So, you want to turbocharge your donkey diesel 4WD to make it faster and add more power. Of course, it will sound better too, and get you there quicker. Before undertaking such a project it’s important to know that the feasibility and complexity of such a modification depend on many factors and it’s not always a straightforward procedure.
Turbo-charging a Naturally aspirated diesel is possible if the engine compression and injection system are compatible. If done correctly, a non-turbo diesel engine’s torque can be increased safely by 40-45% with a turbo upgrade.
While it is possible to install a turbocharger on a naturally aspirated diesel engine, it’s a complex process that requires careful consideration of various factors. Yes, it is possible if the upgrade is carried out correctly and the standard engine is in a healthy state.
This article will touch on some of them to give you a broad idea of what this modification involves.
Can You Put A Turbo On A Naturally Aspirated Diesel Engine
When carrying out a turbo upgrade on a NA diesel, the overall health of the engine should be good. There is no need to do engine upgrades to make the engine more robust before carrying out this modification provided you plan to remain within the engineering limits of the engine. If the modification is carried out correctly it will save you lots of unnecessary upgrades on components that are actually fit for the job in standard form.
FUNCTIONALITY -What does a turbo do?
While it certainly sounds like a good idea on paper to turbo-charge your sluggish diesel, its important to first understand what the turbo will actually be doing. In layman’s terms, the turbo basically forces extra air into the engine by using the exhaust gasses so that it can add more fuel and in turn make more power. Of course, there’s more to it than that and you’ll do well to continue reading if you really want to get more technical.
In a gas engine, this is a simpler process, however, when it comes to diesels there is always the risk of overheating and EGT which stands for Exhaust Gas Temperatures. High EGT is the silent killer of any diesel engine. EGT is essentially how hot the combustion process is in the cylinders and the amount of “afterburning” that is occurring in the exhaust manifold. EGT is also directly related to the air/fuel ratio. The richer the air/fuel ratio in a diesel, the higher the EGT will be.
Unfortunately, with diesel engines, we are limited as to the amount of diesel we can inject before the combusting fuel gets really, really hot and causes damage to the engine. Once this happens, the damage is catastrophic which can result in pistons melting and complete engine failure.
So with that being said, you want to keep a strict watch on the diesel engines ’EGTs (Exhaust Gas Temperature) to ensure you don’t destroy your precious diesel engine without you knowing. Also, a decent ECU tune by an experienced diesel tuner will be key to keeping things under control, but more on that later.
So, let’s now look at which components are necessary to carry out this modification on a naturally aspirated diesel engine.
ENGINE COMPONENTS – What Modifications Do You Need To Do?
Depending on the engine and the available space, you might need to make structural modifications to accommodate the turbocharger and related components.
This could involve modifying the exhaust system, re-routing plumbing and intake paths, and potentially reinforcing certain areas to handle the increased stress.
Ceramic Coating the Pistons
Engine coatings are an excellent idea when you want to upgrade your turbocharger, but is it absolutely necessary on a NA Diesel engine? When you ceramic coat your engine, the piston tops, insides of your intake and exhaust ports, and combustion chamber roofs get coated with a ceramic powder coat for excellent heat control. If you are upgrading from a NA diesel you won’t need any ceramic coating if you stay within the 40-45% torque gains. When going from an already turbo’d engine and you plan a wild tune and chasing aggressive torque figures, then yes the ceramic coating will be recommended to control the massive heat being generated by the massive torque that is pushed out.
Depending on which NA diesel engine you have, most turbo kits today include all the major plumbing necessary to get the turbine installed. If you are planning on installing an intercooler, there will be additional plumbing required so you need to make sure your engine bay can cater for all the extra pipes being routed from the intercooler to the turbo and back.
Gaskets and Seals
When carrying out this upgrade, the intake manifold will be replaced with a completely new unit on the turbo. Once you disturb the OEM gaskets and seals you need to replace them with new ones to ensure a secure seal again. Most modern turbo kits come pre-packaged with all the required seals and gaskets to install the unit successfully.
Your existing injector pump was designed to run at a very low fuel pressure on your NA diesel engine. This offers excellent reliability at the expense of power. Once you have a turbo installed, you’ll need to tune the pump to supply more fuel to compensate for the additional air being forced into the system in order to make more power. If you have a mechanical fuel pump, this can should be done by a professional tuner who knows how much psi the pump can safely handle.
When considering a turbo upgrade on a NA diesel you need to consider the condition of the injectors as well. This is a key component in the system that needs to reliably deliver the correct amount of fuel spray on each cylinder. It’s not necessary to do a complete injector replacement but rather a service and nozzle replacement. This, of course, is all depending on the mileage of the vehicle.
High-mileage trucks will definitely need to have the fuel and injector system serviced to ensure all the pressures are set correctly and that all the injectors’ pressure readings match up correctly. Also, the pump settings, fuel load, and timing need to be checked and set correctly.
