Ep 357 The Big Super charger Kit from Rababak performance

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.

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.

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.

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.

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.

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.

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.

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.

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.

“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 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.

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.

Boost pressure is the increased intake pressure produced by forced induction, often measured in psi. This segment discusses targeting specific fuel/pressure levels and notes their dyno results around mid-single-digit psi.

A fuel pressure regulator controls the pressure reaching the carburetor so the air/fuel mixture stays correct as boost and engine load change. In this segment they describe using the regulator to drop pump pressure down to a lower target (around the mid-single-digit pounds) for dyno pulls.

RPM (revolutions per minute) is how fast the engine spins. The hosts reference RPM points where torque and power come in, which is crucial for understanding how a forced-induction setup changes drivability.

The torque curve describes how engine torque changes across RPM. In this segment, they’re emphasizing that the supercharger setup makes strong torque starting around a specific RPM, which affects how quickly the car feels responsive in real driving.

A billet mainshaft is a transmission input/gear shaft machined from a solid billet of metal rather than formed from a casting. Billet shafts are used to increase strength and durability when power and torque are pushed higher than stock.

“Bolt-on” implies the kit is designed to install without extensive custom fabrication. They’re using it to frame the supercharger kit as relatively accessible compared to more involved engine modifications.

Compression ratio is the relationship between the cylinder volume at its largest and smallest points. Lower compression can help prevent detonation (knock) when adding boost from a supercharger, because the engine is less likely to run into unsafe pressure/temperature conditions.

Carbureted engines use a carburetor to mix fuel and air mechanically, rather than electronic fuel injection. The hosts mention carbureted setups because the baseline power and tuning approach can differ when adding a supercharger.

They reference running “on the ragged edge,” which is a common way to describe operating near the limits where detonation/knock or other reliability issues become more likely. In boosted air-cooled builds, that risk is closely tied to compression, tuning, and fuel quality.

Compression ratio is how much the air-fuel mixture is squeezed before ignition. A “low compression engine” typically tolerates boost better because it reduces the risk of detonation when using a supercharger.

“8.5 to 1” is a compression ratio (8.5:1), which strongly influences how much boost an engine can safely run. Lower ratios generally provide more detonation margin for forced-induction setups.

Cylinder heads contain the intake and exhaust ports and valves, which control airflow into and out of the engine. The hosts discuss head size/valve sizing because airflow needs change between naturally aspirated and supercharged applications.

“Mid-deport” appears to refer to a specific intake port design/geometry (a port “deport” style) used to tune airflow. Port shape can significantly affect how an engine breathes across RPM ranges, especially when paired with forced induction.

“Force and duct” likely refers to the ducting/airflow path and how the supercharger’s compressed air is routed. Intake tract design matters because it affects pressure losses and how efficiently the blower’s airflow reaches the engine.

Horsepower is a measure of how much power the engine produces, often tied to how fast the car can keep accelerating at higher speeds. The hosts contrast the usual relationship between horsepower and torque with what they’re seeing in this Volkswagen setup.

Underdriving a supercharger means using pulley ratios that spin the supercharger slower than it would be at a given engine speed. This typically reduces boost pressure and can make the setup more street-friendly by narrowing the boost window and lowering peak output. In the segment, they describe underdriving to keep the car’s strongest pull where they want it.

A turbo engine uses exhaust gas to spin a turbine that compresses intake air, creating boost. Compared to many supercharger setups, turbo boost often comes on later as exhaust flow increases, which can make throttle response feel different. Here, the hosts are contrasting “not really seeing any boost” immediately with a turbo versus quicker boost behavior with a supercharger.

“10 pounds of boost” refers to manifold pressure above atmospheric pressure (commonly expressed in psi). It’s a way to quantify how much extra air pressure the forced-induction system is adding. The hosts use it to illustrate that with the supercharger, you can feel boost quickly as you rev.

2332 is another common VW performance displacement target, typically representing an even larger build than 2276. Like other big-displacement VW builds, it tends to produce more torque and can make boost feel stronger and more immediate.

