Alternator delete, other engine mods for city driving

[DoctorP82]

Hey all. I mostly drive in the city, and with my Jeep 4.0 Cherokee the engine size significantly limits my ability to gain fuel economy. The best I can do is 18 mpg (still above the adjusted EPA of 14 for in-city driving), and that is with roof rack deletes, P&G, and engine off at lights.

I have been reading some threads about alternator deletes, and was curious about this. Some info was about simply removing the fuse to decrease the drag load caused by the alternator being on. I was wondering if anyone has done this for a significant amount of time, how you go about maintaining battery charge, etc. I had the thought of a switch-controlled alternator fuse, that could be routed to the dash, but I'm no electrician or mechanic, so I need input on that.

Another problem is having an automatic transmission. My ideal cruising speed is about 42.5 mph where my tach reads 1200-1300 rpm, but with starting and stopping it can use a significant amount of gas to try to reach that speed between lights. I had seen people discuss adjusting the choke to augment shifting timing, but thought this was more dictated by gearing than anything else. Would anyone be able to point me in the right direction for finding what gearing options I can find available for vehicles?

Thanks,

JP

[Funny]

Check out AndrewJ's Alternator kill switch in his thread about his Honda here for ideas: Post #149, 5th generation Civic hatchback

Hope that helps.

AndrewJ is one of the most ambitious people on this forum, as far as modifications go, (so are basjoos, MetroMPG, and bbjsw10, just to name a few) So check around and they will provide all the ideas you can handle.

[orange4boy]

The simplest alternator mod is to simply unbelt and disconnect it if you can and run with a deep cycle battery. I have been doing this for several months now and I would never go back. I removed the alternator completely after a week.

You need to be able to charge at home with a good automatic charger and on long trips charge at your destination or run two batteries. Depending on the draw of your particular vehicle you will get surprising range from one battery. Buy a digital multimeter and keep tabs on your voltage. Never let a starting battery go below 12.3 and a deep cycle below 12.1. This is resting voltage. Your battery will read lower when under draw but will rebound when left to rest for a few minutes. This can be a little disconcerting but you will get to know your battery and learn to trust it after time.

It's winter now an I can run an engine cooling fan, heater fan, lights, stereo, wipers, EOC, and shut off at lights and restart with about a 40 mile range.

None of this requires any fancy switches or wiring. For two batteries I used to hook them together with a good set of jumper cables.

I drove 135 miles on two used batteries from Vancouver to Seattle this summer.

I will probably post a DIY thread on this later.

Good luck, keep at it. I started where you are now just a few months ago.

[DoctorP82]

I'd be interested in how this was done. Do you take the batteries out or hook them up for charge when parked at night? How is your multimeter hooked up?

Curious too, I wonder if anyone who does a lot programming wise with their MPGuino whether it would ever be possible to program a way to read a percent charge remaining, or something so that those who are less techy about engines (ie - myself) could follow.

[orange4boy]

If your range is low and you only need one battery, you can just leave it in the stock position and open the hood when you get home to attach the charger. if there is room somewhere you can also keep the charger in the car hooked up all the time and just leave the plug where you can get to it without opening the hood. The same way a block heater works.

Digital multimeters are the best because they give a more accurate reading. Set the multimeter to DCV 20 (Direct Current Volts) and find a power (red) and a ground wire (black) under your dash to attach to. Or run a couple of wires from your battery terminals (install an inline fuse on the + wire near the battery) into the cab and hook the multimeter to those. You can later use these to attach a permanent volt meter.

[orange4boy]

I like the idea of the MPGuino as battery charge indicator but that's way beyond me. You should post that on the development thread. You can say I'm for it too.

I have an auto trans too. It's sure frustrating when you can feel all that wasted energy before the lockup engages. I'm trying to retard the downshift on mine so I can p+g on the highway. No luck with loosening the throttle linkage so far I'm hoping there's a vacuum fix.

[95CHERJUST]

Anybody do a super mid or mpguino on a jeep cherokee pre obd2 yet??