Bosch Long Haul Alternators - anyone tried one?
11-07-2011, 11:29 AM
#17
Electron Wrangler
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Anyway - need to figure out if it could fit, its actually easier to find details on the internal components than on the case dimensions.
Alan
11-07-2011, 12:20 PM
#18
11-07-2011, 09:01 PM
#19
High Temperature Resistance
The Bosch Long Haul Alternators can really take the heat! At operating temperatures of up to 125°C (257°F), the Bosch AL9960LH and AL9961LH sustains operating amperage better than competitive units to supply more power for critical electrical systems.
Regulator Self-Protection
At 125°C, the Bosch self-protection feature reduces output of the alternator temporarily. Output goes back to normal after the extreme temperature subsides. This feature protects the alternator from any permanent damage.
12-25-2012, 04:15 PM
#21
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Jeff-
Hans has done a bunch of work on sourcing a hotrodded alternator, and one is currently working just fine on Dan's Turquoise car. Hans was worried about fitment, since the prototype he had re-wound used an S4 alternator case, which has its ‘adjustable’ insert on the front half of the alternator mounting ears, while the ’91 and ’93 alternators 928 603 001 05, which was used ’90-95, FWIW) have the insert on the rear. I measured the width between the mounting ears on Dan’s 91 and my 93, as removed from the car, and they’re both 80.75 mm.
Hans’ alternator measured about 80.35 mm, so I pressed the insert forward using a C-clamp and 2 sockets. When moved fully forward in the ‘ear’, the space between the ears is 81 mm, so it should snug up when mounted just fine.
The alternator section of the S4 crank pulley is about 139 mm in diameter at the ribs (may be a bit bigger than that, my calipers are too small to reach across the full diameter..), while Hans’ alternator pulley is 40.95 mm. I get 49.5 mm for stock. Putting that into a pulley calculator gives a 21% increase in rotation speed. So at 6500 rpm Hans’ alternator is gonna be spinning at 22000 rpm, while the stock alt would be turning 18200. Likewise at idle.
Hopefully Hans can chime in with current pricing and availability. If I needed a replacement alternator, this is the way I'd go.
I test-fit the alternator on my GTS for a while, I can't say I did any actual voltage measurements while it was on the car but it didn't seem to mind being 20% overdriven at 7000 rpm during some spirited launches.
Looks stock, is not:
Hans has done a bunch of work on sourcing a hotrodded alternator, and one is currently working just fine on Dan's Turquoise car. Hans was worried about fitment, since the prototype he had re-wound used an S4 alternator case, which has its ‘adjustable’ insert on the front half of the alternator mounting ears, while the ’91 and ’93 alternators 928 603 001 05, which was used ’90-95, FWIW) have the insert on the rear. I measured the width between the mounting ears on Dan’s 91 and my 93, as removed from the car, and they’re both 80.75 mm.
Hans’ alternator measured about 80.35 mm, so I pressed the insert forward using a C-clamp and 2 sockets. When moved fully forward in the ‘ear’, the space between the ears is 81 mm, so it should snug up when mounted just fine.
The alternator section of the S4 crank pulley is about 139 mm in diameter at the ribs (may be a bit bigger than that, my calipers are too small to reach across the full diameter..), while Hans’ alternator pulley is 40.95 mm. I get 49.5 mm for stock. Putting that into a pulley calculator gives a 21% increase in rotation speed. So at 6500 rpm Hans’ alternator is gonna be spinning at 22000 rpm, while the stock alt would be turning 18200. Likewise at idle.
Hopefully Hans can chime in with current pricing and availability. If I needed a replacement alternator, this is the way I'd go.
I test-fit the alternator on my GTS for a while, I can't say I did any actual voltage measurements while it was on the car but it didn't seem to mind being 20% overdriven at 7000 rpm during some spirited launches.
Looks stock, is not:
12-26-2012, 10:29 AM
#23
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interesting. last winter when doing a LOT of work, decided to install a bosh rebuild from Roger. why? just because I have everything out and the existing one was not original and looked old. but was working fine.
full disclosure, installed a set of MSDS headers too.
even with the rear cover and cooling hose up into the fender, when temps are 90+ and in slow traffic I see my alt needle really drop low. get going and cool it down, charging returns to normal.
don't really know if I had this issue with the old alt, as until I got the AC rebuilt and working I did not drive in 90+ temps.
full disclosure, installed a set of MSDS headers too.
even with the rear cover and cooling hose up into the fender, when temps are 90+ and in slow traffic I see my alt needle really drop low. get going and cool it down, charging returns to normal.
don't really know if I had this issue with the old alt, as until I got the AC rebuilt and working I did not drive in 90+ temps.
