Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts New!  See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
Small Car Performance, DIY Front A/C Installation
Page: Previous  1, 2, 3 ... 29, 30, 31
Jump to:
Forum Index -> Vanagon Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
MarkWard
Samba Member


Joined: February 09, 2005
Posts: 14769
Location: Palm Beach County, Florida
MarkWard is offline 

PostPosted: Tue Feb 02, 2021 4:20 pm    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

I made a change how the radiator fan switch operates. With my 82 van, I couldn’t figure out how to combine the vintage air and the factory 3 speed fan.

To simplify the “merge” I wired the radiator fan switch to complete grounds instead of power. I used the vintage air compressor switch to complete a ground and the trinary switch to also switch grounds. I used 3 Bosch 40 amp fog light relays to handle all the switching. Works really well. I still have the radiator high speed fan relay but it’s wired to energize with a ground from the fan rad fan switch. It sounds complicated but I’m a big fan of using relays.
_________________
1982 Vanagon Camper with ALH TDI.
1990 Vanagon Camper Syncro.
In Car https://youtu.be/5hbfdUJR88Q
Back to top
View user's profile Send private message Gallery Classifieds Feedback
ScottShelley
Samba Member


Joined: October 15, 2012
Posts: 486
Location: California
ScottShelley is offline 

PostPosted: Thu Apr 01, 2021 11:09 am    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

Forgive me if this has been covered, this is a long thread. How many pound of R134 are most people putting in to the system. I don't have the small car manual and can not find it online. I put in 2.4 pounds and though running cool, I would like to run cooler.

Thanks
Back to top
View user's profile Send private message Gallery Classifieds Feedback
MarkWard
Samba Member


Joined: February 09, 2005
Posts: 14769
Location: Palm Beach County, Florida
MarkWard is offline 

PostPosted: Thu Apr 01, 2021 11:16 am    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

I can't speak to the volume, but what engine and compressor? You should post your low side reading at 2500 rpm. That correlates to the evaporator core temp. When the volume is unknown, you can get pretty close using the low side pressures. The vintage air unit comes with a warning that the expansion valve is tweaked to run lower pressures than expected on a conventional AC.
_________________
1982 Vanagon Camper with ALH TDI.
1990 Vanagon Camper Syncro.
In Car https://youtu.be/5hbfdUJR88Q
Back to top
View user's profile Send private message Gallery Classifieds Feedback
ALIKA T3
Samba Member


Joined: July 30, 2009
Posts: 4452
Location: Honolulu,Hawaii and France
ALIKA T3 is offline 

PostPosted: Thu Apr 01, 2021 11:44 am    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

MarkWard wrote:
I can't speak to the volume, but what engine and compressor? You should post your low side reading at 2500 rpm. That correlates to the evaporator core temp. When the volume is unknown, you can get pretty close using the low side pressures. The vintage air unit comes with a warning that the expansion valve is tweaked to run lower pressures than expected on a conventional AC.


Hi Mark!

I`m also about to fire mine up.

2 questions: what is the target pressure on low side and how do you fill the oil that comes with a new compressor?

THank you!
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget
Back to top
View user's profile Send private message Gallery Classifieds Feedback
kourt
Samba Member


Joined: August 13, 2013
Posts: 1463
Location: Austin, TX
kourt is offline 

PostPosted: Thu Apr 01, 2021 12:03 pm    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

Some values:

Vintage Air says 28oz R134 for a GenIV Magnum system (see page 4)
VAG (Bentley) says 47.6oz R134 (converted from R12 values)--this should be ignored with a Small Car installation, but is an interesting reference.
30-38 psi low charge, [email protected] degrees
troubleshooting, gauge readings Low Side/High Side
H/H: overcharge—bleed out
H/L: faulty reed valves in compressor
L/L: undercharge—add refrigerant
L/H: blockage

I generally pick a day 80 degrees or hotter, set a high idle (2500 to 3000 RPM), set a fan in front of the condenser, and charge to the lowest vent temp, and corroborate it with gauge readings that make sense.

Kourt
Back to top
View user's profile Send private message Gallery Classifieds Feedback
MarkWard
Samba Member


Joined: February 09, 2005
Posts: 14769
Location: Palm Beach County, Florida
MarkWard is offline 

PostPosted: Thu Apr 01, 2021 12:10 pm    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

I fill the compressor crankcase with the specified amount. Others state you can fill it though the ports. I don't think that's a good idea. Remove the drain/fill plug from the compressor and pour out any oil thats in it. To be sure, you might want to pour in a small amount of your oil and pour it back out to sort of flush any oil that may not be compatible.

I believe Vintage air specified 15 psi on the low side was acceptable. Normally you'd expect to see around say 25 psi.

My TDI compressor had an internal valve that I had to disable in order to get the correct pressure. Its called a variable displacement compressor, but it's more of a bypass than a compressor that changes displacement. The vanagon sanden compressors don't have this feature, but I recall some Subarus do. That's why I asked.
_________________
1982 Vanagon Camper with ALH TDI.
1990 Vanagon Camper Syncro.
In Car https://youtu.be/5hbfdUJR88Q
Back to top
View user's profile Send private message Gallery Classifieds Feedback
ScottShelley
Samba Member


Joined: October 15, 2012
Posts: 486
Location: California
ScottShelley is offline 

PostPosted: Thu Apr 01, 2021 12:37 pm    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

28 OZ seems a little light considering the length of the hoses. It is interesting the the stock set up would take so much more.


kourt wrote:
Some values:

Vintage Air says 28oz R134 for a GenIV Magnum system (see page 4)
VAG (Bentley) says 47.6oz R134 (converted from R12 values)--this should be ignored with a Small Car installation, but is an interesting reference.
30-38 psi low charge, [email protected] degrees
troubleshooting, gauge readings Low Side/High Side
H/H: overcharge—bleed out
H/L: faulty reed valves in compressor
L/L: undercharge—add refrigerant
L/H: blockage

I generally pick a day 80 degrees or hotter, set a high idle (2500 to 3000 RPM), set a fan in front of the condenser, and charge to the lowest vent temp, and corroborate it with gauge readings that make sense.

