7.3 IDI Upgrades – Can You Make this Giant any Faster?

The 7.3 IDI diesel engines in Ford trucks can be considered fossil engines today. They are really old and they haven't been used for a couple of decades in any new cars. Their direct successors are the 7.3 Power Stroke engines that have basically the same cylinder block but absolutely different technologies. The 7.3 IDI is old, but what if we make some upgrades?

Key features and my opinion about the engine

• Production years:1987-1994
• Average lifespan of 7.3L IDI:450,000-500,000 miles
• Fuel supply type:indirect injection
• Power range:185-190 hp
• Fuel efficiency:awful
• Engine block material:cast-iron
• Engine reliability score:high
• The most common problems:very sensitive fuel injection system, bad fuel consumption, oil leaks, extremely poor power.

7.3 IDI - is it a good engine today?

Well, it's hard to say for sure if the 7.3 IDI is actually a good engine compared to all modern diesel units. You can think of it as of a dinosaur among engines because it didn't have any modern technologies. On the one hand, it's bad because the engine lacks fuel efficiency and dynamics. But on the other hand, it's not bad at all because the engine is pretty reliable and easy to repair.

You will not find any EGR, DPF, and all other abbreviations that make owners of modern diesel engines shiver with fear. These engines were made when auto manufacturers wanted to make good cars, not just get some money from their customers. And this is an important benefit of the engine.

Here are some important facts about it:

• the engine offers 7.3 liters of capacity, and it may seem a lot, but you should remember that the power was only 185-190 hp;
• the V8 diesel engine didn't even have a turbocharger (in 1993 they introduced one with a turbo, but it wasn't' very successful, anyway);
• the huge engine was equipped with simple and cheap fuel equipment, so the set of injectors will only cost you about $250;
• the engine wasn't equipped with any of the modern ecological equipment which made it durable and relatively problem-free;
• these engines were made for a decade and they were extremely popular among truck buyers, both private and commercial;
• the 7.3 IDI engine can go around 400,000 miles without any serious repair and bad issues.

Well, this is one of the last no-turbo diesel engines. The next series was Power Stroke which came with a turbocharger and allowed to go with more power and torque. But the legend of the IDI engines is still pretty popular. And some guys even hunt for these engines to rebuild and modify them.

Why? Because they are extremely reliable, cheap to maintain, and don't cause any problems. Well, some problems you will still get but they will occur mostly due to the age of the engine, not because of its construction. Today, we are going to give you a quick overview of the most popular modifications for the 7.3 IDI engine and give our opinion on them.

What are the possible 7.3 IDI upgrades?

Among the upgrades that people want to make you will find dozens of things that are incompatible with the 7.3 IDI. The problem is that the engine is classic and very old in terms of technologies, so not all extensions can be easily added to it.

But still, today's specialists will do a lot to make this huge engine work much better and deliver more power.

We have to say about one possible issue. Navistar company (the creator and manufacturer of the engine) tried to modify it in 1993. This resulted in a very poor 7.3 IDI turbo version that lost over half of its longevity because of a few dozens of horsepower. You should remember about this.

So, here are some of the coolest possible modifications for the 7.3 IDI.

• Turbocharging the 7.3 IDI engine

A non-turbocharged diesel engine is something very uncommon today. These engines don't produce enough power although they have high torque even at low RPMs. So, the engines are strong but they can't rotate much and save their power at high rotations.

That's why turbocharging any diesel engine is a good idea. And we've seen a lot of custom turbocharged 7.3 IDI engines that worked pretty well and offered wonderful power. They were not much worse than the Power Stroke 7.3 engine.

Well, yes, you will have to arrange some other modifications to make the turbocharger work fin, but anyway, this is a good thing to start with.

• Exhaust upgrades for the 7.3 IDI

The IDI engines didn't have a good exhaust system. Yes, it was very simple, it had no ecological equipment. But the diameter wasn't big enough to let the engine breathe. So, especially if you decide to turbocharge the engine, you will need a new exhaust system.

Replacing the exhaust pipes along with the muffler is a good idea for these engines. It will allow the exhaust gasses to go through the system faster and this will not reduce the power of the engine. Some extra horses will be there for you.

• Air intake kits for the 7.3 IDI

Unfortunately, the stock air intake wasn't really good. It had some parts the functions of which are still debated. We consider the best idea is to buy one of the available air intake kits on the market and ensure that the engine takes in as much air as it needs with no extra sound and noise.

Also, the new air intake system is pretty important for those who want to turbocharge their IDI engines. A turbocharger takes much more air than the stock IDI system may give. Also, a better air cleaning system is needed for better turbocharger functioning and long life.

• Better fuel pump

Well, you don't need to replace the diesel pump in your IDI engine. The only thing you will need to do is to adjust the fuel pump to work in new conditions. For example, a turbocharged engine may need more fuel, so your pump should be ready to deliver it.

In this case, we recommend adjusting the stock fuel pump because it is quite reliable and powerful to give higher pressure of fuel. But if the pump is very old and shabby, installing a better alternative will not be a bad idea.

• New injectors - worth the money?

The hard question is whether you should replace the injectors. And we can't answer this question. You can try if you use a turbocharger in your IDI engine. But if you don't, just go with the OEM injectors that are pretty reliable, simple, and, what's the most important part, cheap.

These injectors don't offer good fuel economy. They can't be used for really active driving. But they are still good for a truck if you aren't going to use it for racing.

Why wouldn't we upgrade these engines much?

Well, the IDI isn't the best-tuned engine in the world. You can add better exhaust and air intake and you can work with fuel supply to create better working conditions. But we still know some bad consequences of any modifications and upgrades.

And here are some of them:

• you will lose some mileage on your engine - we mean that the longevity of the 7.3 IDI will not be as good as it used to be before your upgrades, sometimes the loss is very significant;
• you are going to pay more for diesel fuel - unfortunately, nearly all modifications will deteriorate the fuel mileage and this will not be good for your budget;
• repairing your 7.3 IDI will become more complicated and that's why you are going to lose money each year on regular maintenance and repair;
• the old engine can just fall apart when you upgrade it to get 20-30 more horsepower, you will just touch something and will need to replace everything;
• the power gain is not that cool - you will not be able to make this engine much more dynamic and much faster.

So, we wouldn't worry much about upgrading this engine. Even the best thing you will get will be plus 30 horsepower. And it isn't worth the money, in our opinion.

Final words

Do you want to drive your F-Series truck for a lot of years? Forget about the total upgrades of the 7.3 IDI engines. These diesel engines are good in terms of longevity and reliability. Don't disturb them with your wish to own a sports truck for a little money. Just let them give you the best they have. But if it's your project vehicle, then you have a lot of things you can do with the IDI to get some pleasure when driving the truck.