IHI RHB53LW — Tipo F120A — 1987–1992

Ferrari F40

Turbocharger Rebuild — VU12B & VU13B — In-House VSR Balancing
Start Your Rebuild Turbo Specifications ↓
1,315 Road Cars Built
478 Horsepower / Factory
2 IHI Turbos Per Car
Engine
Tipo F120A
2.9L twin-turbocharged V8 — 7.7:1 compression
Turbocharger
IHI RHB53LW
Twin water-cooled — 1.1 bar / 16.1 psi factory boost
Boost Lab Experience
Multiple F40s
Rebuilt in-house — paired matched set — VSR balanced
The Engine

Tipo F120A
The Last Enzo Ferrari

The Ferrari F40 was unveiled in July 1987 -- Enzo Ferrari's final car, and arguably his most uncompromising. The Tipo F120A V8 at its heart traces a direct lineage to the 308 GT/4 nearly fourteen years earlier. The same 81.9mm bore and 69.5mm stroke yielding 2,936cc of displacement, but now fitted with twin water-cooled IHI turbochargers and twin Behr intercoolers producing 1.1 bar of boost pressure. Factory output is 478 bhp at 7,000 rpm and 425 lb-ft of torque at 4,500 rpm.

The engine management system uses twin Weber/Marelli IAW units -- one per cylinder bank. Fuel injection, ignition, and boost control are managed separately for each bank. A single external wastegate, controlled by one of the IAW units, discharges boost pressure directly to atmosphere -- producing the signature three-pipe center exhaust that defines the F40's sound. The oversupply valve system, unique to the F40, acts as a boost bypass mechanism during partial throttle operation.

The IHI RHB53LW turbos are water-cooled in addition to oil-cooled. Both the oil and coolant circuits must be in good condition for a successful rebuild to last. The water cooling provides post-shutdown heat protection that oil-only units lack -- critical on a car that is frequently shut down hot after spirited use. Water line condition is inspected and reported on every F40 rebuild.

Tipo F120A — Engine Specifications
ConfigurationV8 90° / Twin Turbo
Displacement2,936cc (2.9L)
Bore × Stroke81.9mm × 69.5mm
Compression7.7:1
Factory Power478 bhp @ 7,000 rpm
Factory Torque425 lb-ft @ 4,500 rpm
Factory Boost1.1 bar / 16.1 psi
TurbochargerIHI RHB53LW × 2
IntercoolersTwin Behr air-to-air
Fuel/IgnitionWeber/Marelli IAW (per bank)
WastegateSingle external / atmospheric
Production1987–1992
Road Cars Built1,315
The Turbos

IHI RHB53LW
VU12B & VU13B

The F40 uses two distinct IHI units -- not a matching pair. The left and right turbos are handed units with different compressor and turbine housing orientations. VU12B is the left (driver side) turbo. VU13B is the right (passenger side) turbo. They are not interchangeable. Both must be rebuilt as a matched set.

Left Turbo — Driver Side
VU12B
IHI RHB53LW — Water and Oil Cooled
The left IHI unit feeding the driver side cylinder bank. Water-cooled journal bearing. The VU12B and VU13B share the same CHRA architecture but have mirrored housing configurations for their respective installation positions. New OEM units from Ferrari North America were listed at approximately $7,000 each when available -- and availability is not guaranteed. Rebuild is the preferred path for any F40 owner who wants to maintain the original components.
136421Ferrari OEM original
164359Ferrari OEM supersession
VU12BIHI internal code
Right Turbo — Passenger Side
VU13B
IHI RHB53LW — Water and Oil Cooled
The right IHI unit feeding the passenger side cylinder bank. Mirrored housing orientation to the VU12B. The right turbo often shows differential wear from the VU12B due to its proximity to the primary heat sources in the engine bay and slightly different oil drain characteristics at the rear-mounted engine angle. Both are assessed independently at teardown and rebuilt to identical specification before being paired and returned.
136422Ferrari OEM original
164358Ferrari OEM supersession
VU13BIHI internal code
⚠
Parts Availability on F40 Turbos
New OEM IHI VU12B and VU13B units were listed at approximately $7,000 each from Ferrari North America when available. Availability is not guaranteed -- these are out-of-production units for a car with 1,315 examples. The rebuild is not just the economical choice; for many F40 owners who want matching original components it is the only acceptable choice. We have rebuilt multiple sets of F40 IHI turbos and treat every pair accordingly -- with full documentation, matched VSR balancing, and a rebuild report that stays with the car's history file.
Racing Variant

The F40 LM
Upgrade

The Michelotto-developed F40 LM racing version used larger IHI compressor wheels mated to the stock F40 turbines -- a critical detail. The LM upgrade does not replace the entire turbo. The original turbine housings and turbine wheels remain. The compressor section is upgraded to a larger IHI unit with greater flow capacity, enabling the LM cars to run up to 38 psi of boost in full race trim.

The LM compressor upgrade has become a popular road car modification. Running at a conservative 20 psi -- only 4 psi above stock -- the Carobu Engineering development engine produced 511 bhp and 422 lb-ft of torque, a consistent 10% increase over the stock engine. The Weber/Marelli management system requires updated chip programming (Carobu's "Razzo Rosso" chips or equivalent) to correctly manage the increased flow, boost targets, and fueling.

We rebuild stock F40 turbos and can discuss the LM compressor upgrade as part of a rebuild. Contact us with your application and we will discuss what is involved.

