Lightweight Battery Project

[Loren]

I got the smallest one available. It's actually only slightly smaller capacity than the MC battery I have under the hood.

Amazon had it on sale yesterday for $24.99. Seemed like a no-brainer. Just have to remember to put it on charge every now and then.

[Tyrelirwin]

If it makes any of you feel better, I was shopping for a set of compact jumper cables last night, and ordered a compact jump box instead. Not only will it start the car if necessary, but I can also charge my phone with it.

But the real question is: how much do they weigh?

[Loren]

It's extremely light. I'd guess less than 1.5 pounds. It's right about the same footprint as my Samsung S7, and 2x as thick.

In this case, I don't care much what it weighs. It's not in the car for competition. It stays in my "pit box" with tools and stuff. It's only in the car for daily driving and transport.

[Tyrelirwin]

In this case, I don't care much what it weighs. It's not in the car for competition. It stays in my "pit box" with tools and stuff. It's only in the car for daily driving and transport.

Ah, that makes sense. Do you race with only a partial tank of fuel, also? And/or what fuel do you use for racing?

[Loren]

Getting a little off-topic here, but I do try to run with 1/8-1/4 tank of fuel. Sometimes I forget and fill up a couple days before an event. 3/4 of a tank in the Mirage is only about 5 gallons, so only about 30 pounds. And it's weight that is very low and centered in the car (though it does slosh around). Not ideal to have, but it's not a huge problem. I can tell the difference between carrying a 180-250 pound passenger or not. I can't really tell the difference between 3/4 tank or nearly empty.

I use premium fuel. My theory is that, because it's a learning ECU, if I always run premium, it's going to learn to never retard the timing as much as it would need to if I ran regular. In theory, my timing MIGHT be a little more advanced than it would be if I always ran 87 octane. Won't make a huge difference, but if it's 2 hp... it's a cheap 2 hp. Maybe 30 cents per gallon difference in price. 7 gallons per fill-up. It's costing me about 2 bucks, and I only fill up about every other week... so $50-60 per year. And I autocross at least 24x per year... so a couple or three bucks per autocross... for 2 hp? Even 1 hp. Totally worth it. And if it does nothing at all, it's still not costing me much.

[Pryme]

The car is designed for 87. You may actually lose power using premium. Along with having the possibility of getting deposits due to not getting completely burned.

[Eggman]

The car is designed for 87. You may actually lose power using premium. Along with having the possibility of getting deposits due to not getting completely burned.

That is interesting. I've heard that using premium is an economic waste unless the car was designed for it. Losing power and deposits are new to me. Pryme, do you have any references for further reading?

[Pryme]

That is interesting. I've heard that using premium is an economic waste unless the car was designed for it. Losing power and deposits are new to me. Pryme, do you have any references for further reading?

Using premium in a car that calls for regular can cause pre ignition. Pre ignition at best causes deposits due to unburned fuel in the combustion chamber and at worst can cause burnt valves.

http://www.contactmagazine.com/Issue...ineBasics.html

As far as losing power, that would be in extreme cases if you do start to burn a valve etc. Being that you beat on your car way more than avg, you could possibly experience the worst side effects.

There is just no chance of increasing performance and it costs more, and will be dirtier, so why?

Your dime and car though.

[stevedmc]

The car is designed for 87. You may actually lose power using premium. Along with having the possibility of getting deposits due to not getting completely burned.

Amen.

[Loren]

Thanks for the tip, I'll read up on it when I get a minute.