Best place to install Pyro on LJ78

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R

RHD Toyota's

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Does anyone have an idea as to where to install a pyro on the 2L-TE motor of my Prado.

My understanding is that it is very crucial as where you install this sensor as it can give inacurate readings if it is placed too far or too close to the turbo.

Any ideas?

Also where exactly do you install the mechanical type water temp sensor? Is it important to retain the factory one for the computer?
 
It's easiest to install the pyro post-turbo, in the elbow at the top of the dump pipe, and read the gauge accordingly, because the EG temps will drop a bit between the manifold and the pyro sensor.

There are actually 3 sensors for water temp on the 2L-TE. The one the ECU uses is on the block somewthere. The other two are on the filler neck. The one facing straight forward is for the A/C. The one facing the front LH corner of the engine bay is for the in-dash gauge, so that's the one to use. Your in-dash gauge will be dead, and that's a good thing!

Definitely a good idea to install both EGT and water temp gauges on the 2L-TE.

Just curious: are you importing these units for resale?
 
Resale yes

To answer your question, yes I am importing these for resale, but I allways spend a little time with each unit, to correct or prevent any problems that they may have.

I'll likely complete these mods soon, as well as fix those strange electric hubs.

Cheers,
Ryan
 
I think that the one worth doing is pre-turbo as this is the temperature that you are really concerned about. Post turbo readings are only guesses at best. And water temperature...well, by the time you see a critical reading there it may already be too late for those fragile 2L-T heads. :D

FWIW...I have my thermocouple two inches away from the exhaust turbine of my turbo in my 13B-T. It's basically tapped into the elbow on the turbo side of the flange.
 
Stone said:
FWIW...I have my thermocouple two inches away from the exhaust turbine of my turbo in my 13B-T. It's basically tapped into the elbow on the turbo side of the flange.
Click to expand...
that is the same location where all mine are located on the factory setups,
 
RHD Toyota's said:
My understanding is that it is very crucial as where you install this sensor as it can give inacurate readings if it is placed too far or too close to the turbo.
Click to expand...

The temp reading by itself has little value, it will be affected on each vehicle by the sensor location, timing, turbo and exhaust setup, condition of the injectors and more I can't think of right now. The correlation between peak cylinder temperature and pressure and EGT temp is far from linear. The "lower than 600C and you're good to go, higher than 700 and you're in terrible danger" is BS. On the other hand its a very useful tool for reading how hard you're making the components work.
 
"The manifold is the best place for the pyrometer, because it reads actual temperature of the parts that can be damaged. The elbow will read about 10 degrees cooler per psi of boost, but this is a rule of thumb and temperature spikes in the manifold can be greater than this." Quote from dodge diesel forums.
I have always been told that the pyro should be in the manifold before the turbo from diesel gurus and Gasser racers. Like the quote says you could have a spike in temp that would show up too late if the sensor is after the turbo. Running 15 psi of boost would mean a 150 degree difference in temp. Your 1250 degrees would actually be 1400. Spend the time to pull the turbo and manifold to do it right.
 
I don't know if this will help in your case, but on a 3b manifold there's a perfect spot for one, it's actually the tapped bung that the heat shield bolts on with on the manifold.

I did the manifold flip turbo thing, so of course cant use the heat shield, so I ran a drill bit through the bottom of this hole, and stuck the pyro in there.
 
Putting mine closer to the turbo meant that I didn't have to remove my exhaust manifold to drill and tap the hole for my thermocouple. It may not be quite as accurate as a thermocouple placed in the manifold closer to the cylinders, but it's a lot more accurate than one placed post-turbo...and this criteria suited me for my stock 13B-T which is only under 8psi max boost.

But yeah, if you want to play with your boost and fuel settings and need as much accuracy as you can get, then BJ-44 is right (and the guys at PDR told me the same thing...but they are playing with Cummins diesels putting out more than 1000 lb-ft of torque). :D
 
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