CaveVan Forum
VW T4 "Eurovans" => VR6 Engine tech => Topic started by: albertr on May 20, 2015, 09:11:14 am
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I would like to replace my stock OEM Bosch alternator (VW P/N 021 903 025 T rated @ 120A max) with some high-output one which would produce at least 200A at cruising RPM's when hot. It also needs to be able to produce around 50A at idle RPM's to power headlight, fan, A/C and radio while sitting in traffic.
Unfortunately, there're no OEM VW/Bosch models in existence to meet these requirements. There're some companies around which re-sell or re-work alternators as "high-output" ones for premium prices. I've tried to contact the following ones:
- Mechman
- DC power
- Mike Singer
- Quality power
and found out that they either not interested in making one for VW/VR6 (since there's no high demand for this particular model), or just plain scam artists like Mechman.
Did anyone successfully replaced their VW/Bosch alternator with a third party unit capable of producing 200A?
-albertr
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The only step up to the stock eurovan alternator that I've seen is the 150A one that's in the Rialta.
http://europarts-sd.com/alternator-150amp2001-2003.asp (http://europarts-sd.com/alternator-150amp2001-2003.asp)
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Well, 150A is hardly "high" output by today's standard. I've seen a few on fleabay which should be direct bolt-on replacement and claim to be "250A" but neither of their sellers wanted to put them on a load test bench and measure the actual output.
I'm still looking....
-albertr
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I gave up on cheap chinese alternators and "custom tuned" US-made ones (the same junk , much higher priced), but found a beat up to shit (but supposedly still working) 220 Amps Valeo alternator from wrecked VW Tuareg.
Based on its picture mount seems to be the same type as on EuroVan (keep my fingers crossed), pulley looks different and most likely needs to be changed. Should be receiving it next week. More details to follow...
-albertr
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Here's an update on my alternator quest -
1. 220A Valeo alternator is using INA F-235449 pulley which has O.D. of appox. 56 mm.
2. Crankshaft pulley in Touareg 3.6L VR6 has O.D. of approx. 440 mm.
3. EuroVan 2.8L VR6 (AXK code) crankshaft pulley O.D. is approx. 434 mm.
4. Touareg 3.6L VR6 engine idles @ approx. 730 RPMs.
5. EuroVan 2.8L VR6 (AXK code) engine idles @ approx. 650 RPMs.
6. There're two clutch pulleys made by INA for various MB vehicles which might be close match to EuroVan 2.8L VR6 (AXK code) belt offset. They might need to be turned on lathe to remove 1 or 2 mm to be exact match:
a. Larger alternator pulley - INA F-557311 has O.D. of 56 mm.
b. Smaller alternator pulley - INA F-239808 has O.D. of 50 mm.
7. Larger alternator pulley most likely would work with stock EuroVan belt and tensioner.
8. Smaller alternator pulley would *NOT* play nice with stock EuroVan belt and tensioner. It would require to either use a shorter 7 rib double sided belt (which is unobtainium AFAIK) or putting in some spacers between alternator and crankshaft to take up belt slack.
9. The 220A Valeo alternator in Touareg 3.6L VR6 idles @ approx. 1825 RPMs.
10. If 220A Valeo alternator coupled with a larger alternator pulley is installed in Eurovan , it will idle @ approx. 1603 RPMs.
11. If 220A Valeo alternator coupled with a smaller alternator pulley is installed in Eurovan , it will idle @ approx. 1797 RPMs.
If my calculations are correct, I'm suspecting that:
1. There's a chance what 220A Valeo alternator would *NOT* be able to get excited @ EuroVan's idle engine RPMs if it's coupled with a larger alternator pulley because of too low RPMs.
2. It most likely will get excited @ EuroVan's idle engine RPMs if it's coupled with a smaller alternator pulley but belt will slip and unless some spacers are used to take up its slack.
3. There's some hope that Valeo has designed their 220A alternator for a variety of different applications where alternators RPMs might be lower than ones on Touareg. In this case, there's a chance what it will work in EuroVan @ engine idle RPMs with a larger alternator pulley. Afterall, Bosch 120A alternator (VAG P/N 021 903 025 T) which came on my EuroVan gets excited @ 1477 RPMs just fine. If 220A Valeo is anything like this 120A Bosch unit, then it might work. But then again 220A is quite a difference from 120A, so it might need to turn much faster to produce it.
Decisions, decisions... Any comments are welcome!
-albertr
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Ok heres one question: What is the approximate idle RPM if the 220A Valeo alternator coupled with current Eurovan pulley? Is it not worth testing and seeing if works in this "worst case scenario"?
The supplier I have been talking with also came up with recommending the INA F-557311 clutch pulley, saying this is very close to an overall match and up to me if I thought worth trying out. There are two hangs ups on this -- the first is that its smaller OD means that the extra belt slack must be absorbed somehow (either through the tensioner or spacers), and the second is that the overall length of the pulley is a bit larger (but I don't see this is an interference issue). He identified another model from his catalog that from the front side of the pulley is an ideal match, and sits at 60mm OD. The hang up with this pulley is that its total overall length shorter, and would require a spacer mounted behind the pulley to get into alignment.
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Assuming that stock Bosch pulley O.D. is 61 mm, we would have: 434mm * 650 rpms / 191 mm = 1477 rpms. Way too low, IMHO. It works with 120A Bosch, but unlikely would work with a 220A-rated unit.
I think belt tension should be fine using INA F-557311 pulley, I have already tested a pulley with 54 mm O.D. in 2001 EVC (2.8L VR6 AXK) and belt didn't slip, so 56 mm should work. I would prefer to go with as small alternator pulley as possible, however don't want to mess around with taking up belt slack if it can be avoided.
-albertr
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He identified another model from his catalog that from the front side of the pulley is an ideal match, and sits at 60mm OD. The hang up with this pulley is that its total overall length shorter, and would require a spacer mounted behind the pulley to get into alignment.
Itsamoto, what was the P/N for the this pulley? Looking at INA catalog I can see that they have a shorter pulley but it's about 3 mm too short. It's INA F-232001 (aka MB 271 155 01 15).
-albertr
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Itsamoto, what was the P/N for the this pulley? Looking at INA catalog I can see that they have a shorter pulley but it's about 3 mm too short. It's INA F-232001 (aka MB 271 155 01 15).
-albertr
Sorry I don't know the number -- the supplier has his own part number for his own catalog and I must not have written one down -- I ruled it out due to the extra machine work needed to create the standoff. The irony, is that it's probably that 7 groove clutch pulley that comes off the Touareg. Maybe you have it already? ;)
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Had some spare time today and removed INA F-235449 pulley from 220A Valeo alternator.
The rotor's shaft protrudes by about 20 mm beyond the case, last 15 mm are threaded.
(http://www.iral.com/~albertr/EVC/alternator/IMG_6133.jpg)
Interesting, there's a spacer installed already -
(http://www.iral.com/~albertr/EVC/alternator/IMG_6137.jpg)
... which measures as approx. 3.67mm thick.
(http://www.iral.com/~albertr/EVC/alternator/IMG_6146.jpg)
It looks like adding another spacer (3 or 4 mm thick) shouldn't be a problem..
I will be receiving a shorter MB pulley soon (INA F-232001 aka MB 271 155 01 15) and will test to see if it fits.
More to follow...
-albertr
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Looks very promising -- right on!
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Well, I'm gladly presenting the pictures of ever first EuroVan running a 220A alternator ;)
(http://www.iral.com/~albertr/EVC/alternator/IMG_6169.jpg)
(http://www.iral.com/~albertr/EVC/alternator/IMG_6170.jpg)
(http://www.iral.com/~albertr/EVC/alternator/IMG_6174.jpg)
Today I have received INA F-232001 and INA F-557311 pulleys and was playing with them. While both can be shimmed to correct offset, I didn't like how they thread on Valeo alternator - it looks like rotor's shaft on alternators used on MB vehicles might be using longer threads and installing these pulleys on Valeo alternator with proper shims to match offset of AXK pulley is leaving only about 5-6 mm of thread exposed for MB pulley to grip on. So disliking it, I followed Itsamoto's advise to try a non-clutch pulley from stock Bosch alternator. And it works!
Proper spacing - no need to add any shims and it grips right on (the same nut and washer from Bosch alternator were used). Valeo 220A alternator gets excited on EuroVan's idle RPMs and produces 14.3V!
I'm gonna do some review with lots of pictures and my wiring schematics, but being busy at work it might take for me a few weeks...
Basically, it boils down to sourcing a 220A Valeo alternator from 2010-2014 VR6 3.6L Touareg and putting a pulley from stock Bosch alternator on it. Very easy upgrade. No messing around with alternator mount brackets or spacing alternator out to remove belt slack.
Saddle mount is exactly the same as on stock Bosch unit. No changes to exciter circuit. Valeo alternator uses the same connector for exciter wire (on my photo you can see some extra wires, but I had to solder them because the voltage regulator on this alternator had it's socket broken off). Very easy swap and direct bolt-on replacement for EuroVan. It looks like my high-output alternator quest is finally over ::)
-albertr
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Great work! Seems like a perfect upgrade for full campers.
