Air con for GTV6 and V6 75 is it worth it

[sportiva]

I

[LukeC]

Thanks for making the effort in posting.

It's an uphill battle get a GTV to have good air with all that glass. As the saying goes: What is hotter than an Alfa GTV? Answer: An Air conditioned Alfa GTV!

That abysmally designed HVAC box is right at the centre of fault. As an old Alfa friend in QLD (commercial A/C engineer) said: Good A/C is all about air flow!

Being a big pansy, and hating heat (why I moved away from QLD 24 odd years ago), I cannot do without air, even in an occasional car. I am pondering which way I will go next GTV I do for myself in regard to the HVAC box.

[Citroënbender]

More proper hotrodding. Good stuff - I'm yet to hear of anyone having problems with the thinwall Galaxy hose. It seems a win-win where originality is not a worry.

Did you effectively increase the system capacity to allow greater charge weight and therefore longer cycle times? Also, I'd have thought a marginal setup might be just the place to use HyChill - or are you with the ARC on this?

[poohbah]

Have you still got the parcel shelf underneath the glove box? You might be able to extend the passenger side vent hose from underneath, and hide it with the parcel shelf. If you haven't (like me), good luck trying to find one

[poohbah]

Thanks for the offer sportiva. Not a high priority right now, but I'll keep that in mind. Cheers

[Duk]

Perhaps you could use a voltaged booster for the fans power supply and get it to run faster. It would probably shorten the fan motor's life a bit, but it should increase its flow rate.

Without knowing the wiring, but knowing Alfa Romeo's, make sure the power supply is switched via a relay if it isn't already and coming from a good, high current capable source.

Using pulse width modulated motor speed controller would allow you to remove the old dropping resistors and mean you won't have them heating up inside the cabin. Obviously they are only in the current path at less than full speed, tho.

As MD showed in his AC upgrade thread, insulate the cabin from engine bay and exhaust heat.
Newer cars can have heat shielding over nearly all of the exhaust system.
Or have the exhaust ceramic coated inside and out and then wrap it in insulation tape aswell.
Insulate the firewall with reflective insulation.

Use dense foam around the condensor so that the air has to pass thru the condensor's core and can't sneak around the edges and pass thru the radiator.
Similar for the evaporator, make sure there are no spots the air can bypass the core. Cores are always a flow restriction and any gaps are a path of least resistance.

Insulate the hose after the condensor where it passes thru the engine bay.

Use bigger, badder radiator fans. Modern fans do a better job than the old Alfa fans. Maybe look at the twin fans from a Falcon or similar. Make sure they are ducted to the entire radiator core area and not just the rim of the fan shroud against the core.

[GTVeloce]

I managed to get effective AC in my last GTV using a mixture of things. I replaced all floor and firewall insulation with dynamat and dynaliner. To give you an idea of how much of a difference this made: as the car was a daily I was forced to keep driving the car while doing the work which meant driving a few days with no interior insulation at all. The tunnel would get so hot that if I brushed my leg against it I would get scalded! With the insulation in I could not feel any discernible difference in temperature of the tunnel after a long drive on a hot day.

I made sure every section of the firewall was sealed. I also put dynaliner on the section of the firewall behind the dash as that was bare metal (directly behind where the hot air collects from outside) assuming you have the eye ball vents closed. Tinted the windows with the best heat retardant tint I could find (not necessarily the darkest).

I rebuilt the air box to original condition but as I was using a TS motor I also used the standard (but rebuilt) TS compressor. Replaced the pipe insulation and all o rings and had to modify piping slightly to accommodate the different compressor. Finally I filled with HyChill.

The outcome of this was a car that could genuinely keep you cool on a very hot day. If the car was really hot to start with it would take a while to dissipate the heat but it would get there.

By comparison, my 75 TS ran a stock AC system (in good condition and with HyChill) with the same tint and was perfectly capable of coping with 45C in Dubai. Definitely a better system to begin with.

The other great advantage of HyChill is (unlike R134A) it has a similar molecule size to R12 and therefore doesn't leak out of the pores of the hoses and can last for years without requiring re-gassing. Case in point: I last refilled my 75 back in 2013 and the AC is still performing well.

[bteoh]

Great post Sportiva.
My 75's , 164 and GTV had R134a that doesn't seem to last long. Might be a leak or the old systems don't seem to hold the higher pressures of R134a. Now I have to find a place in Perth that might do Hychill Minus 30's ? Ideas anyone?

[bazzbazz]

Glad to see someone using Hychill. Just one point, with all the mods and replacement parts, did you add more lubricating oil to the system to replace what you would have lost in rebuilding/replacing parts?

Also, what happened to that poor oil filter, looks like it went 5 rounds with a large mallet!