A/C and Intercooler - Need Advice

[polizei]

Hey Guys,

I'm on the cusp of taking the next steps in my multi-year attempt to turbocharge my 3.2 Carrera, and I need your input! After much consideration, I've decided to go with an air-to-air intercooler rather than water-to-air. The complexity, maintenance and expense of a water-to-air IC deterred me, though I still think it's a really cool solution

I'm planning to replace my Carrera whale tail with one that has provision for an I/C (either 930 or an aftermarket RS America wing - Porsche Rs America Wing Tail Spoiler: Body &amp Tails, Wings Related). The plan is to run 1 BAR of boost. The car will be primarily used on the street, but I do want to run in a few DE events per year. I'd like your help to sort out a suitable combination of an I/C and A/C condenser. My concerns in order:

1. I want an efficient enough I/C that I can enjoy DE events without being stressed about the likelihood of detonation.
2. I want an efficient enough A/C system that my wife will be reasonably comfortable when driving in the summer.

On the detonation end of things, I'm planning to run twin plugs and dual Carrera oil coolers in the front wheel wells.

So what do you think a proper I/C and A/C condenser solution is for me? I don't believe that an OEM style 930 I/C will work (without modification) with a Carrera intake manifold. If I modified a half bay I/C to work with my Carrera IM, would that be sufficient cooling for DE events? Or is a full bay I/C the best choice?

On the A/C condenser end, I've heard of guys relocating their condenser to a wheel well or under the belly. Griffiths has a solution to run dual condensers in the driver's side rear wheel well, and this can be run with or without the rear engine bay condenser (Griffiths supplies a range of air conditioning components for your Porsche 911,911s,911t,911 turbo, and 930, such as: Porsche air conditioning upgrades, Porsche air conditioning improvements and updates: Porsche barrier hoses and hose sets, Porsche c).

Thanks for your input.

[sjf911]

I put a 993 condenser in the left rear wheel well to make room for a full bay intercooler. AC works fine but it does require making custom hoses which was a PITA.

[Ken911]

Think thats where i am going with mine, left rear wheel well. The condenser in the wing is also hard to find. when I swap to efi it will be with a carrera intake and a full bay intercooler. I think griffiths has the hoses to make the swap also but not positve. You probably already know this but, make sure if you put a condenser in the wheel well there is a stone guard and a fan.

[polizei]

Thanks for the feedback guys.

Steve - What kind of temps/humidity does your car see? In PA, we max out usually around 90 F. 100 F once in a while, but that's approaching record temps. Humidity is moderate. Here's a picture of Griffiths rear wheel well solution:



You can either run a single condenser behind the wheel or two condensers (one in front and one behind). I'd be tempted to jump right to the dual setup to ensure that my car stays cool and avoid re-plumbing if just one doesn't cut it. Thoughts?

Also, is there a general, practical rule of thumb for when you should take the jump from half bay to full bay I/C?

[Ken911]

that kinda sucks for me i have a slant with the brake vent in the way for a front one and the intake pipe for the turbo will most likely be in the way of the rear.

[wwest]

You can solve both the A/C and intercooling limitations using 2 radiator cooling fans mounted in the spoiler. My '88 Carrera isn't turbo but the fans improved my A/C efficiency, effectiveness, so much that I was able to disconnect the front condensor blower/fan.

[sjf911]

Originally Posted by polizei

Thanks for the feedback guys.

Steve - What kind of temps/humidity does your car see? In PA, we max out usually around 90 F. 100 F once in a while, but that's approaching record temps. Humidity is moderate. Here's a picture of Griffiths rear wheel well solution:
You can either run a single condenser behind the wheel or two condensers (one in front and one behind). I'd be tempted to jump right to the dual setup to ensure that my car stays cool and avoid re-plumbing if just one doesn't cut it. Thoughts?

Also, is there a general, practical rule of thumb for when you should take the jump from half bay to full bay I/C?

We see 90's to low 100's at peak summer with low humidity. The real problem is the coupe doesn't ventilate well and heats up even on mild days with the windows down.
I also upgraded to the larger front condenser, replaced the evaporator, and blower fan.

[forte500]

Not sure why you would go thru all this trouble? I have the factory A/C in the factory location, albeit continue to use the R12 refrigerant (get at classic car rebuilder) and it's COLD air. I use a std Kokeln intercooler and carerra intake. Car puts 500RWHP at .8BAR.

[forte500]

And easy to work on.....

[Uwon]

Happy New Year,
I thought that I would share my own experience in converting the 911 Carrera A/C system to something more acceptable.
I live in an area that suffers from periods of high heat and high humidity in the summer and about eleven years ago I embarked on a mission to improve the a/c to an acceptable level.
I did look at the various aftermarket systems out there and in particular those that place the condenser in the rear wheel well. My personal opinion has always been that you should strive to get the condenser as close to the evaporator as possible and that the condenser should stay away as much as possible from artificial heat, i.e. the motor, particularly a turbo like mine.
I replaced the compressor with a used one from a 993 (currently $200-300) (see pic). I also removed the rear deck condenser and installed a new one (currently $220 after market) which I installed in the Left front fender (see pic). It hangs from the bottom of the headlight bucket and has a 11” stabilizer arm (see pic) arm attached to the front torsion bar pickup point. I kept the OEM front condenser as it was newish but would not bother to do the same next time. I purchased the largest shallow fan (11” dia. X 3” thick) I could fit (currently $120) and installed it on the 993 condenser and set it up to engage every time the compressor came on. I added a center vent under the dash (see pic). I did replace all the lines as they were original and suffered from some pin-hole leaks. Finally, I did the necessary conversion to R134a refrigerant.
The unit has worked flawlessly for nine years. We have travelled to various PCA events in the southeast in the dead of summer heat and humidity and we have always stayed cool. In fact, the unit has rarely been turned on to full blast. As a result of an unfortunate crash at Mosport in 2009, it is currently being moved over to my new project car without any changes.
If you or anybody else would like any more information or pics, just PM me.
Cheers

[spence88mph]

Great write up Uwon, a few have considered a similar approach but not actually tried it out, I'm sure your system will be the start of many similar conversions. Love to know more about your car too, that intercooler looks huge!