DaveB.inVa

As far as a diesel goes there isn't really a lean or rich as you would think with a gas engine.

A gas engine always runs near its stoichiometric air/fuel ratio of 14.7:1. Basically the stoichiometric air/fuel ratio is when all the fuel is combined with all the oxygen and you have a balanced chemical equation, there is just enough air to burn the fuel present. Having less air than fuel in this equation is considered rich and more air than fuel is considered lean.

A diesel has a stoichiometric air/fuel ratio of about 14.6:1. You'll find that you probably never will get close to that ratio. If I remember correctly at full load a diesel is still only running about 20:1. At idle the ratio is going to be over 100:1. The closer you get to a diesel stoichiometric air/fuel ratio the smokier it will be. This is because the way diesel is injected it is burning in a "rich" zone around the surface of the atomized fuel. That's where you get most of your particulate matter. The closer you get to the stochiometric air/fuel ratio the more "rich" zone you have and the more smoke.

If you have "too much turbo" I would take that to mean that your turbo is just too big. Having too large a turbo just isn't fun, it will have more lag, lower average boost and can surge.

For what you have I would say to run as much boost as you're able to. In other words, if you don't have studs I wouldn't go over 45 or so psi.

EdmontonCanada

Yeah, I know how the a/f ratio works and the turbo on order isn't too big that will cause lag problems.

I'm just looking to protect my engine from whatever might happen from having too much boost. I know about headstuds and will be puting those in when the turbo goes in. I would imagine that even the stock fueling system with large boost can cause damage to parts that haven't been upgraded yet to handle that high of horsepower.

So I can control the fuel like someone has mentioned, but that usually involves adjustments that are not fast (like a computer reprogram). Or...I can use a boost controller to set a limit from inside my cab and within seconds, finding a sweet spot / limit for protection so I don't blow my tranny, etc.

Then for each new mod, like an heavy hauler transmission, bigger injectors, etc, etc, etc. I can simply increase the boost on the inside of the truck to match.

So I'm still not sure why a person wouldn't use one.