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Discussion Starter · #1 ·
Evening Gents,

I had a long and interesting Range Rover related conversation on the phone with Mark Adams of Tornado Systems a couple of weeks ago and then again today.

We currently have two Range Rover P38's with 4.6 GEMS setups in them. Both are running single point LPG and both are now running Mark's Tornado Chips on the engine management system. We compared the cars before and after we fitted the chips on Petrol and LPG and there was a noticeable improvement in the way they ran on LPG.

When I was talking to Mark he mentioned that he was working on chips for the gearbox ECU.

The chips that Mark is working on will allow the gearbox to lock up much earlier then it does at present thus making a significant difference in the economy of the car. According to Mark the difference in economy of the vehicle in lockup and non lockup conditions is 6mpg.

When I leave home at the moment, I'm onto the motorway within 3 minutes of cold starting. It takes around 10 miles of motorway driving at 60 - 70mph before my gearbox will lockup in top gear.

This will be a significant improvement for me as a lot of the journeys I tend to do of a weekend are around 15 miles each way where the car gets a chance to cool down in between both legs of the journey. This chip could potentially save me 2 gallons of fuel over a weekend without even trying.

I am in no way connected to Mark Adams or Tornado Systems through any other means then as a satisfied customer :)

Mark's technical advice over the phone and email is also fantastic, all in all a really helpful bloke who knows his stuff and runs his own P38.

On a side note, Mark is also able to chip the 3.0 TD6 L322's to add an additional 90bhp.

Once I receive more information from Mark regarding this I will update this thread. If anyone has any questions they want answers to, post them here as I'm going to keep in touch with Mark regarding these.

Regards

David.
 

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1995-2002 Range Rover P38A
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I'm surprised that yours does not lock up almost immediately.

I drive very economically, and I can feel mine locking up immediately if I drive lightly ....... I assume that the ecu has learned my driving style?
 

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1995-2002 Range Rover P38A
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I'm surprised that yours does not lock up almost immediately.

I drive very economically, and I can feel mine locking up immediately if I drive lightly ....... I assume that the ecu has learned my driving style?
I would say that there is significant difference on temperature between UK - Dubai... :) I have to drive several km:s before lock up happens at winter. Funny, but it happens at exact same position every time i leave my working place. Steep uphill. Only in coldest temperatures, -20c or below, it takes longer to lock up.
 

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I'm as surprised as Spiggy as although there are various lock up maps it does state (in both GEMS & Bosch ETM's)

"Torque Converter Lock–Up Solenoid – pin 42:The torque converter slips to allow smooth operation
of the gearbox. Lock–Up occurs when the vehicle
reaches a speed of 45MPH or above in either third
or fourth gears."

And this is the same for most torque converters because by 40 mph approx. the input impeller speed and output turbine speed have almost converged.
 

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1970-1995 Range Rover Classic
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It probably waits with lockup when cold because it's better for the gearbox to actually heat the oil up to operating temperature. Spinning the TC heats the oil, lockup doesn't as much.
 

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As Ben said, the gearbox needs to heat up to achieve optimal performance. Just like you need to take it a bit easy on a manual box while it's still cold. So locking up too soon would surely increase wear and tear.
I do experience the difference on cold days, especially if i leave the car outside during a freezing night. Not ideal if, like me, you get on the motorway almost immediately. But it does serve as a good reminder to take it easy on the car as a whole while all the oils are warming up (my other car has an oil temperature gauge, very usefull!).
The V8s auto I have driven, both GEMS and Bosch, locked up pretty much when I wanted them to. Not so on the DSE however. I assume it has a different map for lock-up in a desperate attempt to muster enough torque to offer good driveability.
Also, I do not believe you can gain 6mpgs, not by far! Under normal operation (i.e. not under hard acceleration) the slip is about 10%, so you could save 10% of fuel. There is no fixed speed at which input and output will converge, it all depends on the load and power applied and on the viscosity (and thus temperature) of the oil inside.

