Aftermarket OR Factory Air

[DaveD]

For those of you who have aftermarket AC units, would you still do it if you had enough of the parts to go back factory?

[parsonsj]

Hell yeah.

My aftermarket setup has 30 more years of A/C technology. Vintage Air Front Runner plus a Gen IV Magnum evaporator. You won't find anything like that from the 60s.

jp

[Twentyover]

No. I'd convert to a more modern compressor (and potentially the mount and drive), but the reminder of the system (evaporator and air handling components) I'd keep stock

I have the same setup as John, and had the car come with factory air, I would have kept the components noted above stock. Next car is an 84G body, and it will have the factory air handling components and evap and heater core. Older brothers 72 Malibu works great using a modern pump and the factory cores and air handling systems. The only reason I would switch is that there is too much stuff in the engine compartment crowding out those components, or I NEED a flat firewall.

This is in no way intended to dump on Vintage Air (or any other aftermarket supplier, for that matter). With the constraints they work under, they have developed a good product, it's just that they work under constraints that are different than an OEM.

With all due respect to John's comments, most OEM's use larger core and blowers than the aftermarket, which means they cool faster, heat the interior faster, and have less issue with refogging due to recirculating asiprated moistue. These are facts. Depending on the climate, these may or may not be problems.

During the 60's the OEM's used a number of interesting ideas to control evap temp, first CC-TXV systems similiar to the current aftermarket, STV and POA evap pressure controls, If you elect to keep the factor evap, dump this stuff and use a use a CCTXV evap control- an A/C shop can fix you up relatively cheap and easy. Service and part will be cheaper and easier

One other area I'd look at is air handling- what controls temperature, mode (defrost/mix/floor/bi-level/panel). If you can, blow the system apart and make sure your control head and actators are working OK, particularly if it uses vacuum systems.

If you want to go with aftermarket air, that's fine- I won't be offended. Just have realistic expectations of the limitations and you won’t be disappointed.

[MuscleRodz]

After installing 2 factory air units back into restored cars lately, I am not sure you could pay me enough to do it again. PIA big time.

[parsonsj]

After installing 2 factory air units back into restored cars lately, I am not sure you could pay me enough to do it again. PIA big time.

It took me months of on-again/off-again work to get my V/A kit all installed. I had to completely disassemble the dash, remove the front sheetmetal (hood, bumper, grill, air dam), fender (fender, headlight buckets, bezel), move the ECU and all of it's associated wiring, fabricate an under-dash panel, fabricate my own evaporator brackets, hose, hardline, and bulkhead panel, and re-do my power steering reservoir.



Message being: do your A/C before wiring and painting your car.

jp

[TD509EFI]

No. I'd convert to a more modern compressor (and potentially the mount and drive), but the reminder of the system (evaporator and air handling components) I'd keep stock

+1. If you're not concerned about aesthetics( big suitcase on the firewall) I'd use the factory if all parts are still available. The factory also gives you fresh air intake, none of the aftermarket units do. This often helps cool the interior faster on a hot sunny day ( try cooling 110f interior air compared to let say 90f outside air).

John

[oldcarguy]

Factory always cools better, but all the After market stuff we're using works fine. Lots of questions here, ( & opinions) are you building a Factory Look-Resto, go original ? Mine's a 69 Camaro, smooth firewall, LS1,etc, that suitcase thing was the first to go,even if I had no air.( but I did VA)

Besides, If I want perfect Air, ride,bluetooth, navigation, etc, I'll drive my daily driver, if your building a Hot -rod ? The last 6 cars I had, A/C what's that ?, Fenders, what are those ?,,,,,,,,,,,,,,,,,,,,,

[MonzaRacer]

AS I have posted before, a well thought out plan can make EITHER system function very well. I had a 71 Monte Carlo with vactory POA/STV setup and only low blower speed and that car would throw 38 degree dash vent temp.
I have worked on several aftermarket systems and for the money spend I would have thought they would go in/together much easier.
I have retro fitted several earlier cars with self adjusting orifice tubes , had hose connections silver soldered or tigged to factory evaporators and set them up as AAOT/CCOT systems and get great performance and function and so far the big problem is that they used to say to charge 80 percent of r12 factory charge but most are requiring the same or more refrigerant than stock.
I especially like old Ford TXV (thermostatic expansion valve) systems as they are awesom as they could care less what goes through then.
Big trick is using blue or green orings and proper lubricant. Converted compressors need Ester 100 and totally new compressors need what the manufacturer requires (GM PAG 150 Ford I would need to look up as with Chrysler, one PAG 42 the other is PAG 100 but need to verify which is for which).
BUT also most compressors now come with recommendations so just follow included instructions.
And only use XH7 or XH9 desiccant filled driers with R134A.

