Thread: What happened to your Discovery 2 today?

Originally Posted by shack

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I'd suggest putting the stock controller back in and see if it has less slip.

Yeah it does. Had to test this before condemning the converter, but reinstalling the TD5 TCU converter was fine.
So as you say, the TCU obviously adjusts trans line pressures to suit V8 converter which doesn't work well for the std TD5 converter.

For now it's fine to leave as is. Had it this way for a for few years now, and I drive accordingly. That is, if I need more power/torque/speed at the 80k/h problem speed, I slip into 3rd and use it this way where there's no slip.
Where I live, it's pretty much flat roads as far as the eye can see and beyond that, so no real load on the D2 to cause problems.

V8 converter kit is in the near future plans for the D2 anyhow.

What I'm not sure about tho ... the D2a is all std.
The earlier TCU(D2 rather than D2a) has helped with locking up earlier in the coolant temp range, than the std one. The other issue with the D2a TCU is that it won't hold lockup in 4th at (say) high 70s k/h speeds. Soon as it dips below 80k/h it unlocks. D2 TCU helps with that. But the frustrating part is the cold to running temp operation where it's no locking(until operating temp) .. usually about 75°C.
The V8 TCU does away with all of that. Except for really cold ambients V8 TCU locks up in 4th at 60k/h.
It may seem petty, and it actually is, but sitting on a flat featureless hwy, minimal to no load on the engine/trans, and D2a just screaming its head off for 10-15 kms ... and wasting fuel for no gain ... Ahhhhh!

Does the V8 converter help in that situation? Does the TD5 TCU still command the V8 converter to stay unlocked until operating temp?

Once the D2a std setup is up to operating temp, I don't really have any negative comments re the converter and lockups performance(out here). Yeah, if boot is really heavy it unlocks/dowshifts, etc .. but you expect that.

Originally Posted by Kaaaiju

Yes they drive good even on a vnt as I have tried serval of them but the auto dies shortly after with any sort of decent power and now moving onto zf8hp with my td5 making 260bhp and 600nm

Correct.

Part of the reason for that is that the stock engine tune is simply not calibrated for making that power, and the TCU is also not calibrated for that power, they talk to each other to sort out shift times, shift pressure, line pressure, converter pressure when locked, upshift detorque , downshift detorque...etc etc etc.

These are all wrong as soon as you edit the engine tune for more power, a number of other settings also need to be changed which no one does, I know why, it's taken 1000s of hrs of dev time to get MOST of it sorted. It's a real time sink.

So both of the controllers are clamped for much lower output which causes numerous problems.

The 4hp22 is also not the most robust, however I've been running similar power to your tune and the box is still fine.

Originally Posted by AK83

It may seem petty, and it actually is, but sitting on a flat featureless hwy, minimal to no load on the engine/trans, and D2a just screaming its head off for 10-15 kms ... and wasting fuel for no gain ... Ahhhhh!

Does the V8 converter help in that situation? Does the TD5 TCU still command the V8 converter to stay unlocked until operating temp?

I think you will be surprised how little fuel you will save by lockup at lower roadspeed, I was.

However it is a much nicer drive with lower RPM.

As far as the lockup goes when cold, all TCU's have a software timer in them based on ECT on engine start, the autobox itself doesn't have a sensor.

I can't remember the timer settings off the top of my head, but they are similar across all variants, and the figures that LR quote in RAVE are completely wrong.

Actually most of the figures in RAVE for the autobox are wrong for the TD5, and every other variant from around the world I've got.

I have a feeling the settings listed are most likely based on a pre release software variant that I can't get hold of.

Very interesting, mine is a stock D2a (early 2003) I've done nothing except swap convertors (and reco stock auto) I do run 265/70/17's which drops the revs about 10% ( I still need to get a speedo correction) 90% of my driving is pretty flat highway runs to the airport and back (300km each way) it definitely locks up better and within 5 minutes or so it will lock up in 4th. With my old auto it would occasionally fail to kick into 4th, usually after about an hour or so I would stop for a bite to eat, jump back in and on the highway it held 3rd for ages, then into 4th but still wouldn't lock up, didn't happen every time but enough to know I was in need of a replacement.

A zf8hp is on the shopping list once I pick up Powerball ?

Oh, also I didn't drill another hole to hold the bolt, I just used a flat screwdriver on the back of the ratchet spanner to get it to click, very slow going as only get a click or 2 each the me

Cheers

Redd

Che

Originally Posted by shack

I think you will be surprised how little fuel you will save by lockup at lower roadspeed, I was.

However it is a much nicer drive with lower RPM.

As far as the lockup goes when cold, all TCU's have a software timer in them based on ECT on engine start, the autobox itself doesn't have a sensor.

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I have a feeling the settings listed are most likely based on a pre release software variant that I can't get hold of.

Yah, I know ECT for trans lockup point.
I'm not so sure about timer tho.
When I lived in coburg(Mel) I didn't have anywhere I could drive and get to 80k/h before ECT would hit close to operating temp in the D2.
Here in Pyramid tho, all 4 directions I can drive 1 min and I'm in a 100k zone .. so easy to do highway speeds way before at temp.
The lockup point on the D2a now is at 67°C, every time without fail.
Sunday(25/01) was the only time I ever got to lockup(ie. 67°) at about the time I hot the 100k sign, BUT! it was 44°C here and prior to start up ECT was at 43° anyhow. Normally I it's in the high teens at start up, maybe low 20s.

