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Ultimate High Output Bosch Alternator fits 1985-1995

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Old 12-13-2016, 08:50 PM
  #91  
GregBBRD
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Originally Posted by Speedtoys
Ill take that kit as well.

Any chance to visit and knock out some of our issues over holiday??
PM sent.
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Old 12-13-2016, 09:33 PM
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Upate from me. :-)

Day to day here in LA, in traffic and on the "parking lot conveyor belts" aka Freeways, i see a constant 14-14.2 while moving. Heat soaked (been kinda cool here), the lowest is 13.6-13.8. WAY better then the low 13's and mid 12's i was seeing with the Delco
Old 12-13-2016, 10:10 PM
  #93  
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Originally Posted by Ducman82
Upate from me. :-)

Day to day here in LA, in traffic and on the "parking lot conveyor belts" aka Freeways, i see a constant 14-14.2 while moving. Heat soaked (been kinda cool here), the lowest is 13.6-13.8. WAY better then the low 13's and mid 12's i was seeing with the Delco
What is the story on that Delco alternator? It appeared to have some sort of an adapter bracket to be able to mount it onto the stock 928 bracket.

Who came up with that idea/adapter?

Any idea on how many amps it made, before it got hot? (Old design Delco without exposed windings.....they get really hot.)
Old 12-13-2016, 11:33 PM
  #94  
EMan 928
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Greg, please put me down for one for Turq. Please include what else you think I need since it has your AC upgrade.
Old 12-14-2016, 12:20 AM
  #95  
Alan
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Originally Posted by Speedtoys
Silly question...

Is a voltage drop always the same across a bad connection, regardless of the voltage being fed to it and load behind it?

I want to say "yes".
No - it varies hugely dependant on the resistance. In a highly resistive case you can drop essentially all the voltage across the extra series resistance so the load gets ~nothing or it could be a matter of microvolts dropped that you would never even notice. It is likely that most poor connections will simply get worse over time - oxidation or corrosion continues to worsen - heat causes faster degradation so resistance goes from low to high over time too. You don't need much degradation to start to notice it. Voltage drop is also usually approx proportional to the supply voltage - it varies if that voltage varies.

Alan
Old 12-14-2016, 12:54 AM
  #96  
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Thanks Alan..ive learned some fun new stuff this week.

Ill be hunting down and exploring voltage drop areas around my car this weekend I think.

Now..can you also see a drop on the ground side too..not just in the '+' current path of a circuit?

Like..from the head of a bolt at a ground point to the '-' post of the battery?
Old 12-14-2016, 04:22 AM
  #97  
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Yes. Before or after the main load, resistive elements are all part of the complete circuit, between '+' and '-'. Example in a simple 12V circuit .... 20 ohm load, with 5 ohm resistance before, and 5 ohm after ... '+' to load would measure 2V, across load 8V, and from load to '-' 2V. Every single resistive element (e.g: poor connection or low rated cable) in a circuit will have a measurable voltage drop across it, no matter where it is in the circuit.
Old 12-14-2016, 08:15 AM
  #98  
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Exactly what Dave said!

And note that all conductors (esp small wires) have intrinsic resistance per length, so even before any contact degradation etc there are always some series resistances to the loads - they are just small.

Alan
Old 12-14-2016, 11:38 AM
  #99  
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Originally Posted by GregBBRD
What is the story on that Delco alternator? It appeared to have some sort of an adapter bracket to be able to mount it onto the stock 928 bracket.

Who came up with that idea/adapter?

Any idea on how many amps it made, before it got hot? (Old design Delco without exposed windings.....they get really hot.)

I will have to dig in to some emails, but someone on here with machining skills made that adapter. i want to say it was an 108 amp Delco off of an mid 80's V6 camaro. It worked, but heat was not its friend.
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Old 12-14-2016, 11:49 AM
  #100  
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Originally Posted by Ducman82
I will have to dig in to some emails, but someone on here with machining skills made that adapter. i want to say it was an 108 amp Delco off of an mid 80's V6 camaro. It worked, but heat was not its friend.
I used a marine bilge blower behind the left front grille to blow cool air through a 3" duct to cool my aftermarket alternator. It makes a huge difference on a hot day.
Dave
Old 12-14-2016, 12:47 PM
  #101  
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Originally Posted by Ducman82
I will have to dig in to some emails, but someone on here with machining skills made that adapter. i want to say it was an 108 amp Delco off of an mid 80's V6 camaro. It worked, but heat was not its friend.
Not too difficult to understand why that alternator was affected by heat.

That Delco alternator, like our original Bosch alternstor, has one fan, which draws air through the back, flowing through the interior, and out the front. The "current generation" coils are externally surrounded by the aluminum housing.

When there is a rear plastic cover, like on the stock alternator, the cooling air comes from a remote, cooler, location....which helps some. With that Delco unit, the cooling air comes from behind the alternator, which is pretty hot, in our application.

It had to get very hot, which explains why you lost so much efficiency as the engine got hot.


Never alternator designs (like I used for my upgraded alternator) have two fans, with the "current generation coils" exposed through vent holes in the aluminum, to cool them down much more efficiently.

Pretty cool!
Old 12-14-2016, 12:48 PM
  #102  
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Originally Posted by j.kenzie@sbcglobal.net
I used a marine bilge blower behind the left front grille to blow cool air through a 3" duct to cool my aftermarket alternator. It makes a huge difference on a hot day.
Dave
Great idea!
Old 12-14-2016, 01:03 PM
  #103  
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marine bilge blower
In stock and ready to ship 8>)
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Old 12-14-2016, 01:08 PM
  #104  
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I tried a couple of blowers before I found a quiet one. This is what I used:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I'm sure Roger's is great too.
Dave
Old 12-14-2016, 08:49 PM
  #105  
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Originally Posted by GregBBRD
I don't think anyone has any "serious concern"....just general interest in how the free wheel pulley works and what affect it has under quickly decreasing engine speeds.

When I started this project, some two years ago, I considered many different alternators for my starting point. While some may have fit easier, they didn't "make the cut" in terms of the performance and reliability I was looking for.

The alternator I picked to use comes from a later model 911 (and variants), which all have a hellish engine compartment temperature and high rpm potential (the 911 and 911 variant application has a slightly larger drive pulley size than our 928.)

Frankly, if the alternator can work in a 911 engine compartment (which has temperatures several hundreds of degrees higher than we will ever see in our location) and can survive the rpms of a 911 engine, my intended application was a "walk in the park" for this alternator.

As an added bonus, its made from all brand new components (not rebuilt), completely designed by Bosch (legendary reliability and performance, not "tweaked" by some alternator rebuilder with his own "backyard theory" on how to make more power), has twin internal cooling fans, exposed coils, has this great one way clutch (which significantly reduces belt heat and wear), and was close to what I needed to fit in the 928 location.

This seemed like the perfect starting point for what I was trying to make.....all I needed to do was make it fit.

Here it is....I think it is beautiful....and it works like a dream, in the 928 application.
Just an added note on the Bosch alternators...I had the original alternator in my early '86...still chugging...I had converted it to electric cooling and had same issue everyone else has...low rpm charging...got a souped up version from some folks that added extra windings or something and brought it up to 150 amp..otherwise I'd be signing up for one of yours Greg...I have always admired the quality you put into your executions...

Unbelievable how tough these alternators are...30 years for mine??? No american car would ever have an alternator last that long...


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