BX 2.0 CT Turbo, it begins....

[hilarystone]

The Activa gearbox is geared at 23.5mph/1000 revs in 5th in the Activa with 15in wheels - this equates to 22.1mph/1000rpm with 195/60 14 tyres. The BX TD gearbox is geared 26.3mph/1000rpm with 195/60 14 tyres. This I would have thought might be a bit on the high side for the Activa engine - though the BX is considerably lighter it is less aerodynamic than the Xantia... I think it might well be worth trying as it should give very relaxed cruising and is I think what you are aiming for, Tim. But it will be at the cost of low down pulling power in 5th gear.

This presumes that a BX gearbox will fit the 2.1 engine... I do not know - there may also be problems with getting a clutch to work...

[Tim Leech]

Thanks Hilary, thats good info. I do want a relaxed cruiser so that sounds ideal. Would a bx td clutch and flywheel not fit the Xantia crank?

[hilarystone]

I really do not know about clutches etc there are many people here on the forum who have that sort of knowledge...

[Tim Leech]

I really do not know about clutches etc there are many people here on the forum who have that sort of knowledge...

Ok thanks Hilary, the idea was to mate the standard td box, diff, driveshafts to the CT engine with a new clutch/uprated.

The Xantia uses a front mounted intercooler, could a BX TD arrangement be used instead?

[hilarystone]

I think I would attempt to go with the correct intercooler ... they do not take up large amounts of space.

[citsncycles]

All this used to be so much easier before the advent of transverse engines!

There's no guarantee that a BX flywheel will bolt straight to a Xantia crank, but there is the possibilty that you could either get an adapter made up to go between the 2, modify a BX flywheel to fit the crank, or modify a Xantia flywheel to take a BX clutch. It all depends on the differing dimensions between the Xantia & BX parts. Whichever route turns out best, I'd definately get any modifications done professionally, as they have to be balanced in order to avoid shaking it all to pieces!

Positioning the intercooler is mainly a matter of plumbing and ducting. I suspect the position of the BX intercooler is down to under bonnet space, so you may not have any coice but to fit it there. Having said that, it'll also depend on other matters like the position of hydraulic components and the size and location of the radiator. If you manage to use a BX radiator then I'd also use the BX intercooler set up, but if you decide to go for a different radiator you may be able to position the intercooler up the front somewhere, where it may get better air flow.

[Vanny]

I think I would attempt to go with the correct intercooler ...

The intercooler is wider than the space between the headlights on the BX, so you have to mount it slightly behind the slam panel. The ancillaries on the front of the CT engine will foul against the intercooler in this position, unless you cut chunks out of the slam panel. And from experience, you dont want to do this!

You'll likely find you need to do the calculations and find or order a cooling pack (rad and intercooler) that will perform as well as stock, and fit into the BX. Making the radiator deeper (50mm instead of 40mm) for example should maintain the cooling performance your going to need for a turbo petrol. You'll then need an intercooler that can be integrated.

Remember the BX engine bay is slightly narrower and not as deep (slam to firewall) as the Xantia. The engine might fit, but will the ancillaries?

[Kitch]

DOH! I got the gearing mixed up! Diesel boxes are too tall, not too short!

You definitely want a front mount intercooler. As has been said you're going to be looking at adapting other stuff to fit IMO.

[Tim Leech]

OK chaps, thats something to bare in mind, just for ease I was hoping to use a BX td intercooler set up, bonnet ducting etc and availablity, as I know of a car being broken which will donate its box, rad etc.

Would the TD intercooler not work? Your quite right vanny I dont want to start hacking parts of the car about as I want it to look as stock as possble.

[MULLEY]

Is this a mid-life crisis mate??? This whole project sounds like an absolute nightmare from sourcing the correct parts, the fabrication of parts, all the electrics & hydraulic issues & the cost. Have you done a search to see if anyone else has actually fitted a 2.0tct engine to a BX? If not i'd just forget the whole thing mate, it will be an absolute money pit & annoy you like hell. If i remember correctly, you've already got a xantia that has taken an absolute age to actually get running correctly, how do you think this project of yours is going to be like in comparision???

If you really want to change the engine, why not just fit a turbo or supercharger instead, that by itself is plenty of effort without having to go the lengths that some of the guy's have already started mentioning. This by itself is going to cost you plenty, but will be a fraction of what you're intending, i could see this thing going on for years & costing over £5k to actually get the thing running properly.

You said you dont want a valver, but if you fitted a turbo to one & fitted a TD 5th gear, you would have your sleeper car afterall. I'm sure someone in the netherlands has done this conversion already.

You may of course ignore all my comments, i don't want to sound negative or come across as such, but unless you take your car to a garage to do all the work with a huge bill at the end, i just can't see your mechanical skills saving you much money. I probably know more than you these day's, and i can't change a clutch or a cambelt, & these are fairly basic things to do, what you've proposed makes those things seem as simple as changing headlight bulbs in comparison.

[Vanny]

i can't change a clutch or a cambelt, & these are fairly basic things to do

Isn't it a learning curve thing?
First major job i did on the BX 19rd was a clutch change, took 3 weeks, and one hell of a lot of learning. Second major job was an engine transplant and conversion to a Xantia hydraulic pump, FM IC, addition of a tacho etc I only managed that because I had a lot of free time and a lot of help, took about a week to do the bulk of it, in what was basically a scrap yard for Citroens. Alright i knew a lot about tools, but had never really done much on cars!

What i'm trying to say is if the going in point is that its a project to absorb time and money, then where is the harm?

I've spent a scary amount on the valver, learned a hell of a lot, and as a direct result i got good degree and a good job. It's an amazing learning experience!


PS My record for a clutch change on a valver is 3 hours, so i have improved a little!

[Tim Leech]

Mid life crisis? Im 38 Matt!, no its just something I want to try doing, I am more savvy than you give me credit for these days, plus I know a good few mechanics who will muck in plus a mate whos a vehicle electronics specilaist. I appreciate it wont be cheap but I have a few spare quid I am preparred to chuck at it.

Noone has yet put a TCT in a BX....but theres plenty been put into 205s of the same era so I dont really see what all the fuss is about.

As for the Xantia, ive lost interest in it for now. its in storage with MOT and TAX expired but I will get stuck into that when the weather improves.

Hey if I can just bolt the turbo straight to the 1.6 carb I will be made up, but I dont think it would work....


You may remember last year I turned a heap of a DTR into a car that any BX'er would be proud of, ok I didnt do the paint but all the stripping, rebuilding etc I did myself, 5 years ago I wouldnt of even attempted it.

Nothings impossible.

The tax expires in WTF at the end of June, I want to spend the next 5 months collecting parts, reseraching and working out what to do next week, get the cambelt and waterpump etc changed on the TCT whilst the engine is out the car, then I will start stripping the BX ready. It may take a few years, but I have a space for it, the time and I dont need to worry if its in bits for ages. The DTR was off the road for 10 months.

[mat_fenwick]

The way I look at it is that nobody's born with the knowledge, it's all just what we've learned through our experiences. Even if you give up part way through, so long as you haven't spent a huge amount on custom parts it'll be worth it for all the skills you'll learn.

[Vanny]

Mid life crisis? Im 38 Matt!,

True, mid life is at 30, your 8 years into old age

No one has yet put a TCT in a BX..

Andy and I did it probably 10 years ago, though it was dangling on an engine crane with no ancillaries. At least now you know it will physically go in

[MULLEY]

For some the mid life crisis comes early Just kidding Tim.

It's your money, your project & all the best with it. Once you've built it & it works, i'll put an order in for one as well