Nope the regulator takes control through out the whole power band. Just back out you top needle about a turn. It does have a temp sensor. Here are the actual words that was in the ad when I first purchased the units.
Wouldn't it be great if your mechanic could tune your engine perfectly every time, and you wouldn't have to worry about whether or not your engine was too rich or too lean? Even better, wouldn't it be great if your mechanic could ride along in your model, and adjust it for different conditions that would allow the engine to accelerate and perform better? Sounds like sci-fi stuff ? Enter PC/RC.
PC/RC has been manufacturing hobby electronics such as the Digi-Temp digital temperature probe and Digi-Tach tachometers for years, and realized that if they could put all of that technology into one magic box and add a little software, a system could result that could automatically tune your R/C gas engine. After more than a year of testing and development they had a product dubbed the Electronic Fuel Regulator, or EFR, which was light, performed as expected, and had minimal draw on the battery pack.
Now the average or expert racer can have his engine tuned precisely, while in the heat of the competition, and without worry. How does it work? Think of the EFR as fuel injection. Simply stated the EFR consists basically of three parts - the valve, the controller, and the sensor. The sensor transmits information back to the controller, and tells the valve the proper amount of fuel to allow, based on the carburetor opening. The carburetor opening is sensed via the servo output from the receiver.
Installation Pick a suitable location for the processor, and mount it securely. A small hole is necessary in the exhaust manifold, about 1/4 inch (6mm) from the mouth of the manifold where it attaches to the engine.. The valve simply installs in the fuel line between the fuel tank and the carburetor inlet. Now plug the unit into the receiver and plug the throttle servo into the controller and you are ready to program.
Why is the engine running at a cooler temperature? With manual tuning, a mechanic is trying to find a compromise between two needle valves. The transition from low to high requires a richer setting in the middle, to overlap and a leaner setting on the top needle. This leaner setting on the top is what causes most high temperatures, and premature engine failures. Using the EFR is like having many synchronized needle valves, and since they are not compromising, the results are settings which are more precise and not as lean; therefore cooler.
Another thing which has been observed and could be very important to many drivers is the ability to spot a problem before it becomes a bigger problem. If the engine has been running fine and then suddenly starts to run richer and richer you can bet that the rod bearing or something is going bad inside the engine. In testing there was enough advance warning that complete piston/sleeve replacement was avoided by a simple change of the rod. How many good engines will this save? There will also be an occasion when the unit fluctuates between rich and lean. A check of the fuel tank for leaks or the muffler coupler for rips will usually find the culprit.
The biggest difficulty with gas R/C is the inability to get engines to run right. Some have actually quit altogether because of the frustration of trying to tune the carb or finding a mechanic that could tune it well enough to be competitive. Using an EFR is going to change all of that. The EFR, with its enhanced car programming, will extend the life, and increase the performance of car engines as no product has done before. This same thought process is exactly what R.O.A.R. saw as a good enough reason to approve the product for racing.
The future is here and your radio-controlled model can now benefit from a technology that will not only increase your enjoyment and satisfaction, but ultimately improve the hobby.
EFR 801 benefits are :
Optimum mixture throughout the varying throttle setting
Improve fuel management
Reliable engine performance in varying weather conditions
Consistent performance throughout operation
Increase engine life
Automatic shut down on power failure
No adjustments necessary
List Price: US$159.95