WHY DOESN'T A TURBO WORK WITH HILUX?

[Rusti]

Hi guys,

Just wondering why no one uses turbos in their hiluxs? I've heard a number of people say hilux motors just don't work with turbos but this weekend I met a gent with a 2.8 Turbo Diesel with an intercooler and he couldn't be happier..

Is he in for a nasty surprise of some sort?

[Jaws]

After market turbo systems generally over stress a motor that was never designed for the additional boost and power. Toyota bakkie motor are renowned for being reliable not for making the most power.

[Knuppel]

If you want to turbo a motor you can do it but you need to be 200 % familiar with all the pit falls.
I have done it and the 2.8 d was actually my first one. Yes i cooked it but have never cooked one since. There are many lessons to be learnt before you go that route.

Do your homework.

[Rusti]

Oh ok.. Thats starting to make sense.. If I'm understanding correctly it's the enhanced compression forces that the motor was not designed to take?

I read 2 articles about turbos online yesterday morning. They were very factual about how a turbo and intercooler works but they didn't mention a thing about the motor being over stressed.

Thanks guys. Think I'll give this option a miss.

[Stef]

I believe that a turbo would ruin your off-road experience anyway; if you're only using the vehicle as a runner/workhorse or to tow with, maybe fit one

[Die$eL]

Adding a Turbo does not only add more air into the motor. It adds a bucket load of heat. Into the engine itself and into the engine bay. Meaning things like plastic electrical connectors etc eventually get brittle and break as they were not meant for That much heat. (vehicle dependent)

More air means more fuel, meaning bigger injectors required. Depending on the vehicle, it may mean changing fuel tank, pump + fuel lines

People make it out to seem that adding a turbo is simple. In ways, yes it is, but there is ALOT required to add a turbo and have it run reliably for extended periods of time and distance.

[Knuppel]

@ Diesel, have you had turbo experience?

[Rusti]

This is the article I read. It seems very informative.. I'd like to learn more about mechanics so I'm glad to find websites like this that make it easy for newbys like me..

Would the intercooler not take care of all the additional heat? I'm just asking out of interest..

http://www.enginebasics.com/Advanced%20 ... ction.html" onclick="window.open(this.href);return false;

[Knuppel]

Intercooler takes care of the heat generated by the turbo on the intake side. Compressing air generates heat and then also makes the air less dense.
By then cooling it down through the intercooler the air becomes more dense which equals more air into the combustion chamber which equal more bang with the correct amount of fuel mixture.

So yes it has an effect on the heat going into the engine and will decrease the EGT to some extent. But ultimately the the amount of heat is determined by the Air fuel mixture. To much fuel (Rich Mixture) will generate high EGT's

My comments are based on a turbo diesel engine!

[ChrisF]

This is the article I read. It seems very informative.. I'd like to learn more about mechanics so I'm glad to find websites like this that make it easy for newbys like me..

Would the intercooler not take care of all the additional heat? I'm just asking out of interest..

http://www.enginebasics.com/Advanced%20 ... ction.html" onclick="window.open(this.href);return false;

To add to what Knuppel already said.


standard non-turbo diesel - slow steady and low heat engine

add a turbo - you now add a fair amount of power and a LOT of heat ! The high air temperatures after the turbo limits the air-fuel ratio (density as Knuppel explained), thus the engine is still not producing max power.

add a turbo AND an intercooler - now you force more air into the engine, at a nice cool temperature. Thus the quantity of diesel can be increased for optimum combustion and maximum power. At this high power setting the engine do generate a lot of heat. It has been mentioned earlier in this thread that this requires more heat to be removed via the radiator, and more heat removed from the engine bay - all this for extended use at the max power conditions.



moving away from "heat" for a moment, consider the "engine load/strain".

The formula for engine power is : P= 2 x pi x n x T. Where "n" is the engine speed, and "T" is the engine torque. The engine speed before and after the turbo is the same, thus the torque was increased to provide more power (when talking about more power at a specific speed, ie more power for passing).

To take the maths another step further. The engine torque is : T = Force on the bearing surfaces x Radius.
Again, the radia of the various components did not change, but the torque was increased, thus the forces on the bearing surfaces was increased. In a good engine, with good oil pressure, and quality oil the increased loads may just be okay .... but in an older motor, slight drop in oil feed to some bearings, and the increased forces WILL cause catastrophic failure .....

and of course, modern engines make use of modern materials which are supposed to stand up better to the higher forces of increased engine power (increased forces on load bearing surfaces).



understanding the principles it should be possible to add a turbo to almost any engine. BUT, for each engine one would need to understand the limitations of the heat flow, and the limitations of the various load bearing surfaces .... In some instances it is okay to fit a "mild" turbo and to run it at low boost, in extreme cases a minor rebuild may be needed to fit proper bearings and ensure proper oil flow ....

