The Detailed E30 R-134a Conversion Thread/DIY

[The Dark Side of Will]

Yes and no. Of course for a rapid cool down/dehumidification recirc helps a lot since youre continuously cooling the same air repeatedly and hopefully faster than the heat load can add btus (assuming everything is closed). This isn't a bad "bench test" for efficiency but you have to also consider how long it takes to get to whatever minimum temperature it's capable or reaching. The problem is, I've rarely if ever seen an infrared posting explain the variables present...ie humidity, flap position, moving or not, rpms, humidity and ambient temp. If your cooling 90 degree air with a 20 degree differential eventually you should reach the "absolute minimum" but It's still just a 20 degree differential. This will take longer and have a harder time maintaining comfort in real world driving.

If you're driving in 90 degree weather with a 35 degree differential and 85% humidity but your absolute minimum is 53 (like my cabrio) you'll cool down faster (very fast in fact) and wind up turning down your fan and/or temp setting sooner since most people are quite happy somewhere between 68-74.

Absolute minimum is great for theory and bragging rights but IMO is not an expression of overall performance.

My2c

If your evaporator is at 52 degrees and you push XYZ CFM of air through it for a 53 degree discharge, then you're not pulling as many BTUs out of the air as you would if the evaporator were at 40 degrees and you pushed the same CFM at the same ambient temperature through it.

[S.J.1981]

Finally mounted up everything, new condenser (parallel flow), new o-rings, all lines/pipe(s) removed and cleaned, new drier, pressure switch, compressor cleaned out, fresh oil, expansion valve etc.

Plugged in the new vacuum pump and lines, barely held 10hg vacuum. Checked around and found the adaptor not sealing correctly on the high side. Then found out that there is no vacuum pulled by the pump from the low side. Turns out to be a faulty connector (the one you press to slide into the low side).

No matter which R134a adapter i used on the R12 lines, it never sealed correctly.


Decided to return the whole pump w/hoses back and get a refund, will go to a shop to have them find the correct adaptor and leak/vacuum test the system for me. If all is well, i have 900g of R134a, will let them fill the system as well.

[jeffnhiscars]

You *CAN* judge by absolute temps. That's why the "recirculate" function exists. The heat load from ambient air passing over the outside of the car, radiator air passing underneath the car and solar radiation through the windows is enough for the A/C to fight. Trying to get it to do all that *AND* cool down outside air is not a recipe for great results.

Yes and no. Of course for a rapid cool down/dehumidification recirc helps a lot since youre continuously cooling the same air repeatedly and hopefully faster than the heat load can add btus (assuming everything is closed). This isn't a bad "bench test" for efficiency but you have to also consider how long it takes to get to whatever minimum temperature it's capable or reaching. The problem is, I've rarely if ever seen an infrared posting explain the variables present...ie humidity, flap position, moving or not, rpms, humidity and ambient temp. If your cooling 90 degree air with a 20 degree differential eventually you should reach the "absolute minimum" but It's still just a 20 degree differential. This will take longer and have a harder time maintaining comfort in real world driving.

If you're driving in 90 degree weather with a 35 degree differential and 85% humidity but your absolute minimum is 53 (like my cabrio) you'll cool down faster (very fast in fact) and wind up turning down your fan and/or temp setting sooner since most people are quite happy somewhere between 68-74.

Absolute minimum is great for theory and bragging rights but IMO is not an expression of overall performance.

My2c

[The Dark Side of Will]

I have 55-58 degree results and while it *eventually* cools the cab I personally consider this conversation a failure. Vent temps should be in the 40s consistently for a properly functioning setup.

I am going to try a Sanden compressor next. Or something similar.

Exactly. If 55 degree discharge temp is the best the system can do, something is wrong. For an R12 system, evaporator temperature in F and low side pressure in PSI are approximately equal. R-134 isn't far off that.

[Garemie]

I have 55-58 degree results and while it *eventually* cools the cab I personally consider this conversation a failure. Vent temps should be in the 40s consistently for a properly functioning setup.

I am going to try a Sanden compressor next. Or something similar.

[The Dark Side of Will]

You *CAN* judge by absolute temps. That's why the "recirculate" function exists. The heat load from ambient air passing over the outside of the car, radiator air passing underneath the car and solar radiation through the windows is enough for the A/C to fight. Trying to get it to do all that *AND* cool down outside air is not a recipe for great results.

