840Ci ECU with pre-installed Wokke chip

Hi guys

I have a type-404 ECU (as fitted to early 840, pre-EWSII) fitted with a Wokke performance chip. For anyone who doesn't know about the Wokke chip, have a search on this forum - they are renowned as a very worthwhile upgrade for the 840, improving performance and driveability without reducing fuel economy.

I bought the chip directly from Wokke, and as the 840 was my only car at the time, I didn't want to risk opening the ECU to fit it without having a spare, just in case something went wrong leaving me with no usable car. So I bought a spare ECU and fitted the chip to that, then swapped it over with my original ECU.

I've since returned the car to standard (to put the car up for sale), so I'm selling the ECU with upgrade chip installed. This will make it very easy to upgrade to the Wokke chip, without having to open your ECU and separate the circuit boards - instead of several hours, it takes only five minutes to upgrade. Your original ECU can also be easily swapped back in, should you wish to return the car to standard.

I'm looking for £200 for the upgraded ECU - this is far less than the combined cost of the replacement ECU and the Wokke chip (which will cost you around £130 on its own).

Any questions let me know. I can send a photo of the ECU if desired, although it looks pretty much like any other from the outside!

Thanks.

I have to disagree with you on this. I'm aware that there are different types of ECUs, some of which are relatively straightforward to modify (single board type), but I can assure you this type of ECU will not see a chip replacement job done in 10 minutes - at least not without throwing caution to the wind and taking a high risk of damaging the board in the process.

Splitting the two halves of the circuit board to get to the chip is a delicate operation that should be done slowly to ensure no damage is caused to the board. I am a qualified electronics engineer, and I'm no stranger to working with circuit boards and vehicle ECUs, (including more modern surface mount items) so it's not due to a lack of confidence on my behalf.

I'm not saying this is a difficult job, but to claim that with no prior experience you can pull this ECU, replace the chip, and reinstall it in ten minutes, - that I'd consider to be highly misleading!

Thanks for your input though

Sorry for the delay in replying... I didn't get the email notifications I was expecting!

Thanks for the clarifications. I think there was some misunderstanding over the different types of ECU, and associated difficulty in replacing the chip in each type.

In my experience, splitting the top half of the board from the end where it plugs into the car is the most challenging. I guess it depends on the age of the ECU, how it's been stored etc, but I found the two parts to be very reluctant to separate. Hence the very slow and gentle manoeuvring to ensure no damage was caused in the process.

Either way - I'm selling the ECU and chip for far less than the cost of the two combined, so you're getting the installation for free

Regarding the change after fitting, there seemed to be a slight difference in throttle response but not much (bear in mind the V8 has a cable throttle so not much to change here). Might even have been placebo! I've never found the throttle response to be an issue on the 840. The key difference with the Wokke chip is the way the engine pulls - it just feels stronger, especially at the top end. Makes the engine feel more eager and revvy, which really improves driving enjoyment. I've no idea what the actual performance difference is, as I never measured it (either acceleration or BHP).

I still have this available. I've had a few enquiries from people who were interested but it turns out they have an incompatible version of the 840. This ECU will only work on earlier 4.0 models without EWS immobiliser built into the key. The sure fire way to tell is to look at the numbers printed on your ECU - if the big number ends in 404, this ECU is compatible. If it ends in 484, you have an EWS system and this isn't compatible.

I'm happy to field questions from anyone who is still unsure.

Many thanks Timm. I believe it's also compatible with the E34 540i up to the introduction of EWS.

Cheers
Paul

This chipped ECU is still available...