The sound of a quad-turbo V12
After the work was complete, we recorded the EB110 SuperSport starting up and revving in our Reseda shop. The 60-valve quad-turbo V12 has one of the most distinctive acoustic signatures in 1990s hypercar history.
A 1992-1995 Bugatti EB110 SuperSport recently came through our Reseda workshop for a multi-stage service: a complete clutch hydraulic rebuild, two-source oil leak diagnosis and repair, rear sway bar ball joint replacement, and ongoing air conditioning diagnostics. The work spanned nearly six months from intake to road verification, the majority of that time spent waiting for a custom-ordered AP Racing clutch hydraulic set built specifically for this car.
The car
The Bugatti EB110 SuperSport is the lighter, more powerful evolution of the EB110 GT that Romano Artioli’s revived Bugatti Automobili produced in Campogalliano, Italy. Around 33 SuperSport units were built between 1992 and 1995 before the company’s bankruptcy. The SuperSport identifies through its 110 SS side badge, factory-deleted air conditioning trims (later restored on most examples), and a 3.5-litre 60-valve quad-turbo V12 producing roughly 603 hp.
This example arrived with scissor doors operating cleanly, original interior intact, and the engine bay showing matching-numbers configuration. The customer brought it to us with three clearly described concerns and a fourth that surfaced during inspection.
Scope of work
- Clutch hydraulic system rebuild: AP Racing master cylinder and slave cylinder, custom-ordered
- Two-source engine oil leak diagnosis and repair
- Rear sway bar end-link ball joint replacement
- Air conditioning intermittent operation diagnosis (in progress)
- Full road verification by shop owner John Soneff
Clutch hydraulic rebuild: a six-month parts wait
The owner’s primary concern was clutch hydraulic feel. On the EB110 SuperSport, the clutch master cylinder and slave cylinder are AP Racing units, the same supplier Bugatti specified at the factory. These are not catalogue parts you order from a warehouse. For this car, the correct hydraulic set had to be custom manufactured by AP Racing to the original specification.
From the moment we placed the order to the moment the parts arrived at our Reseda shop, nearly six months passed. We will not substitute generic hydraulics on an EB110, and we will not rebuild seals on units that were originally engineered as sealed assemblies. The customer was kept informed throughout, and the rest of the inspection work moved forward in parallel so the car was ready to install the moment the parts cleared customs.
Once the AP Racing units arrived, installation, system bleed, and pedal-feel verification were straightforward. The clutch now engages with the precise hydraulic response the car had when it left Campogalliano.
Oil leak: two sources, both addressed
During the inspection we identified two separate sources of engine oil seepage on the quad-turbo V12.
Source one: oil supply line fittings. Several threaded connections on the engine oil supply lines had loosened slightly over time, allowing oil to weep at the fittings. We performed a full torque check on every oil line connection, brought them back to specification, and cleaned the surrounding surfaces so any future seepage is easy to spot.
Source two: turbocharger oil drain lines. The EB110 SuperSport runs four turbochargers, and each one returns oil to the sump through its own drain line. On this car, the metal gaskets at the turbo oil drain interfaces had failed and were the second leak source. We replaced all of the metal gaskets on the turbo drain lines and re-sealed each junction. Oil pressure and return flow checked out clean after the work.
Rear suspension: sway bar end-link ball joints
With the car on the lift for the oil work, we inspected the rear suspension and found play in the rear sway bar end-link ball joints. These joints connect the sway bar to the suspension upright and are a common wear point on cars that have not been driven heavily but have aged in place. We replaced the rear sway bar end-link ball joints with correct-specification components and verified the rear stabilizer geometry.
Air conditioning: diagnosis in progress
The car’s air conditioning system is currently behaving intermittently. The compressor cycles on and off without holding a stable cooling state, which points to a control or pressure-side fault rather than a refrigerant leak. Our technician Max is working through the system now. This article will be updated once the A/C diagnosis is complete and the corrective work is documented. Update to follow.
Road verification by John Soneff
Before any car of this caliber leaves our shop, the owner of European Auto Service personally test-drives it. John Soneff put road miles on this EB110 SuperSport himself, confirming clutch engagement, no oil seepage under load, neutral rear handling with the rebuilt sway bar end-links, and overall driveline behaviour consistent with the car’s factory specification. The car drives cleanly.
Why this work matters
The EB110 SuperSport is one of fewer than 40 examples ever built. Hydraulic, lubrication, and suspension wear items on this car cannot be replaced with the nearest available substitute. The waiting time on the AP Racing clutch parts was not a delay we apologized for, it was a non-negotiable part of doing the work correctly. The same applies to the metal gaskets on the turbo oil drain lines, the rear end-link ball joints, and every other component that touches this car at our shop.
About European Auto Service
European Auto Service is an independent specialist in European luxury and exotic vehicles, operating in Reseda, California since 1976. Our technicians average more than 13 years of hands-on experience with brands ranging from BMW, Mercedes, Porsche, and Audi to Ferrari, Lamborghini, McLaren, and Bugatti. We are a California Bureau of Automotive Repair licensed facility (ARD 295530) and we install only specification-correct components on every car we service. For more on our Bugatti capabilities, see our Bugatti repair page.
