Thread: D2 4.6 conversion owners. 4.6 ECU swap & EOI.

Originally Posted by Pedro_The_Swift

So,, after reading your first paragraph Mark,,
we DONT need to use a 4.6 MAF?

just confirming,,,

and yes, I've moved again and still havent dug out the ECM numbers,,

Always wise to confirm!

You don't have to convert to the larger MAF with the 4.6 conversion, but you do need to re-program the ECM to get the best that the conversion has to offer.

Note that the larger engine does push the MAF towards the upper limit of it's measuring resolution.

If you would like to use the larger MAF, then it is worth power and metering accuracy. Again this needs to be taken into account when programming the Bosch ECM.

Therefore if you'd like the larger MAF, it's just good economics to do the whole lot at the same time.

I know you are a moving target at the moment! Hope you're having a great time!

I've already have the 4.6 MAF ,,
and the p38 inlet tubing
which is how I know it will never bolt up to a D2.

the easy way is to find tubing that will change diameter both before and after the 4.6 maf.

Originally Posted by Pedro_The_Swift

I've already have the 4.6 MAF ,,
and the p38 inlet tubing
which is how I know it will never bolt up to a D2.

the easy way is to find tubing that will change diameter both before and after the 4.6 maf.

Very helpful information Peter! As I haven't got a Disco on the test fleet it's not something I can check (we have a lovely P38 on which everything works - at least for the time being|).

The best way would probably be to get used parts from the USA. However I'll check the prices for the two parts required later today.

PHC000110 Air Filter Box Lid 4.6
PDH000480 Hose - MAF to Inlet Manifold 4.6

Mark,, the p38 inlet tubing doesnt have the "storage container" that the D2's have. There must be a reason LR designed it.

I gather you think the complete p38 airbox will bolt in to the D2?

The "storage" container is there to eliminate harmonics at some order (1st, 2nd etc) caused by pulse reversion, usually when the accelerator is backed off and then pressed again. The fluid dynamics mean that the flow hits the closed butterfly and technical stuff happens and without the reserve the technical stuff can go awry.

Thats the short story. It's similar to why a plenum cover on a V engine is joined between the banks and also why it's tapered to be lower at the distal end of the inlets AND why the bellmouths are (very) slightly different heights and lengths. CFD of fluid flow in a plenum and what the air does as the valves close against flow is very cool.



But it looks something like this, but more refined.

Originally Posted by Mark Adams

The best way would probably be to get used parts from the USA.

Do the air boxes and their lids in the UK and AUS have issues cracking?

It seems to be a pretty big problem here, and I'm not sure I'd buy another used one. My 2003 box was in pretty rough shape, and I bought a used one that looked fine. 6 months later, the clamps for the MAF were about to snap off due to cracks in the plastic. I'm not sure if it's climate or what. Personally, I'd buy a new lid, if the prices aren't too bad.

I don't know if they ship internationally, but this site lists the lid for 109USD. Land Rover Parts - Land Rover Parts Center - Call (800) 574-9217 for Genuine Land Rover Parts and Accessories
They are a main dealer in the Kansas City area, and I've purchased parts from them in the past.

It looks like the hose is just as pricey, but the only real issue I've seen with the hoses over time is that the port that goes to the IACV will sometimes come off, but it's pretty easy to remedy in most cases. On mine, I just sprayed it with silicone spray or something and pushed it through from the inside, and it was such tight fit, I'm sure it sealed just fine. I'd have no real issue ordering a used hose.

FWIW
i have the 4.6 maf in mine which is actually 23% larger internally
and the Mark Adams ECU it has the P38 filter box top on it now
and awesome Torque over the 4.0ltr and economy is yet to be confirmed as it has done all hard work from new.
See post in D2 V8's are great(9/2/15)
still need to get the gas retuned for the bigger motor as it seems to lean out then switch back to petrol
biggest problem so far is oil wicking down one of the sump bolts

Originally Posted by Modelsp

FWIW
i have the 4.6 maf in mine which is actually 23% larger internally
and the Mark Adams ECU it has the P38 filter box top on it now
and awesome Torque over the 4.0ltr and economy is yet to be confirmed as it has done all hard work from new.

So this confirms the P38 airbox LID just clips straight onto a D2 airbox???????

Modelsp?