S60 2.5T SE - manual conversion

I suspect what I’m about to ask is in now way a new question to this forum, so apologies in advance.

Looking for some advice. I have a low mileage 2004 2.5T SE which I bought cheaply as a stop-gap and two years on..... I love this car and cannot part with it.

Recently I decided to play with some performance mods and have already upgraded the exhaust and had a re-map done professionally to get a little more out of it. Very pleased with the results, and boy does it sound good. Next stage is an upgrade to a hybrid turbo, with injectors to follow, improvements to cooling etc.

The problem that I have is the gearbox. It is Geartronic so inevitably I'm losing a boot-load of power between engine and wheels and I've already had to fettle a flaring issue (usual problem with duff solenoids), but it is still not quite right. Looking at a manual conversion, so on the hunt for a lower mileage donor car that will allow me (actually my mate at AR Tuning) to swap all the bits across inexpensively. Trouble is that the 2.5 with a manual box is a rare animal and the few that are about are going up in price (most of them are also far too nice to break up).

From some scratching about on the internet it seems like the M56 gearbox might be a good option. I believe it was fitted as standard to the 2521cc S60, but i know little about it. What I'm wondering is whether and M56 from the more common 1984cc is an option. Would this be a straight swap into my 2.5? I know nothing about any differences in ratio, I'm guessing the bell housing will be different and not sure how many parts would be reusable in the swap. If the answer is 'not many' then it's not worth considering....

Apologies if I sound like a muppet here, I'm in uncharted territory and learning as I go. Any advice would be very gratefully received!

Update on the above.

For one reason or another I now have 3 S60s sitting outside the house. My 2.5, see above, a tattier version of the same model and a 2.0S that has been messed with to make it a fairly convincing R lookalike (all mouth and no trousers). The latter two I've picked up cheaply this week for parts donors.

Relative to the earlier post, I'd intended to use the gearbox and assoicated bits from the tatty 2.5 to do a manual conversion on mine. Now I've looked at it, the gearbox is an M56LK, which has quite a low final drive ratio (3.57). If I drop this box into my main car I suspect it's going to turn it into a slow-off-the-mark motorway cruiser, the opposite of what I want. Could someone who knows more than me about these things confirm that?

The R-lookalike has the M56L box, which I think has a 3.77 final drive. Not sure if that is a better option, or even if it would be compatible with my 2.5 which currently has the geartronic box in it.

Can anyone recommend a better box for the this conversion? The M56H I think has a final drive ratio of 4.00, which is probably better for charging off the mark but I'm not sure if that will just mean I'll get throuhg 1st so quickly it will be just about unusable. Also not sure re-compatibility with my car - from what i've read they seem to have been mainly used in the V70.

Ultimately, I don't dislike th auto box, I just worry that I'll lose too much of the power increase I'm hoping for and that, if I can get 300+ out of my motor, that it might just shred itself anyway.

Once again, apologies if I'm being a muppet here. Advice woul be great.....or even just someone swinging by to say hello. I've seen nothing but tumbleweeds since my first post :wavey:

Good evening,

Apologies for re-visiting this post but I am a new member. Hopefully enough time has past and you will have done the swap by now and have all the answers ready for my project! All I have to offer is more questions....

I have an S40 T5 which I love. I would like to use a T5 engine in a kit car that my son and I are building. We are on the hunt for an older, rougher, and cheaper T5. I have reservations about whether a turbocharged engine is in fact right for the kit but first off....gearboxes. Ratios and final drives aren't even on my radar at the moment. I'm more interested in the electronic implications.

Question 1: There are a more autos around for sale than manuals. If I were to replace an auto box with a manual one, how would the ECU react? My logic says that the auto box takes info from the ECU eg. speed, load etc but would there be an information flow in the opposite direction which if the ECU didn't receive would it just put the car in limp mode?
If anyone has done this I would appreciate some advice or if anyone knows the ins and outs of the gearbox /ECU relationship. does the CEM box come into play or is that more for windscreen wipers etc.

Question 2: Re suitability, are the 2.3s and 2.4s more laggy than the 2.5 I have? They have more ponies but I'm thinking the earlier the car, the more turbo lag?

Question 3: What do the S80 6 pot T6 go like?

Question 4: Anyone got a pranged Manual T5 they want to sell me...?


Thanks to ALL