[DeTomaso] How much has EFI advanced over the past few years?

[JFFR]

The aftermarket throttle body fuel injection systems have come a long 
way in the last ten years.The self tuning feature that they have works 
on matching the volumetric efficiency table to the fuel air ratio table 
and limits the amount of time and correction that the system has to make 
under different load conditions. There are also ignition timing tables 
and air temperature tables that control the fuel air ratio at given 
loads and throttle position, along with MAP, Baro, air and water 
temperature sensors. These systems have basic tunes set up in them that 
will allow you to get your engine running and in many cases be able to 
drive it quite well. The problem is that when you try to run a somewhat 
radical engine with a basic out of the box tune the results may not be 
to be good. In my experience the biggest problem is getting the right 
fuel air ratio for your particular engine. Altitude and air temperature 
are a big factor and radical high horse power engines run better with a 
richer fuel mixture. The self tuning feature can only tune the engine to 
what the programs says and even though the MAP sensor and Baro sensor 
are making adjustments in real time, it is what is set up in the program 
tables that actually controls the system.

For guys that want to have fun with a carb, just install an oxygen 
sensor in your exhaust system and get a good fuel air ratio meter. It is 
really amazing at how well you can fine tune a carb and get good fuel 
economy and performance!

I have had a FAST XFI 2.0 bank fired port fuel injection system for five 
years on my 388 cubic inch Fontana/Cleveland stroker engine. The car has 
been driven to the last five Pantera Fun Rallies and even though the 
system was set up and tuned by on a chassis dyno, I did have to make a 
few initial adjustments to the fuel air ratio to allow the car to run 
perfectly at any altitude.