Bigger alternator.

BX Tech talk
Post Reply
User avatar
electrokid
1K Away
Posts: 1764
Joined: Fri May 09, 2008 2:14 pm
Location: Woking

Bigger alternator.

Post by electrokid »

My BX has the standard 50 amp alternator - I know there is the 80 amp option which fits - does anyone know of anything with a higher output - 110 to 130 amps that fits the BX ?
1992 BX19 TGD estate 228K Rusty - SORNed
2002 C5 HDi SX estate
User avatar
MULLEY
Over 2k
Posts: 8406
Joined: Thu Jun 22, 2006 11:10 pm
Location: Derbyshire
My Cars: 1999 Xsara LX 2.0HDI (90) Hatch - Fern
2002 C5 2.0 HDI (110) Estate - Jasmine - SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - SORN
1992 TZD Turbo Estate - SORN
1991 Gti 16V - Blaze - crash damaged, will get repaired - SORN
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN
x 8

Post by MULLEY »

No idea mate, however as a slight off topic question which is about alternators.

Alternators have an impact on fuel economy?

Are there any alternators out there that are of a different/better design than the one's fitted to the humble bx that would make it more economical? Or am i barking up the wrong tree, that was felled some years ago :oops: :lol:

Forgive my ignorance on alternators, i've got very little knowledge on these, i've only started thinking about them because of the 3 that Doc kindly fitted on my txd at gaydon last sunday.

Also, what are the reasons for them failing? I've heard that the bushes can wear out, but also that this is quite rare? & can an absolute amateur such as myself actually re-con one & get it to work reliably?

Sorry electrokid for the hijack, i can always re-post this tosh if you'd prefer?
2002 C5 2.0 HDI Estate - Jasmine - Now SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - My daily
1991 Gti 16V - Blaze - crash damaged, will get repaired.
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN

I'm not just a username, i'm also called Matthew.
User avatar
mat_fenwick
Moderator
Posts: 7326
Joined: Tue Sep 20, 2005 4:08 pm
Location: North Wales
x 19

Post by mat_fenwick »

Ignoring Mulley :wink: (as there are probably better able people to answer him than me) I don't know whether there is an alternative high output alternator that fits. But it may be feasible to get your existing one rewound if you have a spare to send somewhere.
Although I suppose you could always slum it driving the Granny while the BX's alternator is off... :)
Image

1993 1.9 TZD Turbo Estate
1996 3.9 V8 Discovery
1993 VW LT35 campervan
1985 Hyundai Stellar V8
2016 Hyundai iLoad
User avatar
Vanny
Merseyside resident
Posts: 3581
Joined: Tue May 17, 2005 11:48 pm
Location: BXProject
My Cars: BX 16v Ph2 - Jazz
BX 16v Ph2 - XPO
x 79
Contact:

Post by Vanny »

1) Alternators DO impact fuel economy.

2) Better design, yes, significantly more economic, no. Modern alternators are a little lighter, better wound, internally cooled but typically have a bigger capacity because of modern cars have so many electricals.

3)Main reasons for replacement are worn out brushes, rectifier damage, armature damage and bearing failure. On older alternators these can all be repaired DIY, by replacing parts (although significant armature damage is prohibitively expensive to resolve). Rectifier damage can occur as a result of foreign contaminants, very low battery, incorrect jump start, welding (though i'm yet to see it) and sods law.

Back on topic,

Most PSA alternators will fit the BX, i believe there are some on smaller engined cars that don't fit. Also there isn't much to choose between a petrol and a diesel alternator so you can swap them about which is handy. The only significant thing on newer alternators is the number of teeth to a belt. I ran a Xantia 6 tooth alternator on a BX with a 4 tooth belt with no significant problems, but i don't know what the possible implications are.

For a bigger alternator, either look for BX with aircon (75/80 amp) or bigger engined PSA vehicles. I believe the Xantia V6 has a 110amp alternator, later HDi's also seem to have high generation alternators.
User avatar
electrokid
1K Away
Posts: 1764
Joined: Fri May 09, 2008 2:14 pm
Location: Woking

Post by electrokid »

Although I suppose you could always slum it driving the Granny while the BX's alternator is off... :)
:rofl:
1992 BX19 TGD estate 228K Rusty - SORNed
2002 C5 HDi SX estate
User avatar
electrokid
1K Away
Posts: 1764
Joined: Fri May 09, 2008 2:14 pm
Location: Woking

Post by electrokid »

Ignoring Mulley
Ahhh - how could you possibly ignore Adrian... I mean Matthew :-)
Alternators have an impact on fuel economy?
The answer...
1) Alternators DO impact fuel economy.
Not many losses in the alternator itself - that's quite efficient - more losses in the belt that drives it so a more modern design - ie: ribbed belt rather than slotted V belt and slotted V belt better than a plain V. Additional electrical load will impact fuel economy as in air-con etc. 1 brake horsepower = 746 watts - so electrically you'll need an extra brake horse for each extra 53 amps of power consumption - so the effect shouldn't be that great.
I've heard that the bushes can wear out, but also that this is quite rare?
The rotor (the bit that goes round) just has one coil so the brushes only connect to a slip ring rather than a commutator - very little wear.
absolute amateur such as myself actually re-con one & get it to work reliably?


