sportage4x4

so... will the stock miata agm battery crank over an LS1?

i'm starting my swap and the oem battery needs to be replaced as its dead. should i just buy another miata specific battery, or will i need something bigger?

fyi its going to get a high comp 99x83 (5.1L) engine.

mike90miata

I think it would depend on the outside temperature. Personally I would get one of the small drycell batteries. They weigh about as much ans the Miata battery and are about the same size.

fmowry

Many use the Optima D51R. Terminals are correct and it fits in the hole. It's a bit higher than the stock but nothing an extended hold down can't handle.

http://www.amazon.com/Optima-Batteri...6946811&sr=8-3

Frank

Keith

We use the Optimas in our builds.

sportage4x4

so the optima, sounds good to me. thanks.

MRM331

Stock batteries have worked fine for the last 15 years or so in Ford conversions. I can't imagine a GM being that much harder to turn over.

Most of us do run a thick battery negative lead directly from the starter bolts to the negative terminal of the battery to electronically take the place of the PPF.

-Jason

sportage4x4

i would totally try the stock battery, but its nearly dead and barely cranks over the stock 1.6

Keith

I dunno, cranking 6.2 litres of 10.7:1 compression is asking a lot. We tried the factory battery and decided we'd be more comfortable setting our customers up with something a little burlier.

waterwellwizard

Keith, your customers appreciate that line of thinking! Not many things are more frustrating, than when your getting ready to burn a few gallons of high octane, in your pride and joy, on a beautiful day and click,,,click...click, darn, now where did I put those jumper cables? Just one more example of why FM is always at the top of the list, no matter how or what you're measuring. Quality never goes out of style, Wiz.

chpmnsws6

Do you run new power wire or leave the stock (4ga?) wire in place?

Keith

We leave the stock wire in place.

With regards to your signature, if you think "Miata" is often spelled incorrectly, you should try working with "Cameros"

chpmnsws6

That's a relief! One less thing to worry about. I had to shorten the battery cable around a foot.

As far as "Miata", the computer always underlines it like it is a misspelled word... But yes, even within the F-body world, people used to misspell "camero"

chpmnsws6

With 2 gauge wire and the stock battery, the engine turns over faster then it did in the C5 OR F-body with an optima battery and stock wiring!