Most of you know that a bunch of us just returned from the Smoky Mountains a la Tour de Smo.
The report is IN, EFI on an aircooled motor is pretty awesome. My car ran flawlessly all week and weekend. I had put in an altitude compensation curve(thank you Mike Pickett!) and it worked well. I have to lessen the curve a bit, it pulled back the fuel a bit too much in cruise at 5000 ASL but was otherwise perfect. Every time you turn the key on, the ECU samples the current barometer reading and applies it to the fuel curve.
The engine has more power and torque everywhere. This comes from three different areas: compression, dry sump, and EFI. Maybe four for overall performance if you factor in the stickier Vredestein tires, which are fantastic!
As delivered from Jake, my car had 147 ft. lbs. and 172 hp. That was a 009 distributor with Pertronix, conventional wet sump, and Spanish Weber 44 IDF.
According to a bunch of sources I looked up, you get three to five percent more power with dry sump. That is 5 to 8 hp right there.
When I rebuilt the top end, ten thousandths was flycut from the heads to clean them up, plus I removed ten thousandths of cylinder spacers. I went from 9.8 to 10.2 static compression. That's worth a few hp, making the engine more efficient volumetrically.
Then we have the EFI. Back in the Super Vee era, the 1600cc type3 engines gained 5-10 hp when changing from carbs to injection. That was at 130 hp or so. For me, going from 44 IDF carbs with 36mm venturi to 48mm throttle bodies is key. Fifty six percent larger surface area, that's a huge difference in airflow. Also there is the superior fuel atomization from injectors rather than pouring the gas in from a hose. I'd say a minimum of 10 hp, but WAY more torque, and from lower rpm. The car pulls HARD from 2000rpm all the way up to 6700. It used to only pull hard from say 2500-2800 rpm.
So, no, I don't have any dyno sheet or actual figures. I do have seat-of-pants feel though, and some educated guesses. Plus I was pulling away from a certain modern 2008 911S that was following me on the Rattler.
Conservatively, I'd say 185 or 190 hp at the flywheel. Maybe higher. It is very possible I have more, but I'll never know unless I put the car on a dyno.
All I do know for sure is I have more power and torque everywhere. And it is so much FUN to drive!
If you don't believe me, just ask Stan. He drove the car on carbs by himself. Then this year he rode with me on the Rattler. The car is faster even with almost 500 pounds of people on board.
For a while I questioned myself as to the sanity of doing the EFI. I'm not questioning the decision any more.