Rear condenser fan (no tail)

[echecsqueen]

Does anyone know a fan that will fit below the rear condenser in a 3.2? 1988 911
Clearance is tight- i dont have a turbo tail and need additional air flow over my rear condenser due to city driving.

[RSTarga]

Do you have a front condenser with a fan?

[echecsqueen]

Yes. But in our heat it isn’t enough in stop and go traffic

[RSTarga]

Spall makes quite a few different fans, you have to determine how much clearance you have. Where is Rawknees when you need him. New Orleans is tough.

[RSTarga]

Do you have enough room for these?
https://www.spalusa.com/products/fans/14/va08-ap51-3-c-23s-12-14-7-s-3-12v-30101510?returnurl=%2fproducts%2ffans%2f14%2f
Make sure they are suckers not blowers.

[Ctopher]

I had mocked up a SPAL puller fan but never installed because I wasn’t happy with the mount. I was using the SPAL fan mounts and let the project hang around without finding a different mount. The fan was a 7.5in and I think I could mount a 6.5in in the center.






The fans I bought:
7.5″ SPAL Pull Type Electric Fan – 30100394
6.5″ Pull type – SPAL electric fan – 30100402
Spal 30130013 Fan Mounting Rod with Cushion

Honestly a larger washer with some foam or rubber under it would probably be a decent mount that won’t pull through, that was why I stopped. I got pulled into resolving the rising oil temps by pulling lines and cooler to get cerakoted with a dissipating paint and to install a lower temp sensor to kick the fan on sooner.

Also I was looking at installing a Porsche relay in the panel and use that to power the fan(s) to keep it somewhat stock looking.


CTopher

[echecsqueen]

I think I could concoct a mount if I could get shallow enough fans. Maybe even use a badge on the outside to steady the screw so that there would be no pressure on the condenser fins. I have a Trinary switch and could easily wire to either the compressor or to the relay in the engine compartment.


Does this heater blower motor coming on at idle help or hurt me? The shroud over the heater motor is one of the rate limiters as far as room to put the fan. Do I need it?

Where is rawknee when we need him. He ghosted my threads last year?!

[echecsqueen]

Btw ctopher- your engine bay is sooooooo clean. How do you do that?

[Ctopher]

Originally Posted by echecsqueen

Btw ctopher- your engine bay is sooooooo clean. How do you do that?

I know my engine bay heater fan would kick on and help lower temps, thus why I went the front cooler upgrade. I wanted to keep my car mostly stock and having it run automatically, I thought was a good thing.


Thank you. Just basic cleaning. I use simple green aircraft cleaner in a foam cannon. Spray the whole engine bay and using wheel brushes, listed below and the detail brush. The little brush and boar hair brush were mostly used with the Go Detail brush for frame rail, etc. Rinse and foam again and go over stuff again. A good rinse and the best secret is to use a dressing. I’ve used Meguiar's D17001 Hyper Dressing mixed to the lowest shine and recently changed to CarPro PERL in a 1:4 low shine. Just spray it over everything, give it a good heavy mist on everything and close the lid, you are done. You can wipe everything if you want but honestly I’ve been doing this on all my cars and I’ve never wiped any and they level out nicely. Of course it’s nice to do this on a very slight warm car and running it a few mins after spraying the dressing to put the car up might help dry it faster but not needed.

EZ Detail Big and Little Brush Combo
EZ Detail Go EZ Detail Brush
Boar Hair Detail Brush

Good luck and it’s best to do this first before washing the car. And by the time you’ve washed the car it’ll be looking amazing.


CTopher

[RSTarga]

You can mount the fans using nylon pull straps, very simple. Two similar fans would seem to be the ticket.
It is unfortunate you went to R134, R12 works much better when you have fewer condensers.

[echecsqueen]

San Antonio is pretty similar- at the time I didn’t know staying with r12 was an option.

I thought that getting the engine bay wet was a problem so I have never cleaned mine.

[Ctopher]

Why? It gets wet when you are driving in the rain.

You can do it the hard way with a hand sprayer of solution and do small bits at a time but that is a lot of work and takes a long time. The EZ detail brush works great, just stick it where it’ll fit and go back and forth and the Go brush gets in the back where it’s hard to reach. I’ve been doing this for nearly 6yrs I’ve own the car. I use a Kranzle pressure washer with a 40deg adapter @ 1k psi, enough it doesn’t hurt the hand. Just stand back and spray, don’t get close or stay in a single spot. You are washing away the light dust, the foam and scrubbing does all the hard work. I use the same method on 00’ S2000 and 06 Civic Si for years too.

I know people cover up electrical items and you can do that too. You can also pull your negative batt cable if you want. My car still has the fuse cover and I just lightly spray that area. Most parts of the car were made to get wet anyway and the alternator is somewhat protected by the fan. I just give it a quick spray that’s it.

Good luck.


CTopher

[RSTarga]

This comes from Frank Beck in Scottsdale:
Assuming that you're starting with a factory Behr system here are the challenges:

Insufficient fresh air flow across the condenser(s).
Inefficient evaporator and too far away from the dash vents.
Evap fan is inefficient causing low volume.
Stock York compressor is way too large in cubic inches.

