Improved Racing's Flow Series Motor Sport (FSM) oil thermostat is a high-performance, high-flow, universal fluid temperature control solution that can be used with any oil cooler on any vehicle or industrial application flowing up to 20 GPM (75.71 LPM).
The patented internal design (US patent 9,772,632) minimizes the pressure drop by strategically locating the bypass valve mechanism completely out of the primary fluid flow. This design is ideal for demanding applications that require low flow restriction in a compact and lightweight design.
Many professional racing teams, supercar manufacturers, and military contractors rely on Improved Racing's thermostats for the advantages they provide in competition and in critical operating environments. Our professional engineering team has experience customizing thermostats and supporting a mulitude of custom applications. Please inquire if you need a customization to support your application.
Improved Racing maintains exceptionally high quality-control standards. Every single Improved Racing thermostat undergoes rigurous inspection, functional testing, and certification before it leaves our doors. We manufacture them in the USA to the strictest standards and back them with a lifetime warranty – your guarantee of lasting performance and peace of mind.
The FSM thermostat features female -10AN O-ring boss threads and is available with optional fittings in 3/8" or 1/2'' hose barb or AN fittings in -6AN, -8AN, -10AN, or -12AN. The included brackets allow for multiple mounting options.
Why Use an Oil Thermostat?
High performance vehicles require large oil coolers to ensure that the oil does not overheat during strenuous use. These coolers also introduce the danger of over-cooling the oil and delaying engine warm-up, resulting in horsepower loss, excessive engine wear and reduced gas mileage. Oil thermostats perform the critical function of bypassing the oil cooler until the oil has reached its minimum operating temperature.
Operation
Features and Benefits
- Reduces excessive engine wear and horsepower losses while improving gas mileage by preventing oil temperatures from dropping below optimal levels.
- Maintains a minimum fluid temperature according to the typical stabilization temp in the table below, +/- 2°F (+/- 1°C).
- Patented, high flow, low pressure drop design locates the valve assembly completely out of the primary fluid flow.
- Allows a small percentage (less than 10%) of fluid to continually circulate through the cooler to eliminate air pockets and prevent cold fluid trapped in the cooler from shocking the system.
- Thermostat can never fail in such a way that fluid flow is blocked.
- Rebuildable.
- 6061-T6 billet aluminum construction with black MIL-A-8625 Type II anodized finish.
- Lightweight at just 12.7 ounces (360g) without brackets or fittings.
- Supersedes part numbers ENV-100 and EUN-1000.
Temperature Rating Specifications
| Part Number | Typical Stabilization Temp | Activation Temp | Full Flow Temp | Recommended Application |
|---|---|---|---|---|
| FSM-135 | 135ºF (57ºC) | 131ºF (55ºC) | 153ºF (67ºC) | Trans, Diff, PS Fluid |
| FSM-145 | 145ºF (63ºC) | 140ºF (60ºC) | 163ºF (73ºC) | Trans, Diff, PS Fluid |
| FSM-165 | 165ºF (74ºC) | 160ºF (71ºC) | 181ºF (83ºC) | Trans, Diff, PS Fluid |
| FSM-185 | 185ºF (85ºC) | 180ºF (82ºC) | 203ºF (95ºC) | Engine Oil (Street & Strip) |
| FSM-205 | 205ºF (96ºC) | 200ºF (93ºC) | 221ºF (105ºC) | Engine Oil (Street & Strip) |
| FSM-215 | 215ºF (102ºC) | 212ºF (100ºC) | 233ºF (112ºC) | Engine Oil (Road Racing) |
Valve assembly is housed completely between the two ports. No valves, springs, or thermal motor interrupting the primary oil flow!
Compact dimensions (shown in inches)
Brackets allow for multiple mounting configurations
Available with 3/8" or 1/2'' hose barb fittings or AN fittings in -6AN, -8AN, -10AN, or -12AN
Applications
- Engine, transmission, differential, and industrial fluid cooling applications flowing up to 20 GPM (75.71 LPM).
- Passenger car automotive, marine, and experimental aircraft engine oil cooling systems.
- Automotive and truck power steering fluid cooling systems.
- Diesel and gas truck transmission fluid cooling systems.
- Diesel and gas truck differential and transfer case fluid cooling systems.
- Not for use with corrosive fluids. If used with water, a distilled water solution with a lubricant such as ethylene glycol must be used.
Includes
- 1x Remote thermostat block.
- 2x Zinc-plated steel mounting brackets and screws.
Parts Sold Separately
Line Adapter Fittings (Optional)
Use these fittings to adapt the ports to the line sizes listed below. These fittings are required except when using hose ends with male O-ring boss connections.
Note: Our fittings are required to guarantee compatitility with our thermostats, as some aftermarket fittings may cause interference and improper function.
| Line Size | Part Number | Qty Required |
| 5/16" Barb | OB-10-05 | 4 |
| 3/8" Barb | OB-10-06 | 4 |
| 1/2" Barb | OB-10-08 | 4 |
| -6AN | OM-10-06 | 4 |
| -8AN | OM-10-08 | 4 |
| -10AN | OM-10-10 | 4 |
| -12AN | OM-10-12 | 4 |
Inline Sensor Fittings (Optional)
Use these fittings to add an inline sensor to any of the available ports.
| Line Size and Sensor Port Size | Part Number | Qty Required |
| -6AN Male to -6AN Female, 1 x 1/8" NPT Sensor Port | TR-06-02 | 0-4 |
| -6AN Male to -6AN Female, 2 x 1/8" NPT Sensor Port | TR-06-02-B | 0-4 |
| -8AN Male to -8AN Female, 1 x 1/8" NPT Sensor Port | TR-08-02-A | 0-4 |
| -10AN Male to -10AN Female, 1 x 1/8" NPT Sensor Port | TR-10-02-A | 0-4 |
| -12AN Male to -12AN Female, 1 x 1/8" NPT Sensor Port | TR-12-02-A | 0-4 |