AC on Brake mod - idea

kalmar · 07-05-2005, 11:41 AM

I had a look through the "mod" forum but couldn't see this one.. so maybe it has been done, maybe not.
I find when I'm driving a vehicle with air conditioning, and am tempted to use it, I try to just enable it just when going down steep hills, that's often enough to keep the car cool. Of course the insight has an effective regen system, but any time the brake pedal is being pressed, there's energy being wasted

So I was wondering about having the brake light switch connected to a normally-open relay in series with the AC pump clutch. Of course, you would want an extra switch to put the operation back to normal..

Worth bothering with? I may try it..

hawkGT647 · 07-05-2005, 12:40 PM

I like it! That would great for us in the deep south, hot & humid.

Great idea.

Will you let us know the results?

Double-Trinity · 07-05-2005, 12:59 PM

It's a good idea. I always thought it would be good to have the AC have an "econ" mode where the AC only runs when the car is either coasting or braking, I tend to just switch the AC in my civic on and off manually in these cases. For coasting down hills the AC is nice, it can provide just enough exrtra drag to keep the car in control without downshifting further or applying more brake pressure where I live.

flunkysama · 07-05-2005, 01:01 PM

It is would be a bit more work, but you could use a vacuum switch plugged into the intake manifold. Then the A/C compressor only engages when you lift off the gas. You might need a relay and of course a bypass switch mounted inside.

kalmar · 07-05-2005, 01:11 PM

Thanks for the feedback and ideas.. from what you're saying, perhaps off-throttle AC would be a benefit too (of course it's "stealing" some regen opportunity..?). It's sounding like another feature for MIMA_C almost

In the meantime, the suggestion of a vacuum operated switch is a good one, or maybe a simple microswitch to detect "gas pedal completely up".

It might be a while before I get around to trying it so if anyone else wants to give it a go, please do!

Resist · 07-05-2005, 06:11 PM

The only problem with this idea is the cycling of the A/C system so frequently is not good for it in the long run.

kalmar · 07-05-2005, 07:15 PM

Quote:

Originally Posted by Resist

The only problem with this idea is the cycling of the A/C system so frequently is not good for it in the long run.

In what way? Surely the compressor cycles on and off all the time, to maintain the temperature. All this mod would do it prevent it cycling on when the accellerator is pressed..

Guillermo · 07-05-2005, 07:44 PM

This reminds me about my previous car.
The 1998 Subaru Legacy GT turns off the AC automatically during hard or medium acceleration, but my Insight with high tech super duper electronic everything 10x the computer power required to travel to the moon does not turn off the AC when accelerating!

The AC affects the acceration of the Insight so much that some might consider this a safety hazard.
This feature along with those mentioned by others above would be awesome to include in the next generation of MIMA if possible.

Resist · 07-05-2005, 09:12 PM

Quote:

Originally Posted by kalmar

In what way? Surely the compressor cycles on and off all the time, to maintain the temperature. All this mod would do it prevent it cycling on when the accellerator is pressed..

Oh I see, then maybe I misunderstood what was stated.

Resist · 07-05-2005, 09:15 PM

Quote:

Originally Posted by Guillermo

The AC affects the acceration of the Insight so much that some might consider this a safety hazard.

A safety hazard? This is a rather long stretch to be considered a safety hazard. Yes there is a slight decrease in performance due to the A/C, as there is in any car. But a simple press of a button returns that performance when needed. It certainly isn't enough of a loss to cause a safety concern.