LSFBZ3

BMW Z3 / THE PROJECT

V8 POWER. HAND-BUILT DETAILS.

LS-powered. Fastback Z3.

Illustration of the black BMW Z3 with bronze wheels and a carbon fastback hardtop overlooking forested mountains and lakes.
LSFBZ3

Roadster roots.
A fastback of my own.

Explore the build
LS1 V8 / CARBON FASTBACK
LS
LS V8 power
FB
Fastback roofline
Z3
BMW Z3 chassis
From the garage

01 / THE BUILD

The name tells
the story.

An LS1 under the hood.
A fastback roofline in carbon.

LSFBZ3 means LS-powered Fastback Z3. LS for the V8. FB for the fastback. Z3 for the BMW underneath. A 400 whp LS1, a 4.10 final drive, and a custom carbon hardtop bring those three parts together.

The roof starts with the OEM rag top’s shell and reuses all of its mounts. From there, it’s a hands-on process of shaping the fastback profile, laying up carbon, and dialing in the fit.

02 / UNDER THE SKIN

Small chassis.
Big displacement.

An LS1 V8 at the heart.
The hardware to put it to work.

5.7L

Aluminum LS1 V8

400WHP

At the wheels

4.10:1

Final-drive ratio

Front-quarter view of the open-top Z3 in the garage, with its hood raised over the LS1 V8 and bronze wheels visible.
Engine & induction
MTI Stage 2 camshaft, 243 cylinder heads, BTR pushrods, LS6 intake, rails and injectors.
Drivetrain
Spec Stage 1 clutch, Energy Suspension polyurethane engine mounts, and modified CXRacing E36 swap headers.
Chassis & suspension
Randy Forbes subframe reinforcement, M3 differential cover, Ireland Engineering subframe bushings, and BC Racing coilovers.
Wiring & instruments
Wiring Specialties universal swap harness and a recoded factory gauge cluster.
Exhaust & brakes
3-inch exhaust with a Magnaflow muffler; PowerStop rotors and pads.

03 / MAKING THE ROOFLINE

From roadster
to fastback.

Built on the OEM rag-top shell.
Every original mount, reused.

Wooden guides define the new roofline over the original roof structure.
01 / DEFINE

Find the line.

Factory mounting points. A fastback roofline.

Side profile of the Z3 with its shaped foam hardtop form.
02 / SHAPE

Work the surface.

Foam turns the idea into a full-size form.

Freestanding carbon roof shell on workshop supports.
03 / FORM

Make it real.

The carbon hardtop takes its final shape.

Close-up of the hardtop mounting hardware and carbon surface.

The original mounting points.

The OEM rag-top shell provides the foundation, with all of its mounts reused.

Inside the detached carbon hardtop, showing its structure and rear-window opening.

Made around the Z3.

A carbon fastback hardtop built around the factory fit.

THE HARDTOP / AVAILABLE TO BUILD

A fastback for
your Z3?

The cast is made.
It doesn’t have to be a one-off.

I have the fastback hardtop cast and am willing to create more. It’s built on the shell of the OEM rag top, reusing all of the original mounts.

Ask about a Z3 hardtop

04 / THE PHOTO ARCHIVE

Every stage has a story.

A selection from the garage.
Select a photo for a closer look.

26 photographs

The black BMW Z3 with bronze wheels and its custom carbon hardtop.
01 / The car

A Z3, reimagined

The LS1 V8, intake and supporting hardware in the Z3 engine bay.
02 / Powertrain

5.7 liters. 400 whp.

The Z3 cockpit with bucket seats, steering wheel and roll structure.
03 / The car

Built for the driver

Black BMW Z3 with a fabric soft top and silver multi-spoke wheels.
04 / The car

The roadster roots

Side view of the Z3 with the original roof structure exposed.
05 / Roof build

The factory foundation

Wooden guides define the new roofline over the Z3 roof structure.
06 / Roof build

Finding the roofline

Close view of shaped foam over the original Z3 roof structure, with the roof guides and window opening visible.
07 / Roof build

Building up the form

Side profile of the Z3 with the shaped foam hardtop form.
08 / Roof build

Shaping the profile

Close view of the smoothed roof form and its rounded surface.
09 / Roof build

Refining the surface

Chopped carbon fiber during the roof layup.
10 / Roof build

Carbon, up close

Front three-quarter view of the Z3 with the rough carbon roof fitted.
11 / Roof build

Taking shape

Interior of the detached roof shell on workshop supports.
12 / Roof build

Off the car

Side view of the Z3 and hardtop during surface finishing.
13 / Roof build

Dialing in the fit

Custom carbon hardtop resting on stands, with its side and rear openings visible.
14 / Roof build

A roof of its own

Close-up of the hardtop mounting hardware and its surrounding carbon surface.
15 / Roof build

The mounting detail

The inside of the carbon hardtop with the rear-window opening masked.
16 / Roof build

Under the hardtop

Clutch assembly exposed during drivetrain work.
17 / Powertrain

Putting power down

Rear three-quarter view of the Z3 with the carbon hardtop fitted.
18 / The car

Out of the workshop

The Z3 outside with its hood raised over the LS1 engine.
19 / Powertrain

Under the hood

The black Z3 parked outside with the roof off.
20 / The car

Open-top days

The Z3 in the workshop during body preparation, with a rear wheel removed.
21 / The car

Back to the body

The V8 engine on a red workshop engine stand.
22 / Powertrain

Heart of the build

Rear three-quarter view of the open-top Z3 secured on a flatbed.
23 / The car

Heading out

A gray three-dimensional model of the Z3 viewed from the side.
24 / Roof build

A different perspective

Front-quarter view of the open-top Z3 in the garage, with its hood raised over the LS1 V8 and bronze wheels visible.
25 / Powertrain

V8 at home

Opposite front-quarter view of the Z3 engine bay, showing the uncovered intake and supporting swap hardware.
26 / Powertrain

Inside the swap

05 / PROJECT NOTES

A few details.

Project & photo archive by .

What does LSFBZ3 stand for?

LSFBZ3 stands for LS-powered Fastback Z3: LS for the LS1 V8, FB for the custom fastback roofline, and Z3 for the BMW underneath. It’s my 400 whp BMW Z3 project with a custom carbon fastback hardtop. I’m Tim Burton, and this is the build from the garage to the road.

What powers the Z3?

A 5.7-liter aluminum LS1 V8 makes 400 whp, with an MTI Stage 2 camshaft, 243 cylinder heads, BTR pushrods and an LS6 intake. A 4.10:1 final drive puts it to work.

How does the custom hardtop fit?

The hardtop is built on the shell of the OEM rag top and reuses all of the original mounts. The fastback roofline takes shape over that factory foundation, followed by the carbon layup and finishing work.

  1. Start with the OEM rag-top shell and mounts.
  2. Define the new roofline.
  3. Build and shape the foam form.
  4. Prepare the surface and lay up the carbon.
  5. Remove the shell and check the fit.

Can I get a hardtop for my Z3?

I have the hardtop cast and am willing to make more for other Z3 owners. Get in touch to talk about your car and a hardtop build.