Discovery 2 td5 Tuning

[Loeksteyn]

Time for Tuning on my td5

Discovery 2 td5 2000 auto 10P
My DIY passion:

Tune my cars as cheaply as possible with the knowledge I have, I have no serious passion or connection to my cars like many people do. my life is my family and my car is my hobby. so to start off:

TD5 common problems I experienced:
Leaking sunroof - marine Silicone in front end rear and unplugged the relay, fixed for my use.

For the 3 amigos and all diagnostics I bought a diagnostics interface tool from Britt part called Lynx, now its in my ability to program some special features on the ECM, security, gearbox, abs...etc.. easy now to pinpoint a fault, fix, clear code and reduce the struggle to go by feel.

Loosing drive suddenly - In my case the flex plate connecting the torque converter to the flywheel broke off an I lost drive on the highway, this is a 5 hr. fix with me and a helper. we removed the driveshafts, exhaust pipes, transfer case and so on. this is now replaced with heavy duty flex plate I ordered from paddockspared in UK.

Lost first gear drive in town! - This is after the flex plate was fixed, this led me to overhauling my auto box ZF4hp22, opened up and first gear is fried and black, also shiny metallic ATF, big enough job to remove the gearbox so overhaling wile its removed is wise. I did the overhaul in 3 hrs. after the box was removed it’s a very pleasant job, all gears are tight and not worn out after 19 years of labor that gave me the feeling that the gearbox can give me many years of driving.

My tunes, overhauls :
I soldered in place a removable remapped eprom in a spare ecu i had, see thread: «MSB chip swap myself»
This turned out to give very positive results!

PSI tuning chip remote activated
Straight through pipe, or more precise: center box removed
DIY boost box or more precise Zener diode (4.7 v 1/2w ) and 120 ohm resistor ( see picture ) or (1/2w zener 4.7 v) and 47 ohm resistor connected reverse biased on pressure signal input and ground feed for the MAP sensor, now no over boost is registered by the ECU, turbo waste gate actuator adjusted to 4 threads.
AIT sensor feedback signal 3k ohm resistor in series with signal input to ECM. Air intake temp is registered ca 30% less than actual temp. (ecu fooled to think a have an upgraded intercooler )
EGR Removed and destroyed
Converted air to HD +40mm coil springs for load purposes.
HD Steering rods
All bushes, coil springs, shock absorbers, brake discs, brake calipers replaced.
Steel winch bulbar from Britt part, without winch though.
All lightning replaced with Led lights.
reverse light mounted dead center in the rear bumper - a hole saw and battery drill made itself useful. I don’t use cables to connect to the control switches of my lights , I utilize a remote controlled relay, and I connect a switch button of my choice to the pc board on the remote and tape it up so its hidden in the switch panel by the steering wheel.

2 x xenon 100 w ralley spot lights
6 x led flood lights on roof rack
1x osram 50 inch 5D 700w ledbar


Tuning yet to be done:
AIT Hack : Done
Map Hack: Done
Diy reflashed Eprom replacement

Extras work comming:
Instruments, exhaust manifold skim and cut out webbs, manifold studs upgrade.

Install the CDL leaver- I considered using an electric or pneumatic actuator DIY but its easier to save up some cash than it is to hassle under the car for hours. if the need arises I always have a 10 mm wrench in my car to flip the leaver over from underneath the car and then disconnect it again after. I got fed up for the setup and installed a diy CDL leaver not long ago see thread: “ CDL leaver alternative “

Transfer case overhauled myself because of copper glitter in the oil so i knew the copper rings on the planetary gears is fried. Overhauled with original parts and replaced the stock cross pin with HD cross pin.
Auto box overhauled myself with original parts.

Starts first time every time cold or hot, and reacting on my heavy right foot without complaining.


I will start new threads on some of the toppicks above and a have lots more info if someone is interested!

[Hagu13]

Where's your instrumentation?

You should be running an EGT gauge as a minimum with your extra boost and fueling, especially on a 10P

[Loeksteyn]

Where's your instrumentation?

You should be running an EGT gauge as a minimum with your extra boost and fueling, especially on a 10P

Sure this is true! The instruments will be installed as a new year project. By hacking the boost feuling map via MAP and AAP with the diode i can only limmit the signal feedback to 4.7v and thus having a fixed value for anything beyond that, whereas a remap it can be tuned by a curve giving fuel economy and best performance for the duty requested by the driver.

[Loeksteyn]

Main thread post updated according to input from various members.

[Loeksteyn]

Added some more info for reference

[ReynierSnyman]

Thanks for the post. Bought a Zener diode and some resistors. Found that a 60 Ohm resistor keeps the “graph” closer to the norm and just evens out on 4.46V when 5V is supplied thus preventing “limp mode”
I’m trying to find the Bosch 4 pin plugs seperately that goes into the MAP itself (in male and female) in order to keep the standard wiring “as-is” and just plug in the loom with the voltage limiter but the connectors seem to be unoptainable.... might have to buy different plugs though.