Grind Hard Plumbing Co. Project Update: Turning a Burnt Ferrari Into a Twin-Turbo Diesel Rally Monster

Author: Robert Couture. Date: 12.15.25.

Grind Hard Plumbing Co. is deep into one of their most unhinged (and most engineering-heavy) builds yet: converting a damaged, formerly-convertible Ferrari into a hard-top, rally-style car powered by a wildly overpowered twin-turbo V10 TDI diesel. The premise is simple to say and hard to execute: take a massive, modern Volkswagen/Audi diesel drivetrain package, rotate the entire idea into a mid-engine Ferrari layout, and then redesign everything that makes the car “a Ferrari” so it can survive boost, heat, and rough-terrain abuse.

This isn’t a “bolt-on swap.” It’s fabrication-first problem solving: cutting structure, building new structure, and making the packaging work before chasing horsepower numbers. From engine test-fitting to roll cage design, each step is about turning a fragile supercar shell into something closer to a purpose-built rally weapon—without losing the absurd charm that makes the series watchable.

Phase 1: The Donor Tear-Down and “How Big Is This Thing?”

Before the Ferrari gets cut, the shop has to get organized around the swap. That starts with clearing the donor off the lift and stripping it for anything useful: modular suspension pieces, wiring, big power distribution components, and anything that might save time later. Even the fuel removal becomes a project—using transfer and scavenge pumps to pull a significant amount of diesel out of the tanks while the donor is still on the lift.

A theme that keeps showing up: modern donor vehicles are full of genuinely useful subsystems. In this case, it’s everything from heavy-duty fuse distribution to enormous AGM batteries (including surprisingly high-capacity units) that can be repurposed for other shop builds or future experiments.

Phase 2: Engine Packaging in a Ferrari That Has Almost No Rear Structure

Once the space is cleared, the real question becomes physical reality: does the twin-turbo V10 TDI fit inside the Ferrari in a way that makes driveline geometry possible?

Initial test fits show a mixed verdict:

• Height-wise: surprisingly workable. The oil pan sits roughly flush with the bottom of the car, and the engine doesn’t appear to tower above where an engine cover will be.

• Fore-aft position: that’s where the fight starts. Getting the engine far enough forward is required for axle alignment and transaxle packaging, and the Ferrari’s remaining structure isn’t exactly generous.

The workaround is classic Grind Hard: stop wrestling the engine with the car and flip the process. Put the engine on a stand so they can move the Ferrari over it, push the engine forward until it hits, and then identify exactly what needs to be cut. This leads straight into removing interfering mounts, deleting now-useless coolant routing (because the engine orientation has fundamentally changed), and planning significant firewall/structure trimming to move the powertrain forward several inches for better axle placement and weight distribution.

And yes—this is where they confidently claim what might actually be true: it may be the first time someone has taken a cordless concrete saw to a Ferrari.

Custom Mounting: Solving Ferrari Problems With Volkswagen Logic

As the engine position starts to make sense, the mounts become the next constraint. Ferrari mounts might “fit the brand,” but they’re expensive and not ideal for a build that’s going to be punished on rally terrain. The practical solution is to fabricate mount interfaces that allow the use of more available, appropriately-rated mounts designed for the engine’s weight and vibration profile.

That includes:

• Modifying and machining brackets (milling significant material off mounting points for clearance).

• Turning and fitting heavy-wall tubing sleeves for weld-in mount structures.

• Building “mount mounts” that create strong, weldable interfaces to the chassis.

This is the real tone of the build: keep the Ferrari shell, but do not let Ferrari parts dictate reliability, cost, or serviceability.

Rally Direction: Wheels, Tires, Suspension Travel, and Oil Pan Clearance

They’re not building a stance car. The goal is a rally-style setup: more suspension travel, reasonable tire diameter (around the high-20s), and avoiding huge/heavy tires that kill unsprung weight and ride quality.

Progress and decisions here include:

• Confirming smaller wheel options (16" clears brakes, opening up tire choices).

• Acknowledging that tire fitment is still tight even if wheel fitment works.

