Is it worth getting a variable orifice tube ($25) over a fixed orifice tube ($4) for an R134a converted AC system? Anyone have first hand experience of the variable orifice improving system operation?

i had a 2' HIGHER temp after putting one in on a R-12 system.
so no, i would not spend the money again.

From what I've read, the variable orifice improves an R134a system, but doesn't do anything for an R12 system. So your observation is consistent with what I've seen. Have you tried it on an R134a system?

quote Originally posted by summerjim: Have you tried it on an R134a system?

no, sorry.

Interesting article on the VOV (Variable Orifice Valve):
http://www.imcool.com/articles/aircondition/VOV1.htm

When I converted my 81 chevy p/u to 134a I used the VOV and it seemed to work ok. The r-12 system definitely worked better at idle rpms but once the motor was turning over 1500 rpms they both cool pretty well. I can't say that the VOV would have made any difference over the stock orifice. I used a stock orifice in my 86GT and it was freezing me out this summer. I don't think that getting a VOV is big deal.