In this context, “progressive” describes how boost/power ramps smoothly as RPM and throttle position change, rather than arriving all at once. That kind of delivery usually improves drivability because it’s easier to modulate on the street.

Oil cooling is about using engine oil to remove heat from internal components. When an engine is making high power, oil temperatures rise quickly, so cooling (often via an oil cooler) helps protect bearings and other heat-sensitive parts.

“72 plate” is a UK vehicle registration plate age reference (the year/period when the car was registered). It’s often used to quickly communicate the vehicle’s approximate age to other UK enthusiasts.

The induction side refers to the air/fuel path feeding the engine—intake, turbo/supercharger components (if applicable), and related plumbing. The speaker implies that strengthening the induction side is part of why the engine’s top-end performance is strong.

A camshaft controls when the engine’s valves open and close. Changing camshaft profile (lift and duration) can shift where the engine makes power and torque in the RPM range.

A “TCS 30 angle cam” sounds like a specific camshaft design/grind variant referenced by the builder or cam supplier. The key takeaway is that they experimented with different cam designs to see how it affected drivability and torque.

Cam duration is how long the valves stay open during each cycle. Longer duration can improve high-RPM power, while shorter duration often helps low-to-midrange torque—again depending on the whole build.

Cam lift is how far the cam opens the valves. More lift can increase airflow through the engine, but it must be matched with the rest of the valvetrain and head flow to avoid losing efficiency.

The slope separation angle is part of the cam lobe geometry that influences how the valve opens and closes (the “shape” of the lift curve). It helps fine-tune airflow and timing characteristics beyond just lift and duration.

“Web” is referenced as the cam-grinding/engineering partner they consulted to translate their target cam profile into a real camshaft. In VW air-cooled circles, Web is known for performance camshafts and related development.

A “supercharger cam” is a camshaft profile designed to work with forced induction. It changes valve timing and lift so the engine can breathe better under boost, especially for getting exhaust out efficiently. In this segment, they’re discussing how cam choice matters because the supercharged setup changes airflow and exhaust scavenging needs.

A1 Performance Exhaust is referenced as the source for an exhaust system/collector sizing that matches the build’s scavenging and exhaust-flow goals. The hosts discuss how collector diameter (e.g., 2.5-inch) affects flow and can either “choke” the system or help it evacuate exhaust more effectively. This is a practical example of matching exhaust hardware to a forced-induction cam and engine behavior.

Exhaust scavenging is the process of using exhaust flow dynamics to help pull spent gases out of the cylinder and improve the next intake charge. The hosts discuss how a “normally” sized exhaust might work for scavenging, but for their supercharged application they want more emphasis on getting exhaust out. This is tied to cam timing and header/collector sizing.

Back pressure is resistance to exhaust flow that can slow evacuation of combustion gases. The host argues that certain canister-style exhausts create too much back pressure, limiting exhaust velocity and reducing the engine’s ability to move gases out.

The scavenging effect is when exhaust flow from one cylinder helps pull exhaust gases out of another cylinder through pressure differences in the exhaust system. The host describes it as creating vacuum on other cylinders, improving overall cylinder scavenging and helping the engine breathe.

Valve overlap is the period when the intake and exhaust valves are both open around the end of the exhaust stroke and the start of the intake stroke. The host ties overlap to scavenging and exhaust system tuning, since better cylinder pressure dynamics can improve how much fresh charge enters.

“Intake closes” refers to the crank-angle timing when the intake valve shuts. Closing later can increase cylinder filling (and boost scavenging effects), but it can also reduce effective compression depending on overlap and RPM.

Bottom dead center (BDC) is the crankshaft position where the piston is at its lowest point in the cylinder. The discussion is about how long the valves remain open after BDC, which affects cylinder filling and scavenging.

Top dead center (TDC) is the crankshaft position where the piston is at its highest point in the cylinder. Valve timing relative to TDC determines how effectively the engine can draw in and compress the charge, which is especially important for forced-induction setups.