Ok set point has been changed. The reason it shows 0 amps is because the car wasn't running. Tomorrow I'm going to test driving in 94 degree with 65 humidity from the garage. I already know heat soaking in those conditions will not recover.

Hi Guys, looking at the trace, your "cabin" temperature being 6C suggests you have the sensor in the outlet of the vent. This is why you had to set the cabin setpoint so low to get the compressor to work. Your compressor is running at 52% speed in the screen shot.

More often, the sensor goes in the return path of the air from the cabin to the blower inlet so the setpoint is more like 21C.

Either way is ok.

Nditiz1, it would be useful to see a screenshot when the system is running so we can see the compressor speed and current draw.

As you have discovered, heat soak is the enemy. These cars have very little insulation and no UV rejection on the glass. Adding a second condenser increases the ability for the system to reject the heat, especially when it is humid. This does improve the cool down speed. With a single unit, it will get there eventually, but extreme heat soak and short trips do not make that easy.

EDIT* - disregard the -1.5 Evap readings are they are a fluke due to system glitch.


Ok just got back from my test. The car felt great up until I needed to go inside the store. Here are the values for logging purposes

Temps were 90F with 56% humidity
Set out at 1:14, Cabin temp 74.3F, RC CTemp 24.4, Didn't get initial Evap Temp, but most likely 24.4

1:18 Cabin temp 74.3F, RC CTemp (TC) 24.4C, RC Evap Temp (TE)-1.5C, Vent temp 46F
1:24 Cabin temp 76.2F, RC CTemp (TC) 24.4C, RC Evap Temp (TE)-1.5C, Vent temp 46F
First light since highway
1:29 Cabin temp 77.3F, RC CTemp (TC) 24.9C, RC Evap Temp (TE)-1.5C, Vent temp 46F
Parked at store underneath part of a tree
1:33 Cabin temp 77.3F, RC CTemp (TC) 25.8C, RC Evap Temp (TE)-1.5C, Vent temp 46F

So as long as I didn't let the sun heat soak the car, it could have been driven all day in the hot sun with cold air blowing at the highest speed. The final temp outside the store was 92F, similar humidity

I was in the store for about 30mins. The windows were all up.
2:00PM Cabin temp 93.3F, RC CTemp (TC) 30.8C, RC Evap Temp (TE)27.8C, Vent temp 90F
2:04PM Cabin temp 92.3F, RC CTemp (TC) 30.9C, RC Evap Temp (TE)17.0C, Vent temp 61F
2:07PM Cabin temp 89.2F, RC CTemp (TC) 30.3C, RC Evap Temp (TE)17.0C, Vent temp 58F
Kicked blower speed down to 2
2:15PM Cabin temp 88.8F, RC CTemp (TC) 29.2C, RC Evap Temp (TE)15.1C, Vent temp 52F
Stop light after highway with blower speed on 1
2:21PM Cabin temp 89.0F, RC CTemp (TC) 28.6C, RC Evap Temp (TE)12.0C, Vent temp 50F
In garage
2:23PM Cabin temp 88.4F, RC CTemp (TC) 28.6C, RC Evap Temp (TE)8.9C, Vent temp 46F

So as you can see I was able to get colder air out of the vents by decreasing the air flow - this is nothing ground breaking as it had been stated before, but it is interesting to see. At a certain point though the cabin actually increased due to lack of air flow. So even though it was colder from the vents it was not cooling the cabin enough to combat the heat and sun. Setting 1 seems to be useless in hot settings. Also, since -1.5C seems to be the floor for the evaporator I see no reason to kick down to blower setting 2 when heading out as the air coming out will be the same. If it is not freezing your butt then let it blow. Also, when the car was heat soaked as it was 17C seemed like the coolest I could get it at full blower speed. I am wondering if the second condensor drops the TE down to -1.5. That would make a heat soaked car get back to a comfortable place quicker. By the end of the trip it was not hot inside the car, but it wasn't as cold as the first leg.

Here is the latest 3d print duct I am working with. I took Stefan's build and modded it slightly as the previous version he sent it was not directional. I sent him my render and he had already created one. I can send the STL's to anyone needing them. His version looks nice, but I would like to see grills as I feel these make the air feel like it has more force.

