Increasing power band in a diesel

I have been working with the injection timing in a Land Rover diesel. I've managed to improve power overall using a timing calculator from idle to around 3k rpms but it then feels like it hits a wall. I've tried advancing and retarding the timing by some degrees after the 3k rpm but haven't seen an improvement. Is there anything I might be missing to work on

Can; t directly help, other than to suggest it has a rpm limiter, but for those that might it'd help if you identified exactly which engine it is, as there were several different diesel engines used in them.

Sorry, it's a td5 engine. I don't think it's a rpm limiter because it does rev past the 3k rpm, it's just like the power drops even though it still smokes.

I'm not an expert in diesel engines at all but I once read Motec's topic about injection timing for gasoline engines. The effects of that can be seeing only at low and mid RPM where fuel injectors duty cycle is relatively small and it makes a difference when in the cycle you inject the fuel. Once duty cycle became big enough it makes no difference on fuel consumption and power output. So maybe 3000 RPM is your showstopping number... Just a thought...

You'll need to look at some more data if you want to know for sure what the hang up is on the Td5 past 3k RPM. If you have smoke, you likely have fuel - but it's best to be sure your fuel rate (mg or mm3) is still high in the area engine is losing power. You'll also want to check actual fuel rail pressure to make sure it's keeping up with desired. Loss of fuel pressure can cause excessive smoke and poor performance.

If all of the above looks good, you're likely getting close to the turbocharger choke point. In testing we usually see drive pressure rise sharply near the engine redline if we're running a maximum effort tuneup. Making efficient power out past the factory redline usually requires a turbocharger upgrade.

Hope these notes help,

Nick

As Nick suggests, it's most likely the engine is unable to breath efficiently at the higher RPM, and adding fuel make no difference if there isn't the oxygen to burn it.

If you can improve the engine's breathing at the higher rpm, you will extend the power bank - possibly everythere. If you can pick up significantly more mid-range, you won't need the rpm if you may be able to pull a higher gear comfortably - remember, RPM on it's own means little, if you don't have the torque.

If you enter "best td5 performance upgrades" in a search engine, it brings up several sites with recommendations for what to do, and which order to do them in.

Thanks for the input, they are really helpful. I was thinking to work on the timing too, but I'm unsure as to either increase or decrease timing with boost and rpms. I'll work on improving the the breathing with intake and exhaust too.