd recommend under the trunk.
Posted by: Cairo94507 Nov 1 2016, 07:30 AM
If I had not done the GT front cooler set-up for my 3.2, and it killed me to have to cut open the front trunk to do that, I would have had to think long and hard about the alternative.
Maybe, in my little brain, the next best set-up would be in a rear quarter assuming you could fit an oil cooler in there and plumb it so it was as clean as if Porsche would have installed it and it got sufficient air flow.
Posted by: patssle Nov 1 2016, 07:46 AM
http://imgur.com/a/6u4ew
Posted by: rudedude Nov 1 2016, 07:51 AM
earossi,
How well does your cooler in that position work? What size motor and what oil temps do you run and in what ambient air temps?
Thanks
Posted by: Mark Henry Nov 1 2016, 10:08 AM
I don't like the idea of pre-heating air going into the engine compartment, or oil lines going up to the lid.
Although I agree in principal you do have to look at the source of this mod, Supertec is one of the premier /6 engine builders in the country right now.
I'd kill for a Supertec crank and Pankle Ti rod set.
http://forums.pelicanparts.com/911-engine-rebuilding-forum/432332-supertec-supercrank.html
Henry also stated that although it may not be the best solution, it did work and the customer didn't have to cut up his original /6. This was for a So Cal car.
Posted by: Elliot Cannon Nov 1 2016, 11:55 AM
Here's mine. Fans work great when you're stuck in traffic but restrict the flow of air when they are not running. If you often find yourself in heavy bumper to bumper traffic, a fan might be a good idea though. However my next project will be a front mounted cooler. 
Mostly because I've just about run out of things to do to the car. 
Attached image(s)
Posted by: ClayPerrine Nov 1 2016, 12:05 PM
Here are some pictures of the oil cooler on the current engine in my six. It is a 911 carrera cooler, mounted in front of the exhaust on the right rear of the car. One end is attached to the body side of the trans mount, the other end is bolted through the pinch weld. The cooler sits flat against the underside of the trunk, and the fan is on the front. Not the optimal location for the fan, but it works. The fan is wired to a relay that is controlled by the 911 thermal switch in the cooler. The power comes straight from the positive post on top of the starter. 
It brought the oil temp down close to 50 degrees F. when I installed it.
Now I have to engineer another solution when I get the new motor and trans in the car.
Posted by: barefoot Nov 1 2016, 03:31 PM
In the Lapuwali classic forum:
http://www.914world.com/bbs2/index.php?showtopic=108328
Posted by: SirAndy Nov 1 2016, 04:52 PM
Just FYI, you can run a front cooler without cutting up the front trunk.
Posted by: FourBlades Nov 1 2016, 05:13 PM
I have a cooler with a fan mounted under my rear trunk with my 2270 /4. There are pictures somewhere in my Rocking 914 thread.
On the street it is fine.
At Sebring my engine oil temps would climb to 220 after 3 laps and keep going unless I just cruised every other lap.
The rear trunk without some cold air ducting (I have not tried this yet) is not enough for a track car where you are full throttle most of the time.
John
Posted by: JmuRiz Nov 1 2016, 05:41 PM
Just FYI, you can run a front cooler without cutting up the front trunk.
Is that with the under-bumper 'RSR' valence, or is there another way?
Posted by: Mark Henry Nov 1 2016, 06:07 PM
Just FYI, you can run a front cooler without cutting up the front trunk.
Is that with the under-bumper 'RSR' valence, or is there another way?
I think the two small coolers in the blank fog light grills.
Posted by: Cracker Nov 1 2016, 06:10 PM
No matter the engine...I have tried in vain to do all kinds of whacko solutions to keep the cooling in the rear - it won't work on a real performance/race car.
Tony
Posted by: Mark Henry Nov 1 2016, 06:33 PM
No matter the engine...I have tried in vain to do all kinds of whacko solutions to keep the cooling in the rear - it won't work on a real performance/race car.
Tony
Not everyone has a race car, as far as performance car goes
Posted by: Cracker Nov 1 2016, 06:48 PM
Mark - Although I hadn't quoted FourBlades comment - I was piggy backing it.