I'm in the process of working out a 2nd condensor in the drv rear fender. Classic Retrofit has it for $400 + shipping + cost of the hose. This could be closer to $500. A Nissen Condensor runs about $85 and a SPAL fan is about $55. I would just need to fabricate a holder for the fan, run wires to hook this fan into the harness, get some #8 burgaflex hose, and 2 burgaclip letter "E" fittings and ear clamps.

IMPORTANT NOTE* - this is a costly oversight (single condensor). Removing the Freon and readding will add to the costs as well. If you live in a climate above 85F and would like to drive your car after it is heat soaked you WILL need a 2nd condensor - buy it.

http://live.staticflickr.com/65535/5...cb13bd87_c.jpg

Stefan's 3 piece system

http://forums.pelicanparts.com/uploa...1626292247.jpg

Is this what ClassicRetrofit refers to as the blend valve? Their schematic shows AC air going thru it from their blower to the foot wells. Is it present if no factory air? Many thanks.

The blend valves sit on top of these vents ( on the frunk side). The warm cabin air goes into the evaporator unit through the D-shaped opening. The cold air comes out through the snorkel vent.


Sent from my iPhone using Tapatalk

@Bill5900 - This setup is crucial. The hose snorkels shown earlier work, but are not as refined looking as these ones I printed. The directional flow makes you feel cooler as it can be pointed at your knees. The D shaped opening above is providing a decent vacuum. I tested with just the blower on and a small piece of tissue paper. It was definitely trying to suck it up.

I got to check out nditiz1’s car and CR system this morning, it’s still operating in single-condenser mode.

First off, it was hugely helpful to see how it all works and be able to lay my hands on everything. The duct work on the (LHD) driver’s side will obviously be snug and he shared some observations about flex hose diameters which will require a bit of planning once I start ordering it.

Beyond that none of it looked too daunting. Minor variations in what ducts and hoses will be on my car vs. his but nothing hugely difficult.

What was most impressive was the performance. He drove about 20 minutes to our meeting point and invited me to get in the car, which had been in a climate-controlled garage prior to departure. Cabin temps were around 70-71F, vent temps were around 40F. Ambient by then was mid to high 80s and quite humid. We took a drive and the car held cabin temps despite my added thermal load in the passenger seat.

We then parked it next to mine to climb around and check out all the bits so it could heat up in the sun. That heat soak is definitely a challenge, after about 30 mins he started the car again. Vent temps were initially closer to 70 and dropped to 60-ish while running at idle. Still much cooler than ambient but clearly things have to work a lot harder.

Bottom line was the system was easily wife-compatible. I have deliberately not ordered the big alternator and will do the initial setup with my 90A unit. So we’ll be able to compare performance with his 175A / single-condenser setup, my 90A / dual-condenser setup, and, eventually, the 175A / dual-condenser. With a bit of data collection we should be able to see the relative differences at idle and at standard RPM/speed conditions in similar weather.

Thanks again, it was excellent to see the setup and your beautiful car!

It was my pleasure. Always nice to meet another enthusiast, take the car out, and check out a sweet Euro Turbo.

I have started to make the system more efficient while collecting the parts to add the 2nd condenser. These include:

- Adjusting the driver window for the tightest seal of the cabin. My window was a little off after replacing the fixed window for an earlier movable one (imo something that Porsche should have never stopped for Targa's)

- Replacing the smugglers box Rennline cover with the stock one. I'm not sure if it will make a difference, but my thinking is that humid air is being pushed up from the bottom of the smugglers box...as I'm typing this I'm forgetting that the hole that I ran the freon lines and wires is quite large and while the smuggler top would mitigate hot air from entering into the trunk this opening does not. The best approach would be to seal the holes under the chassis where the drain lines are going through thereby making the smugglers box contained which then no outside air should be coming into the Frunk making the system work harder.

As DerPuffinator saw there were several spots of condensation, even over the top of the blend valve on the passenger side. I feel like efficiency is escaping anywhere condensation is forming. I will look to mitigate these things, if anyone has ideas, I'm open to suggestions.

Here are some of the pieces I have acquired so far.

Boxster condenser
SPAL fan

I purchased 30ft of Four Seasons #6 hose. I need to either buy the fittings from CR or another type that will take more work to get them secured. I also need to fabricate a fan shroud. Who is good a aluminum fabrication :)
*Minus the shroud and fittings I'm only into the 2nd condenser setup for $140.

http://live.staticflickr.com/65535/5...a502571c_c.jpg

Nice installs, however I would suggest mounting condensers using rubber isolation washers as the aluminum will eventually fracture from vibration. Oil coolers should also be mounted this way.

