TCU Upgrade in E55K.

[John]

Has anyone had this done yet and what improvements did it make?

I am currently considering an LSD but I'm wondering if this is worth doing at the same time.

I'm a little "if it aint broke" but keeping an open-mind!

 

[daveenty]

Can't help with the box upgrade, but LSD is a very worthwhile mod.

Transforms a good car into an excellent car as far as I'm concerned, particularly noticeable in wetter conditions.

 

[b1g1an]

I was very interested in this but get the impression it's very good when you're on it but makes the changes noticably rougher for normal driving.

 

[Alps]

I have LSD as an option, so cant say what its like without

re TCU heard good and bad dependent on driving style, so ive stayed away

 

[BlackC55]

The LSD is the single best mod you will do. It is epic.

The TCU upgrade can make slow gear changes harsh. But flat out changes are faster.

 

[Vilus]

Worth noting that the TCU remap only only affects the up changes. The downshifts are controlled by the engine ECU IIRC.

 

[John]

I wonder if I already have it.

My slow changes are a bit rough sometimes but I am very surprised how quick the car changes in manual and sport mode when I'm making incredibly-good progress.

I think the price of the LSD is what is currently holding me back although I remember how well my M3 Evo handled which had one as standard - so it is tempting.

If I don't get one now, I will if my airmatic fails and I go with the COs.

Cheers gents.

 

[BFT]

You might need an auto gearbox fluid change mate?

 

[b1g1an]

I wonder if I already have it.

My slow changes are a bit rough sometimes but I am very surprised how quick the car changes in manual and sport mode when I'm making incredibly-good progress.

If it's during down changes, all the 55ks I've driven are like that, the box can be a bit stupid at times when tootling.

The eurocharged tune, ECU not TCU, made it much better but equally makes the odd hamfisted one more noticable.

 

[daveenty]

You might need an auto gearbox fluid change mate?

Nothing like trying the obvious really, this would certainly be my first check and probably the cheapest thing to try.

The simple things always seem to get overlooked...

 

[John]

My first post was worded badly - second line should read:

I am currently considering an LSD anyway but I'm wondering if this TCU (*ECU) upgrade is worth doing at the same time.

You might need an auto gearbox fluid change mate?

No, it's not that as I have that done routinely (every 35k/40k miles). What came out last time was very clean.

If it's during down changes, all the 55ks I've driven are like that, the box can be a bit stupid at times when tootling.

The eurocharged tune, ECU not TCU, made it much better but equally makes the odd hamfisted one more noticable.

This is exactly it - and it is always when tootling as you say!

I think it might be the adaptive trying to work out my driving style which is very hard to predict (sometimes quick interspersed with slower).

Fast changes are always very fast and smooth.

 

[b1g1an]

They are two separate upgrades, the TCU one is just the gearbox and is the one you meant, I've got the ECU one which is the engine tune that is offered on the basis it gives you some more horses and torques.

However, it also changes several of other things for the better and why I got it, the biggest benefit to me, as odd as it sounds, was it also changes certain parts of the gearbox settings. For example, it gets rid of that horrible lurch when you are pulling out from a side road into a queue of traffic, give it a bit of gas to nip out then back off before you drive into the back of the car in front and the gearbox decides to change at just the wrong moment and rather unsubtly, now it behaves just as it should. Someone else on here reported the same experience before and after, think it was Alps in his E55.

That tune also gets rid of the roughness at tickover but still leaving some feeling of having a monster under the bonnet rather than a sewing machine.

 

[ChrisA]

I had TCU software installed and also LSD and noticeable difference when pushing hard through the gears. Much quicker changes and a lot smoother although down shifting has always been a lottery!

 

[John]

They are two separate upgrades, the TCU one is just the gearbox and is the one you meant, I've got the ECU one which is the engine tune that is offered on the basis it gives you some more horses and torques.

Ah right. I mis-understood your earlier post - I thought you were correcting it (i.e. this age of 55K didn't have a separate TCU and it was part of the ECU or similar).

I've already got the EC ECU upgrade so TCU is what I was focussed on.

 

[BFT]

EC TCU in mine and I will be honest drives smooth and well.

I do drive mine like a bellend most of the time though.