Reutterwerk Forums
Go Back   Reutterwerk Forums > Porsche Water Cooled Forums > 928 Forum

Notices

Reply
 
Thread Tools Display Modes
Old 07-23-2017, 07:48 AM   #1
928gene928
User
928gene928 is on a distinguished road
 
928gene928's Avatar
 
Join Date: Feb 2009
Posts: 54
Thanks: 0
Thanked 3 Times in 3 Posts
Default Alternator Conversion

Really tired of my stock alternator not keeping my battery fully charged, and the low charging voltage. Don't drive the car every day, so I keep a trickel charger connected in the garage.

I see where folks have installed the 1988 Camero 105amp alternator, with excellent results. Looks like I'll be making the conversion very soon
928gene928 is offline   Reply With Quote
Old 07-23-2017, 09:19 AM   #2
GlenL
Workin' on it
GlenL will become famous soon enough
 
GlenL's Avatar
 
Join Date: Apr 2009
Minneapolis
Posts: 674
Thanks: 70
Thanked 52 Times in 45 Posts
Garage
Default

What alternator do you have and what are the voltage measurements? The dash gauge is fairly useless unless the alternator is not working.
__________________
1980 928S Euro
1987 944 N/A
GlenL is offline   Reply With Quote
Old 07-23-2017, 10:26 AM   #3
928gene928
User
928gene928 is on a distinguished road
 
928gene928's Avatar
 
Join Date: Feb 2009
Posts: 54
Thanks: 0
Thanked 3 Times in 3 Posts
Default Alternator Conversion

Glen,
Awhile back I measured about 13V. Also have done all the ground clean-ups, and connections to the alternator and ignition circuit. Also made sure the belt wasn't slipping. Have notice that with air conditioning and accessories on things just get worse. Considered adjusting the internal regulator by changing a resistor as described by others, or getting a high output 928 alternator. Frankly the Porsche units are too expensive, compared to $80 from the local auto parts store, with a nice replacement guarantee.

Have also changed the battery a couple of times.

I see from research that many folks have had similar issues, so it's time for a change.

Based on what I have read on-line, the conversion is easy, and provides 105amps. I'll be at the parts store tomorrow.
928gene928 is offline   Reply With Quote
Old 07-23-2017, 11:21 AM   #4
GlenL
Workin' on it
GlenL will become famous soon enough
 
GlenL's Avatar
 
Join Date: Apr 2009
Minneapolis
Posts: 674
Thanks: 70
Thanked 52 Times in 45 Posts
Garage
Default

Some guys complain about the alternator from their dash gauges. Those do all kinds of things like sag as the battery charges. It's just the resistance in the grounds making the meter think bad thoughts.

If it's giving 13.5V (or close) at the jump post when idling then the alternator is doing its job. Turn on the accessories for a test. The alternators are voltage-regulated so it only puts out the current needed to maintain the target voltage. Higher-rate alternators, in Amps, won't necessarily raise the system voltage.

(Translation: a bigger alternator may not solve your problems and you may still need that battery maintainer.)

As for Porsche, the Bosch units are better (IMHO) as they are easily rebuildable for brush and diode failures. Those come in a handy module that attaches from the outside. At least in the past, local parts stores offered Bosch "928" alternators that are really off Audi's but fit and work...except for that the shroud doesn't mount up.
__________________
1980 928S Euro
1987 944 N/A
GlenL is offline   Reply With Quote
Old 07-23-2017, 03:35 PM   #5
928gene928
User
928gene928 is on a distinguished road
 
928gene928's Avatar
 
Join Date: Feb 2009
Posts: 54
Thanks: 0
Thanked 3 Times in 3 Posts
Default Alternator Conversion

Glen,
Thanks for the advise. This is a story that has been going on for years, and based on what has been said about the results by others, it is an inexpensive experiment. I will keep my original unit as a spare. As usual, I have dozens of projects underway at all times, and should get this one done fairtly quickly.

Will let you know how it works out.
928gene928 is offline   Reply With Quote
Old 07-24-2017, 07:44 AM   #6
CurtP
Super User
CurtP is a name known to allCurtP is a name known to allCurtP is a name known to allCurtP is a name known to allCurtP is a name known to allCurtP is a name known to all
 
CurtP's Avatar
 
Join Date: Jun 2009
Virginia Beach, VA
Posts: 3,272
Thanks: 634
Thanked 539 Times in 372 Posts
Default

I hope you meant battery tender, not trickle charger.
CurtP is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 07:44 AM.


Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
DTO Garage vBulletin Plugins by Drive Thru Online, Inc.

Skin design by bogu@project-voyageur

Copyright 2008 - 2015, Reutterwerk.com