C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Help with A/C system

Thread Tools
 
Search this Thread
 
Old May 11, 2011 | 06:09 PM
  #21  
daanbc's Avatar
daanbc
Thread Starter
Melting Slicks
 
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
Default

Originally Posted by mds3013
Hey Dave. Have you put gauges on the system to see what the pressures are running? My late model '77 does not have VIR. I do not know when they changed over. I believe VIR has a dryer under the pass. fender that can be taken apart. Mine has a welded shut dryer. Post a pic. of yours. mike...
Yeah I have a brand new VIR. And yes I am running the original fan with new clutch. I was thinking of placing a fan on the outside of the condensor. But In order to do that I need to remove the hood. If I remove the hood I might as well just replace the condensor since it's there. Do you really think that if I remove the fan and replace with an electric that will solve the problem? I don't want to waste $$ on a fan to find out it does'nt work as good as a new parallel flow condenser will.
Reply
Old May 11, 2011 | 06:47 PM
  #22  
zwede's Avatar
zwede
Race Director
25 Year Member
Loved
Community Favorite
Top Answer: 1
 
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Default

Electric fan(s) help, but are no substitute for a parallel flow condenser.

Here's what mine looks like. I welded on the tabs and used wiper motor bushings to mount it. I local HVAC shop made the fittings.



Last edited by zwede; May 11, 2011 at 06:50 PM.
Reply
Old May 11, 2011 | 07:15 PM
  #23  
daanbc's Avatar
daanbc
Thread Starter
Melting Slicks
 
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
Default

I think i'll go the new condensor route. I've been looking and they go for 80-120 bucks. I just need to find the correct size and one with the connections on one side like our originals. As for brackets thats not a concern. I can always fabricate somthing to make it work. My main issue is the connections. Are they all the same size? Or are some smaller/larger? I'd like to find one that I can unscrew from mine and tighten on to a new one with out any hassle.
Reply
Old May 11, 2011 | 10:42 PM
  #24  
noonie's Avatar
noonie
Race Director
15 Year Member
 
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Default

No matter what other mods you do if using 134 you have to adjust the poa.
Refrigerant pressure from the poa = evaporator temperature. You want it at 33° (as cold as possible without freezing)
Different pressures for different refrigerants.
Reply
Old May 12, 2011 | 08:30 AM
  #25  
daanbc's Avatar
daanbc
Thread Starter
Melting Slicks
 
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
Default

Originally Posted by noonie
No matter what other mods you do if using 134 you have to adjust the poa.
Refrigerant pressure from the poa = evaporator temperature. You want it at 33° (as cold as possible without freezing)
Different pressures for different refrigerants.
I have a VIR, that can not be adjusted. It is for the r134.. I wish my 77 did have a poa.
Reply
Old May 12, 2011 | 10:00 AM
  #26  
noonie's Avatar
noonie
Race Director
15 Year Member
 
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Default

Originally Posted by daanbc
I have a VIR, that can not be adjusted. It is for the r134.. I wish my 77 did have a poa.
The vir has an integral poa inside.
Most will tell that it's not adjustable, not much call for it and more profitable to sell eliminator kit, but I'll see if I can find the instructions.

VIR is definitely the one to consider staying with 12
Reply
Old May 12, 2011 | 12:22 PM
  #27  
daanbc's Avatar
daanbc
Thread Starter
Melting Slicks
 
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
Default

Originally Posted by noonie
The vir has an integral poa inside.
Most will tell that it's not adjustable, not much call for it and more profitable to sell eliminator kit, but I'll see if I can find the instructions.

VIR is definitely the one to consider staying with 12
Are you saying that maybe there is an adjustment that can be made on the VIR? The only way I knew of, was to get two, cut one open and take the so-called pin out, and adjust it and replace it into the other VIR.
Reply
Old May 12, 2011 | 12:47 PM
  #28  
Kevin_73's Avatar
Kevin_73
Le Mans Master
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
All Eyes On Me
 
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
Default

Originally Posted by daanbc
Are you saying that maybe there is an adjustment that can be made on the VIR? The only way I knew of, was to get two, cut one open and take the so-called pin out, and adjust it and replace it into the other VIR.
A VIR (valve in receiver) does not have to be cut open. It has four bolts that hold the receiver can on it. When you open it up you will find a desiccant bag in the bottom, and the POA valve is located in the top.
You can buy a rebuild kit that comes with a new desiccant bag and new o-rings. The last time I had mine apart I adjusted it (per instructions I found on a A/C forum) for 134a. This time I am installing a eliminator kit though.


It appears that the VIR was used on C3's from 73 through early 77.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old May 12, 2011 | 12:53 PM
  #29  
Kevin_73's Avatar
Kevin_73
Le Mans Master
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
All Eyes On Me
 
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
Default

I found the thread from when I did mine.

http://forums.corvetteforum.com/c3-t...t-to-134a.html
Reply
Old May 12, 2011 | 03:41 PM
  #30  
daanbc's Avatar
daanbc
Thread Starter
Melting Slicks
 
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
Default

Im hoping my VIR was already adjusted for R134. Since it was purchased a year ago, I'm hoping it is...
Reply
Old May 12, 2011 | 04:30 PM
  #31  
Kevin_73's Avatar
Kevin_73
Le Mans Master
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
All Eyes On Me
 
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
Default

Originally Posted by daanbc
Im hoping my VIR was already adjusted for R134. Since it was purchased a year ago, I'm hoping it is...
Well if you are opening up the system again you will have to either rebuild or replace it, so you might as well check the adjustment on it while it's out. Or better yet install the eliminator kit instead.
Reply




All times are GMT -4. The time now is 04:05 AM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE