S4ordie

I am very interested in Carl's 200 amp alternator upgrade. I sent an email through his website to get more information about low idle performance but did not hear anything back.

http://www.928motorsports.com/parts/alternators.php

I am adding additional electronics to my car (HO audio+DVD+GPS+....) and I am concerned about low idle, heavy traffic, capability of this high amp alternator. It is my general understanding that high ouput alts work well at higher rpms but not so well at low rpms.

Worst case scenario: stuck in traffic, night time, raining hard (wipers front and rear are on), all lights on (headlight/fog) A/C on high, engine fans whirring, DVD and GPS on.... you get the idea.

I don't think the stock altrnator will meet these requirements. Carl's sounds very interesting but I don't know the low rpm output.

Thanks for any real world information about Carl's alternator or other options with the stock alternator.

Yes, I have read many of the posts about alternators, but never really learned what works for my car.

danglerb

I think Carl is doing Pikes Peak this weekend.

I can't speak specifically to Carl's alternator, but in general alternators have improved, and various pulley options should be able to spin the alternator at whatever speed you need at idle. Good solutions do exist if you need them.

I am not very big on preemptive alternator improvements, or really much of any change from stock until I know whats really needed. Many high amp draws are infrequently used, and I have to wonder about how essential it would be to run the stereo at full blast at night with defroster, defogger, windshield wipers etc. all on at the same time.

BBX

Hey Dan, would your car have any problem powering all those accessories you mentioned as it is now? I'm just curious, but maybe with a really good battery like an Optima? you shouldn't even need a higher power alt.

S4ordie

Mike, I live in the rainiest area on earth. (five miles from my house averages 480 inches / 1220 cm per year. That is avg. 1985 had 860 inches 2180 cm) There is also ample tourist traffic. The worst case scenario I presented is not all that infrequent. Very heavy rain with high humdy and temps at night are pretty possible on any given day.

Sooooooo the low rpm high amp draw requirement is likely when I consider the electronic enhancements along with the other systems, AC, wipers on high, fan(s), lights on, etc. They all tend to run at the same time.

Still interested in feedback on Carl's 200 amp alt or other solutions.

j.kenzie@sbcglobal.net

I have one of Carl's high output alternators on my 84 and it is very nice. I used the smallest diameter pulley I could buy, in order to charge at idle. That is apparently the main potential shortcoming of these units.

S4ordie

Hey Blythe - don't know for sure as the car is still on the mainland for paint, Doc Brown massage and some Champagne. Just want to have all systems sorted before bringing the car here. At 115 amps, the stock alt seems a little anemic already. Adding additional amp eaters on top of the increased electrical loads induced by environment here as well as information I have read from other Rlisters about weak alts, makes me think I need to upgrade.

I think the older cars have lower output alts (85 amp) but less computers so less draw.

S4ordie

Thanks Dave. Others have suggested smaller crank pulley as well. If it is that easy then perhaps the stock alt will work fine. What I'd really like to see is an output chart from idle to 3,000 rpm. That will tell me all I need to know.

j.kenzie@sbcglobal.net

Carl sells Mechman generators with custom mountings. You can find an output chart on their website.
They are very nice items/

BBX

The list of items you listed aren't exactly high draw items. Unless you have some 2000w plus stereo with a large screen (13inch +) dvd unit, I can't see it causing any strain. GPS barely draws anything, the wipers probably draw the most? A/C runs off the engine right, and not voltage?

j.kenzie@sbcglobal.net

Lights, A/C fan, wipers, A/C blower are all high draw items. Add a performance stereo, and your alternator can be hurting.

BBX

I see, I see

S4ordie

Thanks Dave. I'll check out Mechman website for output....

Generators? That is so 1950's

no doubt

Where does one find an easy way to order a smaller pulley for a 928 alternator?

JoeTaylor

Hi Dan,

Unless you are blowing fuses or draining your battery dead while you are driving - IE, you are having problems, I wouldn't worry about a higher amp alternator. You are ok.

VTY,
Joe Taylor

GregBBRD

That's not the hard part.

Where do you find a belt to make that tight of a turn at 30,000 rpm's?