RPM switch for AC

[69 GTX]

Looking for opinions on a RPM activated switch to shut off the AC at 4-5K

 

[bigmanjbmopar]

https://www.hotrodhotline.com/conte...r-fan-shutoff-ron-francis-wiring#.WP5AYvkrJhF

 

[747mopar]

Looking for opinions on a RPM activated switch to shut off the AC at 4-5K

Are you wanting to kill the A/C pump or an electric fan?

 

[69 GTX]

I want to disengage the AC compressor.

 

[Mike67]

As a get by you could use a wot switch as some N20 systems do and wire it through a set of nc contacts on an aux relay.
Im not sure which compressor you are using but i think some will disengage at certain rpms, Im not sure if its designed into the compressor or an ecu...

 

[69 GTX]

I thought about that, but thought maybe something else might be out there.

 

[dryheat]

On a previous vehicle I wired a dash mounted switch in-line with the A/C clutch wire to control the compressor during hard acceleration or on long uphill grades ... seemed to work good. I used an illuminated one so I could tell when the compressor was actually on.

 

[Mike67]

With a non cpu controlled vehicle I only see 2 ways of doing it, using the tps like I mentioned or an rpm activated switch like below...
m.summitracing.com/parts/sum-830452-1?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-summit-racing&gclid=CIC71YfjvdMCFUEdgQodUHQPtA

 

[72RoadrunnerGTX]

I built an A/C clutch cut-out based around a generic RPM switch intended to be used for a shift light. Controls a relay to open the clutch circuit. Also, running a modified micro switch on the center carb acting as a throttle position switch, additionally opens the clutch circuit with heavy throttle input and low RPMs.

 

[747mopar]

Forgive me if this is a stupid question but why don't you just turn it off with the heater control? Sorry, trying to understand the RPM thing... is there an issue with spinning the pump that fast, belt issue or is it there to shut the pump off if you have a spontaneous urge to floor it?

 

[Hemirunner]

Looking for opinions on a RPM activated switch to shut off the AC at 4-5K

Without an ECU, the WOT switch is pretty easy and isn't rpm dependant. They usually have both normally open and normally closed contacts. You could use it to shut off the relays to alot of stuff, even shutting of the alternator field for that extra .0001 in the quarter lol.

 

[72RoadrunnerGTX]

Forgive me if this is a stupid question but why don't you just turn it off with the heater control? Sorry, trying to understand the RPM thing... is there an issue with spinning the pump that fast, belt issue or is it there to shut the pump off if you have a spontaneous urge to floor it?

In my case, two reasons, don’t want find out what the rev limit is on the Sanden and my lead foot tends to show itself somewhat spontaneously, prefer not to have to always plan a head, A/C on or not.

 

[69 GTX]

Above post nailed it

 

[747mopar]

In my case, two reasons, don’t want find out what the rev limit is on the Sanden and my lead foot tends to show itself somewhat spontaneously, prefer not to have to always plan a head, A/C on or not.

I'm running a Saden and twist mine too 6,000 rpm all the time. The Saden is a modern pump and it's not uncommon for modern engines too hit 6,000 rpm. I'll admit I don't run mine much just because I like my windows down but so far it doesn't care.

 

[69 GTX]

My fiberglass hood probably wouldn't fair well if there was a failure......

 

[mopar 3 B]

Fiberglass hood and AC??

 

[69 GTX]

Nobody said I was normal!

 

[Nacho-RT74]

I got a RPM switch like this to make the same you thought ( can't recall if it was this, long time ago, but if not, is REALLY similar )

http://www.ebay.com/itm/Summit-Raci...ash=item5b2bb8ca67:g:mOoAAOSwHaBWkD~8&vxp=mtr

... bought it around 5 years ago, but since my car is still on body job I haven't installed yet.

The switch I got is able to activate or deactivate whatever you want... or even create a "window" where you can set a top and high cut to activate or deactivate between those RPMs

I also will instal a micro switch like 72RoadrunnerGTX did, in that way Compressor clutch will come off at what comes first, throttle ( passing a car on highways for example ) or RPMs

 

[Nacho-RT74]

just noticed the one with digital display posted... when I got mine I remember the diff between the microswitch unit I got and the one with digital display was way higher. I think got it in less than $40 in fact... I went for cheap. I don't think got it from Summit in fact but whatever dealer around. I don't care something fashion or easy to setup, will be hidden down the dash anyway. And is something I wouldn't be changing everytime, just while I set the best RPMs cut suiting my needs. As soon I find the sweet spot will be fixed there.

 

[Gpuller]

I use this cheap switch...