A stock Behr system when operating at maximum efficiency in 110 degree heat will easily drive oil temp to 280 degrees. (I've seen 300+ which eventually makes mush out of a mag case.)

The goal is simple: Increase fresh air flow to the condenser(s) and optimize components given the stock space considerations. Unfortunately execution is a completely different animal. In a perfect world on a stock car here are my suggestions:

Rotary compressor no larger than 7". (We've used as small as 5" with good results.) Or a 6" York if you want a factory look.
Griffiths evaporator, fan, and expansion valve. (The old school expansion valves these systems use are adjustable and you can play with pressures.)
If you're hellbent on retaining the engine pre-heater (AKA rear condenser) it's mandatory to have a second condenser that gets lots of air flow (I.E: David's upright condenser in an RS spoiler.) The 70-73 cars that used the robust squirrel cage fan on the front condenser are much more efficient than the later ones however they use a sheet metal housing that's part of the fuel tank support.
Install a Pro-Cooler. A wonderful device brought to market by Ron Maxwell decades ago. It's a freon jacketed pre-cooler.
Replace all hoses of course and insulate ducting.


If you're building a hot rod and unafraid to modify here you go:

69-73: Single mastectomy of the left battery box and fit a 964/993 condenser and fan assembly. Earlier and later cars this area is open and available.
Lose the engine pre-heater.
Pro-Cooler.
Efficient rotary compressor.
Griffith's evap and fan or if you're really a cowboy mount some type of evap, fan, and expansion valve box closer to the dash. You want the evaporator as close to your face and crotch as possible. In this scenario it's not even necessary to run an aux oil cooler. If the stock rear condenser is used you'll most likely need one.

Misc:

Huge under body condensers like Performance Aire used to sell are worthless in very hot, dry climates. All they do is pick up heat from the asphalt.
Rear wheel well condensers with fans are not horrible but generate much more heat than front mounted.
Aways use R12. I couldn't care less WHAT anyone else tells you. You can expect a 4-8 degree vent improvement over 134a.

Good luck.

[RSTarga]

If this is for your 88, this is way better than a rear fender mount.

[Anjizkit]

Oh interesting. I thought R12 is practically illegal and banned. You can still get access to it? Do yall just cLl around and Check different shops?


Sent from my iPhone using Tapatalk

[pavegeno]

Originally Posted by echecsqueen

Does anyone know a fan that will fit below the rear condenser in a 3.2? 1988 911
Clearance is tight- i dont have a turbo tail and need additional air flow over my rear condenser due to city driving.

I just did a 6 hour round-trip in my 88 911 3.2 yesterday to a cars & coffee event to meet a friend near Mobile, Alabama. Temperature was 95 and the temp over the road was 99. Humidity was very high. By 10am when I departed the event, my t-shirt (GT3RS by the way) was soaked and I had the Cab open the entire time so the car was very hot.

I drove away with the top up and my Griffith's 4-condenser system (engine lid-no fan, front condenser with stock fan, and two left-rear wheel well condensers with electric fans) and R-134. I drove 10 minutes on the interstate to pick up my son. The interior was already cool and vent temps were in the low 30s. I then idled in the parking lot waiting for him for 10 minutes. My rear plastic window was obscured by the condensation on the outside. My engine oil temps never got above the first narrow (90C) mark while idling.

Once he got there we decided to get a quick bite so I turned the car off and forgot to put the sunshade up. Twenty minutes later we came out drove away. Ten minutes later the car was cold and stayed that way for the next 85 minutes. We were driving into the sun for the first hour. I do not have any tinting on the windows.

I have found the extra condenser area in the left-rear wheel well with integrated fans to be the biggest game-changer in challenging climates.

My performance is the same in stop-and-go traffic with no noticeable changes in engine oil temperature.

Good luck!

[917_Langheck]

R12 is mostly illegal and not for retail sale, but if you have the proper certs you can get it here: https://www.refrigerantdepot.com/product/r-12/

Just need the $$$ and wishful thinking and you can have a cool car....

Or maybe apply more modern insulating practices to the tin can we're driving.

[echecsqueen]

I really appreciate all the help.
This is my 88 that I am referring to.
Has Griffith front condenser, Griffith evap and evap fan/ expansion valve, Griffith hoses and drier
Stock style compressor
Stock rear condenser
In stop and go traffic, exterior temps 105+ with 90 percent humidity and several feet below sea level, i generate such high pressures on the high side that my cut off switch cycles the compressor before the car fully cools.
The r134 is the appropriate amount
The cut off switch is high side 375 psi
The ambient temp stuck in traffic on asphalt near the engine is more that 130 degrees.
So other than cooling the rear condenser or adding more condensers, I have no idea what I am missing. And yes the fromt condenser fan (stock) is working.

[echecsqueen]

Originally Posted by RSTarga

If this is for your 88, this is way better than a rear fender mount.

What is that, RST?

[almostordinary]

subscribing.

I want to add AC over the "winter" here in Los Angeles, and do not want to put a condenser above the motor. (whale tail delete 87 Coupe)