Early 911 Battery Mount Ideas

[MrBonus]

When my car's pan was replaced long prior to my ownership, the screw mount for the factory battery tie down was not replaced. As a result, one of the prior owners mounted a 3478 where the charcoal canister traditionally mounts. It is not secured and I would like to remount the charcoal canister properly so I can install a trunk mat.

What are my best solutions? I purchased the Stoddard tie-down not realizing there was no tap to fit it, so I'm not sure this is as simple as drilling a new line or would the Rennline smuggler's box mount be my best bet?

Any help would be appreciated. I would prefer to keep the installation cost efficient, if possible, but if the Rennline unit is my best bet, I'll do it.

Also, if I do the Rennline unit, do I need to remove the smuggler box cover permanently?

[30westrob]

I would install 8mm rivet nuts in correct position for the battery hold down and the canister bracket. Easy quick solution and back to OEM. Any good body shop will have the setting tool if you cannot borrow or bye. Rob

[kent olsen]

I moved mine to the smugglers box years ago. Easy install and you can leave the lid in place.

[thor66]

an Optima can be flipped sideways and shoved into the battery box

[911pcars]

Here's an Optima squeezed sideways into my early battery box. Had to fabricate a holddown and insulate the positive post. Notice the late 20 gal. tank nearby.

[HarryD]

Lots of threads on this. Here’s one: Pics of your longhood/LWB battery box battery tie down solutions

My solution:

[gumby]

I installed this in my 73
https://www.odysseybattery.com/products/hk-pc925-battery-hold-down-kit/

[MrBonus]

Originally Posted by 911pcars

Here's an Optima squeezed sideways into my early battery box. Had to fabricate a holddown and insulate the positive post. Notice the late 20 gal. tank nearby.

Originally Posted by HarryD

Lots of threads on this. Here’s one: Pics of your longhood/LWB battery box battery tie down solutions

My solution:

Thanks!

Which size battery is this?

[MrBonus]

Originally Posted by gumby

I installed this in my 73
https://www.odysseybattery.com/products/hk-pc925-battery-hold-down-kit/

I actually just ordered that exact bracket and battery last night. It seems like the most convenient solution.

[gumby]

Odyssey PC 925 from Battery Mart, I'm now running just one battery, works great with this mount
https://patrickmotorsports.com/collections/battery-mount-packages/products/pmp-911-69-73pc925mnt

[HarryD]

Originally Posted by MrBonus

Thanks!

Which size battery is this?

It is labelled 75/35 (per Optima it is the same as a 75/25). I would have preferred to have the terminals on top to reduce the risk of a short. It looks like a 35 would fit the bill.

Also, I was surprised to see that I have had this battery since 2009 and still going strong.

[MrBonus]

Originally Posted by HarryD

It is labelled 75/35 (per Optima it is the same as a 75/25). I would have preferred to have the terminals on top to reduce the risk of a short. It looks like a 35 would fit the bill.

Also, I was surprised to see that I have had this battery since 2009 and still going strong.

Nice. My 3478 is dated 2007 thus why I’m giving this some thought now.

[MrBonus]

I purchased the Patrick Motorsports Odyssey 925 mount and had a buddy weld in a nut for a mount (the original battery tray mount was just an odd-sized hole that couldn't hold anything). My terminal tops were so old/worn that they wouldn't grip the new battery so I replaced those too.

This allowed me to remount the charcoal canister and install my new Carbone frunk carpet.

Also, the car feels like it gained 25 horsepower and finally got rid of an obnoxious hesitation at mid throttle. The funny thing is, the 15 year-old red top was holding a charge and my voltmeter didn't indicate any problems but that thing must not have been right.

[47silver]

mrbonus very clean look
where did you obtain the positive terminal cover?

[Hi_Fi_Guy]

I was going to ask the same. First time I have seen a positive terminal cover like that. Looks ideal for our early cars.

[MrBonus]

Originally Posted by 47silver

mrbonus very clean look
where did you obtain the positive terminal cover?

Amazon, of course.

https://www.amazon.com/gp/product/B08Z1R67DZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1