And it is the combination of all these factors that lead to the general concensus of which motors are "turbo friendly", and which are not. Not that it is impossible, in some instances it just takes too much effort ...

[Scott]

As Chris said a low boost can be fitted to most diesel motors also known as a compensator.Toyota with all its resources attempted to turbo 3Liter motor(5L) with a very bad outcome.I found this strange as the KZTE motor was available to them.

[Rusti]

Chris, thanks for the in depth information. It was a good read and explains everything involved!

Scott, I'm surprised Toyota didn't get it right. I suppose it just confirms the complexities of a turbo.

[Knuppel]

Rusti,
Toyota did it it right on many occasions but all motor manufacturers have a few embarrassments.

IMHO the KZTE was their biggest embarrassment!

[Die$eL]

@ Diesel, have you had turbo experience?

Yip. I have an aftermarket turbo on my MR2

[Tenk]

n Turbo werk baie goed op n toyota, gebruik net n 1jz of 2jzgte

[Knuppel]

Die$el, but a MR2 is Petrol yes!?

Sliiiiiiiightly different ball game compared to a diesel! was wondering why you needed injectors, fuel pumps etc

[Scott]

Marius I tend to agree that the 2.4D was the best motor to date the Isuzu kb300 has alot better reputation and would be my choice of motor and I believe that Isuzu and Toyota are doing joint development on diesel.

[Knuppel]

Agree 100%. The bottom end of a Kzte motor is capable to do a million k's but the top end aint good for nothing.

I loved those 2.4's, magic motors.

[Jaws]

Rusti,
Toyota did it it right on many occasions but all motor manufacturers have a few embarrassments.

IMHO the KZTE was their biggest embarrassment!

The 3l D4d is basically a Kzte with newly designed head . Unchipped they are very reliable , chipped by a backyard mechanic they tend to destroy the pistons

[Big D]

Intercooler takes care of the heat generated by the turbo on the intake side. Compressing air generates heat and then also makes the air less dense.
By then cooling it down through the intercooler the air becomes more dense which equals more air into the combustion chamber which equal more bang with the correct amount of fuel mixture.

So yes it has an effect on the heat going into the engine and will decrease the EGT to some extent. But ultimately the the amount of heat is determined by the Air fuel mixture. To much fuel (Rich Mixture) will generate high EGT's

My comments are based on a turbo diesel engine!

Even with the Air / Fuel ratio correct, you are adding in more air and fuel to burn. More air and more fuel generates more Temperature. That is why the more cc the engine is, the bigger the radiator, even if all of them run the same air / fuel ratio.

[Knuppel]

Yes, 100% correct. And that is why you make sure your cooling system is in perfect working order to handle the extra heat generated. Most important how ever is regulating EGT when fitting a turbo. Incorrect fuel mixture is the number one cause of engine failure on aftermarket turbo fitments and not the size of the radiator. Incorrect fuel mixture no matter the size of the engine or radiator or the presence of a turbo will let it over heat. The only problem a turbo ads is that the mixture is so much more sensitive to being right. and that is why you need to measure it to make sure it does not get out of hand. Keep the the egt under controll and then it will not overheat.

[Thabogrobler]

Ja, them unreliable 400 000km plus Kz's.....what a dark hour!!!

[ChrisF]

Ja, them unreliable 400 000km plus Kz's.....what a dark hour!!!

just a pity about the heads .....

Neighbour's Prado had the head done at about 175 000km ..... just more than a year later and all the symptoms are back again .... dont want to say more at this stage, as he will be talking to the garage, and the garage is well known to us on the forum and has an excellent reputation. So let's first see how this one plays out.

[Knuppel]

I have two kzte's. Standing 25m away from me. One 646 000km, the other 689 000km!!!!!!!

Very reliable indeed!

Barring the 8 cylinder heads they consumed between the two of them. Very dark hour indeed.
My criticism is based on more than 100 vehicles and not the 5 lucky ones that did not have a cyl head problem.

One beer does not make a party

[ChrisF]

Marius maar gelukkig kos die KZTE se head minder as die injectors op die D-4D .....

[Knuppel]

Dis BAIE waar daai Chris

[Thabogrobler]

Ja, so unreliable...one head on 400 000km...