Tony
No matter the engine...I have tried in vain to do all kinds of whacko solutions to keep the cooling in the rear - it won't work on a real performance/race car.
Tony
Not everyone has a race car, as far as performance car goes
Posted by: SirAndy Nov 1 2016, 07:11 PM
You don't even need the valence, you can easily mount a cooler under the stock bumper.
I have a pic of a GT somewhere that did just that ...
Posted by: Catorse Nov 1 2016, 07:33 PM
No matter the engine...I have tried in vain to do all kinds of whacko solutions to keep the cooling in the rear - it won't work on a real performance/race car.
Tony
Exactly. If you want the best cooling available, the cooler must go in the front. period. end.
Posted by: porschetub Nov 1 2016, 08:15 PM
Here's mine. Fans work great when you're stuck in traffic but restrict the flow of air when they are not running. If you often find yourself in heavy bumper to bumper traffic, a fan might be a good idea though. However my next project will be a front mounted cooler.
Mostly because I've just about run out of things to do to the car. Isn't yours a 4,yes it is ,I think the cooler needs to be set up @ right angles to the truck floor to get flow,wouldn't the fan be working overtime if not mounted that way?
My cars already cut up front which is a pain I need a piece of panel to weld in,car originally was set up for a 3.0.
Posted by: JustinMeier Nov 2 2016, 12:40 AM
I have a 2.7 and the cooler was put in the trunk with an aux fan.. I can't keep the thing cool at all when temps are over 80, and forget traffic.
Posted by: mb911 Nov 2 2016, 10:55 AM
I posted this set-up done by Henry Schmidt of Supertec Performance a while back.
He stated it brought temps down and didn't affect the cooling of the engine.
It was in an original /6 that the owner put a bigger engine in, but didn't want to cut up the car for a front mount cooler.
It's a modified RX-7 cooler.
I just talked to Henry the other day and he said he has one Just like this he would sell to me.. Looks cool
Posted by: socal1200r Nov 2 2016, 11:27 AM
I don't know much about 914s, so I'm guessing the stock coolers, if they have one, are pretty piss poor in function?
To me, it makes no sense to mount an oil cooler anywhere near the engine compartment. Isn't the purpose to COOL the engine oil? At the very least, it should be positioned like the one a couple of posts above, with its own "grill" next to the back window. I doubt this area gets any air directed down onto it, but at least the heat has a place to go. I would think that if someone really wanted to cool their oil, they'd mount it up front like an intercooler and run the lines to the back, or even mount it like it's done on the green 914 but in the front trunk, where it'll be in the air flow.
If you REALLY wanted to cool it, and valued function over form, one could put a small scoop on the front trunk and mount the oil cooler directly underneath it. Think a small rise Subaru scoop (WRX?), styled like an STI scoop but not as tall. I know, blasphemous...but I'm sure it would function a lot better than a lot of these locations in this thread...
Since most oil coolers are rectangular in shape, a matching shape in a hood scoop should work quite nicely...
http://parts.glanzmann.com/p/Subaru__Impreza/Hood-Scoop/49924556/90821FE080NN.html?partner=BingShopping
https://www.amazon.com/04-05-SUBARU-STYLE-CARBON-FIBER/dp/B01LZO2NF4/ref=sr_1_4?ie=UTF8&qid=1478106708&sr=8-4&keywords=Wrx+Hood+Scoop
'Course one could also mount it on the inside of the rear fender, and use a vent piece like this, with the openings pointed towards the front, to force air thru the cooler as well.
https://www.amazon.com/dp/B01J0OZ1XM?psc=1
But if I were to tackle something like this, I think my first choice would be doing something like the cooler with its own grill behind the rear window, but putting it on the front hood somewhere instead. Next would be on the front hood, but with a small scoop. Third would be at the rear window, like the one pic shows. Last choice would be anywhere in or near the engine compartment.
Posted by: Mark Henry Nov 2 2016, 12:15 PM
I don't know much about 914s, so I'm guessing the stock coolers, if they have one, are pretty piss poor in function?
In stock form, stock engines the coolers are fine, for the most part we are talking about bigger than stock engines or race cars.
