Design Notes: WangSpec Lightweight Battery Tray for Toyota Supra & Lexus SC

May 6, 2025

WangSpec Battery Tray – Build Notes

This tray was developed for the Toyota Supra (JZA80) and Lexus SC300 (Z30) platforms with one main goal: reduce front-end weight without modifying the chassis.

The factory battery (Group 24F) weighs ~39–42 lbs. The AntiGravity ATX-20HD weighs ~5 lbs. That’s roughly 35 lbs of reduction off the nose — a non-trivial improvement in weight distribution.

Design Constraints

Must use the OEM tray mounting holes — no drilling
Must fit the ATX-20H
Must clear the OEM chassis rail crush points
Must allow space to relocate the coolant reservoir (common with FMIC installs)
No rubber isolators — just precision cut + preload through bolt torque

Development Process

The first version was hand-measured and 2D modeled. It worked, but didn’t clear the chassis rail contour cleanly. I had another flat tray from a different brand that ran into the same issue — it sat uneven over the OEM crumple zones.

I moved to 3D scanning after that. With the scan data, I revised the perimeter geometry to wrap around the chassis rail bulges without compromising battery position.

The mounting holes were tested through back-and-forth fits until the alignment was tight with factory threads. The ATX-20HD itself had minor dimension discrepancies vs the manufacturer specs, so I purchased the battery and modeled it directly.

Final revisions included a cutout in the top plate for access to the ATX-20HD’s built-in button — a small detail that saves you from removing it for voltage checks or resets. The final version is CNC-cut from 6061 aluminum and includes stainless steel hardware.

Electrical Compatibility

This tray was positioned to retain the factory battery cable lengths.
No cutting, extending, or relocating necessary — the cables just need to be re-oriented slightly to reach the ATX-20HD posts cleanly.

It’s a simple solution for anyone who’s not ready to fully relocate the battery but still wants the weight savings.

Electrical Performance

The ATX-20HD has a slight bump in cold cranking amps (CCA) compared to the factory Toyota Group 24F battery. Despite the massive weight drop (~35 lbs), there’s no compromise in starting performance.

This tray was designed specifically around the ATX-20HD’s dimensions, and I run it on a 10.0:1 compression Supra with zero cold-start issues.

Notes

Designed for a snug fit
Works for Supra and SC300 using OEM battery tray holes
Leaves space to mount coolant bottle
Kit includes both stainless steel countersunk bolts and hex flanged bolts

Installation & Availability

Looking to install one? We’ve put together a short install reference here with bolt torque specs and terminal orientation tips.

The battery tray kit is available here and ships with both stainless countersunk and hex flanged hardware.

👀 Coming Soon

You might notice a strut bar prototype tucked into the background of one of our test renders. We won’t say much yet — but it’s real, it’s billet, and it’s designed to do more than just look pretty.

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