I was at the NHRA Arizona nationals last week and took some photos that might be of interest to Thai racers. The NHRA has several classes for modified 4-cylinder classes. I took photos of nthese two engines. The first is a turbocharged 2600cc General Motors 4-cylinder "EcoTec" engine for the DD/AT class (restricted turbo size, cc-to-weight ratio limit, 1000 kilos, alcohol, etc.). Notice the 3 injectors per cylinder and the belt driven distributor instead of individual coils. This car ran a 7.69. on it's first run and blew the turbo on the second run. The second motor is a 3400cc N/A 4-cylinder Chevy with a billet cylinder head that runs on race gasoline in the K/A class. It weighs only 550 kilos and was the #1 qualifier with a 7.85 second run. Amazing. Both of these cars utilize an automatic transmission.