Thread: Diesel Tuning Chip for Land Rover Discovery 4

Originally Posted by Dougal

It doesn't take much of a remap to get a 600Nm engine past the 650Nm gearbox limit. An EGT gauge throwing a fault isn't "calibration". It's "back off or melt your pistons". Your EGT gauge doesn't give the full and accurate measurement until the manifold and everything has heat-soaked. This is why it hit you after a few runs. A sustained uphill run would do the same thing.

This is talking about the 6 speeder; how about the 8 speed ZF gearbox?

I think it's the same box used in the V8 FFRR that does 700Nm, so should be good for at least that.

Does that mean MY13 onwards is fine with remap?

Originally Posted by phl

This is talking about the 6 speeder; how about the 8 speed ZF gearbox?

I think it's the same box used in the V8 FFRR that does 700Nm, so should be good for at least that.

Does that mean MY13 onwards is fine with remap?

phl, please have a read of Gordon's second to last post.

Just because one bloke says Land Rover drivelines can't handle it (extra power) doesn't mean he is right, especially when he won't back up his assertions.

"I know its not the same but i cant help remembering all the old gismos one could buy to put on cars in days gone. parts that claimed they saved fuel etc. even back in the 1930 and 50's there are adverts in old magazines to buy some gismo that clamps around the fuel line or a coil lead etc and like magic it was meant to make everything work better and save you dollars, or rather pennies in those days.

cheers
chippy"[/QUOTE]

Chippy, this reminds me of the Energy Polariser that was promoted around 1980 by Peter Brock. It drew (from memory) on the blue-coloured excess sexual energy in the atmosphere, and not only improved performance but also handling! The timing seemed odd to me, as it seemed to belong more in the late '60s. It took Brock a while to recover his standing as a serious engineer after this. At the time I thought that it would never happen, but it did.

FYI
I'll throw this bit of info in about the L322 TD6. The auto gearbox in these is a GM 5L40E . Torque rated to 340 Nm. Stock TD6 puts out 390Nm. Have see tuned versions to 560 Nm. So even in stock form the motor out performs the gearbox by a considerable amount.

Just saying

Gary

Originally Posted by 33chinacars

FYI
I'll throw this bit of info in about the L322 TD6. The auto gearbox in these is a GM 5L40E . Torque rated to 340 Nm. Stock TD6 puts out 390Nm. Have see tuned versions to 560 Nm. So even in stock form the motor out performs the gearbox by a considerable amount.

Just saying

Gary

Well thankfully we don't own L322 RR's.

Originally Posted by gghaggis

Well firstly, your initial HP28 link points to an HP26 document. Secondly your Z spec sheet is for the "standard" product - many manufacturers upgrade their boxes for their application, and the max available to a car-maker would be the max for the 6HP range, which is 850NM. Both LR and Ford state that their versions of the ZF HP28 are "upgrades based on the standard model". Neither quote a maximum permissible torque figure, but I sincerely doubt that LR would put a 650NM max box in a 600NM car, as it's far too close to the upper statistical value you'd expect. The figure of 720NM has been bandied about by quite reputable tuners in the UK who work on race/rally tuning, so would presumably have a better idea than you or me on this upper figure.

Thanks for letting me know about the link, I've fixed it and it's here too: http://www.zf.com/media/media/produc..._DataSheet.pdf
This is an official ZF document showing the 6HP28 only goes to 650Nm in it's best form.
I'll take official information over people bandying about figures on the internet every time.

It is the 6HP32 (not used by landrover) which is rated to 750Nm. Not 850Nm. Again, these are ZF's official figures. Not mine.

Originally Posted by gghaggis

I agree to some extent that towing with a chip box needs the driver to be aware of the situation, but I don't agree that the transmission strength is the issue - I would have thought that the stress on the box of 600NM in low-range would far exceed the stresses of 680NM on the road.

Low range greatly reduces the load on the gearbox due to the gear reduction.
The highest loads on gearboxes are found in higher gears under hard acceleration/towing. This is because the engine has time to fully load up and develop max torque. Not just accelerating through at lower load as they do in lower gears.

Originally Posted by gghaggis

Thirdly, the SDV6 has at least 3 temp sensors in the turbo pathway, at ingress, output and general manifold, probably others. The system tries to maintain the temp at 600degC, although the turbo itself can withstand in excess of 800degC, so it's cutting out at well below the "melt your pistons" level.

Cheers,

Gordon

Those three sensors will all give very different readings. The two on either side of the turbo will be reading about 200C different under load. 600C makes sense for the downstream temp probe but at no time does a turbo diesel try to maintain those temperatures, they will be upper limits.

Where did you find this 600C figure? Have you monitored your own under sustained load?

Originally Posted by phl

This is talking about the 6 speeder; how about the 8 speed ZF gearbox?

I think it's the same box used in the V8 FFRR that does 700Nm, so should be good for at least that.

Does that mean MY13 onwards is fine with remap?

The gearbox should be fine. You've still got all the engine concerns.

For a great example of how bad tuning can kill an engine. Think of the Nissan ZD30.

does the latest LR4 use a diesel particulate filter (DPF)? i was told by the dealer that it is Euro 5 compliant which i understand means they have a DPF?

if not then surely the newer Discovery (not called LR4 now apparently) that can be ordered now i believe, has a DPF ?

if it does then when re-mapping they can remove the DPF (according to the guy at the 4wd show that had the booth for a well known mob that does re-mapping at around $2k).

that might make the car (engine) run 'easier' with better fuel economy and possibly a longer lasting engine, assuming it was done correctly or well?

obviously it doesn't help if the trans or other running gear cant handle the extra output



cheers
chippy