 | Home > Maintenance & Mods (L322) > TD6 Ecotuning gearbox |
 
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| ahebron Member Since: 01 Jan 2012 Location: The other Eastbourne Posts: 341  
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To stop us hijacking another thread
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18th Nov 2012 9:17pm |
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| kingpleb Member Since: 07 Jun 2011 Location: Maybe here. Maybe there, I get everywhere! Posts: 8455  
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Ahhh so its not a unit sent to you and a unit sent back jobby??
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18th Nov 2012 11:32pm |
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| ahebron Member Since: 01 Jan 2012 Location: The other Eastbourne Posts: 341
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It may be because I live in NZ it is easier for them to send me a complete unit. Otherwise my car would be out of action for too long. If you are UK based then I assume it would be send them yours and they modify it and send it back.
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19th Nov 2012 12:08am |
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| Gazellio @ Prestige Cars Member Since: 22 Jan 2010 Location: Chilterns, UK Posts: 11309 
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Would be interesting to hear from somebody with the Mod done already? |
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19th Nov 2012 8:56am |
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| kingpleb Member Since: 07 Jun 2011 Location: Maybe here. Maybe there, I get everywhere! Posts: 8455
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If I get a chance i'll ask if they do an exchange service and when i get paid if i have enough left after xmas stuff and holidays then i'll give it a whirl |
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19th Nov 2012 11:47am |
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| spanner Member Since: 05 Jun 2011 Location: uk Posts: 134 |
I did 130 euro for the mod 150 euro bond on exchange unit orded mine today |
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19th Nov 2012 1:40pm |
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| ahebron Member Since: 01 Jan 2012 Location: The other Eastbourne Posts: 341
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Good man Spanner
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19th Nov 2012 8:19pm |
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| SteveMFr Site Sponsor Member Since: 22 Nov 2009 Location: Strasbourg, France Posts: 1641 |
OK, I had a look through the site today. Some very interesting stuff - and possibly a good idea or two as well as a substantiation of what we have been saying about these transmissions. I've PM'd RRPhil as resident automatic transmission guru to see if he'd like to chime in here and make a qualified judgment. Here a google translation with mild 'English-tuning' to make it more understandable: Does ECO-tuning harm my gearbox? Absolutely not. I change nothing on the transmission, I only change the already existing (TCC) lock-up point down to about 50 km / h, so, I repeat, does already existing function converter lockup earlier. I make no changes to the transmission shift logic. The switching operations like Fast Kick, kick-down, etc. are still there. In addition, the TCC opens briefly at each gear change and opens fully at Kick Fast and kickdown to use the multiplication effect of the torque converter. Think about it yourself: Standard TCC (lock-up) is at about 100-110km / h where the power is highest, why should then lock-up from about 50km / h damage the gearbox? Quite the contrary: The abrasion in the transmission is reduced, the heat lowered (open torque converter is a source of heat in the gearbox), the speeds and noise levels go back etc. So what he does is change when TCC lock-up occurs (I also discovered that he apparently changes how lock-up occurs - much more quickly with less slip. See last paragraphs in post). I am not sure what to think about this - above all I can imagine that adverse effects on driving characteristics are much greater in the heavy RR than in a relatively light BMW. In general when 'chip-tuning' or 'remapping' is done on an engine, the compromises engineers make during development are shifted: longevity of the engine and or pollution control devices, comfort (engine characteristics), fuel consumption, emissions, etc. are all affected. In some cases, the compromises made during development can all be tweaked with nearly no negative consequences as the motors were delivered in a very conservative 'state of tune' - such as with the M57D (TD6) motor. In other cases, the negative consequences are very real and very noticeable - such as with the TD6 predecessor, the P38 DSE. The M51D motor in these RRs suffered from cracked cyl. heads and emitted noticeable soot on hard acceleration when 'chipped'. My point is, though, that you can not expect only dramatic upsides from something like this. As a TD6 owner, I know how much the heavy RR benefits from the torque multiplication effects of the TC during acceleration. The Eco-Tuning people argue that the TCC locks-up at 100-110kmh "where the power is highest". Without having thought about this in detail before, I would venture to guess that exactly the opposite is true. First, diesels make lots of low-end torque and at 50kmh the TD6 is prob somewhere close to peak-torque (and torque not power puts strain on the TC). Second, in 95+% of all cases acceleration is all but completed at 100kmh and the torque being put through the TC is relatively low (unless you are accelerating on to a motorway and are very ambitioned about reaching speed quickly). This means that the TCC has little torque to overcome upon lock-up and hence slips only a short time. At 50kmh I would guess that this would be the opposite - so that wear on the TCC could actually be increased. I hope RRPhil will chime in here and correct me if I am wrong... And I will be extremely curious to hear what spanner has to say. The one thing that I did discover that I thought was very interesting: many have described one symptom of the transmission failing is a rumbling or vibration. This seems to be 'chatter' of the TCC. He writes: My BMW E39/E46 diesel hums significantly in certain speed ranges, and a drop in engine speed of about 50 rpm can be noted on the tachometer. What is this? It is the effect of the changing frictional resistance of the wearing converter lockup clutch. The engineers who have made the gearox and software have not thought far enough, because the coefficient of friction varies with age, stress, mileage of the oil. All four factors together provide a modified coefficient of friction which causes "chatter" of the clutch. This also includes not clean disengagement and engagement. This process is called "TCC vibration" and creates a pervasive, perceptible signal that the TCC must be replaced soon. It feels as if one crosses the boundary line of the roadway. By the modification of the transmission control unit the use of the converter clutch can be varied and almost arbitrarily defined. I close the clutch firmly and without slippage or slides - there should be no more vibrations previously reminiscent of a gearbox failure. This would seem to indicate that TCC wear would be greatly reduced. This does seem plausible to me - but maybe it is just wishful thinking.  
