Saab’s Twin-Turbo V6 Build #2: The Turbo X Rescued From the Scrapyard Is Now the Foundation

The moment this project stops being theoretical

The first episode of the KM-Tronics twin-turbo V6 prototype series established the engine: a Saab development-era twin-turbo V6, sourced from the NEVS sale, linked on KM-Tronics’ own project page to a Turbo X-R concept with factory targets around 500 hp and 650 Nm. Episode 2 answers the question that separates serious builds from garage mythology: what is the car that will actually carry this engine, and why does that choice matter?

The answer is a Saab 9-3 Turbo X – not selected from a listing, but recovered from the edge of being scrapped.

The donor car was not chosen – it was rescued

Mark van Kampen explains in the episode that the Turbo X chassis was located at a Saab specialist in Apeldoorn, already partially stripped and effectively written off. The engine had failed, the transmission was damaged, the prop shaft was gone, and the previous owner had neither the time nor the budget to continue. The car was staged for dismantling when KM-Tronics stepped in and bought the shell.

This matters beyond the story. The Saab world has seen too many structurally sound cars disappear because repair costs outpaced market value. Van Kampen‘s stated principle throughout the project is not to remove a healthy enthusiast car from the road – to use a chassis that would otherwise be lost and rebuild it into something better than it was.

The body itself is in reasonable shape. There is some surface rust on the fuel tank heat shields, which Mark flags as a future repair item, but the fundamentals are there. It is a Turbo X, and that is not an arbitrary starting point.

Why the Turbo X is the only architecture that makes sense here

The Turbo X was Saab’s first production model to integrate XWD fully, and it was engineered around the 2.8 V6 from the beginning. That matters for a project pointing at twin-turbo outputs significantly beyond the production car’s widely cited 280 PS and 400 Nm, because the platform already knows what a transverse V6, an XWD driveline, and elevated torque delivery look like when Saab draws the lines.

A standard 9-3NG with XWD would require solving problems Saab had already resolved once in the Turbo X program – prop shaft routing, subframe geometry, driveline load assumptions, Haldex integration logic. Using a Turbo X removes that layer of uncertainty. The project inherits the factory engineering work without having to recreate it from a weaker baseline.

KM-Tronics also named the project concept a “Turbo X-R” direction from the outset on its project page, so grounding the build in an actual Turbo X chassis makes the idea architecturally coherent rather than aspirational.

A stripped interior is an advantage, not a problem

The car arrived already partially stripped, which for most acquisition scenarios would be a concern. Here it becomes a gift. KM-Tronics has direct access to the complete body shell with no existing trim to work around, and rather than treating that as damage control, they treat it as the correct starting condition for what they want to do.

Episode 2 focuses almost entirely on that opportunity: converting the bare shell into a foundation that will deliver a significantly quieter, more controlled cabin than the production car provided.

Making it quieter before making it faster

The NVH work – noise, vibration, and harshness, as Mark defines it clearly in the video – is the dominant theme of this phase, and it is deliberate. The goal is not silence as a luxury statement. It is acoustic selectivity: reduce road noise, wind noise, and tire noise to the point where the engine and exhaust become the dominant sounds the driver hears. Mark is explicit about this both in the video and in direct communication with SaabPlanet: the whole idea is to make the car more quiet against environmental noise precisely so the powertrain comes through clearly.

The work starts with the lower body – trunk area and seating floor – where butyl-based vibration damping mats are applied across the full surface. Before any material goes on, the body panels are vacuumed, degreased, and wiped clean. This preparation is not glamorous and Mark says so, but adhesion quality directly determines whether the insulation performs or creates air pockets that undermine the whole process. He takes about an hour on cleaning alone before the first mat goes down.

Applying butyl-based sound insulation inside the Turbo X chassis, with heat treatment and pressure to eliminate air pockets and ensure full surface adhesion.

The material itself is unbranded butyl, around 4 mm thick, and the choice is deliberate. Unlike branded products that typically include a protective top layer, the unbranded sheets can be punctured, reheated, and reworked if an air pocket forms. Mark demonstrates the technique during the episode: pierce the bubble with a screwdriver, press the material back together while still warm, and the panel becomes one coherent surface again. For large flat sections like the floor and trunk, workability is more valuable than the label.

For tighter applications like door cavities, where flexibility matters more than thickness, Mark expects to shift to branded materials. The point is not budget vs. premium – it is matching the material to the task.

The weight question is answered honestly

Adding 4 mm butyl across 20 to 30 panels per zone is not light work, and Mark does not pretend otherwise. The trade-off is managed rather than avoided. Heavier material sits low in the chassis, which minimises its impact on the car’s center of gravity. For the roof, where top-heavy mass becomes a real handling concern, lighter material will be used. The plan acknowledges the compromise and designs around it instead of ignoring it.

Saab’s familiar resistance to simple jobs

A detail that will resonate with anyone who has stripped a 9-3: even routine disassembly produces surprises. Mark spends roughly 15 minutes on a single trunk clip, working carefully to avoid breaking it, because replacement parts for this kind of trim detail are not always straightforward to find. Removing the headliner requires extracting the A, B, and C pillars first, and Mark notes it was the first time he had done it himself – something that tested patience before it tested tools.

These are not complaints. They are the honest texture of working on a car that was engineered carefully and assembled tightly, and KM-Tronics’ approach throughout is to do the slow work correctly rather than force it and pay later.

What Mark said directly: the OEM mindset behind all of this

In direct communication with SaabPlanet after the episode went live, Mark described the philosophy driving every decision in the build. The goal is not to build the fastest Saab in the world. The goal is to build what Saab itself would most likely have created – a car that is fast, but also refined, quiet, and comfortable at an OEM level. He frames the approach as being “in that spirit,” trying to build the car in the mindset that Saab would have applied.

He also points out that Saab did something notable for the production V6 that is often overlooked: they gave it the same sound insulation level as the diesel, a deliberate decision to keep the V6 cabin quieter than the powertrain might suggest. That precedent is directly relevant here. A twin-turbo V6 with 500 hp was never going to be a subtle machine, but the way Saab would have packaged it – based on everything KM-Tronics knows about how the brand worked – would have prioritised refinement alongside performance.

Mark adds another dimension that goes beyond the build itself: Saab would almost certainly have distinguished such a car visually. He references the 9-3X body kit approach and notes that Saab was producing race-oriented body kits for the 9-3 around the 2006 era. KM-Tronics is actively looking for a period-appropriate body kit that reflects that direction – something that gives the car a visual identity consistent with what a factory Turbo X-R program might have produced.

What is coming in the next episode

The next phase extends the NVH work into the areas that tend to define how a car feels at motorway speeds: doors, wheel arches, roof, and – significantly – windows. Mark confirmed directly that the plan is to add plexiglass panels to create a double-glazed configuration on most windows, initially excluding the driver’s side. If the rear window mechanisms allow it, those will be included as well.

He acknowledges this may not have been done to a 9-3NG before, and the engineering questions involved are real: sealing, regulator load, fitment tolerances, long-term durability. But the logic is the same as everything else in this phase – reduce the noise that competes with what the car is meant to sound like, and do it with the care Saab would have brought to the problem.

After the NVH work is complete, the build moves into harder territory: integrating the prototype engine, solving the control strategy, and delivering on everything KM-Tronics has publicly committed to. Episode 1 proved the engine is not a rumour. Episode 2 proves the car is not a placeholder. What remains is the part where the project either becomes what it was described as, or doesn’t – and KM-Tronics has already tied that outcome to a public deadline at Saab Festival 2027.