ECU chip for the 300 TDi EDC controlled Discoverys

Mudron said:

Chip will be here soon. Then pics. I am expecting to see 135bhp without reseting boost pressure, 145 with boost pressure, and 145-150bhp with a large intercooler.

This is just guesstimating at the mo based on similar engines etc, I will run a few dyno tests soon.

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Let us know how is that going on the chip.

I have the Tunit box, got it under a considerable discount. I don't know what it does to the performance, but I think it over-fuels the engine. Once I turn the screw to maximum position the car starts to smoke like a beast. Otherwise I am very happy with the Tunit, it gave the car a lot more torque and hp. I have Allisport intercooler too (not the full with, only the deep replacement).

Maybe I will try to ask Tunit to send me the performance curve of the TDI with their ship, so we can compare with your mods later.

Mogindo said:

Thanks man, I will try to move it higher somewhere, because now it sits very low in the footwell. I think a surgical glove and vaseline could do the magic on waterproofing the box and the connector If I was to move it higher, I would have to extend the entire loom of cables and that would be a major job, but maybe it would be sufficient enough to move it just under the dash somewhere and seal it.

I am not planing on going submarine, but as you saw in the video clip @ 5:05 min there is a chance we will get wet. Maybe also new door seals are in order, mine are almost falling off.

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I've just checked the price for TD5 ECU cable extensions - £400


Glove and Vaseline it is then

I can explain the tuning and similar boxes very easily.

These boxes all work the same, the basic principle is the EVRY mod used to fool the pump into supplying more fuel by either (depending how its wired up) telling the ecu the fuel is cold (more pumping force needed) or that the fuel supply collar isn't far enough forward.
This is done by grounding the required wires over a set resistance, typically an adjustable resister pot and a switch to arm and disarm it.

These digital tuning boxes basically use the map or maf sensor to start the grounding process gradually and at a set boost/rpm/maf point, so the transition is smooth and tends not to trigger the CEL light. This gives smooth power curves, slightly better mpg and more toque.


The one major downside is that they will always be just a device to fool the ECU, nothing more, they don't alter maps. A refined ecu map will give better mpg because the tuner will smooth out all the flat spots and improve on not just the amount of fuel injected, but also, crucially, when it is injected in the cycle. They also improve cold start (better egr control on cars that use egr for closed loop faster engine warm up) and initial boost response if brought in sooner.

The tuning box torque/bhp curve will closely match the factory one, all be it higher up the graph and starting slightly sooner.

I prefer remapping/chips, fooling the ecu is safe if done carefully, but it will never be as good.

Also, as a final point, the injectors on 300 tdi's, have 2 stage injection.
This means a small pilot jet to 'warm up' the cylinder, and a main jet for the power stroke. As the injectors wear, the initial pilot spray becomes less effective, hence why older worn injectors make an engine louder and less powerful than new injectors and nozzles set up properly. The point of he pilot injection is to make better fuel economy and quieten the direct injection engine down.

Mudron said:

I can explain the tuning and similar boxes very easily.

These boxes all work the same, the basic principle is the EVRY mod used to fool the pump into supplying more fuel by either (depending how its wired up) telling the ecu the fuel is cold (more pumping force needed) or that the fuel supply collar isn't far enough forward.
This is done by grounding the required wires over a set resistance, typically an adjustable resister pot and a switch to arm and disarm it.

These digital tuning boxes basically use the map or maf sensor to start the grounding process gradually and at a set boost/rpm/maf point, so the transition is smooth and tends not to trigger the CEL light. This gives smooth power curves, slightly better mpg and more toque.

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Yeah, I also prefer the remap, the box works fine, but i was never easy with fooling the ECU, plus it really seems that it increased the smoke.

Until I found this forum (and You) I could find anyone that would do it. I live in Asia, and that sometimes makes things more complicated. So please once you figure it out, let us know

Interesting you mentioned CEL light, my comes on between 1,200 and 1,700 rpm outside of that range its fine, no light. I have not had a chance to resent the fault code in the ECU as the only diagnostic I had was Ultragauge, and it didn't work at all in my car.

Thanks for the effort mate.

thebiglad said:

I've just checked the price for TD5 ECU cable extensions - £400


Glove and Vaseline it is then

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Top gear used vaseline and condoms once lol

shenton24 said:

Top gear used vaseline and condoms once lol

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Yeah, that was in the Bolivia Special It worked for Clarkson in RR Clasic

Hey Mudron,

How is the chip development going? Any progress?

Cheers,

Any progress on this?

I have a Tunit chip for sale for this model at CONSIDERABLE discount if anyone interested. New (Old) stock, never been used. My company used to supply them.
If interested contact me