yes theoretically, but some guys run bigger batteries back there to get better weight distribution.

can't find the video, but one of our pca/nasa buddies went to nasa nationals and lost the championship because his little battery wouldn't crank his engine over. he actually went to feet in, he's not a newb, but he had a brand new twin disc clutch and ultralight flywheel, and with the adrenaline and new clutch he stalled his 993 and was out the race.....and the championship!

I've got a D51R in my 99, but then I pulled all the trunk liner stuff out ages ago.

It's great, way better than the useless WestCo I suffered with for several years. The early Hydra in my car doesn't start it properly if the battery is at all low (gets confused and fires the spark at the wrong time, stopping the engine or something like that). The Optima fixed all that.

--Ian

This.

Exide Orbital only for me now.

Cool. Do you have any pics to upload?

Something about that just seems like a band-aid fix to me. This is a terrible comparison, but you won't see any formula cars hanging ballast over and behind their rear wheels.

My battery preferences?

Female and with lots of cranking amps...

I prefer to forgo the battery all together and just find people to help push start me. Saves me money on buying a battery.

lol

I'm trying to order a battery now and need to make sure I'm ordering the right one. Normally I use the OEM Westco (I think it is) but I'm thinking its time for something a bit beefier.

Looking at a Yellow top Optima D51R on Amazon. http://www.amazon.com/Optima-Batteri...owViewpoints=1

I see a couple reviews from miata guys on there and they say the rod needs to be extended but that it fits the tray otherwise. I just measured and it seems it'll be too wide for the Optima.

Can you guys just verify for me that this is indeed the correct yellow top. :bigtu:

A yellow top D51R will fit my 93 or my 94. I don't use a plastic tray. Just use the existing factory metal brackets that hold the factory battery base in place to hold the base on the Optima.

I did need to buy a longer battery hold down bolt and reused the upper battery hold down without any modification.

So, basically you just need to buy a D51R Optima and a battery hold down bolt to make it work.

John

The Odyssey PC680 is a nice compromise between race and street. I've let mine drain way down several times by forgetting to hook up the trickle charger. So far it's recovered fine.

Ok cool, thanks guys.

I'm gonna go ahead and order the Optima yellow top and 2 K&N cone filters from Amazon. The filters are on sale for $15 each and the battery is listed for more than $50 less than FM has it listed for. :bigtu:

I making this a Jesus thread... Will a D75/25 yellow top be an overkill? I am tired of having electrical issues :wavey:

kind of, you probably have some other issue. i'm running a lawn tractor battery, plus only drive my car a few times per month.

Get the D35. It'll outlive your electrical problem.

I've drained mine twice due to complications with power flowing backwards through a boost solenoid into the megasquirt and then charged it up and let it sit for almost a month.

Car started right up.

The D51R is lighter and the yellow top Deep cycle starting battery is way more resistant to abuse than the larger red tops in my experiance.

Bob

I've had better luck with Duralast in my turbo car than Optima, and that car sits for weeks at a time, and gets lots of cranking.

I'm talking yellow top... that is the right size for an NB trunk with stock mounting hardware (minor mod required) and correct post orientation.

fits like glove!

D35 => 36.4 Lbs

D51R => 26.0 LBS

They are both heavy as I think the stock battery is ~24 lbs. Severe abuse of the D51R has not killed it for me. the D51R fits in the stock loacation for an NA, might be too tall in an NB to be just like stock.

After trying a few super light batteries in the 5 and 6 lb range I now have a Bikemaster True Gel I think YTZ14S
It’s 7.8 lbs. It most of the time gets the car started but with very little margin. The car can sit for a week and it starts right up but turn it off for a short time and sometimes it won’t. I have found the Hydra ECU is extremely picky about not having enough voltage while cranking. The car will crank just fine but the ECU wont give it spark or fuel unless it sees ~11 volts. This is a problem for small batteries while cranking.
Bob

Run a jump pack while your in the pits?

The D51R fits in an NB, but you need a slightly longer bolt for the hold-down. I keep meaning to cut a length of pipe to use as a spacer, but that's not really necessary.

And yeah, my Hydra is also very picky about starting voltage.

--Ian

you keep your ten pounds, i'll keep my 37% more cold cranking amps.

also the 35 costs a bit more. but whatever, i love it.