I know this is a common subject, but I think a lot of the purpose is lost when discussing batteries and alternators. I will show you what I have, what it does, and why that important.

First, the battery. I suggest getting an Optima. These batteries are amazing. They hold a charge above 12V on the shelf with no charging. Mine has 13V after 6 months on a shelf. I put a tender on it, and I got 13.30V. Now, here's the amazing part, and I snapped a pic to show you.

I started the engine, and with the alternator not at full output...meaning the engine was at idle...I had 15V !!!

For anyone who understands...that's amazing. 15Vs will make any and all of your electrical accessories and equipment run better and faster. 16V would be the limit before having to upgrade the wiring.

I believe the key to this 15V system voltage is the yellow top Optima...but part of it is an upgraded alternator. I installed a CS130 in my car. It's a newer alternator that I switched to a V-belt pulley, and spliced a CS plug where the old SI plug was. It runs great, and as you can see...at idle...I have plenty of system voltage.

 

Here's a pic of the CS130 installed, and a good idea of how I wired it.

 

I am not trying to be a downer, but 15VDC is too high, and will eventually cook your battery....maybe your regulator is not working properly.

Here is a good tech article from MAD: http://www.madelectrical.com/electri...witworks.shtml

Scroll down to the section "ALTERNATOR, VOLTAGE REGULATOR and BATTERY".

 

I'll test at the alt with a DMM and see what it's putting out. I did this before I installed the Optima and it was just a hair over 14V so I don't think the regulator is cooked. Also, the Optima went into the car and was immediately raised to a full 13.30V charge by a Tender.

 

Why didn't you get the CS144

 

Because I had 3 free CS130s laying around from when I bought all the TPI and serp stuff. I didn't pay for one of them. I gave one away, and picked the the one that looked the best for the engine. It's temporary anyway, since the new LT1 405 that's going in in the spring is going to have a pair of CS130s.

I like the smaller look of the CS130 also.

 

why do you need all that current? I have ECU, Injectors, Electric guages, Fuel Pump, Lights, 16" spal fan,.... all on 86A

What you could do is to establish your current needs and size everything to work together...

IMHO

 

Add to what you have, a stereo that pulls around 100 amps. I don't want the lights to dim when I drive at night with the stereo on and the fan going. With the pair of CS130s, I'll have just over 200 available amps at idle, and slightly more when at RPM with a steady draw. Obviously, they won't make that much unless the system is calling for it.

 

So the case of the 144 is larger, is it to large and I would have trouble mountong it. Is the 144 a much better altenator or are they about the
same

 

The CS144 does have a slightly larger case, and is prone to a cooler operating temp while at or near full output. The CS144 will fit most small blocks, but you will have to either lower the adjustable support arm a bolt on the block, or cut it down a little. Also be aware which case the CS144 you have has, as there are a few different case styles with different mounting locations.

 

I had my alternator dynoed at 52A @800 engine RPM...

This is my sound system before installation...

 

Great looking motor man. What alternator did you use? If it's a CS, even the smallest one...it'll make more or less than the 52 amps based on what's drawing. Did you have fans, lights, or anything else on? If not, and the battery was absorbing most of the draw, the alt will do just enough to 'keep up.' Hens the 52 amps.

A CS should put out almost 100 amps at idle IF there is enough draw to require that output. That's all.

By the way...I too like the sound of my Vette engine...and that's why there is a stand by button of the head unit.

 

Yes i think it should be 6 oclock position

 

Well the 6 o'clock part doesn't change. It's either 10 & 6, 12 & 6, or 2 & 6. Your stock SI alt will probably be 12 & 6.

 

12and 6 sound right

 

I'm familiar with DC circuits.

Alternators have a very definite output/shaft rpm curve. The dyno run is into a load bank.

You usually need 900-1000 shaft RPM to get output and in general 5000 Shaft RPM to get maxumim output.

I blew (bad bearings) up two of those Reman Delco 10SI's in less than 500 miles...

I went with at Denso Race Shop unit... Balanced and geared to my particular RPM range and load. No Issues at all... also switched to a 20mm belt from a 10mm belt.
1000 miles and multiple runs to the far side of 5800RPM and no issues.

 

So you're still using an SI alternator? They were known to have a big difference between idle and high RPM outputs. I'm no expert...I'm just saying that's a common idle amperage for a low output SI alternator.

 

No a Denso.

 

Hmm. Well no matter. I have it planned out pretty well I think. Two alts, a good battery, and upgraded wiring. At least I won't have to worry about electrical short comings.