Trabant Tech Forum

Keep something in mind. Don't go too crazy on the alternator amperage because it will effect the idle speed when the electrical system demands more load. On a 100 HP engine, with a 60 amp alternator, you probably wouldn't notice this but on a Trabant it's more dramatic.

The original 6 volt generator does not charge at idle so it doesn't effect the idle speed. After I put this 60 amp alternator on my Trabant, when I turned the headlights on, it would drop the idle speed a couple hundred RPMs and sometimes the engine would stall. I know an AC compressor pulls about 7 HP, a supercharger about 14 HP, I don't know what a 60 amp alternator pulls but just guessing, maybe around 5 HP.

I compensated by bumping the idle speed up a bit. But later on I had an issue where the electrics went dead and traced it down to bad battery cables. After replacing the battery cables, the idle speed does not drop as much. So I'd replace those while I was at it.

I don't know how what your wattage is on your Trabant but on mine I've added:

60/65 watt 6 volt H4 bulbs
55 watt auxiliary lights
12 volt converter which powers the electronic ignition, radio, fuel guage, LED backup number plate light and eventually the heater blower fan.

And my 60 amp alternator works just fine.

How many amp does the Trabant alternator put out?

Thank you for your advice....Appreciated.

I have had experience of "rev. drop" before, on another vehicle,...so, will be expecting that, thankfully!
(Set revs for daytime AND then again, when using the vehicle for night driving....Somehow, that goes with the "Trabi experience"?!!!!).

Regards.

Once I replaced the battery cables, I no longer experienced the massive drop in idle speed when I turned the high (main) beams and auxiliary lights. I did set my idle speed to 700 rpms with the high and auxiliary lights on just in case.

You can buy just the alternator adapter for about $40 from this place:

http://store.alternatorparts.com/a200-universal-alternator-mounting-bracket.aspx

Here is the belt tensioner bracket I used made by Mr. Gasket. I did have to cut it down and redrill the mounting hole and space it out with flat washers.

http://www.jegs.com/i/Mr-Gasket/720/9851/10002/-1

Many thanks for the details and advice.

Regards.

Spent most of Sunday afternoon sorting out the fitment of the new/replacement Lucas-type Alternator...along with very careful alignment of the pulley, with the fan and crankshaft pulley!
Getting there....Just need to get the correct length of v-belt sorted out tomorrow, on my travels, if I can.
10 x 1000, as per std. Trabant Alternator belt is too short, whereas the 10 x 1050 which comes with the Mikuni carb conversion/std. alternator re-mount kit is too long.
Not surprising, as I am doing something, that no one seems to have doe before?!....I always seem to be the one in that situation, with machinery and cars!!
Shouldn't be too difficult to sort out, as I will buy several belts of same spec., but slightly different lengths, such as 1035, 1030 and 1025...and then hopefully ONE of them SHOULD give me enough adjustment to allow for bedding the belt in...and conversely not allow the alternator to hit the crankcase casing... (Mid way, would be nice, on the adjuster bracket!).
I'll let you know how I get on, during this coming week, with any luck and perhaps try and put some pics. up on the forum thread, if I can.

Did the Lucas alternator mount up to the Trabant alternator bracket?

Take an old extension cord (2 wires) and wrap it around the pullies. Set the tension belt adjustment in the middle so you have some play room to play with. Then mark where the ends come together. Then take it to an autopart store and have them wrap then around their V-belt measuring tool.

In my case I had any issue where the gap between the belt sizes that the autopart store had was too much. Belts are typically sold in imperial over here. The belt width (10mm) equals 3/8" so that was not an issue.

The issue was I had to use a longer belt than I wanted. Don't quote me on this length but I needed something like a 45.0" belt. They had 43, 43.5, 44.0 then the next size up they had was like a 46.5. Luckily the Mr. Gasket adjustment bracket I used, had plenty of adjustment.

Thanks for that info.....However, just got home, with a selection of metric v-belts that I had been able to get from y local trade supplier!
Thankfully, one of them is pretty well spot on, as gives me approx. 1/3rd of the alt. adjuster bracket, with the slot. for re-tensioning, s the new belt beds-in, etc.
So, its, now aligned correctly, with the 2 x engine/fan pulleys, adjusted with correct 10-15mm deflection between alt. and engine fan pulley and all the alt. mounting bolts are done up!!
When getting close to commissioning the running gear and getting some help from my auto electrician, I will get him to upgrade the thick existing cable, from the alt. to the starter and back to the battery, as the cable needs to be able to take the 70 amp alt. output safely.
Might put an in line blade-type fuse in too, for good measure.
Lastly, will need to make sure that my dashboard-mounted Ammeter is up to the increase in charging amps, as otherwise these are know to go "pop", I gather?!!....
Incidently, as I am fitting the Mikuni Carb kit, from Trabantwelt.de......I received a modified altern. mounting bracket in the kit anyway, as the std. DDR -type alternator has to be able to miss the new carb assy. AND have a longer v-belt, consequently. Having upgraded the alternator to a LUCAS one, the new bracket only needed its' mounting holes elongating a few mm's, so as to achieve a better v-belt alignment,...thankfully!!
I will update this thread and hopefully put some pics on, ass mentioned before,.....in due course!