Economy 12h-t (1 Viewer)

[GooSe77]

I have a 12h-t running im my J75 series and need new injectors soon. In the old days we had a god of diesel tuner here in Germany and he used to tune old truck diesels. On thing he did was to change the injectors to smaller and more holes for a better "burn". Has anyone ever tried to do this to a 12h-t or 1hdt? I know you get bigger ones wit +50% more fuel....
What else can be done?

 

[GTSSportCoupe]

I have a 12h-t running im my J75 series and need new injectors soon. In the old days we had a god of diesel tuner here in Germany and he used to tune old truck diesels. On thing he did was to change the injectors to smaller and more holes for a better "burn". Has anyone ever tried to do this to a 12h-t or 1hdt? I know you get bigger ones wit +50% more fuel....
What else can be done?

12HT is one of Toyota's most efficient diesels in OEM form. If it were me, I'd replace with OEM injectors. HJ61 owners in our club here regularly get 10l/100km from the 12HT.

But I suppose better atomisation of the diesel could lean to a better burn, but at the cost of some power loss? Also, what impact would this have on the injection pump?

Intercooling and running a more efficient turbo at a bit higher boost (more and colder air) would lead to a more efficient burn also.... This increased economy of my diesel by about 2l/100km.

 

[GooSe77]

I'm running a max of 1 bar boost and my EGTs hit 700°C pre turbo under load, up a hill, peel to the floor
My fuel economy is between 12,5 to 14,5L/100km .... basically that's OK considering the 3,2-3,5t weight and that roof, but less would be better.
With those 4,56 gears I move along quit well here in Germany.

I did try 3.7 diffs, didn't move that god and economy was the same, witch I don't understand.

So Intercooler and more Boost ( how much ) really saved you 2 liters ? That would be insane!

 

[GTSSportCoupe]

I'm running a max of 1 bar boost and my EGTs hit 700°C pre turbo under load, up a hill, peel to the floor
My fuel economy is between 12,5 to 14,5L/100km .... basically that's OK considering the 3,2-3,5t weight and that roof, but less would be better.
With those 4,56 gears I move along quit well here in Germany.

I did try 3.7 diffs, didn't move that god and economy was the same, witch I don't understand.

So Intercooler and more Boost ( how much ) really saved you 2 liters ? That would be insane!

Mine is the 2LTE which is poorly tuned by Toyota from stock. So it was easy to improve. I run 17-19psi maximum (intercooled measured at intake manifold). My pre-turbo EGT's never exceed 500C. This means I have plenty of air available for the fuel to burn efficiently. Basically I've found the motor is more efficient with a leaner AFR (more air with no increase in fuel). Now IDI might be different in this respect to DI.

 

[cruiserpilot]

In my opinion gearing and economy get effected by weight more than realized. I went from
3.73 to 4.11 when I added heavy bumpers and roof tent and all the add-ons. The tall 3.73 gears
really only benefit long haul open road driving, otherwise they are detrimental.
I upgraded my boost to 20 psi / 1.38 Bar and installed a large intercooler. You can see what I
did in the build thread on my signature line.
I would recommend pulling and just rebuilding your injectors with factory spec nozzles. Get the
injection pump timed, compression check the engine before and after you rebuild the injectors.
Make sure the head gasket is good, if it’s old and original with high miles you could set yourself
up for potential future problems of extra boost.
There is a fairly comprehensive procedure for getting the fuel adjustments on the injection pump
for boost compensation and full throttle in factory service repair manual.
Under RESOURCES here on the forum you can download the manual I posted for free.
There is a really good company in Germany who do a remarkable job building turbos for the
12HT. I personally went with GTurbo out of Australia, who I highly recommend.

 

[GooSe77]

There is a really good company in Germany who do a remarkable job building turbos for the
12HT.

Can you tell me who that is? Although I'm thinking of ditching the ct26 and using a Borg Warner or Garret - something more modern

 

[cruiserpilot]

The name WINK comes to mind. I got the name through one of the other threads
in the diesel section forum.
Found this. Really interesting. Turbocharger product series

 

[GooSe77]

Wink4x4 - I know them, bur there in the Neatherlands. That confused me a bit

 

[Greek Cruiserhead]

Mensch! Gleich um die Ecke!
Just around the corner!

======
1984 BJ42, frame-off restored, factory 5spd tranny, 4E9 Toyo beige
1983 BJ45 P/Up, factory P/S, resto project