RPMs vs A/C temp

[kroberts]

I've never been completely happy with the discharge temp of my AC system. I've noticed that it gets very cold during and just after I accelerate down a freeway on-ramp for example. Once I get up to highway cruise, the temp is mediocre at best. In traffic it sucks altogether.

Is this a function of refrigerant volume?

Obviously a compressor works best at higher speeds, what about changing pulleys? Is that a viable fix?

How much oil should be added to the system during initial charge?

Is it possible that the garage put too much oil in the system and the reduced r134 volume is affecting system function?

Any input or advice would be appreciated.

TIA

[Liam]

R134 is not as efficient as R12 and also operates at different pressures...

Was the expansion valve and receiver dryer replaced when it was converted?

[Todd Black 88]

Its a function of head pressure of the refridgerant used. Different refridgerants have different ideal head pressures for efficiency.

You need rpm to increase the head pressures to increase the cooling ability, thats why it works best at high RPM and not at cruising or idle.

They shouldn't be adding any oil afaik, just gas. The system is quite small so its really only a few ounces of gas i believe..........typically.

Big thing is r134A is not as good a gas as the old R12 gas. It was made as a conversion for r12 systems because its properties are similar and you can reuse your existing R12 compressor. Its also environmentally friendly.....er than R12.

No A/C gear comes with it anymore because its really a pretty crappy gas. Tere are better out there but you need a different compressor to run it.