Disco 2 LS Swap Shift Points Mod
Thread Starter
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Rock Crawling
Joined: Jun 2016
Posts: 469
Likes: 193
Aaron,
This is incredible. I have just completed swapping my 2003 D2 with an LQ9 6.0 engine using the ACE kit. Along with most others who have done this swap, I love everything about it but the shifting leaves something to be desired. I am 100% interested in a turn-key solution. Would you mind to send me a PM if this is something you would be willing/able to do?
Thanks in advance!
This is incredible. I have just completed swapping my 2003 D2 with an LQ9 6.0 engine using the ACE kit. Along with most others who have done this swap, I love everything about it but the shifting leaves something to be desired. I am 100% interested in a turn-key solution. Would you mind to send me a PM if this is something you would be willing/able to do?
Thanks in advance!
4wd Low
Joined: Dec 2022
Posts: 10
Likes: 1
I'm curious about the mention of the Rover MAF. I have a weird plan to place it inside a section of 6" tube to allow its body to take up enough space for it to get a good read on the portion of airflow it should be seeing compared to air flowing into the larger displacement engine. This way, the RMAF is not a choke point, and might be getting good data. With other folks not using the Rover MAF, I'm curious about what you found out.
Thread Starter
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Rock Crawling
Joined: Jun 2016
Posts: 469
Likes: 193
The 99-02 TCM provides a subtle change in shifting in my opinion compared to the 03-04 TCM. It holds the RPM slightly longer between shifts. It's also plug-and-play with your factory TCM. I listed some part numbers that I had assembled in the past regarding the different TCMs. Not positive on the accuracy of these, but if you go that route, might help in making sure you get the one you want.
Land Rover Discovery (US Spec) - Transmission Control Module Part Numbers
LR UHC 500 010 - 2003 4.6, 2004 4.6
LR UHC 000 080 - 2002 4.0, 2001 4.0, 2000 4.0
LR UHC 100 360 - 2002 4.0
LR UHC 000 010 - 2000 4.0
LR UHC 100 240 - 1999 4.0
The modification above provides a more noticeable change over the TCM switch. Holds shifts longer, downshifts quicker, but is not plug-and-play.
I have put together a small book of info on this MAF now. The MAF needs to be left in the factory-sized housing to get accurate data. If it is placed in a larger tube, the signal is significantly reduced (e.g., bad data). The signal can be corrected for the discrepancy electrically, but this is an estimate that has to be done carefully based on the change in tube size to be reasonably accurate. It also appears to need a screen in the larger tube to cause laminar flow to get accurate results. I'll follow up with more.
Land Rover Discovery (US Spec) - Transmission Control Module Part Numbers
LR UHC 500 010 - 2003 4.6, 2004 4.6
LR UHC 000 080 - 2002 4.0, 2001 4.0, 2000 4.0
LR UHC 100 360 - 2002 4.0
LR UHC 000 010 - 2000 4.0
LR UHC 100 240 - 1999 4.0
The modification above provides a more noticeable change over the TCM switch. Holds shifts longer, downshifts quicker, but is not plug-and-play.
I'm curious about the mention of the Rover MAF. I have a weird plan to place it inside a section of 6" tube to allow its body to take up enough space for it to get a good read on the portion of airflow it should be seeing compared to air flowing into the larger displacement engine. This way, the RMAF is not a choke point, and might be getting good data. With other folks not using the Rover MAF, I'm curious about what you found out.
Thread Starter
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Rock Crawling
Joined: Jun 2016
Posts: 469
Likes: 193
I have done a number of measurements with the Rover MAF. I’ve come to two central conclusions: (1) changing the tube diameter changes the output and (2) the output is heavily influenced by maintaining laminar flow (using the MAF screen in front of the sensor).
In a number of tests, sticking the MAF in a larger diameter pipe (3.5 internal inches vs. factory 3 inches) came up with a number of results. Without a screen, the MAF in the larger pipe read a little more than half of what it should. The readings were also highly inconsistent because the sensor was no longer positioned in air with laminar flow.
By adding a laminar flow screen in front of the MAF in the larger tube (such as this one: https://performancemrp.com/i-3049756...er-screen.html), the MAF readings, despite the larger pipe were much closer to normal (roughly 6-10% low) and significantly more consistent.
Because airflow readings lower than normal (and therefore torque estimations) would cause lower shift pressures, which would not be good, an amplifier can be used to increase the signal from the MAF to the Rover ECU. This uses a linear approximation for adjustment (it is not perfect, because the mass air flow curve is roughly a fifth order polynomial). However, it appears to be close enough to provide decent adjustment. It uses a potentiometer to be able to adjust the signal increase.
At a minimum adjustment (to get it about where it would be factory), it appears to work normally. Adjusting it higher so that it is overadjusted (e.g., sees more airflow than is there) makes it so that it shifts quicker and faster (with more shift pressure).
Each setup is going to be different though and require more or less adjustment. But it does appear that the Rover MAF can be used in a different sized pipe and maintain proper readings if the proper adjustments are made. Using this setup does seem significantly better than deleting the Rover MAF entirely.
