1994 Toyota Celica ST

Triangulated Rear Strut Brace

I thought about making a triangulated rear strut brace for the Celica for a long time and I finally got around to it in 2024. As always my primary goals included light weight and simplicity.

The GT4 factory rear strut brace is strong and light, plus it has a nice finished look with the trim pieces and padded cover. So I decided to use the GT4 rear strut brace for a starting point and convert it to 3 points while making sure the trim pieces and padded cover will still fit.

GT4 rear strut brace (strap is used to secure a tool bag)

The first step was to made a strong base plate that fits over the rear seat mount using all three bolts, so it was not necessary to drill any holes in the chassis. This was made from 1/8" 4130 alloy steel. Weight 6.5 oz.

Base plate with stainless bolts and lock washers

7/8" OD tubing was selected to match the tubing of the Toyota strut brace. I used 4130 alloy steel 0.875" OD 0.759" ID 0.058" wall seamless tubing. Each piece is about 26" long and about 18 oz.

A leftover piece of 7/8" 4130 tubing

I installed the base plate and fabricated the two diagonal tubes in place.

Diagonal tube fabrication (tubes held in place with magnets)

To maximize rigidity I attached the two diagonal tubes as far outboard on the strut brace as possible. As a result they are welded to both the brackets and the horizontal tube.

Attachment point

This made them pretty tricky to shape correctly for joints with minimal gaps.

Weld joint fitting

I tack welded the diagonals to the main bar and then tested the fit on the car.

Test fitting

The next steps were to tack the bottoms of the tubes to the base plate, test fit on the car again, and then finish welding all four joints.

Welding the diagonal tubes to the base plate

Gloss black paint came next. This finished part weighs about 5.4 pounds (about 2.5 kg).


Then I installed the finished strut brace.

Brace installed for the final time

Finally I replaced the trim pieces and the padded cover and reinstalled the back seat.

The finished installation