td5 performance chip

Yes, I have (and the insurers know about it as well.) Mine's a '99 manual.

I tried the Superchips chip and was pretty impressed. It drove very well. But speaking to Superchips, it seems they're not doing anything particularly clever - they're adjusting the injector pulse length.

I then looked at some torque curves and decided the van Aaken Smartbox would probably be a better bet. I've been running it for about 4 months, so I've had a chance to get used to it. At first I found it was pretty naff, actually, but recently I've had it back to van Aaken and they've fiddled with it, and it's much better. The extra power/torque comes in at about

1800rpm, which is a bit high really, but if you look at everybody else's versions, none of them seem to do much below that, which is a shame.

The van Aaken box has jumper settings so you can tweak it by hand. It has 4 settings (one of which is 0 = "don't change anything"). The first setting, which is what they supplied it on, will make the engine run nice and smoothly but doesn't produce a huge difference in performance. It also made mine run slightly more economically. The second setting, which I'm using now, feels good and doesn't smoke too much, but I've found my economy slightly worse than it was before. The third setting makes it run like a beast, but produces clouds of black smoke and economy in the early 20s, so I've only tried it once.

Again, the Smartbox is only changing the injector pulse length. In theory, a reprogammed TD5 ECU can alter the fuelling, timing & turbo boost pressure. So neither Superchips nor van Aaken are making the most of the tools they have to work with. Autologic/Diagnos have their own modification too, which I've heard is a lot more ambitious than the others in terms of what it changes - although Diagnos haven't been able to confirm to me exactly what they're fiddling with. This looks, on the face of it, to be the one to look at, but I've not tried it. It's a reprogram, rather than a module, so you'll need a flash-upgradeable ECU (about £330 if you don't already have one) to take advantage.

There's also a thing called a Dastek Powerplug (available from Discoparts), which I've not tried, but shows pretty big torque gains on the curves they publicise. And there's Jeremy Fearn, who seems to do the most extreme things to a TD5, but it's up to you how far you want to push the envelope.

I've found the torque / power curves from the different manufacturers are all over the place. In some tests, the modified car isn't as powerful as the unmodified curve in some of the others. I've plotted the curves from all the above in an Excel spreadsheet,

take a look and you'll see what I mean. I've tried to normalise these by plotting the "Delta" performance between each individual company's unmodified vehicle and the modified one, but quite honestly I think these curves are largely rubbish.

For example, van Aaken's curves show an increase in torque starting at

1000rpm, and levelling out at 1750 - looks good on paper, but in reality the box doesn't seem to do *anything at all* before it gets to 1800rpm. Speaking to van Aaken seems to corroborate this. I must ask them why their curve tells me different things than their engineers.

One thing to consider is do you want more power, or torque - for example, Superchips say they produce more power than van Aaken, but van Aaken claim to produce more torque than Superchips. In the Disco you're really looking for torque. But having said this, you'll really struggle to differentiate the torque between the different companies' claimed improvements, because they all use different testing kit and methods. So even if somebody says they're producing bags of torque, don't take their word for it. Best thing is to try them, if you can. Bear in mind your insurer may charge extra for upping the power - mine ups the premium in bands depending on the power difference - but won't even understand the word "torque".

If I were you I'd try the Diagnos upgrade and see what you think. I'd be interested to know what it's like, particularly if you can compare it to the Superchip or one of the others.

Have fun, David

Saw the Unichip is now in the UK

Had 4 Td5's done in Africa and puts it up to 120 kW and 275 Nm torque.

Saw some LR dealers are also supplying them so don't know impact on warrantee.

Sorry ....375 Nm torque ;-)

What does it do to economy & emissions?

With more oomph, my fuel consumption actually got a little better (not nearly enough to claim I recovered it in any way) and on emission ....... I am in Africa where that is a complete and utter unknown issue. Having UK offices I would assume it should comply with local rags.

Can tell you that Pieter de Weerdt, the designer of Unichip and owner of Dastek does a lot of work on the rolling road and my EGT was still below LR max after the conversion. LR SA quotes 750 deg C as max, std was 695 deg C on the day and with chip 706 deg C. I also fitted a larger intercooler that took it down to mid 680's but I tow a lot in heavy sand and ambient temp. is also slightly raised in Africa ;-) I would not bother with the intercooler in the UK unless you intend to go to the Sahara.

I've only had experience of the remapped chip so can't make any comparisons but the remapped chip is well worth looking at. It makes the vehicle a whole lot easier to drive and far more responsive. It even made me think about changing the V8 'til SWMBO slapped some sense into me :-) The one I tried was the AutoLogic one. There's some details/ graphs etc... at:

cheers

Dave W.