[John Wright]

The only thing that i don't like about the factory air on my 70 camaro is the lack of velocity and air volume, even on max air the air velocity and volume is no where close to my 04' Silverado's system. If I could get the velocity and volume up on my old camaro, that would be the ticket.

[Twentyover]

Replace the motor and blower resistor with parts from a modern car, and be sure to run high blower through a relay so it gets full voltage.

In addition, IIRC the outlets on the 70 Camaros suck. Two small center vents and one each on the driver's left knee and passenger's right knee. Just what I need when I'm trying to cool down is frozen kneecaps. I added a face level vent in the wiper/light switch areaa of the panel, relocating these switches to the lower dash area. I rerouted the driver's kneecap vent to feed this face vent. If I had it to do again (and I might, just on principle), I'd add another face vent on the opposite side to make sure I'm flooded w/ air at good velocity and directional control.

[ProdigyCustoms]

One of the things I LOVE about the Vintage Air Gen IV is how hard it blows!

[John Wright]

Replace the motor and blower resistor with parts from a modern car, and be sure to run high blower through a relay so it gets full voltage.

In addition, IIRC the outlets on the 70 Camaros suck. Two small center vents and one each on the driver's left knee and passenger's right knee. Just what I need when I'm trying to cool down is frozen kneecaps. I added a face level vent in the wiper/light switch areaa of the panel, relocating these switches to the lower dash area. I rerouted the driver's kneecap vent to feed this face vent. If I had it to do again (and I might, just on principle), I'd add another face vent on the opposite side to make sure I'm flooded w/ air at good velocity and directional control.

Great idea with the face vents! Someone told me that the blower motor from a mid-90's fullsized pickup will work in there.

Uh Frank...TMI there buddy.....LOL nbl
I missed seeing you guys out there at Carlisle this year.

[Twentyover]

One of the things I LOVE about the Vintage Air Gen IV is how hard it blows!

Which is actually kind of funny- the thing I don't like about the Gen IV is that it doesn't flow enough air.

'Blowing hard' doesn't make for a good A/C system. Airflow volume is one of several keys to a good combination. Modern systems flow somewhere between 250-300 cfm when running a zero body test (no body pressure resisting airflow). While I've never bothered to zero body the car my Gen IV is in, based on subjective judgement, I would suggest it hangs around 150 cfm.

While there are many satisfied customers with the Gen IV (and I would include myself in the satisfied group, because I have realistic expectations of the system's performance) for one to suggest that a Gen IV can compete with a factory system would be displaying their lack of understanding of first principles of airflow, acoustics, and human comfort in automotive envirornments.

It has been suggested in the past that the Ford GT uses the Gen IV system, so it must be OEM quality. This ignores the fact that while a similiar controller is used, the actual air handing components are different and additional functionality of fresh air is available. This would be the same as saying a Camaro and Metro are the same because they both use similiar tires. With the majority of components being different, the comparison falles apart.

Once again, not bashing VA stuff- but it is important that one be well informed if one is be satisfied with one's purchases

[Adam@Autoloc]

me and my dad used Zirgo. Price was good and the tech support was good too..

Zirgo AC systems

[ProdigyCustoms]

Tonight I drove home a original 1970 Chevelle with a working factory A/C system in good shape. Last time I drove it I felt it needed a recharge, added a couple ounces, pressures are pefect, engine cooling fan is working great. I was also was concerned the fan was not blowing wide open, I hot wired it direct to be sure. We also check the condition of the vents and made sure the trap doors are working. And I sweat the entire way home. And I have repeated this many times over the years. The factory air simply does not blow as hard as the Gen IV.



Mammals (and only mammals) feel wind chill. Because of the perspiration, the moisture on our skin, wind makes us feel cooler. Wind is a huge part of the cooling effect coupled with the air temp of that wind. So blowing harder, feeling the breeze, makes a big difference in what we feel.


As for the fresh air option, I have no need for it. I want things tight a closed in the cabin as possible.

Here is the Chevelle in question, Its For Sale BTW, LOL!

[mikedc]

There are multiple aftermarket evap setups out there, and more than one size of evap available . . . aren't any of them nearer to the factory sizes than the 150cfm gen-IV?