RRC 2Dr, RRC 4Dr, P38, and 2 L322s (wife thinks I'm nuts - prob right, too) |
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20th Nov 2012 11:03am |
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| Sea Aitch Member Since: 17 Feb 2011 Location: Hertford Posts: 120 
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This all looks very interesting, so I've bitten the bullet and sent the money (280 Euros). This apparently includes 150 Euros for a refundable surcharge on my original ECU. I'll report back on progress (so fingers crossed).
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20th Nov 2012 12:21pm |
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| kingpleb Member Since: 07 Jun 2011 Location: Maybe here. Maybe there, I get everywhere! Posts: 8455
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the problem IME is that at 50kmh-100kmh the TCC and box will slip and sometimes change down without much power being applied, to get the speed up. Ideally if it would lock in 5th just about 30mph the torque would be a good way to pickup speed and save some fuel. instead it would actually be in 4th and has often changed down to 3rd to pickup enough. The TD6 takes VERY gentle ideas towards acceleration upto the legal limit/100kmh.
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20th Nov 2012 12:33pm |
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| ebajema Member Since: 24 Mar 2011 Location: New Plymouth Posts: 4782 
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Does anyone know of a similar service for the ZF gearboxes ??? I wouldn't mind sending my transmission ECU for an update that makes it better |
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20th Nov 2012 3:40pm |
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| RRPhil Member Since: 22 Aug 2011 Location: Blackburn, Lancashire Posts: 1000
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Clearly the car manufacturers know that torque converters are highly inefficient and their use wastes fuel.
Legislation/regulation forces car companies to improve drive cycle fuel economy and emissions year on year and an obvious way of doing this is to lock up the torque converter as soon as possible after launch once its slip and torque multiplication characteristics are no longer required. However, open torque converters are fabulous at isolating driveline torsional vibration, especially at low engine speeds. Applying a lock-up clutch at too low an engine speed can generate NVH issues that are not only unacceptable to the driver and passengers but can also damage the driveline (I have seen crankshafts snapped in half by torsional vibration). The �standard� method to get around this issue is to fit the lock-up clutch with a torsional vibration damper (not unlike the spring centre in a manual gearbox clutch plate). This isn�t a complete solution but it certainly improves the situation. However, when ZF designed the 5HP24 they decided that in order to save space, weight and cost they would not fit a TV damper in the torque converter but, instead, would control the lock-up clutch at low engine speeds by deliberately allowing it to slip i.e. rather than the LUC being either �on� or �off� it had a third �continuous slip� mode. This slipping would provide the necessary vibration isolation. To prevent unacceptable power dissipation in the LUC the slip speed across it is continuously monitored by the ECU and the engagement pressure modulated in proportion to engine torque to maintain a constant slip rate of around 3%. My measurements indicate that the torque converter is never locked solid below vehicle speeds of 56mph in the 4.4 V8. The GM 5L40-E transmission used in the TD6 also has the same three LUC modes of operation. However, GM did fit a torsional vibration damper to their lock-up clutch.
Clearly the straight-six engine will have perfect primary & secondary balance (but the firing impulses from a diesel are greater than for a petrol engine). It may well be the case that, because a TV damper is fitted to its LUC, the TD6 is more tolerant to early �full engagement� of the LUC. We of course know that wear of the LUC friction lining through slip is very common in this transmission and ultimately leads to generation of metallic debris which is often the final nail in the coffin leading to total failure of this transmission when used in the L322. I guess my main concern would be that locking up (i.e. locking solid) the converter at lower engine/vehicle speeds could potentially introduce damaging torsional vibrations in the driveline. However, this risk must be offset against the potential benefit of reducing the LUC wear which we know is a weak point for this transmission. I notice that ZF are currently extolling the virtues of their twin-damper lock-up clutches which allow engagements to be made at even lower engine speeds in the interests of saving fuel : http://www.zf.com/zfXmlServlet?resultUrl=/...#toggleBox Phil Admin note: this post has had its images recovered from a money grabbing photo hosting site and reinstated 
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22nd Nov 2012 10:33pm |
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| barracuda816 Member Since: 11 Jun 2012 Location: oxfordshire Posts: 213 
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RRPhil, I am wandering if you can shine some light on a question i have. On the GM5L40 can you increase the line preassure by a simple mod to the calibration screw on the main pressure valve?
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22nd Nov 2012 10:54pm |
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| RRPhil Member Since: 22 Aug 2011 Location: Blackburn, Lancashire Posts: 1000
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Your red arrow seems to be pointing to the feed limit valve
i.e. the second valve down on the right, between the pressure control solenoid valve and the TCC PWM solenoid valve. Is this the one that you mean? If so, I�m not aware of any screw adjustment. The feed limit valve�s job is to limit the main line pressure to a value that�s acceptable to the solenoids so that they aren�t overloaded. If line pressure is below the limiting value then the valve has no effect. If I�m interpreting your sketch wrongly could you maybe take a photo of the part that you mean? Phil Admin note: this post has had its images recovered from a money grabbing photo hosting site and reinstated
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23rd Nov 2012 1:35am |
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