I think use of CC also makes a difference and speed too for when lockup happens. On the road south, I can drive 30km before I have to use brakes/slow down/etc. On one trip, just to see what happens ... I use cruise from the moment i hit that road. Using CC, set speed to about 90-ish(IIRC) and had no lockup all the way for that 30k ~30min leg of the drive. I think because of CC. If it is timed like you say ... it's pretty inconsistent. Its like the TCU gets confused as to what it's supposed to do. Soon as I stop the CC and use the pedal, lockup happens, and from that point lockups event works as normal when CC is used. Its very strange how that works. So my normal routine for this kind of situation is.. I use CC until ECT is at about 67ish switch off CC, use pedal for a few seconds, converter locks up, then hit CC again. Only way to get lockup in 4th ASAP on pretty much any drive out of town.

For fuel consumption, I can confirm that using lockup, even down to 60 in 4th saves quite a bit of fuel at constant speed. I can only do this in the D2, but it's hit and miss about monitoring this at the moment. Reason is, I use the TD5Spy. Problem is, it doesn't work consistently in the D2(no idea why). When I first got them(one for D2, one for D2a) it worked fine in the D2. Works all the time in the D2a, unless I connect to the D2, when it then stops working in the D2a too(using the same device). So the problem child is the D2 for some odd reason. For about a week or two it worked flawless, then out of the blue it disconnected itself(again dunno why) and since then it only connects for about 30mins and won't connect again unless I don't use it for a bit. Overall its a handy device to have, but with the D2 it's frustrating. But it does show fuel consumption in real time. I've tweaked it to get more accuracy(obviously on the D2a) but the D2a has 245/75s, and speedo is out. So it's speedo is out by about 5% .. so have to watch my speed. 76 in an 80 zone kind of monitoring.
The TD5Spy 'system' is also frustrating in that you can get logs of a drive, but they limit the usefulness of it. You can only see the last 5 trips, and you can't download them. Anyhow ... I can explain all this in another thread if needed .. just to explain that when it did/does work on the D2 .. I could see all this info. Tuned D2(EU3) uses less fuel for the same trip than std D2a.

Originally Posted by AK83

Soon as I stop the CC and use the pedal, lockup happens, and from that point lockups event works as normal when CC is used. Its very strange how that works. So my normal routine for this kind of situation is.. I use CC until ECT is at about 67ish switch off CC, use pedal for a few seconds, converter locks up, then hit CC again. Only way to get lockup in 4th ASAP on pretty much any drive out of town.

What revision TCU are you using?

All TCU's have separate CC shift and lockup maps.

They also have different settings on the software timer.

The timer uses ECT at startup to set the length of time in seconds before lockup can occur, so if you start the engine and the ECT is 50°, it will lockup sooner after start than if it were 25°.

The V8 one handles things slightly differently, but I haven't done as much work on them, mainly because of concern that it was running incorrect line pressure that was killing the converter.

Originally Posted by Reddirt204

it definitely locks up better and within 5 minutes or so it will lock up in 4th. With my old auto it would occasionally fail to kick into 4th, usually after about an hour or so I would stop for a bite to eat, jump back in and on the highway it held 3rd for ages, then into 4th but still wouldn't lock up, didn't happen every time but enough to know I was in need of a replacement.

This behaviour was possibly because output shaft speed wasn't high enough to allow the shift to occur for current RPM and throttle amount, basically failing converter as your have mentioned.

Originally Posted by shack

What revision TCU are you using?

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In the D2a I had IGG 000 070. The spare, out of the D2, is IGG 100 010.
I pulled the D2a '070' TCU and replaced with the D2 spare '010' TCU.
Doing that I remember did change lockup due to ECT(on the highway) from low to mid 70s to low to mid 60s.

I remember one other anomaly was that on first drive from cold, the 070 TCU wouldn't let the D2a lockup in 4th until you hit 100k/h. Once the first lock event occurred it would then lockup at 80 as expected tho .. just that first lockup.
Was only ever a problem on first start with an overnight stop period. Never happened if the stop period was during the day.

eg. drive to brothers place to help him do a reno. First thing in the morning this 100k/h lockup issue would happen. pass 100k/h drop back and lockup. Hit the dirt road a bit later and lockup at 80k/h no problem.
Sometimes would be at brothers house 10 hours, regularly 8 hrs ... so D2a had plenty of time to cool down, BUT the 100k/h anomaly wouldn't happen. Theres an 80k/h zone about 1 min from bro's house and for about 5 mins. Lockup at 80 on that road, with CC going ... no problem.
This timer thing is weird as hell. But to me it's like they force you to use the pedal, not CC, until warm or something similar and only after that would you get normal lockup routines.


Going by the photos I have, was Dec '24 .. ie. over 12 months ago.
Also: there is a 50/50 probability that the 100 010 TCU that the D2 had may have been swapped prior to brother, then me owing the D2. Can't tell, but some indications point to this possibility.