The chip should not be causing massive amounts of black smoke to come out of your exhaust. Diesel chip tuning is quite a simple process, especially in comparison to petrol chip tuning but that does not mean diesel engines are indestructible.
While you do not need to worry about detonation with a diesel engine, you do need to worry about exhaust gas temperatures. If exhaust gas temperatures go too high you can damage your cylinder head, your valves and possibly even your turbo.
Unlike with petrol engine where adding more fuel cools down exhaust gas temperatures, adding excess diesel has the opposite effect and this is why you do not want to use a chip that causes excess black smoke.
You can increase the power of your diesel engine without resorting to tonnes of black smoke.
If you are taking your car to the track then excess black smoke maybe okay for short periods, but constant and repeated black smoke events and the excess heat that goes with it, must take a toll on the life of the engine.
Excess black smoke can also damage/clog your DPF but decent heat shielding to keep the DPF at a high temperature can larger offset the effect of the extra soot by making the DPF more effective. DPF (Diesel particulate filters) like to work at high temperatures, driving around town for example is not good for a DPF, they like to see good exhaust flow and good heat so they can clean themselves effectively.
Diesel Chip Tuning – What can I do to reduce black smoke?
If your diesel tuning box is adjustable then you can reduce the amount of fuel that is injected. This would be the cheapest and most straightforward thing to do.
However you can also improve the breathing of your engine so more air is available to burn with the fuel. Probably the biggest improvements to engine performance on a turbo diesel comes from improving exhaust flow. If your catalytic converter is mounted close to the engine, moving it away will help a lot and increasing the diameter of the pipe leading from the turbo will also give big gains in power and fuel efficiency. The aftermarket is making more and more performance exhaust parts for diesel engines but the amount available is far behind the amount of parts available for petrol engines. Which is a shame.
Generally increasing the diameter of your exhaust system will pay big dividends just like it does on turbo petrol engines.
The next step is to improve the intake system.
Simply fitting a freer flowing air filter can make a big change in throttle response as well as outright power. I would not recommend going for a panel filter, they will probably not outflow a brand new paper filter, instead I would recommend going for a cone filter. There is no reason to be scared of these products, they dramatically alter the appearance of your engine bay but if ultimate power is important to you, they are a necessity, the fact that they also sound good is the cherry on top.
Diesel Chip Tuning – Summary
1. Tuning boxes are generally safe
2. Avoid products which create excess black smoke and are not adjustable
3. You can get big power gains on diesel engines by fitting a larger bore exhaust from the turbo back and by fitting a larger air filter.