I've spent months scouring this and a couple of other websites for anyone successfully running a rear mounted radiator in a bug, over a period of time. I've yet to find any one. I'd prefer running an above-the-transaxle setup if possible. If you have this type of cooling setup, could you share your experiences and possibly pics? I'd like to use the car as a summer daily driver, so a solid low maintenance system is a must.

Thanks in advance for your feedback!

-Rob

midlifecrisis should chime in here, they're baja ran a rear mount radiator with no issues Maybe sent em a pm.

This was on a baja, with the radiator mounted at teh rear of the barwork.

Thanks bajachris88, but I'm more looking for confirmation that there is ample airflow above the transmission to support sufficient cooling. Anyone else?

Hi

Airflow under a Beetle is not ideal. I'm having brain fade but a guy on here did a rear mount in a bay Kombi very successfully, his setup is different to what you will need but his attention to detail netted good results.

Have a read on this forum as well http://vwkd.com/ 

What sort of Beetle is it and what sort of motor are you planning to use?

Lou on here has rear mount in a Beetle sports sedan but it takes up the whole rear seat and he's had some cooling issues.

Steve

The beetle is a 72. The engine currently is a ported 12a. I will most likely change that up to a 13b TT once everything else is done. Little heat generators they are.

I'm not sure I've checked out that website yet. I'll dig in and see what I cant find.

Thanks!!

Hi

Is it a Super beetle or standard? Are you in Australia?

I'm not sure where you are located (please fill your profile, it helps to know where people are located), in NSW you must multiply the Beetles standard tare weight by 3 for NA and 2.5 for turbo motors.

The heaviest Beetle sedan is a 1303 or L bug, they come in at 890 kgs.

So NA you can run a 12a which on a 1303 weight calculates out to 2670 cc max or turbo you can only run 2225 cc motor.

Steve

I'm actually from the US. My bug is a standard.

OK, well disregard what I said unless you live in a nanny state like I do

radiators make a lot of heat , so you need to insulate the back of the car good, some people have radiators heating there homes
A lot of people forget about serviceability and will it be easy to work on does it need to be removed to work on motor or trans etc.
good luck

For what its worth, not much likely, but I ran a Toyota MR2 (ebay brand new) above my transaxle (auto) in my VW trike (Subaru ea81 conversion). Much more air flow than a standard beetle and still both thermo fans (12") came on at 100kph every 3 kms or so on a day of 22 degrees.

Eventually an Alfa 33 radiator went to the front and no issues.

The Alfa33 early type is no longer available in Oz. The later one is 80mm taller and 50mm slimmer fully imported only.

Member "Joel" from memory has had an Alfa early type radiator rear mounted in his bug. He is da MAN to speak to. Has helped me heaps on my supercharger.

Tweety,

Your setup is totally different than mine, so there is much to compare with. Joel's setup was a BIG radiator up front. Its not looking good for a rear mounted radiator.

Thanks!

Hey Joel,

I must have pulled up the wrong pic. I'm starting to see that. I really didnt want to run lines to the front, but I'm not seeing an alternative. About your alfa radiator. What model is it and how well does it work? Thanks for chiming in!

Its worked well for over 3 years on a high compression 2.5 with A/C condenser in front of it.

It's for 79-90 Alfa 33, sprint and Sud but it seems they are impossible to get in the US and even now here in Oz (if anyone one wants one let me know)

I would go slightly bigger with a rotary engine as they run slightly warmer.
There are easier to get and cheaper alternatives to the Alfa rad.

Mk1 Scirocco/Golf 8v are similar size but just slightly bigger and you can get the thick core racing aluminium ones which is what I'm running in mine now.
THey fit a standard beetle front wheel well nicely.

THe only time my fans run is after I've stopped moving for more than 4-5 mins, when I'm driving they never come on and it just sits on the thermostat opening temp.

running coolant lines to the front and mounting a rad in the spare wheel well is a pain but it has lots of benefits.
The long lines means you have much more coolant capacity, conductive pipe work means free extra cooling in the road draft and the radiator is where all the natural air flow is so just a small intake hole is all you need.

This is all my old rotary powered bug had for air intake, with bumpers on it and the mesh painted black you couldnt even notice the intake.

This is probably how I'ts going to be. I'll probably try the scoop method under the apron first, and then if that doesn't supply enough air, go to your setup.

On a side note, what did you think about the move from rotary to Suby? I've toy'd with it, but already having the rotary conversion, its hard to walk away.

Im not a good one to ask as I'm not a rotary guy at all and bought that bug with the intention of swapping it to Subi as it was already setup for water cooled.

The rotary screws with the handling too much, fine in a straight line but it throws off the center of gravity, not enough to worry some people but I like my cars to corner really well.

