TPI alternator options

[MaineShark]

Okay, so TPI needs more power than the stock alternator is able to provide. What are my options?

I've heard that the alternator from a 1991 'Vette is a good idea. Any particular reason for that specific year, and specifically the 'Vette alternator? Will it mount to the original bracket, or will a new bracket be required?

Joe

 

[Stallion]

The TPI is a fuel injection system, right? What exactly does an alternator do and what is its purpose in the system?

Thanks and good luck with everything!

TR

 

[MaineShark]

Alternators produce electric power to run the electrical systems on the car. There is also a battery, but that is just to store power (to start the car, as well as to run accessories like the radio, when the engine is off).

A car with a carb has limited electrical needs. Ingition system, lights, guages, radio, etc.

A fuel-injected car has added needs. Draw from the computer is there, and the fuel injectors, themselves, draw a pretty decent amount of power. The electric fuel pump also draws quite a bit. It all adds up to the need for an alternator which can produce more power (about half again as much as the stock alternator can handle).

There are two ways to increase power: more volts, or more amps. Now, voltage is sort of like water pressure, and amperage is sort of like the physical amount of water which flows. Either could be increased in order to increase the power, but it is much easier to just increase the amperage, and leave the voltage the same. Again using the water analogy, imagine a pair of faucets attached to the same pipe. And then imagine that you need more water out of one faucet. If you increase the pressure, you may cause leaks. If you increase the amount of water that flows through the pipe, the second faucet can draw more of it, and you don't risk leaks.

The same way, increasing the voltage can cause damage to some components, due to the increased electrical "pressure." Increasing the amperage merely allows the components that need more power, to draw it, without forcing more on others.

So, you keep your stock 12-volt (really, 13.4V, but that's just a matter of labelling) system, and increase the amperage rating of the alternator.

Joe

 

[topless82vette]

maineshark

GM has the large style alternators in up to 94 amp had one on my 84 trans am, the 91 alternator that your talking about is the smaller one and it wont directly bolt in

 

[Stallion]

Okay, I understand what you mean, Joe. Where exactly is the alternator located in the Corvette? Something that if you open the hood you'll easily see?

Thanks!

TR

 

[KANE]

If you need more thump.....

You can use a 91 vette alternator but you need to swap out the serpentine pulley for a v belt pulley. You will also need to swap out the connector for the 91 style as well.

You can get one good for 105 amps for around $100.

 

[KANE]

Oh-

The 91's case lines up with the original brackets. Its a 12 o'clock accessory and tension bolt arrangement, just like the original 10si. Dimensionally, its a little smaller.

 

[MaineShark]

I'm assuming that the pulley's just have a set screw and a keyway, right? Same shaft diameter and all?

Is there any particular reason why the 'Vette alternator is favored over the others? Or is it just a matter of the smaller size looking nicer and weighing a little less?

And why '91? I can see the 'Vette having a smaller, lighter alternator, but usually you see a range of years being discussed. This specific referrence to a single year is making me curious.

What are the pros/cons of the '91 'Vette alternator vs. the higher-amp version of the original-style alternator?

Stallion: you'll see it. It's one of the forward accessories, driven off the belt system at the front of the engine. There are generally two large accessories at the top: alternator and air-conditioning compressor. The alternator is on the left in the C3's (at least, on every C3 that I've looked at).

Joe

 

[Stallion]

Okay, thanks a lot, MaineShark! And good luck with everything!

TR

 

[KANE]

In 10 years, I have replaced about four of the original 10si-s. I have not replaced omne of the new style alternators.

 

[phoenix73]

I am putting in the summit 100 amp one wire alternator. $89 shipped (black).

I like the clean look of the one wire, but from what the EFI documentation says, they recommend not switching to a single wire alternator, although I am not sure why.

 

[patsnitrovette]

Maineshark,you can change the serpentine pulley over by removing the nut and putting the vbelt pulley back on.Im running the smaller 10si on mine.

 

[MaineShark]

Thanks for the input. I guess I will go with the '91 'Vette alternator, if it will bolt right up, and only needs a pulley and connector swap.

I'm still curious why '91 (instead of '90 or '92, or some other year) is so special. Anyone know?

Joe