Great advice. I will definitely pick some up and add them to the first condenser as well as the 2nd. That should be added to the kit for at least under the headlight mount. They come in the washer bottle relocation kit.

Just a little update -

Got the shroud built and will start to mock up the mount in the driver side rear wheel. Waiting for the reduced barrier line from FL (first set I got will work, but the hose is 20mm thick vs 15mm so the ear clamps would need to be larger). The fittings and clamps from CR are in transit.

http://live.staticflickr.com/65535/5...6ea5608d_c.jpg

http://live.staticflickr.com/65535/5...855d0bba_c.jpg

http://live.staticflickr.com/65535/5...edd0d138_c.jpg

2nd condensor is secured in the rear wheel well. I found the correct reduced barrier AC hose Galaxy 4860. It is pretty much the same as the Burgaflex in the kit. It has the same ID and OD. It will accept the #6 ear clamps. I decided to run a separate relay for the setup. I will mount it close to the seam of the inner wheel well. The only wire I'm running to the back of the car will be the signal wire(white, 86 off the relay). This tells the 2nd condensor to kick on when the AC kicks on. I have the power wire for the fan going to spot 2 on the engine fuse box.

Tomorrow I am scheduled to have the freon vacuumed out. Then I can open the system to add the two lines - Out of the 1st condensor and into the 2nd and then out of the 2nd and into the drier. Unfortunately the special fittings I ordered from CR are stuck in UK customs purgatory. Does anyone know if #6 AC compression fittings can be purchased from anywhere in the states? Burgaflex does not even list the condensor fittings on their website.

http://live.staticflickr.com/65535/5...a3aa0418_c.jpg

I am no expert, but you might need to rotate your condenser 90 degrees for proper performance. It does fit better the way you have it. I remember seeing it illustrated in a sketch that Charlie Griffith posted on another thread.

Jonny developed those a/c pad fittings in house. There might be an adapter that you can use between a burgaflex flare fitting and the condenser.

I'm not sure if that matters as the guide shows the CR condenser mounted in a vertical position as well as a horizontal. The condensers are virtually the same design with the exception of ports being on the same side vs different sides. Maybe Jonny can chime in on this.

I have no input re the AC system but your condenser appears to be in front of the torsion bar cover plate meaning that you’d have to remove the condenser to do any rear suspension work… I might offer that relocating it just a bit would save major headaches later- working with spring plates and torsion bars is already a pain, making it more of a pain is just masochistic.

I thought about that. Only 2 bolts hold the condenser in place. Compared to everything needed to get the inspection plate off to remove the torsion bar it's a walk in the park. I think there is 5 screws that hold the sideskirt on underneath the rubber strip.

Is the CR blower motor variable speed? If it is, one could probably devise a control to replace the LED switch.

You don't need to have the button installed to use the CR system. If you don't use the button and just want to turn on the AC whenever you use the fan you just need to set the flags in the config.

As far as responding to the Griffiths variable speed controller I'm pretty sure all blower motors, even stock, can utilize this. I'm not an electrical engineer, but I believe it is just a reostat and or resistor that limits the amount of power going to the motor to allow for infinite adjustablility. I'm not all that interested in $300 to allow me to infinitely adjust the blower speed as I usually just leave it on max all the time. If it were to get me more fan speed then I would definitely install it, but that's not the case.

Also I believe CR is working on an interface to make the 3 sliders into a modern looking AC control which I believe does incorporate an infinitely adjustable fan speed. This kit will most likely not be cheap as it will also involve servo adjusted blend valves - the old cables will be no more.

Thanks for the reply. I have the short wheel base. I realize CR is working on something but it may or may not suit my car. The Griffith system is in the same category. What is interesting is that you always need highest output if I understand what you said in your post. While I’m not in a tropical weather condition often, I’d like the flexibility to crank it up or down. From full air to just fresh air. Which brings me back to the CR kit. The website is short on technical info. We don’t know the blower motor characteristics, among other things. I imagine a skilled person can figure various things like this out. But frankly you and others sharing on this board are beta testing a product supposedly ready for market. But for you and a few others who have the tenacity to do this and share I would not have ordered a kit. So thank you.