Hi everyone, Im considering a remap on a "FR 2 - 2.2 SD4-GS" Im advised it will take my 190HP to 230 HP. Has anyone had one done and are there downsides? Any advice would be appreciated.

I've had a stage 1 remap done on my 08 Td4 and am pleased with the outcome. Slightly better fuel economy but more impressed with torque at lower revs. The only thing I was warned about was the gearbox not being able to handle higher torque, especially in 1st gear, so I'm always mindful to change up quickly. Hope that helps.

LR24U said:

Hi everyone, Im considering a remap on a "FR 2 - 2.2 SD4-GS" Im advised it will take my 190HP to 230 HP. Has anyone had one done and are there downsides? Any advice would be appreciated.

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The engine should be fine, the gearbox not so fine. The reason the SD4 is limited to 188 BHP is for the gearbox as that is the maximum torque capacity of the unit. Exceeding the gearbox maximum torque capacity will massively reduce its working life, which is not great as it is.

adrianhartopp said:

I've had a stage 1 remap done on my 08 Td4 and am pleased with the outcome. Slightly better fuel economy but more impressed with torque at lower revs. The only thing I was warned about was the gearbox not being able to handle higher torque, especially in 1st gear, so I'm always mindful to change up quickly. Hope that helps.

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Thanks buddy, just the input I need, I’ve got an automatic so hopefully it works out. Thanks once again for your effort to respond

Nodge68 said:

The engine should be fine, the gearbox not so fine. The reason the SD4 is limited to 188 BHP is for the gearbox as that is the maximum torque capacity of the unit. Exceeding the gearbox maximum torque capacity will massively reduce its working life, which is not great as it is.

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Omg, you guys are so knowledgeable… I’ve got an Automatic, is that better or worse? Really appreciate your effort to respond.

LR24U said:

Omg, you guys are so knowledgeable… I’ve got an Automatic, is that better or worse? Really appreciate your effort to respond.

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The SD4 only came with an auto, which has a maximum torque limit of 440Nm for short periods of time. However the torque converter clutch has a torque limit of just 400Nm (not an issue cruising), which means that whenever more torque is needed, the TCM disconnects the TC clutch to prevent damage. A remapped ECM won't necessarily command the TCM to unlock the TC clutch, resulting in very rapid clutch failure, an issue that this box already suffers anyway.

The manual gearbox has a maximum torque limit of 420Nm, except in 1st gear, where its 360Nm. The ECM is programmed to limit maximum torque to 420Nm, except in 1st and reverse, when it's reduced to 360Nm so the gearbox remains inside this lower maximum torque limit.
Remapped ECMs don't always have this torque limiting in any gear, so without care from the driver, gearbox failure is a possibility.