what is the difference between dual injectors and single(8 versus 4) what are the pros and cons of each system.

Thanks Chris

To find out how much hp difference, on the average, the engines with 8 injector systems make over their older 4 injector counterparts, you need to talk to an outfit with dynamometer experience - Hyper and Guhl Motorsports come to mind. Either one will be happy to give you good figures on that.

Where the $ meets the track, a 4 injector system methanol conversion runs about $750 and an 8 injector system runs about $1150 to $1600, depending on the make and model of engine. The 8 injector system costs a lot more, and the upper injectors (probably due to their smaller nozzle size) meed to be cleaned more often than the nozzles in the older 4 nozzle systems. Do they make more HP? Probably, but because we are not dealing with the same year engines here, and don't know what other changes the manufacturer of the engine may have made, I can't tell you how much of the increase is due to the 4 more nozzles and how much is from other sources. As long as we are with the two different engine makes we have 4 nozzle systems for, we'll use the older systems on the newer engines (along with the older ECU) as long as we can, simply because of the cost factor.