Trippi's Hummer the Final Chapter (Eye Candy on page 36 & 52)

[ProMaxx316]

dem yoga pants tho.

I'll be honest i was staring at that pic for a while to the point where i started to drool a little.

[Lbox88]

I'd be more concerned about just belt stretch/breakage than actual pull on the engine, it's not like he's powering these with a little 4 cylinder.

At startup, it's going to take a couple 2-3 seconds for the field current to get the alts up to charge at 15.8V from first fire. That is also not going to be at a full 100% draw on the alts unless the batteries are completely depleted.

Now just to do some out loud thinking/typing:

In electrical power, 1HP = 746W

So since P = I*V, and these are 300A alts (IIRC?)

We can say 300A * 15.8V = 4740W

4740W * 12_alts = 56,880W

56,880 / 746 = 76.247

So the alts will in a sense be stealing roughly 76HP from the engine to run at full draw.

Gotta remember, when the alts aren't turned on the resistance they provide isn't ungodly, I know I could turn mine just fine.

[03 Xtreme Fosgate]

And Keith77 for the win again. Thank you soo much for that sir.. I had to quote just so everyone could see this again..

[Keith77]

Can always count on Keith to provide some yoga pants lol.

dem yoga pants tho.

I'll be honest i was staring at that pic for a while to the point where i started to drool a little.

[Wicks]

I'd be more concerned about just belt stretch/breakage than actual pull on the engine, it's not like he's powering these with a little 4 cylinder.

At startup, it's going to take a couple 2-3 seconds for the field current to get the alts up to charge at 15.8V from first fire. That is also not going to be at a full 100% draw on the alts unless the batteries are completely depleted.

Now just to do some out loud thinking/typing:

In electrical power, 1HP = 746W

So since P = I*V, and these are 300A alts (IIRC?)

We can say 300A * 15.8V = 4740W

4740W * 12_alts = 56,880W

56,880 / 746 = 76.247

So the alts will in a sense be stealing roughly 76HP from the engine to run at full draw.

Gotta remember, when the alts aren't turned on the resistance they provide isn't ungodly, I know I could turn mine just fine.

Funny...I was just thinking about doing this math when I scrolled down to your post

The thought just hit me....damn with 12 Alts, that must require a lot of HP to run at full tilt.

Considering the Alts aren't 100% efficient either, they probably draw a bit more then that as well.

I wonder what a Hummer engine (6.0 liter I believe) does at idle?

Suppose those Alts would stall the engine if you hit the system at idle...........

[n8ball2013]

depending on year. the hummers engine is either 395 08-09, 325 07- 05, or 316 hp 03-04 at 5000 rpm. I dont know what year this is

[Lbox88]

I'd be more concerned about just belt stretch/breakage than actual pull on the engine, it's not like he's powering these with a little 4 cylinder.

At startup, it's going to take a couple 2-3 seconds for the field current to get the alts up to charge at 15.8V from first fire. That is also not going to be at a full 100% draw on the alts unless the batteries are completely depleted.

Now just to do some out loud thinking/typing:

In electrical power, 1HP = 746W

So since P = I*V, and these are 300A alts (IIRC?)

We can say 300A * 15.8V = 4740W

4740W * 12_alts = 56,880W

56,880 / 746 = 76.247

So the alts will in a sense be stealing roughly 76HP from the engine to run at full draw.

Gotta remember, when the alts aren't turned on the resistance they provide isn't ungodly, I know I could turn mine just fine.

Funny...I was just thinking about doing this math when I scrolled down to your post

The thought just hit me....damn with 12 Alts, that must require a lot of HP to run at full tilt.

Considering the Alts aren't 100% efficient either, they probably draw a bit more then that as well.

I wonder what a Hummer engine (6.0 liter I believe) does at idle?

Suppose those Alts would stall the engine if you hit the system at idle...........

Funny you say that because it hit me after I posted that there is still going to be more loss than that because all I posted was the power out And I have no real way of calculating the power in. If I assumed that alts were 76% efficient at producing power from what they're given then we'd be looking at robbing the engine of 100hp, but I have no idea how close that is to what the actual values are.

[Wicks]

I'd be more concerned about just belt stretch/breakage than actual pull on the engine, it's not like he's powering these with a little 4 cylinder.

At startup, it's going to take a couple 2-3 seconds for the field current to get the alts up to charge at 15.8V from first fire. That is also not going to be at a full 100% draw on the alts unless the batteries are completely depleted.

Now just to do some out loud thinking/typing:

In electrical power, 1HP = 746W

So since P = I*V, and these are 300A alts (IIRC?)

We can say 300A * 15.8V = 4740W

4740W * 12_alts = 56,880W

56,880 / 746 = 76.247

So the alts will in a sense be stealing roughly 76HP from the engine to run at full draw.

Gotta remember, when the alts aren't turned on the resistance they provide isn't ungodly, I know I could turn mine just fine.

Funny...I was just thinking about doing this math when I scrolled down to your post

The thought just hit me....damn with 12 Alts, that must require a lot of HP to run at full tilt.

Considering the Alts aren't 100% efficient either, they probably draw a bit more then that as well.

I wonder what a Hummer engine (6.0 liter I believe) does at idle?

Suppose those Alts would stall the engine if you hit the system at idle...........

Funny you say that because it hit me after I posted that there is still going to be more loss than that because all I posted was the power out And I have no real way of calculating the power in. If I assumed that alts were 76% efficient at producing power from what they're given then we'd be looking at robbing the engine of 100hp, but I have no idea how close that is to what the actual values are.

Hmmm, maybe toss the Hummer on a vehicle dyno and get some HP numbers at idle and at speed(rpm).

Then apply a known load to the Alts and do some measurements.

Should be able to figure out the HP difference and then be able to tell how much power is going into and out of the Alts.

Yeah, off hand I don't know how efficient a typical alternator is?

This would be an interesting test, especially with the sheer number of Alts compared to a usual system.

[iwannabeloud]

[basebalz13]

Like I said, please no one respond to Dom and feed into him. Only thing I'm going to respond about is me wrecking the batts for letting them "sit". They haven't been wired up and maintained with the intelli battery chargers... Probably why when you got it they was not low.