Technical
Verdict Motorsports' Technical Page
Max speed / "Max Impeller Speed" Explained
This is the maximum speed the supercharger can operate at. So if a supercharger is rated for 55,000 rpms, you should not be running the charger at those rpms while at lower engine rpms. The general rule of thumb that we use is to pick the max setup @ 80%. Why 80%? 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 do not want to stress the internals as much as possible, so sizing the charger to the engine for the operating conditions for the intended use. The balance of the charger is critical especially when operating at the higher end of the max rpm range.
"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 import factor to consider when properly sizing your project with a new supercharger.
Component Failures & Solutions
Bearing Failure
Results are loud bearing operation and/or impeller making contact with compressor housing.
Solution: higher rated bearings such as ABEC 7's or ABEC 9's. Making sure the charger components are capable of running at desired speeds. Not exceeding 80% of "Max impeller speed"
Bearing failure caused the impeller below to self destruct. Solution: New impeller, bearings and compressor housing.
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
The general opinion is that going "turbo" is better and cheaper, and most of the time that is well founded, well at least initially. A supercharger will cost more on the initial purchase due to the complexity of parts needed (brackets,pulleys, piping and the most expensive part the charger itself) On top of this there it is not easy to source the parts needed to build your own kit in order to save money, where as a turbo setup you can piece together as all the parts are available individually.
Oil Changes
Race applications/high boost (18psi+): 3,000 miles or every track day
Street applications : 3,000 miles MAX!
Suggested Rebuild Intervals :
Race applications/high boost (18psi+): 5,000-10,000 miles. The reasoning for this is; The bearings are exposed to operation at high rpm range and lots of heat exposure.
Street applications : 30,000-50,000 miles. This mostly depends on the driving habit of the setups owner, more abuse requires a shorter lifespan on the wear and tear items.
Other technical data coming soon!
VR6-S/C 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,V9
Stock Injectors
Appropriate Software
Stage II [8-10psi]
Vortech V1, V2, V9
315cc Injectors (30lb/hr)
Appropriate Software
Stage III [12-13psi]
Vortech V1, V2, (Max Vortech V9 level)
Mk3/Corrado or MK4 Cogged Setup
380cc Injectors (36lb/hr)
Appropriate Software
Short Runner Intake Manifold (Required for MK4s)
Header or Downpipe
Stage IV+ [12-15psi+]
V1 / V1-T Trim / V2 / P1SC
Mk3/Corrado or MK4 Cogged Setup
380cc (36lb/hr) or 440cc (42lb/hr) Injectors
Appropriate Software
256 FI Supercharger Cams (some opt for 248's/262's/268's but 256's are most common)
9.4:1 Head Spacer (Required for T Trim and P1SC)
Cylinder Head Port Work
Short Runner Intake Manifold
Air/Water or Air/Air Intercooler
Larger Downpipe, Header and or Ported Exhaust Manifolds
Stage V [15-18psi]
P1SC / D1
Mk3/Corrado or MK4 Cogged Setup
440cc (42lb/hr) or 630cc (60lb/hr) Injectors
Appropriate Software
Big Valve Head
9.0:1 Head Spacer
256, 262 or 268 Duration Cams.
Short Runner Intake Manifold
Air/Water Intercooler
Larger Downpipe and Ported Exhaust Manifolds
Max speed / "Max Impeller Speed" Explained
This is the maximum speed the supercharger can operate at. So if a supercharger is rated for 55,000 rpms, you should not be running the charger at those rpms while at lower engine rpms. The general rule of thumb that we use is to pick the max setup @ 80%. Why 80%? 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 do not want to stress the internals as much as possible, so sizing the charger to the engine for the operating conditions for the intended use. The balance of the charger is critical especially when operating at the higher end of the max rpm range.
"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 import factor to consider when properly sizing your project with a new supercharger.
Component Failures & Solutions
Bearing Failure
Results are loud bearing operation and/or impeller making contact with compressor housing.
Solution: higher rated bearings such as ABEC 7's or ABEC 9's. Making sure the charger components are capable of running at desired speeds. Not exceeding 80% of "Max impeller speed"
Bearing failure caused the impeller below to self destruct. Solution: New impeller, bearings and compressor housing.
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
The general opinion is that going "turbo" is better and cheaper, and most of the time that is well founded, well at least initially. A supercharger will cost more on the initial purchase due to the complexity of parts needed (brackets,pulleys, piping and the most expensive part the charger itself) On top of this there it is not easy to source the parts needed to build your own kit in order to save money, where as a turbo setup you can piece together as all the parts are available individually.
Oil Changes
Race applications/high boost (18psi+): 3,000 miles or every track day
Street applications : 3,000 miles MAX!
Suggested Rebuild Intervals :
Race applications/high boost (18psi+): 5,000-10,000 miles. The reasoning for this is; The bearings are exposed to operation at high rpm range and lots of heat exposure.
Street applications : 30,000-50,000 miles. This mostly depends on the driving habit of the setups owner, more abuse requires a shorter lifespan on the wear and tear items.
Other technical data coming soon!
VR6-S/C 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,V9
Stock Injectors
Appropriate Software
Stage II [8-10psi]
Vortech V1, V2, V9
315cc Injectors (30lb/hr)
Appropriate Software
Stage III [12-13psi]
Vortech V1, V2, (Max Vortech V9 level)
Mk3/Corrado or MK4 Cogged Setup
380cc Injectors (36lb/hr)
Appropriate Software
Short Runner Intake Manifold (Required for MK4s)
Header or Downpipe
Stage IV+ [12-15psi+]
V1 / V1-T Trim / V2 / P1SC
Mk3/Corrado or MK4 Cogged Setup
380cc (36lb/hr) or 440cc (42lb/hr) Injectors
Appropriate Software
256 FI Supercharger Cams (some opt for 248's/262's/268's but 256's are most common)
9.4:1 Head Spacer (Required for T Trim and P1SC)
Cylinder Head Port Work
Short Runner Intake Manifold
Air/Water or Air/Air Intercooler
Larger Downpipe, Header and or Ported Exhaust Manifolds
Stage V [15-18psi]
P1SC / D1
Mk3/Corrado or MK4 Cogged Setup
440cc (42lb/hr) or 630cc (60lb/hr) Injectors
Appropriate Software
Big Valve Head
9.0:1 Head Spacer
256, 262 or 268 Duration Cams.
Short Runner Intake Manifold
Air/Water Intercooler
Larger Downpipe and Ported Exhaust Manifolds