In a number of tests, sticking the MAF in a larger diameter pipe (3.5 internal inches vs. factory 3 inches) came up with a number of results. Without a screen, the MAF in the larger pipe read a little more than half of what it should. The readings were also highly inconsistent because the sensor was no longer positioned in air with laminar flow.
By adding a laminar flow screen in front of the MAF in the larger tube (such as this one: https://performancemrp.com/i-3049756...er-screen.html), the MAF readings, despite the larger pipe were much closer to normal (roughly 6-10% low) and significantly more consistent.
Because airflow readings lower than normal (and therefore torque estimations) would cause lower shift pressures, which would not be good, an amplifier can be used to increase the signal from the MAF to the Rover ECU. This uses a linear approximation for adjustment (it is not perfect, because the mass air flow curve is roughly a fifth order polynomial). However, it appears to be close enough to provide decent adjustment. It uses a potentiometer to be able to adjust the signal increase.
At a minimum adjustment (to get it about where it would be factory), it appears to work normally. Adjusting it higher so that it is overadjusted (e.g., sees more airflow than is there) makes it so that it shifts quicker and faster (with more shift pressure).
Each setup is going to be different though and require more or less adjustment. But it does appear that the Rover MAF can be used in a different sized pipe and maintain proper readings if the proper adjustments are made. Using this setup does seem significantly better than deleting the Rover MAF entirely.
Drifting
Joined: Jan 2023
Posts: 49
Likes: 9
I have done a number of measurements with the Rover MAF. I’ve come to two central conclusions: (1) changing the tube diameter changes the output and (2) the output is heavily influenced by maintaining laminar flow (using the MAF screen in front of the sensor).
In a number of tests, sticking the MAF in a larger diameter pipe (3.5 internal inches vs. factory 3 inches) came up with a number of results. Without a screen, the MAF in the larger pipe read a little more than half of what it should. The readings were also highly inconsistent because the sensor was no longer positioned in air with laminar flow.
By adding a laminar flow screen in front of the MAF in the larger tube (such as this one: https://performancemrp.com/i-3049756...er-screen.html), the MAF readings, despite the larger pipe were much closer to normal (roughly 6-10% low) and significantly more consistent.
Because airflow readings lower than normal (and therefore torque estimations) would cause lower shift pressures, which would not be good, an amplifier can be used to increase the signal from the MAF to the Rover ECU. This uses a linear approximation for adjustment (it is not perfect, because the mass air flow curve is roughly a fifth order polynomial). However, it appears to be close enough to provide decent adjustment. It uses a potentiometer to be able to adjust the signal increase.
At a minimum adjustment (to get it about where it would be factory), it appears to work normally. Adjusting it higher so that it is overadjusted (e.g., sees more airflow than is there) makes it so that it shifts quicker and faster (with more shift pressure).
Each setup is going to be different though and require more or less adjustment. But it does appear that the Rover MAF can be used in a different sized pipe and maintain proper readings if the proper adjustments are made. Using this setup does seem significantly better than deleting the Rover MAF entirely.
In a number of tests, sticking the MAF in a larger diameter pipe (3.5 internal inches vs. factory 3 inches) came up with a number of results. Without a screen, the MAF in the larger pipe read a little more than half of what it should. The readings were also highly inconsistent because the sensor was no longer positioned in air with laminar flow.
By adding a laminar flow screen in front of the MAF in the larger tube (such as this one: https://performancemrp.com/i-3049756...er-screen.html), the MAF readings, despite the larger pipe were much closer to normal (roughly 6-10% low) and significantly more consistent.
Because airflow readings lower than normal (and therefore torque estimations) would cause lower shift pressures, which would not be good, an amplifier can be used to increase the signal from the MAF to the Rover ECU. This uses a linear approximation for adjustment (it is not perfect, because the mass air flow curve is roughly a fifth order polynomial). However, it appears to be close enough to provide decent adjustment. It uses a potentiometer to be able to adjust the signal increase.
At a minimum adjustment (to get it about where it would be factory), it appears to work normally. Adjusting it higher so that it is overadjusted (e.g., sees more airflow than is there) makes it so that it shifts quicker and faster (with more shift pressure).
Each setup is going to be different though and require more or less adjustment. But it does appear that the Rover MAF can be used in a different sized pipe and maintain proper readings if the proper adjustments are made. Using this setup does seem significantly better than deleting the Rover MAF entirely.
Mudding
Joined: Aug 2020
Posts: 110
Likes: 25
From: Vancouver, BC
Hey Aaron, can you throw a pic of your intake up?
Where do you have your rove MAF positioned?
Mine is connected to the Airbox, then I have the GM MAF right behind the AC
Does it matter where they are or which one is first?
Where do you have your rove MAF positioned?
Mine is connected to the Airbox, then I have the GM MAF right behind the AC
Does it matter where they are or which one is first?
Thread Starter
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Rock Crawling
Joined: Jun 2016
Posts: 469
Likes: 193
I made a thread specifically about the MAF modification that is more specific: https://landroverforums.com/forum/en...ations-117656/
I think the MAF modification may be an overall better / easier solution than what is described in this thread.
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