Hennie I took a quick look at my Chilton book at similar engine sizes and their associated hp ratings as reported, and 2.3L to 2.5L engines were coming in at 100 to 105 hp by several manufacturers. Bear in mind that these are EFI engines with computer management engines so there is some advantages in the performance department there. If you desire to truly get these numbers, there is a source for bolt on fuel injection made for the VW that someone posted a while ago. I searched for it, but I cannot find it. There was a link to a webpage detailing the package, how it was installed and operated. It uses a simple controller like the Holley TBI fuel injection kits where you set the idle speed desired, mixture at idle, at cruise, and amount of enrichment during acceleration. Most of the V8 systems I have seen give you a basic fuel curve, but require the use of a laptop computer to interface and program for exactly what you need. I really liked the simplified controller that has knobs on the outside that you just set like a carb. They give you starting recommendations to get cranked up and then you tweek it from there. The down sides are that it takes longer to install, you have to have a return fuel line for recirculation of fuel, a higher pressure pump than you have now, and another hole in the firewall for the computer wiring harness. I don't think the one I saw did closed loop operation, so it was like dialing a carb. No need for O2 sensor install etc...
I stand corrected if someone is either getting these numbers from a carburated VW, or has at least dyno-ed one to these hp numbers. I personally feel like the max hp number is a little inflated, and probably closer to 90 hp peak. From my research, EFI is good for 10 to 15 hp increase in most smaller engines (dependent greatly on the engine's output to begin with), so taking that away you have 90 hp peak and between 80 to 85 hp at cruise. If you do get those hp numbers you may find that your prop is under pitched and needing to be out closer to 54 or 56 pitch to be able to use all the torque available. A netter posted some very informative and complete information discouraging the use of the Hirth engine due to quality control issues and the total lack of factory support after the sale and problems began. Sorry I do not remember who it was, but if memory serves he was in your area, South Africa. I would research this extensively before using their engines. It is my understanding that they are used primarily by the Ultralight crowd. Colin Rainey Apex Mortgage Company 386.615.3388 Office 407.739.0834 Cell 407.557.3260 Fax brokerpi...@bellsouth.net
