Alternator v. no alternator - 10% gain @ 70 km/h

[shatto]

Originally Posted by mikehallbackhoe

the optima 31a yellow top battery is probably the biggest battery I can get and still fit under the hood. I believe it is optima's biggest battery. I also do a lot of EOC, so I doubt I will have any problem running low on battery power

What we are suggesting is that a car with fuel injection, electric fuel pump, solenoid operated shifting, a computer, starter motor, windshield wipers, electric windows, a clock, solid state instruments, won't be like Erik's ancient tractor, a Model A or cars from the 60's that can run without a battery.
Somewhere you get to where what you do has no practical purpose.

[mikehallbackhoe]

I drove for two hours mountain driving. 1st the good, power was up, I gained a gear on some of the hills. where I would normally run in 3rd gear at 2000 rpm, I was able to use 4th at 1500 rpm. now the bad, after an hour or so , I noticed that when I let off the throttle and pushed in the clutch, the rpms would be 3000 rpm. when I got to work I put the stock battery back in and installed the alternator belt. on the way home, no issues. The crx has an electric choke,combined with the lightened load on the engine, may have kept the high speed idle circuit on.

[DRW]

Thanks for the feedback. It's always interesting to try something new and see what happens. Did you monitor battery volts to see when the electric choke is activated?

[shatto]

Originally Posted by mikehallbackhoe

I drove for two hours mountain driving. 1st the good, power was up, I gained a gear on some of the hills. where I would normally run in 3rd gear at 2000 rpm, I was able to use 4th at 1500 rpm. now the bad, after an hour or so , I noticed that when I let off the throttle and pushed in the clutch, the rpms would be 3000 rpm. when I got to work I put the stock battery back in and installed the alternator belt. on the way home, no issues. The crx has an electric choke,combined with the lightened load on the engine, may have kept the high speed idle circuit on.

If some electrical genius could make an attachable unit that accomplishes what the Prius 'B' gear position does, increase braking battery regeneration, only shutting off the charging of the alternator.....

[mikehallbackhoe]

I checked the voltage after two hours, and the voltage was 12.32 volts. I also listened to the stereo most of the way.

[mikehallbackhoe]

now I wonder if I should leave the ignition on, even with the alternator hooked up. to keep voltage going to the choke

[trollbait]

Originally Posted by shatto

If some electrical genius could make an attachable unit that accomplishes what the Prius 'B' gear position does, increase braking battery regeneration, only shutting off the charging of the alternator.....

That isn't what B does. It keeps the the valves open instead of shutting them during engine off and coasting. So the engine pumps air like a traditional car during DFCO. The energy captured by regenerative braking is usually reduced while in B.

In the next few years, I think we'll start seeing smart alternators appearing on cars. Some luxury models already have it. A smart alternator only(tries to at least) chargers while the car is coasting or braking, keeping alternator load off the engine while there is demand for the engine.

First heard about it with BMW, but recently saw an article mention it with Ford.

[JanGeo]

You need to find an air conditioner clutch pulley and put it on the alternator so when you are engine braking you can run the alternator to charge the battery and slow you down a bit then shut off the clutch when you want to save power / fuel. I think there is power supplied to the alternator on older models from the ignition switch which activated the regulator and field winding. On newer vehicles you would have to interrupt the power going to the regulator built into the alternator or at least shut down the power to the brushes energizing the field winding, you would still have the alternator fan load however which is why the clutch pulley is the best way.

[mrbillhf]

Like that ac clutch idea... Hey someone mentioned the 87 hf needing a specific alternator for its feature to work properly. Do you/anyone have that part number info? My alternator looks like a newer replacement I'd like to look into this.

[GasSavers_Erik]

I don't have the part number- you could likely go to the majestichondaautoparts website and get the honda part number. I think all of the aftermarket alternators are the same- they will work on the HF just fine, but they will not cut off charging when like the HF is supposed to. Perhaps it is a function of the voltage regulator- so maybe you could find an HF voltage regulator and swap it into your alternator.

Putting a volt meter in your cigarette light outlet will show you if the alternator is cutting out as it should (probably when braking).