The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Grant 302

basic and well known psychic
Please post yours, just starting the thread with my Braille B2015 install and to highlight some of the minor issues I had. I used their FRP bracket with 8" J hooks, and some reflective battery insulation from Jeg's.

Before getting started, checked the voltage of the new battery:
Card inside said 13.07V and mfg. date of 11/14/17 so I would have been fine with anything above 12.7 or so.

Plugged in the cigarette adapter and hooked it up to the charger:
Hooked up the charger on 13.6V power supply mode:
Not needed to change the battery, but good to use if you don't want to clear the KAM and maybe presets and any other stored data.

Positive terminal came off easily, but the negative side looked like the clamp had really dug into the post. Enough so that prying it off took this ring of lead with it:

Insulated the new battery:

Initially I was going to align the clamp on the negative terminal side and re-use the OEM strap shortened for a snug fit:






So I abandoned the strap and drilled the other side of the tray for the J-bolts.


Checking the charge (still through the cigarette port):

I thought I should switch over to the charger pigtail...CRAP! :mad: Forgot to put that in too!

Attached the positive lug here:

Negative lug under the nut for the terminal clamp:

Charging port zip tied and plugged:

I was putting everything away and I saw these:

And then I realized I could have put the pigtail on the side terminal screw location using these spacers and screws to better hide it. The pigtail would just go with the battery, if you needed to pull it out anyway. CRAP, CRAP, CRAP! :mad: That would have made more sense.

At that point I was too hangry to bother with changing it, and I already trimmed the positive side rubber cover for the lug. I guess that's where it'll go when I get around to changing the one on the Boss. :D
Exp. Type
W2W Racing
Exp. Level
20+ Years
Snowy North

I can scan you a copy of my template... including mounting holes.

Not sure though if S197 and S550 OE battery boxes are identical.
Nice work gentlemen. To me this makes more sense than relocating the battery to the trunk on a street driven car. Race car is a different story.
Nice work gentlemen. To me this makes more sense than relocating the battery to the trunk on a street driven car. Race car is a different story.

These batteries are getting so light that it makes relocation to the trunk debatable even for a race car. You end up adding 50% plus of the battery weight in cable. Although both the cable and battery are lower in the car.

I decided it wasn’t worth the added weight and complexity for my race car build and stuck with the stock location, having previously relocated the Battery on the Boss.

Exp. Type
W2W Racing
Exp. Level
20+ Years
Snowy North
Absolutely correct. You have a 6lb battery... pixie dust .

But relocating even a 10 or 15 lb battery to the trunk returns few sensible benefits when you look at the big picture.
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Did this a while back, but thought I'd contribute here.

Machined up a quick platform mount and hold down from 6061 T6 Aluminum:

Bent up, bead rolled, welded and polished a quickie aluminum box to keep under hood heat at bay.


And VOILA! Securely mounted and protected from engine heat.


Made this one for Kevin's car. @Albino500
It's similar, but Kevin wanted an open top with an airgap all around. So he he got one. ;)

Last edited:
Gosh those sure are nice! More info please, Fabman! Which Shorai is that? Any feedback on using it?

I have used Lithium Ion batteries in my motorcycles for years and have been very happy with them. I continue to be curious about using them in my Boss and Focus RS (the Focus battery weighs over 40lbs!?!).


Spending my pension on car parts and track fees.
Exp. Type
Exp. Level
10-20 Years
Do you mean instead of a battery?
No, with a battery. There appears to be enough room to mount a battery and a small pump for a trans cooler.
Curious if anyone has attempted this mod.
Is there room to mount the battery turned 90 deg from the way you have it in the pic? This would likely allow for a pump to fit between the battery and the fender on the battery tray.
Last edited:

Grant 302

basic and well known psychic
There could be room, *if* the cables can be manipulated to one side. Pretty sure it could be done by removing or relocating some of the cable/harness ties. I'll try to get measurements tomorrow to confirm room for the battery alone.

Grant 302

basic and well known psychic
Looks like it could fit clocked 90º. Tray is ~8 1/8" wide/clear (front to rear) and the Braille B2015 is 6.8" long per the spec sheet. Seems like it would be easiest to rotate mine clockwise 90º and move inboard, but the cables would be facing outboard and into the space you'd use for the pump. Just my thoughts. Maybe there's a more creative way to arrange it.

TMO Supporting Vendors