Turning an alternator into a motor (while still being an alternator)

[Frank Lee]

How much gain do you expect from <2HP assist?

[Christ]

Well, in a small car, that's half the power it takes to maintain 40MPH right?

[Frank Lee]

Thus putting the ICE into an even more inefficient state of unloadedness?

[Christ]

Well, yeah. Duh. LOL

[Frank Lee]

OK, it's no good for cruising... how much does it help during acceleration?

[bestclimb]

so at what, 50 hp for a 3 cyl metro add 2 (optimistically) and you now have 52 hp to accelerate with.

stock:
1376 lbs and 50 hp= 27.52 lbs/hp
a 0-60 of 13 seconds

with 2! extra hp:
it's 1376 and 52hp= 26.46 lbs/hp
a guess of 12.5sec 0-60 at a very optimistic gain.(13/27.52=.472=12.49) This is a very very best case situation, as a car heavier than a metro, or more powerful than a metro (IE just about any other car on the road) will have less performance change due to higher weight and higher horsepower premod, also 2hp is extremely generous. If using a lower gas power setting for acceleration 2 extra hp would help a little more. How long would the belt/belts last getting subject to near their maximum holding power (both for the discharge and recharge)

To recharge after the acceleration the alt would be drawing more power (putting more load on the engine and reducing cruise MPG till the battery is topped off)? If so the maths that I would do before even investigating how to go about doing it is to figure out if the fuel saved during acceleration is more than the increased fuel used during cruise.

If regen braking is to be wired in will decelerating with engine braking and the alternator recharging near it's max be capable of getting back the energy spent or would it still be better to just coast down?

Most hybrid systems that have been successful deliver over 10% of the max available power, they are also capable of regenerating that power quickly. The insight for example with a 67 hp engine has a 13hp electric motor(nearly 20%)

[ECONORAM]

2hp? Better than zero, I guess. Truth be known, I'd really like something like this: Integrated Starter Generator | Denso Global Products
Frank, I still can't help but laugh at the cat...

[Frank Lee]

How is <2HP better than 0?

I love that kitty too!

[ECONORAM]

I figure if you only use it going uphill, another 2 hp is better to have helping... Although on a mountain climb, the battery may not be up to the task...

[Frank Lee]

It would be about like adding pedals. Or like throwing a glass of water into the ocean.

For example: http://www.060calculator.com/

100 HP, 2600 lbs., m/t, fwd = 10.417 seconds 0-60
+2 HP-----------------------10.263, .15 of a second faster.