[jeffnhiscars]

You can't judge the system by absolute temps. It's the differential which is a measure only of its ability to remove btus AND humidity. If it keeps you comfortable it's working..

[The Dark Side of Will]

I’m getting a steady 56º at highway speeds in 90º weather. I drove through a thunderstorm and briefly got a vent temp of 39º.

Glad you're happy with it. If the car's been baking in the sun at 90 degrees, then 56 out the vents is good. Enjoy your year-round E30!

Does E30 AC just suck? Should be able to get down to 40 at highway speeds with accompanying engine RPM.

[cory58]

I’m getting a steady 56º at highway speeds in 90º weather. I drove through a thunderstorm and briefly got a vent temp of 39º.

I have to say a huge thank you to all the people that have contributed to this thread. The parallel flow condenser and the spal fan made my car available to me in the hot months, completely comfortable in my South Carolina climate. I get pretty grumpy when I cant drive my car.

Next thing I’m going to do is get my windows coated with ceramic film. You know, the kind that has zero tint but blocks UV. I should get it done in the next couple of weeks and I think it will really help, just as much as functioning A/C.

Glad you're happy with it. If the car's been baking in the sun at 90 degrees, then 56 out the vents is good. Enjoy your year-round E30!

[S.J.1981]

This is the one that I was advised to get, it works great. A little loud, but cool A/C is worth it.

https://smile.amazon.com/gp/product/B009OBOKI4/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

Using the basic Hayden Automotive fan mounting kit I re used the factory rubber grommets from the original fan, cut some fuel hose to fill the gaps, drilled holes in the fan walls, and pulled the mounting zip ties through. Secure and no vibrations.

Thank you, that SPAL 30100382 is also named SPAL VA08-AP10/ C-23S here in Germany. Sadly i already finished up the A/C system in the engine bay yesterday (condenser replaced, all hoses flushed, new o-rings, new drier/receiver, drained compressor and filled with fresh oil).

Will be tackling the expansion valve and evap today, but im glad to know which model to get incase i realize that the fan needs to be upgraded, would be easier to remove the bumper and replace the fan than re-do everything again.

Do you maybe have a model/part number for that mounting kit as well? we may have it here too!

[325e '87]

Is this the correct SPAL fan if i wish to ditch the factory condenser fan for an upgraded one?

Model: SPAL VA10-AP50/C-61A

If it is not correct, id appreciate the correct one. Looking for as close to bolt on as OE/OEM. Or is the factory fan enough with the upgraded condenser?

This is the one that I was advised to get, it works great. A little loud, but cool A/C is worth it.

https://smile.amazon.com/gp/product/B009OBOKI4/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

Using the basic Hayden Automotive fan mounting kit I re used the factory rubber grommets from the original fan, cut some fuel hose to fill the gaps, drilled holes in the fan walls, and pulled the mounting zip ties through. Secure and no vibrations.

[325e '87]

What's the temp coming out the vents?

I’m getting a steady 56º at highway speeds in 90º weather. I drove through a thunderstorm and briefly got a vent temp of 39º.

I have to say a huge thank you to all the people that have contributed to this thread. The parallel flow condenser and the spal fan made my car available to me in the hot months, completely comfortable in my South Carolina climate. I get pretty grumpy when I cant drive my car.

Next thing I’m going to do is get my windows coated with ceramic film. You know, the kind that has zero tint but blocks UV. I should get it done in the next couple of weeks and I think it will really help, just as much as functioning A/C.

[S.J.1981]

Is this the correct SPAL fan if i wish to ditch the factory condenser fan for an upgraded one?

Model: SPAL VA10-AP50/C-61A

If it is not correct, id appreciate the correct one. Looking for as close to bolt on as OE/OEM. Or is the factory fan enough with the upgraded condenser?

[jeffnhiscars]

Holding a vacuum doesn't mean there's no air or residual moisture in the system. Not being able to give it a full charge typically means there's something in there that shouldn't be. It's so easy to let some air back in after pulling a vac

[cory58]

Ok, I replace the condenser and the dryer, resealed and held 30” vacuum for about 12 hours.

I cant get my system to draw in more than about. 10oz. Of refrigerant. I’m getting kind of angry and considering pumping it back down to vacuum and trying again.

My pressures are nearly factory, 40psi low, hovering around 200psi high. I know the pressures need to go up from where they are but Ive been running my engine for an hour now, revving sometimes. When I rev it my low side drops to around 20psi, high side drops a little.

What's the temp coming out the vents?