I just got my 1983 Trans Am running after 8 years with rebuilt 355 and rebuilt T5, now I remember my car used to show about 16 volts on the gauge years ago with old motor, now it only shows 12-11volts, I went and bought a big new exide battery 875 cold cranking amps, and just bought a new alternator i think was 750 amps inplace of the original. Now im wondering is my H.E.I still firing off at 18 volts? should my gauge show 18 volts? I added an accel super coil, cap and rotor, with new wires and plugs aswell. How can I boost my voltage?

Thanks for any info you may have.

 

the motor is a chev 350 4 bolt main upgraded oil pump, bored.30 over, flat top pistons, hydraulic lifters, smaller chambered heads, crane cam, edelbrock intake holley carb, upgraded timing chain i dunno if it matters but also i should mention the radio isnt in right now so there is not much draw on power.

 

First off, don't trust the gauge, measure the actual voltages with a digital multimeter, with 13.5 to 14.7 Volts being the norm with the car running. Radio or not doesn't matter. 2nd, a car alternator is never 750 Amps.. 3rd, what's that about the 18 Volts?

 

My new alternator is around 750 amps i forgot exact how much, and i was reading in my haynes manual that the H.E.I is supposed to bring the spark or whatever up to 18 volts?

it made sense to me why would they call it high energy ignition if it was 12v then it would just be 12v ignition

 

You must be mistaken about the details about most of these things.

750 Amps is over 10 kiloWatts, which amounts to over 15 horses. That is too much for the belt and pulley to handle. It's 10 times as much as an ordinary alternator. It can't be 750 Watts either cuz that would only be 52 Amps. Are you sure it's not just a model number?

A 12V HEI might survive supply voltages up to 18V, but that's not why it's called HEI. The spark voltage would be in the range of 30-50 kiloVolts, - 18kV is what (barely) keeps your lawnmower going.

Now get those voltages measured or nothing can be said about the state of your charging system.

 

Biggest alternator I have heard of is like, 350amps. But those are for dB drag racing cars.

I learned first hand dont trust the gauges. Mine reads 12v and its powering 13.7 with AC/lights on and idling at 800.

 

well i dunno thats how the parts guys go by i distinctly remember them saying the alternators go up to 850 amps as well but they didnt stock them also the amps were stamped on the alternator, also maybe you are confused? my batery is about 1000 amps and has 875 cold cranking amps?????

 

Alot of parts guys are stupid and tell you the wrong things.

e. http://www.powermastermotorsports.co...ternators.html

 

Ok I officially have a problem, I bought a new battery it went dead so i bought a new alternator boosted the car the battery didnt charge after running it for awhile and was dead, so i took it back to the store the battery failed their charge test and i got a new one. Now it is going dead aswell. I figure it has to be the two wires? thats only thing left right? my mechanic switched the terminals to top post as side are pain in the you know what. and added a new accel super coil and cap and rotor other than that no electrical drain on the batt. So do you know if you can just buy that wire set pre made? is there a way to upgrade it or upgrade the voltage and charging for the car?

 

I am not sure about yours, but on mine, the main wire goes to my battery post, and there is another wire that comes out of the regulator that also goes to the post. There is also (I believe) a ground that comes out of the firewall connector.

(Mines an 89 RS with a serpentine setup.)

As for upgrades, use a thicker positive wire feed? I am running 6ga to the post. I might have to goto a 4. I also have a powermaster 140amp alternator.

 

your right parts guys are stupid i worry like hel# everytime i need a part from them. And i always get stuck with the youngest employee.

But my alternator has 2 wires one ground and i went back to work so i dont have time to look until the weekend but im pretty sure it goes to the starter.
the wires feel cooked or hardened so probaly are toast, either way i wanna do all new wires for power and cahrge system, is there a best way?

Also can someone clear up this alternator jumble bout the amps

And who knows their H.E.I systems?