Sometimes they are a very simple fix - so if you have one of the duff ones just dig in and see what you can find and possibly learn more about the critters at the same time. I can also be failure of some of the diodes or the regulator - those are things you have to measure rather than being able to see the problem.
the 3 that Doc kindly fitted on my txd at gaydon last sunday.
Yeah - glad it got fixed - well done Doc :-)
Sorry electrokid for the hijack,
It probably deserved it :lol:
But it may be feasible to get your existing one rewound if you have a spare to send somewhere.
That is an interesting idea -thanks:-)
Most PSA alternators will fit the BX,
That's useful to know - thanks Vanny :-)
and bearing failure
Well I wasn't going to talk about Granadas - but since Mat brought it up :-)

You know the screaming noise that tells you that your fanbelt is loose - well on the Granny...

Fanbelt loose
aircon belt loose
PS pump belt loose
any alternator bearing
waterpump bearing
aircon clutch rubbing
brakeband slipping / gearbox about to die

ALL make EXACTLY the same noise ! !
1992 BX19 TGD estate 228K Rusty - SORNed
2002 C5 HDi SX estate
Defender110
Over 2k
Posts: 5917
Joined: Wed Dec 16, 2009 8:02 pm
Location: Harwood, Bolton
My Cars: Land Rover Discovery Series 1 200tdi 3 door
Land Rover Discovery Series 2 Facelift TD5
2020 Fiat Panda cross 4x4 twin air.
x 27

Post by Defender110 »

Don't forget if you upgrade your alternator you should upgrade your battery to suit, a higher output alternator can rapidly dry out the cells on a lower rated battery.


Mathew;

You could always decorate your TXD with solar pannels to allow you to get a few more chips per...sorry miles per gallon :lol:
Kevan
1997 Mercedes C230 W202
2003 Land Rover Discovery Series 2 Facelift TD5 - Daily driver / hobby days and camping.
1993 Land Rover Discovery 200tdi Series 1 3 door - in need of TLC
2020 Fiat Panda 4x4 Cross Twin Air.
User avatar
MULLEY
Over 2k
Posts: 8406
Joined: Thu Jun 22, 2006 11:10 pm
Location: Derbyshire
My Cars: 1999 Xsara LX 2.0HDI (90) Hatch - Fern
2002 C5 2.0 HDI (110) Estate - Jasmine - SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - SORN
1992 TZD Turbo Estate - SORN
1991 Gti 16V - Blaze - crash damaged, will get repaired - SORN
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN
x 8

Post by MULLEY »

:lol: :lol: :lol:

Cheers for all the info chaps, even though i highjacked electrokids post.

You'll have to let us know what alternator you decide to go for.

Kevan, you mentioned that a higher output alternator may dry out the battery cells, is there any guide on what type of battery you might need if you fitted a higher output alterantor as per electrokids idea?
2002 C5 2.0 HDI Estate - Jasmine - Now SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - My daily
1991 Gti 16V - Blaze - crash damaged, will get repaired.
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN

I'm not just a username, i'm also called Matthew.
User avatar
electrokid
1K Away
Posts: 1764
Joined: Fri May 09, 2008 2:14 pm
Location: Woking

Post by electrokid »

if you upgrade your alternator you should upgrade your battery to suit
Upgrading to 80 amp shouldn't be a problem for the standard battery - going any higher might do - but my battery is way over standard anyway.
You'll have to let us know what alternator you decide to go for.
Will do :-) I have the germ of an idea but it will take masses of current - that needs to come from the alternator not the battery hence the question.

I also have an idea for heated windscreen wash using thin stainless steel tubing with 12 volts connected to each end - that will take lots of current too but only for a very short time - that's just what a car battery is designed for so no probs. Stainless steel surprisingly has fifty times the resistance of copper !
1992 BX19 TGD estate 228K Rusty - SORNed
2002 C5 HDi SX estate
User avatar
Mike E (uk)
1K Away
Posts: 1115
Joined: Sun Aug 14, 2005 9:10 am
Location: High Wycombe, Bucks
x 1

Post by Mike E (uk) »

All BX16V have a larger 80A alternator, even if aircon is not fitted.

Not sure why, but it is good for powering my 400W headlamps.

It has a different pulley from the normal alternator IIRC.

Mike
la BX 16 soupapes: sachez apprecier avec moderation.