@Fleter, lockup is when the torque converter in an automatic gearbox engages its mechanical clutch, so it no longer allows any slip between the input (engine) and output (gearbox).
 

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Discussion Starter · #8 ·
The reason why it does not lock up into top gear when cold is that it is intended to heat up the catalysts, not the gearbox. In P38, there is no gearbox temperature sensor input to the process, although this is found in some other applications. Here is an excerpt from the official ZF Training manual:

“In order to limit pollutant emissions when the engine is warning up, the catalytic converter must quickly reach its operating temperature. To do this, the engine must rotate at relatively high engine speeds for a certain amount of time after starting. The solution consists of using a specific set of gear changing laws during this operating phase.”

In the P38, the decision about revving the engine harder by not permitting it to lock up is influenced by both ambient and coolant temperatures. Note that the rules are quite different for 4.0 and 4.6 engines, high and low compression versions, Discovery or P38, petrol and diesel engines, and GEMS or Motronic engine management.

Mark told me that his P38 is Motronic which receives information via CAN bus from the Motronic ECM. GEMS uses discrete signals, and is a little less stringent in applying the rules. Apparently his P38 locks up very quickly in summer, however in the winter when the ambient is around freezing, it can take around five miles and must be fully up to working temperature before it will lock up.

My brother in law has a Discovery TD5 and when it's cold he can wait 8-9 Miles for lock up.

Mark also told me if you monitor the instantaneous consumption at 50 MPH via the OBD-II data stream (not the on-board computer), it is perfectly clear that it just drops by 6 MPG when the converter locks up. Apparently he has run the test in other vehicles too, and the difference is the same.

As I said, I thought I'd mention what Mark was working on as I've had good experiences of the chips he does for LPG on our P38's.

I just wish he could magic a chip up that would make our Freelander V6 drink a little less like a fish!

David.
 

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This lock-up is all new info to myself (not ashamed to say it!). How do you know when lock-up occurs and can their ever be a fault where lock-up couldn't occur? I've noticed several times that when I'm on the motorway doing 70ish the MPG will start low (17mpg). After maybe 10-15 miles the MPG starts to go steadily up until it maybe gets to 21-22mpg. Could this be down to lock-up coming in late for some reason?
 

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I have been looking for someone to alter the gear change points in my Bosch (diesel) gearbox ECU.

I have chipped the engine and it is putting out quite a bit more power. Torque is on a par with the 4.0L.

I have just recently fitted a HP24 gearbox along with an uprated diesel torque converter from Ashcroft Transmissions.

The new torque converter has less slip and locks up earlier. On a gentle throttle it now locks up at 45 to 50 mph. The old converter locked up at 50 to 55 mph.
 

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You'll notice a slight RPM drop (~100-200 rpm probably) when it goes into lockup, vs the ~1000rpm drop when shifting.

As for when it wouldn't occur, not sure about that, probably when it feels like it...
 

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I didn't (still don't) really understand a lot of what has been said here, so just to be sure i when out with a multimeter on the MV3 (lock up solenoid) and it locked up bang on 45mph, after just 2.2 miles approx. which was about 4 mins driving from cold.

As soon as the coolant was up to temperature (gauge in normal half way position) and transitioning passed 45mph the solenoid was grounded and after about 2-3 seconds of PWM, it had full battery voltage going through it, 13.7 volts. I'm sure if it was hard acceleration this would be slightly different (just delayed) but this was driving to the prevailing road conditions.
 

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Discussion Starter · #15 ·
Larry, off topic... On you're video it looks like you've got the later dials on your dashboard rather then the early P38 ones.

Did you swap them? If so, were there any issues doing so?

David.
 

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No, not really. Although the cluster apparently had less miles than mine i didn't want to risk it (without seeing it first hand) and so just swapped the gauges themselves over, so it's later gauges in the original cluster.

I have the later clock and switches but as you can see not got round to it yet, the blue wire is a LAN cable going to the fuel usage wire (on the cluster) and i have a instantaneous fuel reading, not in mpg as i don't have speed into it yet, but it gives milliLiters per second.
 
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