• Identifying oil pan ground clearance as a critical issue—and planning a serious fix: cut the oil pan down, plate it, and add back volume elsewhere to preserve oil capacity.

In other words, it’s not “make it fit once.” It’s “make it fit and survive impacts.”

Hard Top Conversion: Fitting the “Last Hard Top Ferrari Ever Made” (to This Car)

With transaxle decisions still unresolved, Grind Hard pivots to body structure—because the roof needs to fit before they can safely reinforce the chassis and build the roll cage around real geometry.

That means removing and cutting:

• leftover windshield frame pieces,

• soft-top remnants,

• welded and glued body sections (including surprisingly permanent fender attachment methods),

• and anything that prevents the roof from sitting where it needs to be.

They quickly discover what every Ferrari labor invoice has always known: even “simple” panel removal can be brutal when panels are glued, spot-welded, and assembled in ways that were never meant to come apart cleanly. The upside is they’re not chasing concours condition; they’re building a race car, and everything will be reinforced, repaired, and refinished later.

The Transaxle Problem: The Build’s Current Bottleneck

Here’s the main engineering wall they keep circling back to: what transaxle can handle the power, fit the layout, and be adaptable to the diesel V10?

Complications include:

• A bellhousing pattern that requires an adapter approach.

• A truly annoying crank/flywheel interface: an 11-bolt, asymmetrical pattern that appears to be uncommon enough to make off-the-shelf solutions unlikely.

• The need to design a full clutch/flywheel solution that mates the diesel to the chosen transaxle.

Eventually, a major milestone appears: a six-speed Porsche Cayman transaxle arrives—lightweight, reportedly robust, cable-shifted, and at least a plausible candidate. It’s not a guaranteed forever-solution (they openly admit the diesel might still destroy it), but it’s real progress and allows physical fitment, measurement, and adapter planning to begin in earnest.

Safety and Structure: Roll Cage Fabrication Begins

Once the roof and engine placement are close enough to “real,” the project turns serious: roll cage work. The goal is to achieve rally durability and the possibility of future racing compliance, so tubing choice is based on known requirements (inch-and-3/4, 0.120 wall is mentioned as a practical baseline for a vehicle in the estimated weight range).

What follows is a very Grind Hard version of precision fabrication:

• mocking seat position first (using their Humvee seat as a stand-in),

• welding floor and A-pillar plates where the structure is thick enough to matter,

• building a main hoop that takes multiple attempts and a lot of tubing,

• solving compound angles and “twist bends” that are hard to calculate and harder to test-fit,

• and gradually building forward structure, harness bar placement, and bracing that still preserves access for the future engine cover and service work.

The cage work also exposes an unexpected reality: this Ferrari is tiny inside. Fitment and head clearance become design drivers, not just aesthetics.

The Grind Hard Factor: Side Quests, Shop Life, and Controlled Chaos

Between major fabrication beats, the transcripts capture the rhythm that keeps the channel’s builds entertaining:

• a “science project” exploring thermoelectric generators and heat scavenging from a wood stove chimney,

• a rotating cast of shop mascots (including an injured goose temporarily living in the shop and receiving “bling”),

• practical shop improvisation (shipping crate tubing becoming structural bracing),

• and the usual mishaps (including drone casualties and the comedic reality of learning curve moments).

It all reads like a shop diary: high-effort engineering punctuated by the stuff that happens when you’re building the kind of projects no rational person would start.

Where the Build Is Headed Next

Based on what they’ve completed and what’s still blocking progress, the immediate next steps are clear:

• start physically fitting the transaxle and mapping adapter requirements,

• solve the flywheel/clutch interface for that odd 11-bolt pattern,

• finalize axle geometry and outputs,

• continue roll cage bracing and ensure roof/cage compatibility,

• build the engine cover structure with sealing and service access in mind,

• and complete oil pan modifications for real ground clearance.

The result is already evolving from “diesel Ferrari swap” into something more specific: a hard-top, tube-reinforced, rally-intended Ferrari that’s being re-engineered around durability and serviceability—not tradition.