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A step in the right direction
The goal of the project is to give a substantial improvement in gas mileage on full size GM pickups and SUVs . The reason for this target group, is there are 5.5 million such trucks on the road produced from 2001 - 2007. These models share much of the same drive train and body components. Because these trucks/SUVs use so much gas, each conversion would save significant amounts of oil. We hope to produce a kit one can install in in about 3 days and obtain at least a 25% improvement in gas mileage AND add a 20% boost in torque and towing power. Unfortunately the plan did not quite unfold that way. After about $7500 and 20 months of effort the system is in and working. But it only yields a 8% improvement in overall mileage. On a strict city loop of 3.2 miles with 3 hills and 12 stop signs I can get 17.3 mpg with electric assist versus 14.9 with the system off. See the chart below for a summary of 18 test runs from 3 days.. The brains of the system is the EMIS (Engine Motor Interface System) made by Netgain technologies. The EMIS reads your speed, throttle position, battery voltage and several other factors and turns on the Altrax controller to send up to 500 amps to a TransWarp7" electric motor also from NetGain. The motor sits between the transmission and driveshaft and then we need to add a battery pack with charging system. I had hoped one would gain a faster, more powerful car, which plugs in at night to reduce gasoline consumption. Think of it a green turbo charger. Again I saw a slight performance improvement. At a local drag strip the truck ran the 1/4 in 18.2 seconds before I started. After all the batteries and changes to the drive shafts, time increased to 18.5 with electricity off but decreased to 17.9 with electric assist. While electric power is not free it appears that one can get a "gallon" of energy for about $0.55. When the batteries are depleted (after about 25 miles of city driving) the gas engine provides all the power. A normal recharge takes me about 6 KWH. I am not the only one working on this technology see www.salidaconversions.com. They modified the gas tank so they could put a larger 9" motor in place. A larger motor would help but I am not willing to make such an extensive modification. There was a nice feature in our local paper about the conversion.
The EMIS has an aggressiveness factor one can set. With the EMIS off I average 14.9 MPG. With the aggressiveness set at 2 mileage increases to 16.5 and with the aggressiveness at 9, I reach 18 MPG. But with such a high aggression the batteries did not last long, less than 15 miles before needing to be recharged. I now have the aggressiveness set at 6 and the batteries last for about 25 miles of town driving giving me about 17 mpg. . If the EMIS unit can be modified to read the accelerator rather than the throttle body position we should be able to get an extra 5% in performance and gain a smoother ride. I have been given hope such a modification can be made by NetGain.
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