Working on finding upgraded Alternator info.

[Magnus]

I need more Juice, so I've been researching Alternator options.

I have heard that the Saab 900's & 9000's have the same geometry of our alternators @ 115amps. But, since the S14 is a buzy/peaky little bugger, I am cautious as to using it since it does not use bushings. It is a nice option without the need of a custom bracket.

Stan has suggested that I have the alternator upgraded to a higher amperage output, or maybe using an upgraded /adjustable regulator pumping out around 14.4 volts. I can have the Altr. rewound (stator) to put out anywhere from 130 - 160 amps, as well as increase the volts to 14.4v.

A stock alternator probably puts out anywhere from 35-45amps at idle. But if the stock unit is rewound to 130-160 amps, it will not average down at idle the way a stock unit does. I've been told that at idle a stock Altr. will give you roughly half the amperage amount. But, the rewound unit will give you anywhere from 20-40% of the total peak amps. So a 160amp Altr. might give you 55-60amps at idle (at most).

Someone even suggested using a smaller pulley on the stock Altr. , but I have assured him that my car can hit 1,200 rpms , so the pulley would just get whittled down to a pencil point.

What do you suggest? I want greater power at idle without totally killing the alternator up top during peak amps.

Forget about why, think about how? :idea:

[Nick-NY]

This may be of some interest to you, do you think this will work?

http://bimmer.roadfly.org/bmw/forums...1962834&page=1

[wookie1976]

You think that it is possible to use the "guts" from the Saab alternator and put them into your stock housing? Just a thought, since you said that they were the same dimentions. Did this imply that they were from the same manufacturer and family? I went to alloembmwparts.com and looked up both a '90 M3 and a '90 Saab 900 Turbo alternator. Looks like Bosch made them both, and they have very similar part numbers (F4000-10015 vs. F4000-10012). Maybe close enough to do the swap.?

[Eric]

ouch, 160amps through that 10awg wire! you need an upgrade that wire. first off the stock power wire on my E30 M3 is now 16 years old, the insulator is very corroded, and the wire is corroding as well from 16 years of oxygen beating at it. this creates more resistance in the wire, which could lower your cars electrical performance.

I will have to check my electrical current chart tomorrow, but for 160amps or even 100amps and up I would use at least a 4awg wire for power and ground. I'm using a 0awg wire for alternator to ground, a 4awg wire to the fuse box (old one was too corroded, and I like to upgrade tim allen style) and I ground my engine with 1 0awg wire and 2 4 awg wire's

whatever alternator you use, I would upgrade the wire, with the wiring that I did, I noticed that with all the electrical components on, the car has much less voltage dips (headlights dim etc)

I would like to know what alternator would work, since I'm going to be running a more powerfull stereo soon. I've been thinking doing the 535i mod that somebody else mentioned.

[Stan]

You can put in a ~1990+ 535 voltage regulator to go from 90 to 115 amps and gain some volts, about 15-30 bucks if you shop around. That may be the main electrical difference between the E30 and Saab alternators. You can rewind the guts to gain plenty more and still keep it bolt-on. There are also drop in adjustable VRs. You can gain 1/2 volt for a couple bucks and some tweaking if you interupt the VR ground and solder in a certain diode. My car always measures on the low side of suggested voltage. These days alternators often put out around 14.5 volts. Lots of M3s put out a volt or so lower than that. If you want to rewire the ground could be upgraded and the output wire could be replaced. I haven't traced it but it likely terminates at the power junction behind the coolant tank under the black cover, to the right of the relays as you face them.

Stan

[wookie1976]

I found a good price on the voltage regulator. A generic one from Germany is around 15.64, and a Bosch brand is 41.20. I found these at www.alloembmwparts.com
I have found in the past that their prices are very good, and I usually get my parts in 1-2 days tax and shipping free.
And no Im not affiliated with them!

[Magnus]

Thanks for the replies!

As I've been reseaarching a full upgrade, a guy quoted me a price of $550 to upgrade my alternator. He's nuts! All he would do is order a rewound stator and a upgraded the regulator and install it. The average price for a total upgrade is between $175 - $300 on the web. This is very expensive considering the parts are cheap and the labor does not take long. If you go to a local shop (like 99% of people do), you can have it done for you from around $95-$130 bucks.

Stan (our resident Guru) has also suggested that I upgrade my battery to something with around 900ca. You can imagine the beating my current one is taking.

What would you think the amp idle output would be when the regulator is switched out? Will it be Ample? And when should I really start considering replacing the gauge wires used between my ground and electrical system?

[Reelizmpro]

Magnus, one of the guys on Roadfly who bought an Alpha N kit has a race car that has some sort of high output alternator. I think his name was Jefrem? apparently he has a shop. Might want to contact him about it.

[Magnus]

Thanks. I emailed Him and the guy Nick linked us to.

[Stan]

The won't-start-cuz-the-parked-M3-drained-the-battery-problem is not really a cranking amp thing. It's more of a capacity thing as in amp-hours, another battery rating. You can't use up all the battery capacity because the car won't start way before the battery is fully discharged. Higher cranking amp ratings DO tend to go with higher capacity though. One easy mod for capacity is to use an M5 battery. It goes right into the stock M3 tray, using the other threaded hole for the screw-in mount. It weighs 10 extra pounds. Here's a picture:



I'm playing around with a passive solar battery charger. I wouldn't really call it a charger, more of a maintainer as it puts out only 125 milliamps. But that is way, way more than the parasitic drain the battery experiences in a parked M3, so the battery should hold about even if the gadget gets adequate light each day. Somewhere around 20-40 Ma of parasitic drain and higher and your battery won't start the car back up after some reasonable time parked as a fun car since the battery is being continuously discharged. Many alarm systems draw over 20 Ma all by themselves. Compounding the problem is that M3s tend not to be driven daily, and the charging system tends to charge the battery only part way back up on average. Also, if you deeply discharge a battery once or twice they tend to be weaker from that point onward. The car will still start fine if it is driven regularly though. The solar gizmo is inexpensive, light and can be hardwired. I'm just plugging it into the cigarette lighter receptacle for now. You can get larger ones that can do an amp or so but they cost $100-200, and are larger and heavier.



Stan

[Stan]

>>>I'm using a 0awg wire for alternator to ground, a 4awg wire to the fuse box (old one was too corroded, and I like to upgrade tim allen style) and I ground my engine with 1 0awg wire and 2 4 awg wire's<<<

Nice. Where does the alternator output wire go? To the fuse box on the LHS, to the 12V terminal near the relays on the RHS, or somewhere else?

Stan

[wookie1976]

This is a great page on wire information!
http://www.epanorama.net/documents/w...esistance.html
Should answer all of your wiring questions

[Magnus]

Ha! That site doesn't help with my dyslexia. Is there a scratch an sniff version?

[Stan]

>>>Nice. Where does the alternator output wire go? To the fuse box on the LHS, to the 12V terminal near the relays on the RHS, or somewhere else?<<<

Found it. According to the ETM (Electrical Troubleshooting Manual), the Alternator output wire is 10 square mm in cross section (about 6-8 gage). It goes to a splice which also leads to the Starter 12V input, the battery junction near the coolant reservoir, and diagnostic connector pin # 14. The ETM doesn't show the gage of the alternator ground but it should be of the same gage or thicker than the output wire.



Stan

[Nick-NY]

I used to have the same "Die Hard" M5 battery, Boy was it heavy,it worked well for a few years and died a slow sulfated painfull death similar to all the others. So now i have a Optima gel redtop starting battery, still the battery has let me down over the winter.
Thank god for the invention and cost effectiveness of the portable jump-starter box.