If you REALLY wanted to cool it, and valued function over form, one could put a small scoop on the front trunk and mount the oil cooler directly underneath it. Think a small rise Subaru scoop (WRX?), styled like an STI scoop but not as tall. I know, blasphemous...but I'm sure it would function a lot better than a lot of these locations in this thread...
Since most oil coolers are rectangular in shape, a matching shape in a hood scoop should work quite nicely...
http://parts.glanzmann.com/p/Subaru__Impreza/Hood-Scoop/49924556/90821FE080NN.html?partner=BingShopping
https://www.amazon.com/04-05-SUBARU-STYLE-CARBON-FIBER/dp/B01LZO2NF4/ref=sr_1_4?ie=UTF8&qid=1478106708&sr=8-4&keywords=Wrx+Hood+Scoop
That's real rice
Sorry the whole reason guys don't want a front cooler is because the "best" way to do this is cutting a big hole into the front of the chassis and of bottom of the trunk, mods you can't even see from the outside when done.
A good number of us hate to drill even a single hole into our cars.
Posted by: SixerJ Nov 2 2016, 05:10 PM
I like the idea of a rear cooler on the grounds of clean lines, but far from convinced in its effectiveness in comparison to traditional front mount. The factory had lots of experience with what was effective and what was not
If you are going to do a front cooler don't do what my cars PO did and cut a hole in the front then vent out the hood without a well fitting ducting solution
A) it looks
B) when traveling at speed, hood hinges cut through windscreen slam panels really well once the hood goes
Posted by: sjhenry1075 Jan 17 2017, 02:38 PM
At what point do you need to think about adding an extra cooler? At what displacement is the stock cooling system no longer effective? I know a lot of it depends on driving, but minus any sort of racing, is there a standard for when to add an extra cooler?
Posted by: MoveQik Jan 17 2017, 03:14 PM
I've been running this set up on my 3.2 since 2006 with no issues. I like to think Arizona is a pretty good test bed for cooling needs.
Excuse the mess....this was pre-paint/detailing. 
Attached image(s)
Posted by: JmuRiz Jan 17 2017, 03:20 PM
Good to know, I have the same cooler, going to mock-up that location when I plan mine out. How are your lines routed, and what's your thermostat set for...that may have something to do with it too.
Posted by: 6freak Jan 17 2017, 04:07 PM
I have a 2.7 and the cooler was put in the trunk with an aux fan.. I can't keep the thing cool at all when temps are over 80, and forget traffic.
how do you get airflow if its in the back boot, im assuming its the back...
Posted by: BeatNavy Jan 17 2017, 04:38 PM
At what point do you need to think about adding an extra cooler? At what displacement is the stock cooling system no longer effective? I know a lot of it depends on driving, but minus any sort of racing, is there a standard for when to add an extra cooler?
To this question, I think most well-built/tuned 2056's are probably fine with the stock oil cooler. That's what I have, and temps get to 220, but that's about it. I've looked into building/buying a 2270 at some point, and based on the reading I've done I'll definitely need an external oil cooler at that point. May not have to be front-mounted, but something external will be required.
Posted by: stugray Jan 17 2017, 05:23 PM
I installed mine in the front headlight buckets behind the foglight holes.
http://www.914world.com/bbs2/index.php?showtopic=56102&st=240
This is a pic before the vents and duct to dump out the wheel well was done, but you get the idea.
Now that the car is done, you cant even tell they are there.
And there would be room to keep the headlights if I wanted to.
One of the two coolers has a fan, but I havent even had to use it yet, even during a race
Posted by: Dave_Darling Jan 17 2017, 10:25 PM
At what point do you need to think about adding an extra cooler?
When your oil temps are too high, of course!
There isn't any single displacement or power level that requires a cooler, it varies from case to case.
--DD
Posted by: JustinMeier Jan 18 2017, 09:24 AM
I have a 2.7 and the cooler was put in the trunk with an aux fan.. I can't keep the thing cool at all when temps are over 80, and forget traffic.
how do you get airflow if its in the back boot, im assuming its the back...
Exactly!!!!
Why it got put there is beyond me. However, I could use the holes where the cups for the top are to pull in fresh air from the grill. This of course means that I wouldn't be able to store the top in the trunk. Hope that makes sense.
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