Try thjis for a bit of info

http://www.offroadvw.net/bajawes/ 

I also run a radiator on the back of my manx, have done for about 5 - 6 years .....relies on the thermofan a bit more then i would have hoped but I am still yet to play with different things like restrictors like the boys in the USA and maybe an aftermarket thermofan controller in place of the ECU control off the water temp switch on the coolant manifold.....which is setup to work perfect in the conventional format but may not be ideal for less airflow in the low pressure system at the back of the car....other things like running a rear window may help with my setup but its done its job so far ...I just need some time to tinker....



the Geko Ute buggy also has a radiator above the gearbox without issues....bit of a trick to bleed and burp but there seems to be enough airflow around there.....the arguement that airflow pushes up past the gearbox and over the motor seems to be somewhat valid.....

all of these vehicles have been on the road for quite some years....theres no doubt that up front is optimal but theres limited options without hacking into the looks of your car...from an offroad perspective I put mine up the back to avoid catastrophic damage in the event of driver error

While your car is too different of a setup, Bajawes is almost exactly what I am looking for. I'm not sure if it being a baja will change the air flow much, but its the first thing I've seen that at least validates a possibility of it working.

Thanks for that!

if I was to do it all again I would stick the radiator in the front. I think my problem is that with the twin turbos running on a race track at 6000 rpm plus the heat generated by the turbos and the air going thru the radiator is just too much to get rid off. Last weekend I ran my car without the whaletail and just had the whole rear exposed and it still got hot but did take a couple of laps before it got to 120 degrees. I get enough air across the radiator with my two scoops but I am not getting the air out the back efficiently enough to keep temps under control. (handled like shit too!)

I'm not giving up though and am about to start work on reducing the hot air inside the engine area as well as re-route the turbo cooling lines etc. Oh what fun!

What kind of radiator are you running? Any chance of pics of your setup? My engine wouldnt put out the heat that yours is. At this point, I feel like I'm grasping at straws to keep my rear radiator setup, but I really dont want to have to string hoses to the front of the car and then hack up the front sheet metal.

seach tampico racecar lots of photos there. Agree with Shuffs it's getting all that hot air out that's the problem.

This is a good summary of my V6 conversion;
http://www.offroadvw.net/bajawes/Big%20Bad%20Baja%20-%20Part%202.pdf 

I found on the highway it would get a little hot as the area above the gearbox would be a deadzone of air flow. I put this little temporary scoop on the trailing arm and it works so well it's been there ever since. The V6 has been in the car for 10years now. I unbolt it when I go offroad or up the beach.





The hot air goes out over the top of the engine. In a beetle you'd need decklid lifters and/or additional vents in the decklid.

If you end up with a rear radiator, the xj jeep cherokee rad from about 83 to 86 is almost the same dimensions as the beetle firewall, if you can fit this with enough space and pressurise it with air from underneath or from naca style ducts in panels behind rear side windows it may work for you, the heat should flow over motor and be drawn out bottom of beaver tail which is a low pressure area.
I have not run this but this is what i set up with subaru motor in a 64 beetle before changing my mind and sticking it in a bay window, i still have the jeep rad in the rear, it is not sealed and cools ok when moving, i hope you try the rear set up and succeed.

Here is a rear rad setup
http://bb.bbboy.net/vwengineconversions-viewthread?forum=8&thread=89 

Hi Rhowde
Yeh a rear mount radiator is do-able. mine is a Baja as smileys says but quite suitable conversion for a std beetle rear end. I used a alloy aftermarket chinese V8 jeep Cherokee 3 row radiator horizontally over the subi EJ25 engine, it is all covered by a fibreglass beetle / Porsche replica whale tail hinged bonnet. the jeep radiator doesn't have a cap housing with was ideal as I welded a billet alloy cap housing into the side of the radiator which pokes thru the whale tail.

works great, plenty of air flow over the roof and caught by the whale tail. I will add some photos tonight.

Here's some reading for you
68 started with a rear and then switched
http://www.dunebuggyarchives.com/forum/topic_show.pl?tid=1491 
Green bug shown earlier with rear radiator:
http://shoptalkforums.com/viewtopic.php?f=19&t=143859 
Ghia with rear rad:
http://shoptalkforums.com/viewtopic.php?f=19&t=141390 
front mounted:
http://germanlook.net/forums/showthread.php?t=10369 

"Put it in the front"
"Put it in the front"

come on everyone, you know the words

"Put it in the front"...........

If the goal is to preserve the original bodywork as much as possible why not try a "whale-tail" engine lid and put the radiator inside?

Pressure recovery would not be optimum, but at least it would prevent recirculation. The flow might actually be upward through the radiator since the air speed above the tail would be greater than the air speed below.