Kourt
Back to top
View user's profile Send private message Gallery Classifieds Feedback
kourt
Samba Member


Joined: August 13, 2013
Posts: 1463
Location: Austin, TX
kourt is offline 

PostPosted: Thu Apr 01, 2021 1:46 pm    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

What I've found is that I usually empty two 12oz R134 cans into the system, and then start really paying attention to my vent temps on the third can.

By the time I get about halfway done with the third can, the vent temps have bottomed out and are usually starting to creep back up.

Experience has taught me that a slightly underfilled refrigerant charge will perform better than on overfilled one, so nowadays I am familiar with the rate of change in the vent temp gauge (I use a digital multimeter with a temp probe) such that I can predict when the temps will bottom out, and stop filling when I feel it's at the bottom.

Other details: my refrigerant ports are at the front of the van. That means I can keep the engine lid closed and the van closed up for maximum cooling efficiency during the charging process.

kourt

Image may have been reduced in size. Click image to view fullscreen.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
ScottShelley
Samba Member


Joined: October 15, 2012
Posts: 486
Location: California
ScottShelley is offline 

PostPosted: Thu Apr 01, 2021 2:14 pm    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

Good Information. Thanks

kourt wrote:
What I've found is that I usually empty two 12oz R134 cans into the system, and then start really paying attention to my vent temps on the third can.

By the time I get about halfway done with the third can, the vent temps have bottomed out and are usually starting to creep back up.

Experience has taught me that a slightly underfilled refrigerant charge will perform better than on overfilled one, so nowadays I am familiar with the rate of change in the vent temp gauge (I use a digital multimeter with a temp probe) such that I can predict when the temps will bottom out, and stop filling when I feel it's at the bottom.

Other details: my refrigerant ports are at the front of the van. That means I can keep the engine lid closed and the van closed up for maximum cooling efficiency during the charging process.

kourt

Image may have been reduced in size. Click image to view fullscreen.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
ALIKA T3
Samba Member


Joined: July 30, 2009
Posts: 4452
Location: Honolulu,Hawaii and France
ALIKA T3 is offline 

PostPosted: Fri Apr 02, 2021 10:11 am    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

Thank you guys!!

Mark, I'll hit you up for the Tdi compressor mod, I too have a Tdi compressor, AHU style. I'd like to go ahead and do everything before filling....
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget
Back to top
View user's profile Send private message Gallery Classifieds Feedback
MarkWard
Samba Member


Joined: February 09, 2005
Posts: 14769
Location: Palm Beach County, Florida
MarkWard is offline 

PostPosted: Fri Apr 02, 2021 10:37 am    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

I actually stumbled across it on the TDI club forum. The valve is what attaches the reed plate to the compressor head. They were removing the valve and replacing it with a nut and bolt. I could not find a bolt that held the reed plate centered enough for me. So, I drilled and tapped the valve and installed a set screw. Basically disabling it. I then reinstalled the valve body. It's fairly straightforward when you get it apart. I was able to reuse the original gaskets.
_________________
1982 Vanagon Camper with ALH TDI.
1990 Vanagon Camper Syncro.
In Car https://youtu.be/5hbfdUJR88Q
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Zeitgeist 13
Samba Member


Joined: March 05, 2009
Posts: 11057
Location: Port Manteau
Zeitgeist 13 is offline 

PostPosted: Fri Apr 02, 2021 10:59 am    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

Is that mod mandatory? I have factory A/C with the stock ALH compressor, and it works pretty good, but I wouldn't mind improving output if possible.
_________________
Casey--
Volkswagens powered by Volkswagen
'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender VR6 -->2.5 TDI Syncro?
Oly Bulli
'87 300TD OM606 7mm Myna pump and HX30
Back to top
View user's profile Send private message Gallery Classifieds Feedback
MarkWard
Samba Member


Joined: February 09, 2005
Posts: 14769
Location: Palm Beach County, Florida
MarkWard is offline 

PostPosted: Fri Apr 02, 2021 11:09 am    Post subject: Re: Small Car Performance, DIY Front A/C Installation Reply with quote

The vintage air uses and old style expansion valve. That type of valve was adjustable, though no one really adjusted them. There were 2 set screws in one of the fittings. I imagine Vintage air is setting them lower to work with R134.

The symptom on mine was I could not get a decent low pressure. This valve was really just a bypass of the reed plate. So, by eliminating it, you have returned it to the early style like the vanagon originally had.

VW was attempting to lessen the compressor cyclings by the late 90s. Eventually coming up with a computer operated valve on the CR TDI.

So, if your low pressures are good, probably no reason to do this mod. The later H type expansion valve the vanagons used is only available now for R134, but works with other gasses.
_________________
1982 Vanagon Camper with ALH TDI.
1990 Vanagon Camper Syncro.
In Car https://youtu.be/5hbfdUJR88Q
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Vanagon All times are Mountain Standard Time/Pacific Daylight Savings Time
Page: Previous  1, 2, 3 ... 29, 30, 31
Jump to:
Page 31 of 31

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2020, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB