Ep 357 The Big Super charger Kit from Rababak performance

Rababak Performance is the company behind the supercharger kit being discussed in this episode. The hosts talk about how the kit was developed and validated with both street testing and dyno testing.

A supercharger kit is an aftermarket forced-induction system that increases engine airflow using a belt-driven compressor. On classic Volkswagens, these kits can significantly raise power but also require correct fuel, tuning, and supporting upgrades to stay reliable.

VW Trends Magazine is promoted as a VW-focused publication. For listeners, it signals the show’s community ties and where enthusiasts often learn about events, builds, and parts.

Ross Wolf is mentioned as a source for high-quality aftermarket parts for Volkswagen enthusiasts. The episode highlights their approach to sealing components by matching original factory wheel seals and using Viton seals to reduce leaks.

A rear wheel seal set is a service part that prevents gear oil or grease from leaking at the rear wheel area (commonly around the axle/hub assembly depending on the VW platform). The hosts emphasize that Ross Wolf’s set is designed to match original factory seals and reduce leakage.

Viton is a brand of high-performance elastomer (fluorocarbon rubber) known for strong heat and chemical resistance. Using Viton seals can help them hold up better in environments where oil, heat, and time would otherwise harden or degrade cheaper rubber.

Icon Pistons is referenced as a high-quality aftermarket piston brand for Volkswagen applications. Pistons are critical for engine durability, especially when you add performance upgrades like forced induction.

Wrist pin height refers to the vertical location of the piston pin relative to the piston crown and the engine’s crankshaft centerline. Changing wrist pin height affects piston deck height, compression ratio, and how the engine’s geometry works—especially in stroker builds with different crank strokes.

Compression ratio is the relationship between the cylinder’s volume when the piston is at the bottom versus at the top of its stroke. Higher compression generally increases efficiency and power potential, but forced induction often requires careful compression ratio selection to avoid detonation.

The hosts mention “icon pistons” sourced from “Type you motorsports,” indicating a specific piston supplier used for these VW performance builds. Pistons are a critical part of engine durability and performance, especially when combined with higher boost and displacement.

Whipple is a well-known American manufacturer of superchargers, especially for high-output street and drag applications. Their units are popular because they’re designed for efficient boost delivery and are commonly supported by tuning and installation communities.

Standoffs are spacers used to position components at the correct height/clearance. In a supercharger installation, standoffs help ensure the kit fits in the engine compartment and maintains proper belt alignment and clearance to surrounding parts.

Prototype motor setups are test engines built to validate fitment, boost targets, cooling, and reliability before a kit is finalized. In forced-induction projects, prototypes are especially important because small changes in packaging or tuning can significantly affect drivability and engine safety.

Rabbit-back Performance is the specialty shop being highlighted for building a Volkswagen supercharger kit. In this episode, they’re presented as the builders behind a specific twin-screw supercharger setup.

A twin-screw supercharger uses two intermeshing rotors to move air and create boost. Compared with some other supercharger types, twin-screw designs are often chosen for strong midrange power and relatively efficient boost delivery.

The hosts are discussing how supercharging technology has evolved over time—from early, larger setups to smaller, more targeted blower configurations. In practice, this evolution is about balancing boost response, packaging, cooling, and reliability for different uses (street, sand cars, racing).

Volkswagen is the brand the hosts connect this supercharging discussion to, implying the community and platform they’re working with. In air-cooled VW circles, supercharger and turbo setups are common because the engines respond well to forced induction when built and cooled correctly.

“Low compression” refers to reducing the engine’s compression ratio, which helps prevent detonation when running higher boost from a supercharger. Pairing a low-compression setup with forced induction is a common strategy to keep the engine safe and “snappy” under load.

The “371 blowers” refers to a specific supercharger blower size/model used for forced induction. Blower size affects boost characteristics: smaller blowers typically spool/pressurize quicker for response, while larger ones can support more top-end power but may be less immediate.

Electric fans are used to manage cooling when the supercharger setup (and associated airflow constraints) makes traditional cooling less effective. The hosts specifically tie electric fans to logistical/cooling issues on a high-boost blower configuration, implying cooling is a key limiting factor.

A “root style” supercharger (often called a Roots blower) uses intermeshing rotors to move air into the intake. Roots-style blowers are known for strong low-end boost and immediate throttle response, but they can be sensitive to heat management and airflow efficiency.

B&M is referenced as a comparison point for the blower size/type (“pretty much like a B&M”). In the performance world, B&M is commonly associated with aftermarket forced-induction and transmission-related products, so the mention likely frames the blower category and expectations for performance.

Compressor size (and overall blower displacement/flow capacity) affects how much air the supercharger can move and how quickly it can build boost. The hosts connect this to engine airflow limits—if the engine can’t ingest enough air, extra blower capacity won’t translate into more pressure or power.

Displacement is the engine’s total cylinder volume, which strongly influences how much air/fuel it can process. In the segment, they explain that their supercharger setup was limited by displacement and that they tested different sizes to find where performance falls off.

“1914” is shorthand for an engine displacement of about 1914cc, commonly used in VW air-cooled builds. The hosts say they tested up to that size and then hit a limit where the setup no longer works as intended.

The analogy describes a mismatch between the supercharger’s ability to move air and the engine’s ability to ingest it. If the engine’s displacement/flow limits are reached, boost can fall off or the blower can’t create enough pressure/airflow to match the demand.

The Buick Century is a midsize American car that’s often brought up in classic and enthusiast circles, especially when people talk about engine swaps and cooling upgrades. The podcast context mentions a specific setup with a 371 and electric fans, including how the fans were mounted (“centrally mounted” and “electric fans”). That kind of detail matters because cooling and packaging are key when modifying older engines.

A side alternator refers to relocating the alternator from the more typical position to clear space or support belt routing for the supercharger. This kind of packaging change is common in custom forced-induction kits where pulley alignment and accessory clearance are critical.

This highlights a key dependency: the cooling fan is belt-driven, so any changes to belt routing, pulley size, or belt tension can affect fan speed and cooling effectiveness. That’s why they call cooling “the biggest thing” during the conversion.

A serpentine setup uses one long belt routed around multiple pulleys to drive accessories. Compared with multiple separate belts, it can simplify routing and improve packaging, but it requires careful pulley alignment and belt sizing.

The hosts contrast serpentine routing with using two separate belts to drive accessories like the alternator and other front-end components. Two-belt setups can be easier to adapt in some conversions, but they add complexity in belt tensioning and alignment.

The Dodge Charger is a performance-focused American muscle car that’s often discussed in the context of engine upgrades and forced-induction setups. In the podcast context, it sounds like the conversation is about a Whipple supercharger (“Whipple charger”) and how the belt drive is set up for that system. That’s why it comes up: the belt routing and parts selection matter for reliability and correct operation when boosting power.

Dyno testing measures engine performance on a dynamometer, allowing controlled pulls and repeatable data. The hosts mention doing both street testing and dyno testing, and they reference dyno pulls as a key part of validating the setup.

A blow-through setup routes air through the supercharger first, then mixes fuel after the blower (typically via fuel injection or a carb positioned downstream). The segment uses it as the comparison point to explain why their configuration is draw-through and how that impacts cooling and drivability.

Pulley size on a supercharger changes the belt speed, which changes how fast the supercharger spins. Smaller pulleys typically spin the supercharger faster (more boost), while larger pulleys spin it slower (less boost).

With forced induction, the “effective compression ratio” rises because the engine is compressing a denser air charge before combustion. That increases cylinder pressure and can make detonation more likely unless ignition timing and fueling are managed.

Ignition retarding means delaying spark timing to reduce peak cylinder pressure and combustion temperature. It’s commonly used under high boost to help prevent detonation (knock) when the engine is running more aggressive conditions.

Snow Performance is an aftermarket company known for methanol/water injection systems used to cool intake charge and reduce knock on boosted engines. Their kits are often paired with tuning changes to safely run higher boost.

Methanol injection is an aftermarket fuel/charge-cooling system used on boosted engines. Injected into the intake/manifold, it absorbs heat and helps suppress detonation, allowing higher boost or safer tuning under load.

Torque is the twisting force the engine produces, and it strongly influences how quickly a car accelerates, especially at lower RPM. The segment uses torque figures to describe the engine’s “pull” characteristics.

“Stump pullers” is a slang term for engines that make strong low-end torque and feel like they can pull hard under load. In this context, it’s describing the character of the build rather than a specific technical component.

A camshaft controls valve timing and lift, which strongly affects how an engine makes power across the RPM range. A “custom ground” cam means the grind profile was tailored to the build’s goals—here, matching the supercharged setup’s target horsepower and torque curve.

“Supercharged motors” refers to engines modified with a supercharger to increase intake air pressure and power output. The discussion highlights the shop’s experience building multiple customer supercharged setups and learning how small changes affect results.

A turnkey kit is an all-in-one package designed to be installed with minimal sourcing of individual parts. In this case, the supercharger kit is “ready to go,” with most components supplied so the buyer mainly needs to handle the remaining major item (the supercharger).

In supercharger terminology, the “snout” is the extended housing/drive section that connects the blower to the drive pulley system. Longer snouts can create packaging and alignment challenges, so removing it (via direct drive) can improve fitment and reduce stress points.

Pulley alignment is critical in belt-driven supercharger systems because misalignment can cause belt wear, noise, and reduced drive efficiency. This segment highlights that firewall clearance and pulley alignment had to be balanced during the design.

Custom pulleys are often required in supercharger installations to achieve the correct belt geometry, ratio, and clearance. Here, the hosts describe an R&D phase where multiple pulleys were custom-made before settling on a mix of off-the-shelf and machined components.

A billet steel crank pulley is a machined pulley made from a solid block of steel, typically chosen for strength, durability, and precise fitment. In this segment, it’s used as the base for further machining to match the supercharger drive requirements.

“Ampie” appears to be a supplier/source for a billet steel crank pulley used in the kit. The key point is that the build uses a billet steel crank pulley as a starting component, then machining is performed to fit the application.

A merged header is an exhaust manifold design where exhaust pipes combine (“merge”) into a common section to improve scavenging and exhaust flow. The segment suggests they tested different header/muffler configurations and saw changes in how the system behaved.

The collector is the part of the exhaust where multiple exhaust runners come together before routing to the rest of the exhaust (like the muffler). Here, they describe cutting the collector and welding the muffler directly to it, which is a common fabrication approach to reduce restrictions and improve fit.

The transcript discusses using pistons and piston rings that are appropriate for high cylinder pressures and heat from forced induction. It emphasizes that cheap or basic piston/ring setups may not survive, implying the need for stronger, purpose-built components.

In this context, “conditioning” refers to preparing or selecting engine internals (like pistons, rings, and related parts) so they can reliably handle forced-induction conditions. The speaker frames it as more than a basic parts swap—it's about matching components to boost pressure and heat.

Total Seal rings are a brand/type of piston rings designed to improve sealing and reduce blow-by. The transcript ties ring choice (including ring spacing) to forced-induction reliability, suggesting the builder is optimizing for pressure and heat control.

“224 ring spacing” refers to the distance between piston ring grooves, which affects ring placement, sealing behavior, and piston strength under heat and pressure. In performance builds, ring spacing is chosen to match the piston design and the expected operating conditions.

H-beam rods are connecting rods with an “H” shaped cross-section that’s commonly used for strength in performance engines. The speaker lists them as part of the minimum component set for keeping the engine together under forced-induction loads.

Cylinder head temperature (CHT) is a key heat metric for forced-induction engines because it reflects how hot the combustion chamber area is running. Builders monitor it to avoid overheating and to decide when to back off or stop, especially when intercooling isn’t practical.

Forced induction increases air temperature when it’s compressed, which can raise engine heat. The transcript highlights a packaging constraint: there may not be enough space on a supercharger outlet to fit an intercooler, so the builder must rely more on monitoring and operating limits rather than cooling the charge.

A dyno run is when a car or engine is tested on a dynamometer to measure power and tuning behavior under controlled load. It helps builders validate fueling, ignition timing, and heat management before (or alongside) real-world driving.

Cajon Pass is a well-known steep mountain grade in Southern California, often used as a real-world stress test for engines and cooling systems. A long climb can reveal heat-soak issues that might not show up during flat-road driving.

“Brother’s Machine” appears to be a machine shop supplying cylinder heads for this supercharger kit application. In performance builds, the head casting and machining quality can strongly affect flow, combustion efficiency, and durability under boost.

