I have a stock (enginewise) 92rs with an lo3 that is about to undergo an engine swap. Its a pretty stout 355 and I want to know how many rpm's can my stock a/c handle before it craps out.

Is 7000 ok?

 

uhh, flip it off before racing i'd say. I think you won't have a problem, I think theres a clutch or something to keep it from spinning too fast.

 

I don't know about the R4 compressors, but I have run both the A6 and H6 styles well over 9,000 compressor RPM and not blown one. On my old 305 the crank had an 8" diameter pulley and the pulley on the H6 compressor was 4.25". That gives a 1.88:1step up (8/4.25). The EBL shut the compressor off at 5,000 engine RPM or whenever I hit PE. At 5,000 rpm not in PE (saw many times), the compressor was turning around 9,400 RPM!

The old 305 when carbed had an A6 compressor on it. The crank pulley was 6.75" and the compressor pulley was 5". That gave a 1.35:1 ratio. That compressor was used without any type of cut-off on it, other than the cycling switch (surely it cycled as the RPMs shot through the roof). I ran that engine to 6,500 rpm ALOT of times. That is around 8,800 RPM compressor speed.

A6


HR6


Here is the R4 that is on your car.



It has a 4.96" pulley on it. The crank pulley should be right at 8". I would consider 10,000 compressor RPM to be the absolute MAX.

 

Good.. because I live in south louisiana and if I had to choose between a/c and racing, well I'ld be doing all my racing in winter!

 

To repeat what Sonix said...just turn it off when you plan on runnin up the rpms. Move the slider to 'OFF' and the compressor won't cycle.

Another possibility is to get some electronic device to block the signal when a certain rpm is exceeded. That would be cool, not having to think about it when your racin in the summer.