Quote:
Originally Posted by cjperformance
I think you only need LT4 fueling above 580 RWHP, but a good idea if you plan on going over that at any point. More specifically, my understanding is if your injector pulse width is over 5ms.
1 Bar = around 14.7 psi, which is also atmospheric pressure, so a 1 Bar can not measure boost. For example 7 psi of boost is actually 21.7 psi (14.7 ambient + 7 psi boost) or 1.5 bar. Basically the tunes that dont use a 3 bar are fudging the values, or faking it. That's my technical explanation.... just faking it. I'll explain more when I understand it myself.
The breakout allows you to measure atmospheric pressure outside the pressurized intake tract by adding in another map sensor. One outside the pressurized intake tract to measure atmospheric pressure, usually your old 1 bar, and another (usually the 3 bar) to measure boost (or vacuum for that matter) in the intake. This allows correct calculation of the pressure ratio which is dividing the intake pressure by the ambient pressure (or vice versa maybe).
For example, 21.7 intake press / 14.7 atmospheric = 1.47 pressure ratio, which affects VVE table calculations (or lookups....) . Again, at least that's my understanding. If I'm wrong, please correct me  |
Injectors can be higher then 5ms. 6.2ms is about max peak. I try to keep them < 6.0ms sustained in PE mode. Anybody going FI should at minimum get the LT4 fuel system, install a flex fuel sensor, and run a blend of Ethanol. A lot of power to be gained being able to go from 12 degrees of timing to 17+. Let a lone the cylinder cooling you get from Ethanol which will help keep those piston rings butting from high cylinder temps.