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Cool mod. Two wonderings:
1) curious how MPGs will be affected by this
2) how was the stock 120a alternator failing you/falling short of your needs with regards to charging?
Justin
2000 EVW 5-spd TDI
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Well, if I'm not mistaken, I think mileage might get affected only when alternator is under considerable load, i.e. when it produces more current than stock Bosch 120A unit. AFAIK, if it's not loaded, I consider its electricity "free", more or less. Even if it will result in some mileage drop I'm willing to take a hit in exchange of extra 100Amps.
The reason why I upgraded from stock 120A Bosch unit is to regain ability to charge my coach batteries when driving.
I have upgraded to 300A AGM batteries and using Magnum MMS1012 which charges batteries with current upto to 50A DC.
Here's a short writeup on my electrical upgrade:
http://www.iral.com/~albertr/EVC/battery/battery.html (http://www.iral.com/~albertr/EVC/battery/battery.html)
Assuming Magnum is about 80% efficient I need about 60A*14.3V = 858W delivered to Magnum. The power gets delivered as AC via some cheap no-name chinese 1kW interter, so assuming it's 80% efficient, I need about 1030W (or 1030W/14.3V = 72A ) out of alternator just to charge coach batteries. Running fridge and charging laptops might add another 10-15A. Then all regular demands of van electrical system on top of that.
I'm planning to spend upcoming weekend driving van around the town and on a highway so should be able to measure some currents produced by this Valeo alternator.
-albertr
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Had a few spare minutes to work on a van tonight. I posted earlier that 220A Valeo alternator gets excited on AXK idle RPMs. And it does... when engine is cold and starting RPMs go into 800-850 range. Here's not so good news - when engine is hot and idle RPMs are not crossing 600-650 range, Valeo alternator doesn't get excited. I sorta suspected that it might need a bit higher RPMs, but wait - here's good news - when you step on a gas pedal to bring RPMs up to 800-850 range it gets excited and it **STAYS** excited until engine is shut off.
I don't mind to help it to get excited when starting hot engine, but... here's not so good news - I lost "LOW BATTERY VOLTAGE" indication on the dashboard. So I have no clue whether it's excited or not unless I measure it's voltage output, which is not practical in the field.
I'm pretty sure that I'm using the correct terminal for exciter wire (Valeo alternator has two terminals on it;s connector, but only one - the same as on Bosch unit - produced output voltage). Measuring it;s output shows that it';s around 11V when it's **NOT** excited and around 13V when it is. I ran additional positive and negative 2AWG wires directly from alternator to the battery, so when alternator delivers 14.3V to battery, it reads around 13V on exciter wire, so there's voltage drop. I know that EuroVan is using LED in the dashboard for low battery indicator light. Maybe it doesn't have enough resistance? I can try to put additional passive load in series to this LED to increase voltage drop if it can help it... but I'm curious what voltage reading in on exciter wire with Bosch alternator? I guess it might be different enough so indicator LED works with Bosch unit... Any ideas?
-albertr
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UPDATE: Very happy with 220A Valeo alternator after being using it for a few days now. Valeo alternator can self-excite itself, so no need to use external exciter circuit. I lost "Low Battery" light in the dashboard (it stays off all the time), but that stimulated me to build a digital voltmeter, so now I have very accurate voltage reading in my dashboard (it turned out that microcontroller I picked up for this project has a better ADC than my Fluke meter).
Anyways, I still need to do a full load test to find out the true limits of this alternator, but I ran a quick test and was able to draw 30A DC for my battery charger when A/C is on and headlights are on... and on engine idle RPMs ... and when it's very hot and voltage still stays around 13.6- 13.8V! That looks very promising.
-albertr
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I recently got an 03 Weekender with a bad alternator, and took it to a shop to replace before reading this thread. They added a 90A one (as per the recommended specs according to the mechanic). Well, I have had issues with it not charging enough even the starting battery with load at idle. I took it back to the shop to see if I could get them to upgrade at a reasonable price, but the price for the 120A bump was I think 260 more. I have been wanting to get a 220A one and found one off of a 2017 V6 at a decent price (at this point I am not positive whether it will fit) but the mechanic got me thinking of something else: when he mentioned the only possible upgrade was the 120A he cited among other things the wires running to the battery. I know you mentioned swapping the pulley, but would I need to upgrade them as well is I go with a 220A?
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Wow, sorry I missed your question, since I haven't visited the forums in the last couple of years...
I did "upgrade" the wiring to 24AWG wire between the alternator and the battery and between the alternator and my inverter. I've replaced the positive wire and ran an extra negative wire.
Overall, I'm very happy with my Valeo 220A alternator - while driving, I can run fridge, laptop charger and charge my house batteries all at the same time.
-albertr