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

Would give it more again for sure mate. I just didnt trust the filtration. Cheers

Originally Posted by jafir

Sometimes RAVE contradicts itself. I believe this is the way the earlier GEMS computers worked, but not that Bosch computers. Later in the same section of the manual, it says that you have to reflash the eeprom to change tunes:

"The ECM can be reprogrammed, using TestBook/T4, with new engine tunes up to 16 times to meet changing specifications and legislation. The current engine tune data can be accessed and read using TestBook/T4."

Normally the testbook will flash the computer based on the VIN number. Here is some info from BBSGuy, that seems to indicate that settings cannot be edited in the ECU, and only a complete reflash, but I might be reading more into his words than is really there: VIN on motronic V8 D2 using nanocom

You're absolutely right Jafir. GEMS did work that way, although there was a booby trap. Although you could actually switch between 4.0 and 4.6, manual and auto software, sometimes the chips only actually had one tune in them (notably the the 4.0 auto Defender). Therefore whatever it was set to, you still got a 4.0 auto (for example).

With Motronic, the settings cannot be edited or switched without a re-flash. The basic ECM can be loaded with any one of a number of different software versions, but is constructed of many components to suit the build of the vehicle.

We know there are four different Bosch ECM part numbers for these vehicles, but we have found over 150 versions of the software so far! In all cases, the software is specific to the ECM hardware it is intended for. I have tried running alien versions of the software and although they run, they don't run well. The hardware is just different enough to stop it working properly.

Originally Posted by ozscott

Edit...i read elsewhere that the throttle body is larger also in NAS 4.6 D2...

Cheers

All Thor motors have the same size throttle body on them. Although there are a couple of different part numbers, the changes were actually to do with the water heating jacket underneath it which was prone to leaking in early models.

Originally Posted by ozscott

Thanks mate. So its an odd shaped MAF. Presumably its the same part as say a 99 4.6 p38A RR?

Cheers

You are right - it is the same as a P38 RR. I have put a picture of the P38 and Disco MAF next to each other on our Facebook page here:

https://www.facebook.com/tornadosystems

Here's the words for those who don't want to look at Facebook:

This picture is for Land Rover Discovery II owners, equipped with the Bosch Motronic-managed Thor engine. It shows the difference between the standard Mass Air Flow (MAF) sensor used with all 4.0 Litre versions of the Disco II, and the larger version used on the P38 Range Rover and 4.6 Litre Disco II sold in North America.



The P38 has an internal diameter of 76.5mm, whilst the Disco II is 70mm. This doesn't sound like a huge difference, but the available area is proportional to the square of the radius, less the area obstructed by the measuring bridge (which is the same for both meters). The difference is nearly an 19.5% extra area!


As yet, we haven't managed to get a Disco II on the rollers for a back-to-back comparison. Anecdotally from our clients, it appears to offer a gain of around 10 BHP which is especially apparent after 3000 RPM. This is clearly going to be different for 4.0 Litre and 4.6 Litre engines, but it appears to be a worthwhile modification to do at the same time as reprogramming the ECM with a Tornado upgrade.

Mark you are a champion. So i understand can i get a p38A air box lid and a 4 6 P38a thor motor MAF and the lid will connect up to the 4.0 D2 air box base and the 4.6 MAF will connect and fit to the 4.0 plastic intake tube that runs up to the throttle body?

How would such a mod go without the Tornado upgrade....i know Tornado would be the ultimate but any downside in the meantime to me doing the 4.6. maf?

Cheers

The 4L thor inlet ducting is the size to go over the 4L maf
it has to be managed/massaged to fit onto the larger 4.6 maf

this from last year,
http://www.aulro.com/afvb/showthread...19#post2456319

The RR Thor inlet is the total wrong shape(but right size) to suit the D2
The P38Airbox lid fits and is the right outlet shape to suit the 4L tubing.

any help?

Thanks Pedro. Does the massaging (stretching) cause splitting in the long run or are we talking just a little bit tighter. Have you run the bigger MAF?

Cheers

Its been done,,
just not by me yet.(sorry Mark!)

apparently you just get it warm/hot and stretch it over the maf