BXProject

[David]

This is a subject I have often wanted to do something about. I've always felt that in a TD, the gap between 4th and 5th isn't quite enough. 80mph at 3000 rpm seems just everso slighty hurried. I'l like to see 2600 at 80, and hence be at 2250ish for 70 (and hence right on peak torque, and hence peak thermal efficiency.)

But.... How to do this without buggering up the lower ratios, which are already fine... Am I right in thinking that the TD top ratio is the highest there is in any BE?

[Philhod]

As far as I know it is David, however I've no idea what other vehicles that use the same box have in them. I'm thinking here Xantia , vans, Berlingo etc the latter just could have longer legs.
Provided you don't change the final drive, whatever you put in as replacements for 4 and 5 shouldn't alter the output of 1,2 and 3 or their characteristics. With a slightly higher 4th and a
say 12% higher 5th should give you the results you are looking for.

The only differences I can foresee are that you may have to hang on to 3rd a bit longer, going up and you would have less engine braking coming down till you got to 3rd, then it would seem greater.

[Bx Bandit]

BX TD 5th gear is the longest of all BE3 boxes as far as I know. Certainly the 1.9TD and pug 306 5th gears are the same, not sure about final drive.

By calculation I'm doing 2380rpm at 70 mph and 2720 at 80 mph

you don't notice 1st and 2nd being different. I rekon there'll be another BE3 box with slightly lower 3 and 4th gear sets than the TD, giving the possibly of matching standard TD final drive ratios (for 3 and 4) with a taller diff.

A pug 205 diesel (but I forget which variant) has the same diff ratio as mine, which is 3.59:1

[David]

Do any of the BX3 boxes have a taller diff ratio? That would be the way to make the top gear a bit taller, and then maybe put some lower ratios in 1st and 2nd if they've been made a bit tall (for towing if nothing else.)

[Bx Bandit]

BX GTi 8v has the same diff as mine 3.58:1. I think all 1st and 2nd ratios are the same though on *I think* all BE3 boxes. Seriously, 1st and 2nd are no bother. I towed the Xantia home t'other day nay worries.

[David]

Is that the standard TD diff?

[Philhod]

According to my book it is, but my latest Haynes (1993) is down at Derek's.
I've got a feeling that the later version of the box (with REV down right) were all the same,
ie. 3.59. I'll give him a ring in a bit and ask him to avalook.

[Bx Bandit]

I towed the Xantia with the 3.58 diff David, the diff from smiffys 2.0l ZX which is the same ratio as the BX GTi 8v.
One of the reasons I chose the lower/closer geared 3rd & 4th was because I'll be towing a trailer, although I think they are a little too short really.

None of the BX diesels came with a 3.58 diff. Certainly the TD is 3.96 (or there abouts) and I guess the n/a were a bit shorter again.

If you can get on the Citroen PR net thingy then all the ratios are listed in the drawings associated with each gearbox spec.

[Philhod]

Various other and earlier models boxes BH3, BE1. and the later BE3, contain a range of final drives. 3.58881:1 , 3.6875:1, 3.8666:1, 4.0265:1 and 4.1875:1.

Do the maths and see which gives the best combination for your purpose

[docchevron132]

do that mean I can use synchros from a td box to go on a 16v box dude?

In a word...no.

Would you like a set of cones dude?

Do any of the BX3 boxes have a taller diff ratio?

In another word...no.

Except mine.. 3.0:1. Only cost £1250 cash.

Am I right in thinking that the TD top ratio is the highest there is in any BE?

Yep, There is no taller.
Oddly Bandits quoted revs / MPH are not that much higher than mine! So it appears I could have saved some cash by using a diff from a GTi.. Ho hum.

[David]

'old on just a moment.

The BE3 gearbox fitted to a TD model has the tallest 5th gear pair available, but the diff ratio is 3.86:1, and a taller diff (3.59:1) is available?

Correct so far?

[Bx Bandit]

/\ Yes-ish, the diff ratio on a td (all td's I think?????) is 3.96:1, but yes a taller diff i.e. 3.59:1 is available via a BX GTi and other spec BE3 boxes (e.g. ZX sporty thing...2.0 ltr volcane is it called?)

[Bx Bandit]

do that mean I can use synchros from a td box to go on a 16v box dude?

In a word...no.

Would you like a set of cones dude?

If you have them mate and can spare them, then I'd do rude thing to your choccy starfish!!!! Being realistic, it has to be on the road asap and then pretty much on the road full time. So even if I had the bits, it'd be a while before they get put in.

Oddly Bandits quoted revs / MPH are not that much higher than mine! So it appears I could have saved some cash by using a diff from a GTi.. Ho hum.

I've not actually read the mph vs rpm in the real world yet! I'll do so for a check but my speedo needle has a +/- 5mph reading as a minimum!

[Vanny]

question, how would you convert a gearbox to fit a BE3 equipt engine (for example XUD9te) that has been mounted longitudinal instead of transverse!

[Way2go]

A: with difficulty!

[docchevron132]

If you have them mate and can spare them, then I'd do rude thing to your choccy starfish!!!!

I dont have any in stock right now, but I can get a set if you wish, nay bother.
Although feel free not to invade my shitter!

Vanny, I'm not sure I entirely understand what you're asking here?
Do you mean you want to convert a BE3 box to drive a propshaft to a rear axle, or use a RWD box on an XUD, or retain FWD with an XUD using a box for RWD?

[Vanny]

eh? i want a longitudinal mounted engine with front wheel drive. The engine currently accepts a BE3 gearbox.

[Bx Bandit]

er phuck knows. Isnt the Passat a longitudunal fwd? You need a big long bonnet non?

Doc, a set of 3rd.4th synchros would be great mate (and as you insist, I'll leave your shitter alone!!)
Speaking of the valver, I found a hole in n/s boot floor!

[Vanny]

i've got one of them Bandit, though mine still has a wafer fin skin of paint accross it!

[Bx Bandit]

/\eh? Got one of what? A Passat?