It might be clever now, but it won't be in the morning!
User avatar
mat_fenwick
Moderator
Posts: 7326
Joined: Tue Sep 20, 2005 4:08 pm
Location: North Wales
x 19

Post by mat_fenwick »

Defender110 wrote:Don't forget if you upgrade your alternator you should upgrade your battery to suit, a higher output alternator can rapidly dry out the cells on a lower rated battery.
Hmmm, not sure sure this is strictly correct - charging current flows dependant on the internal resistance of the battery and the voltage difference between the battery and the alternator output.
A flat battery will draw more current from an alternator, but a larger alternator (with the same output voltage) will not drive any more current through a battery than a smaller one.
Image

1993 1.9 TZD Turbo Estate
1996 3.9 V8 Discovery
1993 VW LT35 campervan
1985 Hyundai Stellar V8
2016 Hyundai iLoad
User avatar
Vanny
Merseyside resident
Posts: 3581
Joined: Tue May 17, 2005 11:48 pm
Location: BXProject
My Cars: BX 16v Ph2 - Jazz
BX 16v Ph2 - XPO
x 79
Contact:

Post by Vanny »

Twin alternators? I've seen it done on Land rovers before now, it really can't be that hard.
User avatar
rayfenwick
1K Away
Posts: 1718
Joined: Sat Mar 27, 2010 9:16 am
Location: Kingston upon Hull
Contact:

Post by rayfenwick »

electrokid wrote:I also have an idea for heated windscreen wash using thin stainless steel tubing with 12 volts connected to each end
Very interesting!

Ok, another hijack (sorry!) but definitely not far off topic:

Why does aircon use lots of electricity? Isn't the compressor driven from the engine via a belt? Other than compressing the gas and then rapidly decompressing in the heat exchanger (or whatever it's called) what's happening that needs a 30A fuse (on my XM) and indeed melts the fusebox! (common S2 XM problem...) and a bigger alternator? I understand the aircon "clutch" is electrically operated, but surely it can't be drawing all that current all the time? scratch...
Ray

The Fleet (most recent first):
2000 Citroën XM 3.0 24V V6 Exclusive Auto (pre-MOT)
1997 Citroën XM 2.0 TCT Exclusive Auto (for sale)
1979 Citroën CX 2.4 EI Cmatic Prestige (slowly being restored)

1992 Alfa Romeo 164 Lusso 3.0 v6 12v Manual (on the to-do list)

www.citroencarclub.co.uk
User avatar
mat_fenwick
Moderator
Posts: 7326
Joined: Tue Sep 20, 2005 4:08 pm
Location: North Wales
x 19

Post by mat_fenwick »

It's to power the radiator fan(s), that keep air flowing over the condenser even when you are stationary or at slow speeds...

Regarding the windscreen wash - perhaps I have a simpler solution? I know it's most unlike me to go for the simple option, but I've built something using 2 lengths of copper pipe (15 & 22mm), one inside the other. They are joined by reducing T pieces, so you have a water jacket around the 15mm pipe that you connect to the washer circuit, and the 15mm pipe to the coolant system.
I haven't yet fitted it, but I would imagine that the windscreen wash would boil off as it was sat in the jacket, but when the pump is operated would heat up pretty quickly as it passed through.
Wouldn't work with a cold engine though, which might be its fatal flaw...
Image

1993 1.9 TZD Turbo Estate
1996 3.9 V8 Discovery
1993 VW LT35 campervan
1985 Hyundai Stellar V8
2016 Hyundai iLoad
User avatar
electrokid
1K Away
Posts: 1764
Joined: Fri May 09, 2008 2:14 pm
Location: Woking

Post by electrokid »

Hmmm, not sure sure this is strictly correct - charging current flows dependant on the internal resistance of the battery and the voltage difference between the battery and the alternator output.
A flat battery will draw more current from an alternator, but a larger alternator (with the same output voltage) will not drive any more current through a battery than a smaller one.
Yes I wasn't sure about this either -but... always willing to bow to greater experience.

When upgrading a... er certain other type of vehicle :-) - one that has the luxury of an ammeter on the dash - from 50 to 80 amps all I noticed was the recharge time was a lot quicker. After starting the alternator has to replenish the battery - with the 50 amp that took about 5 minutes for the ammeter to read zero - with the 80 it took about 3 minutes.

So a higher output alternator does produce more current under the same circumstances - if you look at alternator specs they quote a current at specific alternator speed in revs (it's always less than the max output of the alternator) - so it's regulated at the same voltage (but that's the max voltage output - that's where it settles at zero output) but before it reaches that point the lower impedance / higher output capability will produce a higher current.

Car batteries are 'starting batteries' as opposed to deep cycle designs, and are vaguely designed around a certain number of starts with a particular starting load so whether or not the extra charge current for a shorter period will overfuck (sorry - it's late - couldn't think of another word etc :-) ) the battery - I don't know.

Anyway...
It has a different pulley from the normal alternator IIRC
Deisels for example usually have a smaller alternator pulley - so the alternator spins faster for a given engine speed - and they just aint gonna reach 6K :-)

And the pulley sizes are arranged to spin the alternator fast enough without overloading the belt - in the... certain other vehicle - those fitted with 80 amp versions also have two belts - try running it on just one and it only lasts 5 minutes :oops:
Most PSA alternators will fit the BX
Looking through the citroën TIS I found that a version of the C8 has a 180 amp option :shock:

No really - :shock: :shock: :shock:

Time for bed ! !
1992 BX19 TGD estate 228K Rusty - SORNed
2002 C5 HDi SX estate
Post Reply