Suggestions for light weight racing battery

15 or 20 Amp Hour batteries will not have enough reserve capacity for typical street use.

360 Challenge race cars use dry cell sealed type battery rated at about 26 Amp Hour. And there is a quick connect Anderson type plug for an additional jump start battery. At 26 AH we find the reserve to be marginal for a racing 360C with no accesories other than radiator fans. So we upgraded to a 40 AH Odyssey PC1200 drycell sealed battery for all our racing 360C. You will have to make a new battery mounting tray and terminal as they are different size from 360 Modena OEM FIAMM batteries.

These drycell type batteries have very good cranking power and are safer in a crash with no loose acid floating around. That's why we use them. And they require no vent tubes. Weighs about 38 lbs so it's lighter than FIAMM. So far we are very happy with them.

 

I have an Odyssey PC680MJT in my 348, and it only weights 15.4 pounds. I have no problem at all getting it to start my car. It costs around $140 retail. Here is their website. http://www.odysseyfactory.com/

 

20 AH is not quite 20 amps for 1 hour. Odyssey battery ratings are done over 10 or 20 hours at a much lower current draw. For example PC680 mentioned by Ernie is rated 17AH over 20 hours and only 16AH over 10 hours. So at 1 hour I suspect it will be a lot less than 16AH. On top of that I don't think your alternator charges your battery to 100%. I remember reading an article on one of the battery manufacturer's web site stating alternators only charge car batteries to about 85% - 90 % capacity.

We use Odyssey PC680 battery on our Formula Renault race cars. It has very good hot cranking amps for such a small battery to easily start the 2000CC Renault race engine, but if we have to restart the engine a few times, then sometimes the battery begins to get quite weak and can fail to start even this small 4 banger. That's just our practical experience with this size battery.

For our 360C race cars, once we had to start from pit lane because the 26AH race battery was too weak to re-start the engine on the grid, due to a combination of hot weather and running both radiator fans for 10 minutes. So that's why we upgraded to Odyssey PC1200 with a 44AH rating over 20 hours or 40AH rating over 10 hours. We have not had a problem since then.

360 Modena uses a 70AH FIAMM battery (piece of junk IMO). Do keep in mind that 360 has a lot more ECUs than a 348 to drain your battery while parked, so even a 0.05A drain over 4 days will eat up almost 1/3 of the capacity of PC680 if not constantly trickle charged.

Personally I think saving battery weight equivalent to only 3 gallons of gasoline is not quite worth giving up 2/3 of the battery reserve capacity. The smallest battery I'd put on a constantly trickle charged 360 Modena is a Odyssey PC1200.

 

Your an interesting read cwwhk and you seem to know your stuff.

I guess the reason why people want a smaller battery is because of the $/kg weight saving. Its one of the cheapest. Of course 11L is the same. But when you go to the limit and save 11L and a smaller battery is pretty cool

What would you put in a 348 for good street use?

Thanks!

 

zakeen:

I'm all for saving weight, but it's really up to each owner to decide what cost/benefit they are comfortable with in deciding to cut out 10 or 30 lbs worth of battery. For me, I would NOT use a battery smaller than an Odyssey PC1200 for a street car. Compared to OEM FIAMM, it has much higher instantaneous cranking amps, is about 10 lbs lighter, and still has a 40AH rating.

If you go with a PC680 you'll save an additional 20lbs, but that weight difference equals to only about 0.2 to 0.3 seconds per lap at Shanghai F1 track for 360C with good pro driver. So unless you can drive your car consistantly to within 0.3 seconds per lap, you won't be able to really tell the difference.

If shedding weight is of utmost importance over everything else, then why stop at the battery? Without spending any money, you can take out the tool kit and spare tire if so equipped, remove the owner's manual, drain the windshield washer fluid, keep fuel tank 3/4 empty, etc.. Of course if you ever need to use any one of those then.....

Not having any safety margin is usually not very wise. Just two months ago my alternator blew while holding a comfortable 3rd place. With the extra reserve capacity of my battery, I managed to salvage a 4th place finish. Had I been using the smaller Challenge spec 26AH battery I would have DNFed and completely ruined my points standing in my series.

 

As heavily laden as a 360 is with voltage sensitive electronics I think it is a real mistake to go to less battery. It is exactly why the auto industry has for several years been trying to go to a higher voltage system...to take much of the marginality of the 12v system out of the car. Saving weight is a good idea but there are better ways. The 360 battery is probably too small. It was chosen for packaging reasons.

Euro bumpers are a whole bunch lighter and are on the ends so you get a two fer in handling. Brembo or Girodisc floating rotors are lighter and get rid of unsprung weight.

Ther are other ways as well but with the cars electronics I would be going bigger, not smaller.

 

Ray:

Stock FIAMM weighs 44 lbs.

 

Very true. OEM seats, wheels, and glass also weigh a lot too. It can get rather expensive in a big hurry to go on an all out diet though.

 

cwwhk,

you really know your stuff !

.

 

Thanks for the compliment. There is still so much more to learn.

 

A 360 is not a race car. If you want to save a few pounds with the battery, that alone is pointless. You need to rip out the carpets, ditch the window motors, lose the stereo, get racing seats, etc. etc. etc. Change your suspension; learn how to set it up for maximum performance (which will also result in minimal comfort).

What you'll be left with is a challenge car, with a stock motor. You'll loose a few 10ths which is huge for a race car, moot for a street car.

If you want to go faster, take some driving lessons. Lose some weight if you're overweight. Exercize your body; the neck in particular so high g's in corners with a helmet won't be so bad.

Leave the stock battery, or upgrade to a better if not lighter battery. Or better yet, buy a track car and then you can go nuts with a pound here and pound there.

my $.02.

Ken

 

Amen and wish i'd done that from the get go.

BTW: have a 308QV with modded ignition, modded adjustable suspension, race seats, Schroth belts (HANS compatible of course), Odyssey PC680 battery... etc. Car weights 2900 wet with 1/4 tank gas and me in it. She is still an underpowered car great for learning but useless for 'real' racing as in various leagues she gets classified into cars that easily are better.

Fully agree with your buy a track car comment. i would have been better off leaving the 308Qv stock and buying a nice race spec open wheel car. Am getting a bit tired of driving saloon cars on the track anyway.

 

there's no harm messing with a stock road car.

people who are sensitive to their car will notice even small changes.

and its fun.

.

 

I'll be running an 8 lb battery and 11 lb kevlar seats for everyday street use....this will offset the added weight for roll cage.

I'm not ready to state mfg's but when it is finished I'll post pics.

As for the Bride Gias seats...If you are considering?? do your homework first before you buy.

 

i had PC680MJT and Sparco Roadster seats, cut down A LOT of weight.

 

It's battery time for my '05 F430. Any updates, PC925 still the best solution? Who should I buy it from? Price?

Thanks,

Gary

 

Bought my Odyssey from Portable Power Systems, in colorado IIRC. Best price I could find.