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Verdict Motorsports' Supercharger Technical Page


Max speed / "Max Impeller Speed" Explained

This is the maximum speed the supercharger's impeller should operate within. So if a supercharger's impeller is rated for 55,000 rpm, you should not be running the charger above 55k. The general rule of thumb that we use is to setup the system with an impeller speed of 85% of max @ peak engine rpm. Why 85%? The reasoning is simple, the mechanical components within the supercharger (bearings, gears, seals, shafts and impeller) will wear as load is induced on them, thus you shouldn't be stressing the internals during everyday operation. Therefore sizing the charger to the engine based on the normal intended operating conditions is key.


"CFM" Explained

CFM is the cubic feet per minute measurement of air. This can be calculated using the following formula:

Air speed (feet per minute) X area (square feet) = CFM

Superchargers, turbos, (and typically anything that compresses air) is rated per their manufacturer and vary between impeller and compressor housing size/design. This is an extremely important factor to consider when properly sizing a supercharger to your engine.

A common misconception when modifying or building supercharger systems is to base everything off of "boost". This however is incorrect and an uneducated way of going about things. Boost is a measure of resistance and varies between engines, compression ratios, volume of inter-cooler, charge piping and so fourth. Calculations and systems should be built around FLOW.


Component Failures & Solutions

Bearing Failure:


Typical symptoms are loud bearing operation and in severe cases the impeller making contact with the compressor housing.

Solution: Replacing the bearings with stock or perhaps higher rated bearings such as ABEC 7's or ABEC 9's depending on your use.

Bearing replacement should be looked at the same way as regular scheduled maintenance for your engine. Mechanical components will and do wear out. Every supercharger at some point in its life will require a rebuild. The key is building or running a setup that doesn't stress components that end up needing rebuilds on a regular basis.
Ensuring the charger is capable of withstanding the impeller speeds it sees day in and day out. As mention earlier, not exceeding 85% of max impeller speed will exponentially increase your charger's life expectancy. Exceeding max impeller speed almost always results in damaged blowers.

The blower below was run in excess of Max Impeller Speed:




Oil Seal Failures

Tend to lead to oil starvation on the charger. This in turn typically causes shorter life for the bearings as a result from the reduction in lubrication. The most common seal to fail is the input shaft seal (located on the pulley/belt side of the charger) A miss-aligned belt can also cause premature seal failure from the micro movements of the input shaft "in and out" as the belt pulls the shaft into alignment.



Rebuilds & Maintenance

Oil Changes
Race / High Boost Applications: Every track day or 3,000 miles.
Street Applications: 3,000 miles.

Recommended oil weight:
15w50 or 10w60 depending on your climate.

Oil changes should be treated as a preventative maintenance measure. Oil is not only the blood of the engine, but the supercharger as well. Being a mechanical component the supercharger requires quality lubrication.  The weight of the oil is just as important as the intervals it sees. Low weight oil will lead to premature bearing failure and seal wear.

Oil Injector Cleaning
Race Applications: Every track day or oil change
Street Applications: Every other oil change or 6,000 miles

The oil injector is an extremely crucial part of the supercharger system. Its job is simply to spray oil coming into the head-unit onto the rotating parts within. Not many people know or think of this part during regular maintenance, however it is extremely important! The oil injector has an internal screen that will stop small debris from clogging the injector and entering the supercharger.

This screen will get slugged up over time and if left unattended will eventually limit flow into the supercharger. Damage to the bearings, gears, and even the case itself will result.

As preventative maintenance we recommend un-threading the injector and spraying it out with carburetor or brake clean. You may also need a small pick to remove any larger pieces of debris that may be stuck in or around the screen.

Below is what could be laying in your oil injector:




Suggested Bearing Intervals :


Race Applications:
10,000-15,000 miles or every race season. The reasoning behind this being the bearings are consistently operating at high rpm speeds and increased heat exposure.

Street Applications:
30,000-50,000+ miles. This depends on the boost level run (proximity to max impeller speed), driving habits of the operator and frequency of oil changes. Light weight oil and prolonged oil changes will result in a shorter lifespan of the wear and tear items.

Below a V9 undergoes bearing and seal replacement:





Verdict Motorsports VR6 Supercharger Stage Kits Broken Down:

Below you'll find the main hardware components of our supported and custom s/c kits.

Stage I [6psi]

- Vortech V1, V2, V3, V9
- Bosch 710 bypass valve
- Stock injectors
- Appropriate software

Stage II [8-10psi]

- Vortech V1, V2, V3, V9
- Bosch 710 bypass valve
- 315cc injectors (30lb/hr)
- Appropriate software

Stage III [12-13psi]

- Vortech V1, V2, V3 (Max. Vortech V9 level)
- Standard or auxiliary drive cogged
- MadMax bypass valve
- 380cc injectors (36lb/hr)

- 256, 262, or 268 camshafts
- Standalone engine management
- Short runner intake manifold (required for MK4s)
- S2 metalwerks header or down-pipe


Stage IV+ [12-15psi+]

- Vortech V1, V2, V3, V7 / Procharger  P1SC
- Standard or auxiliary drive cogged
- Vortech max flow race bypass valve

- 380cc (36lb/hr) or 440cc (42lb/hr) injectors
- Standalone engine management
- 262 or 268 camshafts
- 9.4:1 head spacer (Required for T Trim, P1SC or Larger)
- Big valve & ported head (optional)
- Short runner intake manifold
- Air/water or air/air inter-cooler
- S2 metalwerks header or custom down-pipe and extrude hone exhaust manifolds

Stage V [15-20+psi]

- Procharger P1SC, D1 / Vortech V1 T-Trim, V2 w/928 impeller, V7 YSI
- Standard or auxiliary drive cogged
- Vortech mondo bypass valve
- 630cc or 870cc injectors
- Standalone engine management
- Big valve & ported head
- 9.0:1 head spacer or forged pistons
- 268 or custom ground camshafts
- Short runner intake manifold
- Air/water inter-cooler

- S2 metalwerks header or custom down-pipe w/ extrude hone exhaust manifolds

Other technical data coming soon!