twr7cx

Member
I'm interested to know what methods others are using for the MAF issues that arise when running larger turbos/VNT/VGT or sometimes even the standard turbo with the waste gate adjusted a lot.

One method I have seen but not tried myself, is the MAF bypass hose - I believe for this a secondary output is put from the air filter box to the rocker cover breather connection on the pre-turbo air intake pipe allowing some air to bypass the MAF and enter without having been metered by the MAF. Anyone had issues prior and then success using this method?

Previously Alive Tuning (formerly TD5Alive) offered a modified MAF which worked. I notice that it is not listed on their website and if I recall it wasn't previously either, I think you had to contact them directly. Sadly it was based on the aftermarket MAFs and the quality was horrendous - it started separating in the first week I had it. I also had concerns about the automatic transmission as there are many stories about it acting strange or gear shifts being rough due to aftermarket MAFs which are resolved when the genuine item is installed.

I then replaced this with a genuine MAF and the IRB Developments Two-Channel Turbo Boost Box (two channel as one does the MAP signal as per the other Turbo Boost Boxes available, but the second channel does the MAF signal). This has worked well since fitting and adjusting in early 2013 but recently my D2a TD5 is running crud (check out IRB Developments Td5 Dual/Two Channel Turbo Booster Box adjustable tuning instructio? for error details) and I suspect due to a failed IRB Developments Two-Channel Turbo Boost Box. I have checked the wiring loom, connections and power and earth to it. Sadly due to the black stuff they put all over the circuitry I cannot test or see if there is any issue in there.

So, I'm hesitant to modify the air filter box (but probably shouldn't be as I'm sure a new lid can be easily sourced from a wrecker), have concerns on returning to the Alive Tuning MAF due to the build quality and Ian at IRB Developments is ignoring my e-mails, Facebook Messages (of which Facebook advises he has received) and What'sApp messages so I don't seem to be able to purchase a replacement and am therefore curious if in the six years that have elapsed since I last looked into this there have been any further developments or options arise?

Also found Diablo Demon Tuning which offer their M.A.F. DemonLand Rover TD5 MAF controller performance tuner . I'm not sure that it actually does what I'm trying to achieve though, I think it might do the opposite? They seem to also make their version of a turbo boost box for the MAP sensor called the Boost Demon which is a quiet neatly packaged to sit next to the sensor itself with the original wiring loom plugging straight in - Land Rover TD5 performance Pro Boost controller boost box and fueling adjustment .But there seems to be no purchase options or contact details on there site to discuss further? Strange.
 
I unplugged mine. Left it, running fine past year or so

You dont really need it

I am however very interested in this MAF bypass mod, any pics?
 
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There are some pictures online. Can be found Google search TD5 MAF bypass. I'm told that it's not ideal as it causes air to not be measured all the time including when the MAF is in range.

If you've never had the issue you might have the Euro 2 spec 10P motor which don't utilise the MAF sensor readings as much as the later Euro 3 spec 15P TD5's.
 
There is some really interesting reading available on http://www.discotd5.com including, if you dig deep enough, some comparisons on different tuners maps. Generally though, it would seem that previously tuners were a bit limited in what they were/could modify and due to this the electric trickery solutions came about (turbo boost boxes, dual channel variants, variants for the MAF too and modified MAFs) or physical solutions (such as disconnecting the MAF or air bypasses). It would seem that the research and investigation further into the Td5 map tuning by Paul and his associates documented on that site, has opened up the potential within the tuning to resolve these issues through the tune itself. Judging from this link https://bellautoservices.co.uk/store/td5-1-4-bar-boost-ecu-recalibration/ it looks like Bell Auto Services have adopted this for the MAP.
 

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