Honestly I am a little surprised at the way the aftermarket & hot rodders have handled the HVAC setups in cars.

With so many things, car guys have started out by retrofitting a decent one from an OEM application for years, found ways to improve it, and gradually gone to making the whole thing aftermarket. Witness all the Camaro subframes, C5 and Mustang II suspensions, Ford 9" axles, etc.

So why haven't we followed some kind of similar path with HVAC setups? Isn't there SOMETHING in the local junkyard? Some dirt-common american car or truck with a decent self-contained evap box that can be slapped onto any flat firewall with a reasonable amount of room under the dash?

[John Wright]

self-contained evap box that can be slapped onto any flat firewall with a reasonable amount of room under the dash?

LOL, that reminds me of when I was just a kid...I remember my uncle had a brand new 68 Cutlass with some kind of dealer add-on air....that thing had this huge evaporator/blower box that bolted to the bottom of the center of the dash. What makes that stick out in my mind is...I was 3 or 4 when I rode in that car and I had to sit in the middle of those front seats, straddling the console with that cold air blowing on my lil chicken bone knees.

[John Wright]

Sweet Chevelle Frank!, Reminds me of MCJohn's

[Twentyover]

I'll take a stab at mikedc's question...

First, I don't KNOW what the flow rate is- it was an estimate based on a subjective feel from bench tests I've been involved in the last couple years. My personal experience with aftermarket has been a no-name in dash G-Body unit and engine compartment S10 from the 80's, VA Gen II Supercooler (never installed) and a Surefit Gen IV in my Camaro. None of these units have air handling components sized similiar to a modern OEM.

Most vehicles of interest to members of this board have relatively steep windshield angles. This permits the use of an engine compartment evap and blower unit and an interior mounted heater core and control doors, and this design is expedient to assemble on these cars in a factory assembly envirornment. This results is the presence of the so-called suitcase on the passenger side firewall.

During this same time, the Japanese were typically using what are now known as lateral flow HVAC units that fit in dash. While air handling components were generously sized, blower motors and registers were frequently undersized and poorly placed or lacked controllability. When American cars started using shallow windshield angles, this general configuration was adopted on some of those models. In time, these systems were also adopted on rwd platforms

If one were to scratch build a system for in dash use, looking at a modern lateral flow designs w/ it's blower motor, heater core, and evap whould be a good starting point. Be creative as far as orientation of the blower motor and heater core- the evap needs consideration to make sure you get good condensate drainage.

Spculating, the reason that aftermarket companies do what they do is because they're not building dedicated units that have a customer specified performance values, in volumes of 250m to 1M units over a couple year run to justify unique design and tooling, along w/ dedicated assembly lines to fit a given model and maximize it's performance. They are building maybe on a good year a couple of percent of that number, so they need to make sure the units fit a large number of vehicles. This is needed to maximize ROI on tooling. To maximize performance wuld require a greater number of configurations, resulting in even higher cost of the unit And we're not even talking about performance measurables like control linearity, register to register and bilevel temperature stratification, control hysteresis, designing air mix chambers to provide consistent temperatures as mode changes.

Tooling ROI forces the manufacturers into physically smaller packages to provide clearance. Every time you shrink a component, you raise the pressure drop through the component, reducing airflow and increasing acoustic impact.

The real reason we don't have what I consider to be OEM quality aftermarket HVAC system? It's not sexy. How often do people oogle the underdash area of your car and marvel at the clean wiring harness, the clever placement of components? I'll wager less often that they check out your brakes or tires. Does it cut your et a tenth, or increase lateral grip? No, owners treat A/C as something they need to do, and they accept limitations either because they believe that's the best they can get, because they don't know any better, or- well, there's as many reasons as there are people. People tend to spend money where it shows.




Responding to the OP's question- my position is, the reason one uses an aftermarket system is because you want a flat firewall or you don't have enough factory parts, or because you want to. If you are not satified with the OEM's performance, find out whay it's not working to your satisfaction before you consign it to the junk heap. If there's inadeqtae airflow, check for flow restrictions in the inlet tract, replace the motor with a more powerful one. If it's OEM duct design is junk (like the Camaros mentioned above), add a face vent or two. If it's not cold enough, make sure the doors seal, make sure the water valve is in place and working.

Unless you want to change.

[John Wright]

Too bad we didn't have dual climate zones in 1970 camaros...LOL

I love that feature on my Silverado, my wife can adjust her side of the truck according to her moods....LOL