A solid step in the right direction
The goal 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 2002 - 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 2 days and obtain at least a 25% improvement in gas mileage AND add a 25% boost in torque and towing power.
We are a bit short of our goals with about a 18% improvement in city driving but it is a start! And we have an idea to allow us to exceed our goal.
See a video of the project. taken at work at Eastman Chemical by our AV team. A second video is available from the Knoxville EV Show. There was also nice feature in our local paper about the conversion and it was featured in July edition of CurrentEVents.
After about $9500 and 20 months of effort the system worked for over 50,000. At this point I need larger batteries as the old ones gave up. The time was mostly due to waiting on parts that are now available. The 18% improvement is in city mileage. On a strict city loop of 3.2 miles with 3 hills and 12 stop signs I now get 18.8 mpg with electric assist versus 15.9 with the system off. See the chart below for a summary of the first 18 test runs over 3 days. Since those tests I have replaced the lead batteries with new lithium batteries which gave a noticeable boost in mileage and gives more range.
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 powers 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. The battery pack and charging system is along the frame between the wheels.
I hope one would gain a faster, more powerful car, which plugs in at night to reduce gasoline consumption. Think of it a green turbo charger. The system has dropped my 1/4 mile time from 17.9 seconds to 17.4 seconds. While electric power is not free it appears that one can get a 1/2 "gallon" of energy for about $0.50. When the batteries are depleted (after about 40 miles of city driving) the gas engine provides all the power. A normal recharge takes about 5 hours.
EMIS test results with 600lbs of lead batteries.
The EMIS has an aggressiveness factor one can set. With the EMIS off I average 15 MPG with these early tests. With the aggressiveness set at 2 mileage increases to 16.5 and with the aggressiveness at 9, I reached 18 MPG. These results have since been slightly improved with the swap to lithium batteries which shaved off over 400 lbs of weight. The lithium batteries last for about 40 miles of town driving giving me over 18 mpg and the base mileage is now 16 with the lighter load.