Engine
Stock
Tipo F120A
Factory Boost
Stock
16.1 psi / 1.1 bar
LM Road Boost
LM Upgrade
20 psi conservative
LM Race Boost
LM Full Race
Up to 38 psi
Stock Power
Stock
478 bhp @ 7,000 rpm
LM Road Power
LM @ 20 psi
511 bhp @ 6,700 rpm
Compressor
LM Upgrade
Larger IHI compressor
Turbine
Stock F40
Original turbine retained
Failure Analysis

Why F40 Turbos
Come In

The IHI RHB53LW is a well-engineered unit. Nearly every F40 turbo failure traces back to the car's operating environment rather than any deficiency in the turbo itself.

01
Long-Term Storage and Dry Bearings
More F40 turbos fail from sitting than from being driven. An F40 that has been in a climate-controlled garage for three years, started occasionally but not driven, develops oil varnish in the CHRA passages from oil that never fully circulated and then degraded in place. The bearing surfaces run dry on the next serious startup. Journal bearings require a continuous oil film and the F40's IHI units are no exception. A car returning from extended storage should have the oil system primed and the turbo inspected before any boost is applied.
02
Oil Coking from Hot Shutdowns
The F40 is frequently driven hard and parked immediately. The mid-mounted engine sits directly behind the cabin with limited airflow at rest. The IHI turbos are water-cooled -- but the water cooling only circulates while the engine runs. Shutting down immediately after a circuit session or spirited road drive traps heat in the bearing housing with no active cooling. Over time this bakes oil into carbon deposits. The water lines should be confirmed flowing freely, and a proper idle cooldown after any hard use is essential.
03
Degraded or Incorrect Oil
The F40 manual specifies oil requirements that some shops overlook when servicing a car they rarely see. Modern full synthetic oils that are not compatible with the F40's IHI turbos -- or oils that have been left in the engine well past their service interval on a low-mileage collectible -- cause bearing wear that accumulates slowly and invisibly until the shaft play becomes audible. On a car worth what an F40 is worth today, the oil service history should be known and correct.
04
Cracked Water Cooling Lines
The rubber coolant supply and return lines for both IHI turbos deteriorate with age -- these are 30+ year old components on even the youngest F40 road cars. A cracked or hardened coolant line eliminates the post-shutdown heat protection the water cooling provides, accelerating oil coking damage with every subsequent shutdown. Water line condition is checked on every F40 turbo rebuild. Any line showing age-related hardening or cracking should be replaced before the rebuilt turbos go back on.
05
Differential Wear Between Left and Right
The VU12B and VU13B sit in different positions within the F40 engine bay with slightly different exposure to heat sources and slightly different oil drain characteristics given the rear-mid engine angle. The right turbo frequently shows accelerated wear relative to the left on high-mileage examples. This is exactly why both units must be assessed at teardown regardless of which one presented the initial symptom -- a fresh VU12B paired with a worn VU13B is a mismatch that will surface quickly.
06
Previous Non-Specialist Rebuild
F40 turbos that have been rebuilt by shops unfamiliar with the specific IHI RHB53LW architecture -- or worse, rebuilt with non-OEM equivalent bearings -- come back with premature bearing failure, oil leaks from incorrect seal installation, or shaft play outside tolerance. We see this. Every F40 rebuild that comes through our shop gets a full teardown regardless of recent rebuild history. We document what we find and quote accordingly.
Questions

Frequently Asked

Yes. We have rebuilt multiple sets of Ferrari F40 IHI RHB53LW turbos in-house. The F40 is not a turbo that accommodates guesswork -- the parts are irreplaceable, the costs are significant, and the consequences of a poor rebuild are the last thing an F40 owner wants to deal with. We treat every F40 set with the documentation and care that the car warrants. Contact us before shipping and we will discuss what we expect to find and what the rebuild involves for your specific car's history.
We strongly advise against it. The VU12B and VU13B operate under the same conditions and accumulate wear simultaneously. The right turbo frequently shows differential wear from the left given its position in the engine bay, which means the unit that fails first has been pulling the other unit toward the same outcome. A fresh VU12B paired with a worn VU13B creates a boost imbalance that the Weber/Marelli management system was not designed to correct for. The cost of removing one turbo from a mid-engine Ferrari is virtually identical to removing two. Rebuild both. The labor cost difference is negligible; the protection against a return visit is significant.
Availability is uncertain and was already limited when they were listed. Ferrari North America had OEM replacement turbos (original part numbers 136421 and 136422, superseded by 164359 and 164358) listed at approximately $7,000 each. Whether they remain available, and at what wait time, depends on Ferrari's current spare parts inventory for the F40. The rebuild is the reliable path. It preserves the original IHI components with the car, and for matching-numbers purists it is the only acceptable solution regardless of new OEM availability.
The oversupply valve is a boost bypass system unique to the F40 -- it is not part of the turbocharger itself but is part of the boost management plumbing. It can influence boost pressure and turbo behavior if it fails or sticks. It is not rebuilt as part of a turbo rebuild, but if your F40 is exhibiting boost anomalies that have been attributed to the turbos, the oversupply valve is worth inspecting independently before assuming the turbos are the sole cause. Let us know if you have symptoms and we can help you narrow down whether the turbos or the boost management system are responsible.
Drain any residual oil from the oil inlet and outlet ports on both units. Drain and plug all coolant ports. Plug all openings. Label each unit left and right before packing -- do not rely on memory for which is which on an F40 where the housings are handed. Double-box both units together with foam padding on all sides. Ship via UPS or FedEx with appropriate declared value to 37833 Pineapple Ave Unit A, Dade City, FL 33523. Contact us before shipping and we will send a receiving confirmation and discuss the rebuild scope for your specific car.
Rebuild Inquiry

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Your F40

Every Ferrari F40 turbo rebuild is documented from intake through return shipment. VSR balancing in-house. Matched pairs rebuilt to identical specification.

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sales@theboostlab.com theboostlab.com Dade City, FL