Installing an intercooler on a NA diesel is a debatable issue. There is not always a straightforward answer and It also depends on which vehicle you plan on doing the upgrade on. You might have to search online on vehicle-specific forums or consult with a reputable mechanic who has performed this upgrade before for some advice.
Remember, your NA diesel engine wasn’t originally designed to handle an intercooler, and by installing one your project cost and risk rise significantly. The reliability of other components such as your clutch kit comes into question since you will be producing over the safe 40-45% torque figures. Once you venture into the 50% and higher zone you are placing immense strain on supporting components that were never designed to handle this kind of power and torque.
When your turbo upgrade is carried out correctly, the engine will remain reliable for a very long time provided you remain within the 40-45% torque gain limit. In this instance, you get better performance without sacrificing the reliability of your trusty diesel engine.
An exhaust upgrade is definitely something you will want to include in your upgrade, especially if the vehicle has quite a bit of mileage on it. An exhaust with blockages won’t do your new turbo any favors in terms of heat build-up and EGT temps. If it’s possible and within your budget, it is highly recommended to consider a 3” stainless steel exhaust to make sure those hot gasses are blown out easily enough and your new turbo can spool up without any restrictions.
Before carrying out a turbo upgrade on a NA diesel or any engine for that matter, it’s important to know the health status of the engine. The best way to determine this is to carry out a compression test that reveals the condition of your engine’s valves, valve seats, and piston rings and whether these parts are wearing evenly.
Good compression on a diesel engine falls in the range of 275 to 400 psi. A healthy engine means you don’t have a variance of more than 10% between cylinders.
A leak test is another important test that needs to be done to determine the engine’s health and its ability to hold compression. An engine leak test is basically a compression test in reverse. Instead of measuring the engine’s ability to create pressure, compressed air is introduced into the cylinder through the spark plug hole. This will reveal if the engine can maintain pressure without any leaks.
STRUCTURALY – Can You Put A Turbo On A 4 Cylinder?
Yes, technically any engine can be turbocharged. The amount of additional pressure you are planning on adding to the system will determine if the engine is robust enough or not. If you work within the limits of the original engine design then you would not need to make structural changes to reinforce certain areas to handle the added stress. You also want to make sure there is enough free space in the engine bay to accommodate the additional plumbing and hardware associated with a turbo upgrade on a NA vehicle.
TUNING & CALIBRATION – Getting More Power Out Of A Turbo Diesel Engine
Once your turbocharger has been installed on your previous NA diesel engine, the ECU or Engine Control Unit needs to be tuned to accommodate the additional air and fuel being forced into the engine. The ECU is basically the brains of the engine and tells the engine how long the inlet and exhaust valves need to remain open and closed and how much fuel needs to be sprayed into the combustion chamber etc. This process requires specialized knowledge and equipment. It’s crucial to work with an experienced tuner who can optimize the engine’s performance while ensuring its reliability.
WATCH – Is Your Car Safe to Turbo (VIDEO)
User Experience & Feedback
Possible? Yes. It is done quite often by automotive OEMs and engine manufacturers.
Possible in a home or roadside workshop? No. A lot of core engineering work is involved which is typically well beyond the capabilities of service workshops. Also, such a major change requires re-certification of vehicle emissions as well as homologation of the vehicle as a whole for it to be approved as road-worthy.https://www.quora.com/Is-it-possible-to-convert-a-natural-aspirated-diesel-engine-into-a-turbo-engine
Technically this can be done, but…https://www.quora.com/Is-it-possible-to-convert-a-natural-aspirated-diesel-engine-into-a-turbo-engine
The fuel injection system is defined and designed for the amount of air you get in the cylinders at atmospheric suction, so less than 1 bar you will have losses.
Now you load the cylinders in overpressure, say 1.5 bar and you get a lot more air in.
Your injection is not suited for that and will deliver the amount of fuel for atmospheric loading which is not enough. So it won’t work properly and needs adjustment, most probably replacing. Your EMS is not suited either.
The load on the engine will be a good deal higher and is it suited for it or will it blow up? So a load of very specialized and expensive conversions is required. I think you better buy a car with a turbo, that will keep you out of trouble at a far lower cost.
Providing the engine is strong enough then there is no problem adding a turbo to a diesel after all they were invented for diesels. Now whoa a moment!
The air filter will need to be bigger. The exhaust system will need mods and will certainly need to be increased in size.
The fuel injection will need reprogramming if it is CRDI and will need the injection pump maximum delivery adjusted if an old mechanical system.
In summary, there is nothing you can’t do as long as you have time and money. I would take it to a place that specializes in turbo diesel as they are likely to know what exactly is needed for your engine. Fitting to a diesel engine should be simpler than doing the same thing to a petrol engine because you won’t have to stuff around with wastegates and decompression plates, spark reprogramming ECU reprogramming of the fuel, and spark timing curves.https://www.quora.com/Can-you-fit-a-turbo-to-a-non-turbo-diesel-engine
Photo by Tim Meyer on Unsplash
In summary, It’s recommended to consult with experts or professionals who specialize in diesel engine modifications to determine the feasibility and suitability of your specific engine.