Qestion about power

['57turbo]

I was wondering if anyone could help me understand the diesel performance a little better.
I have worked and work on gasoline turbo engines for a little while now. On the a gas engine I modify the base fuel map, ignition, accelerator circuit, and more boost to get my optimum power and economy. But from what I have learned so far the diesel has no throttle body so the engine is at WOT at all times. So if you want more power just feed it more fuel. I have also been wondering how the aftermarket companies have been making more power and better fuel economy, because
there is no ignition timing to enhance and you can’t lean it out for better fuel economy. Is the wastegate was controlled by anything but the spring in the canister?

Can someone explain how more power and better economy is accomplished?

 

[95_stroker]

[QUOTE='57turbo]I was wondering if anyone could help me understand the diesel performance a little better.
[/QUOTE]

I'll try.

[QUOTE='57turbo]what I have learned so far the diesel has no throttle body so the engine is at WOT at all times.[/QUOTE]

This isnt really a true and correct statement. WOT on a gasser means that the throttle body venturi's are alla way open and the intake manifold vacuum is pulling in as much air as it can take and the fuel is being metered in at an obvious higher rate. Result = more HP. Diesels dont operate with a vacuum on the intake, they are a positive pressure engine, throttle position on the PSD determines how much fuel gets squirted. Once the fuel is squirted in you'll get an increase in exhaust gasses causing the turbo to spin faster which in turn increases your boost pressure giving the engine a much needed breath of fresh air. Result = more HP.

[QUOTE='57turbo]I have also been wondering how the aftermarket companies have been making more power and better fuel economy, because
there is no ignition timing to enhance and you can’t lean it out for better fuel economy[/QUOTE]

While its true we dont have a spark ignition timing that can be enhanced (advanced or retarded) we do have injector timing that can be manipulated. This is where the ever popular CPS comes into play, it is the device that tells the PCM where the engine is at in its stroke and which injector to fire and when. The aftermarket tuners manipulate the injector timing to coincide with where the piston is at during its stroke. This gives us oil-burners the ability to advance or retard our ignition so to speak. Reading different variables of engine operation, the tuner can manipulate the operation to produce both higher HP and more economy.

[QUOTE='57turbo]Is the wastegate was controlled by anything but the spring in the canister?
[/QUOTE]

I dont have a WG on my truck but............. I think it gets a little pull from the vacuum pump also.

[QUOTE='57turbo]Can someone explain how more power and better economy is accomplished?[/QUOTE]

I hope I helped a little, there will be others in shortly to hopefully add to this over simplified answer I gave.


Mike

 

['57turbo]

Thanks for your time and effort. I am still trying to learn this oil-burner but am having fun with the truck at the same time. The aftermarket tuners would have to give more fuel at the hit of the throttle and then lean out the cruising steady state speed in order to get better throttle response and better fuel economy.
That would be my guess

I see it is only 79 deg @ your place. That would feel great about now, it is 104 deg now and to hit 115 deg. whoooooweee
Thanks 95 stroker.