The Alfa Romeo GTV is a sporty Italian coupe known for its driving feel and enthusiast-focused engineering. In the podcast context, the discussion is about cylinder heads and whether certain head configurations will work with a specific setup (“other heads won’t work?” and “you can run the amp… GTV two heads”). It’s being discussed because head compatibility and the right parts selection directly affect how the engine can be built and tuned.

Cylinder head castings are the raw cast aluminum/iron forms that get machined for valves, ports, and combustion chambers. The discussion contrasts stock-style castings with “heavier duty” castings that have more alloy/silicone and thicker areas for strength and reduced need for welding.

“501s” and “502 castings” refer to specific cylinder head casting variants. The hosts describe them as heavier-duty castings with more alloy/silicone and thicker sections where needed, which can matter for durability when running a supercharger.

The “140” and “100” likely refer to supercharger sizing options (commonly different compressor sizes or flow ratings) chosen to match the vehicle’s goals. Without more context in the excerpt, it’s best understood as selecting a larger or smaller blower for the customer’s build.

The “cool shroud” is an aftermarket-style shroud used to package the supercharger while still managing airflow and cooling. The key detail here is that it avoids a doghouse-style layout and uses slanted sides to position the supercharger more centrally.

A doghouse refers to a specific style of fan shroud used on some air-cooled Volkswagen engines that improves cooling airflow to the oil cooler. This kit’s shroud is described as not having a doghouse, which matters because it changes how cooling and packaging are handled around the supercharger.

This segment focuses on how the supercharger is positioned “more central” using a specific shroud design to clear surrounding components. Packaging/fitment is critical because the distributor, alternator location, and belt routing all have to coexist without interference.

The distributor is an ignition component that must be accounted for during supercharger installation because its location affects clearance and component routing. The speaker specifically mentions setting the distributor as part of the installation context.

A self-oiling supercharger means it has an internal oiling system that lubricates the blower without requiring a separate external oil reservoir. Even so, it still needs periodic oil changes or service intervals to keep bearings and gears healthy.

A side-draft carburetor setup positions the carburetor so airflow enters from the side, which can improve packaging and tuning on certain engine bays. The hosts mention using a side-draft setup as part of a new intake system prototype.

The Volkswagen Type 3 is a classic air-cooled model line known for its compact engine bay packaging. The hosts discuss whether a Type 3 supercharger conversion is feasible, but note space constraints and belt routing challenges.

The hosts mention an up-to lead time of about eight weeks for the supercharger when ordering the kit. This is a practical buying consideration because forced-induction kits often require sourcing components and scheduling installation.

A Whipple supercharger is a brand of positive-displacement forced-induction system that uses a screw-type (twin-screw) design. It’s commonly chosen for making boost efficiently and smoothly compared with older rotor styles.

A screw blower is a supercharger that uses helical rotors (like an “Archimedes screw” concept) to compress air internally as the rotors spin. Compared to roots-style blowers, screw designs typically build boost more efficiently and can feel smoother because of how the air is trapped and compressed.

A roots blower is a positive-displacement supercharger that uses two rotors to move air from the inlet to the outlet. It’s often associated with “boost by pushing” rather than compressing internally, which is why it can have different boost characteristics than screw-type designs.

The speaker references a “B&M 90” as an example of a roots-style blower used on older applications. The key takeaway is the comparison of rotor/packaging and how that style differs from screw-type blowers.

“Cubic inch” blower size is a displacement rating that indicates how much air the supercharger moves per revolution (or per cycle, depending on the design). Larger displacement generally supports higher potential boost/power, but it can also affect drivability and efficiency.

In this context, “corkscrew” is being used as a descriptive nickname for the screw-type supercharger rotor/airflow concept. It’s not a separate supercharger brand here—it's describing the helical screw action.

A blow-through fuel/air setup routes the pressurized air from the supercharger through the carburetor while boosting is present. This often changes what fuel system components are required (like whether you need a return line) because fuel pressure must stay stable under boost.

For high-boost forced induction, the fuel pump must supply enough fuel volume and pressure to prevent lean conditions. Here they specify a high-quality pump producing “eight to ten pounds” and then use a regulator to set the carburetor pressure.