This article has been written to help you understand the benefits and drawbacks of fitting a front mount intercooler to your Toyota Hilux N70 KUN26 fitted with the 1KD-FTV engine.
On a Toyota Hilux, the intercooler serves the purpose of cooling down the turbocharged air as it leaves the turbo before it enters the intake. The Toyota Hilux CT16V VNT turbocharger is essentially an air compressor driven by the energy of the exhaust gas from the engine, which means a few things,
- As a higher volume of air is compressed into smaller area, it heats up.
- The turbocharger is driven by exhaust gases, therefore the nature of it’s proximity to the hottest components in the engine means this air is being heated.
- The more boost we run, the worse these factors can influence our intake temperatures. As the turbocharger begins to run closer to it’s maximum efficient speed, there becomes a point where all it will be doing is generating extra heat without providing beneficial air volume.
- Diesel engines are almost always using turbo boost. At 100 km/h, they usually run with 8 to 15 psi of boost. In contrast, most turbo petrol engines spend a lot of time in vacuum — meaning there’s no boost — unless you’re accelerating hard.
Because diesel engines are always under boost, they depend heavily on the intercooler to cool the air going into the engine. This makes the intercooler even more important on a diesel than on many high-performance petrol engines.
Statistics and Information
The factory intercooler is what we refer to as a ‘top mounted’ intercooler.
This mean it gets it’s airflow from the bonnet scoop, with ducting routing that air onto the intercooler.
It’s a common myth that since the ‘manufacture made it a certain way for a reason’ therefore it must be good, or work.
I suspect this done purely from an economical and emissions perspective.
It was probably the cheapest option available to be produced at a large scale, while working just good enough to improve emissions on paper, without redesigning the front of the car. The manufacturer, does not care about your performance they way you do. If they did, it would have more than 130hp and 330nm at the wheels from factory.
Turbocharged air leaving the turbo can be upwards of 150° Celsius.
This effect of cooling down our turbocharged air is very important to providing the most efficient delivery of compressed air into our engine.
This is even more important when towing, or loading the vehicle up heavy.
The goal of any good front mounted intercooler (in my opinion) is to get your IAT (intake air temperature) within 5 degrees of ambient, consistently.
If it’s a 30° Celsius day outside, we want to see consistent 35° IAT’s.
Does a front mount intercooler really make a difference?
Yes. The difference is immediate and noticeable. On a stock standard Toyota Hilux, we would expect to see the intake air temperatures to dramatically be reduced when towing or loaded up.
You will also see a drop in exhaust gas temperatures between 50-150c depending on your setup.
How much HP does a front mount intercooler add?
On a standard Toyota Hilux, none. The idea is to not give you more HP as a maximum value, but to be able to provide you the same amount of HP for longer.
As the factory top mounted intercooler begins to heat up, eventually heat soaking to the point where everything is so hot even sufficient airflow struggles to bring it back to a reasonable temperature, the factory ECU tune will reduce the horsepower and torque the engine is allowed to make.
On the Toyota Hilux diesel engine, fuel and boost is governed by the factory ECU. There are maximum and minimum allowable amounts of boost and fuel that can be delivered to the engine, and the ECU will never exceed these on a factory tune.
What adding a front mount intercooler will do though, is allow you to stay in the safe areas, for as long as you could imagine. This means you will not suffer a reduction in power or torque by the time you reach the top of a hill for example, or if you’re towing, you can maintain the same speed for as long as you’re driving.
Ok, but my car is tuned?
Perfect. All this information is EVEN more valuable to you.
Imagine everything we’ve discussed but your factory intercooler has to work twice as hard, as you’re running more boost than standard.
If you have a tuned Toyota Hilux N70, fitting a front mount intercooler is most valuable to you. This is where you’re going to see a 10-15% performance increase just from fitting it. Because your vehicle is already running higher than standard amounts of fuel and boost pressure, getting consistent IAT’s are going to be your best friend.
So what is better, a top mount or a front mount?
A front mount intercooler on a diesel Toyota Hilux is ALWAYS better. Logically, we have to consider what is working AGAINST that top mount intercooler.
- It’s inside the engine bay, with all the other hot things like exhaust manifold, radiator, the intake, the EGR system and the engine itself.
- It has extremely reduced airflow. You’re only getting whatever air passes through that little scoop. And I am doubtful it was ever wind tunnel tested for efficiency… even if it was, I bet the minimum passing standard was low.
- Add a bull bar to the front of your vehicle, and that flow of air to the bonnet aerodynamically is going to be changed. So, it might not even be getting any airflow at all.
- It’s tiny. Need I say anymore?
What are the downsides?
The only downsides to fitting a front mount intercooler is the cost, or cost and time if you are DIY’ing it. They take about two afternoons, or a full day to fit neatly. The kits we recommend however, do come with everything like instructions, mounting brackets, pipework and the intercooler itself.
It is definitely a DIY friendly job. Common tools required are,
- Air hacksaw (for cutting the holes next to the radiator)
- Socket set
- Spanner set
- Screw driver set
- Can of paint to polish up some of those fresh cuts through the radiator support)
If you already have accessories fitted behind your grille (for example, I commonly see battery chargers for dual battery systems mounted here), you will have to adjust or move them. It’s worth it, though. I promise.
What options are there for fitting a front mount intercooler to my Hilux?
We use and recommend the PDI Intercooler kit (also known as Performance Diesel Intercoolers) for the Toyota Hilux N70. We have found this kit to be the most comprehensive, DIY friendly, readily available and best designed kit on the market.
That kit, is available to be viewed by clicking here.
We really like the fact that is comes with the end tanks on the intercooler fully cast into it. This means you aren’t ever going to run into the risk of an intercooler hose blowing off behind the grill where it cannot be accessed.
We did a full run down video on the PDI Intercooler kit for the Toyota Hilux N70 below.
