Fabrik8

Normally only if the center of gravity (CG) of the engine is ahead of the front axle line, which it is on many cars but not an S2000. If the CG is forward of the front axle line, the axle l becomes the pivot of the proverbial see-saw and you counteract some of the weight on the rear wheels. Just like a see-saw, it depends on the amount of weight and how far forward that weight is from the pivot.
The front of an LS-family engine is roughly at the same point as the strut towers on a S2000, so the CG is well behind the front axle line. That's good, because the closer any amount of weight is to the center of the car, the lower the polar moment of inertia and the easier the car will change direction.

You're still adding weight to the front end, and are also adding weight to the rear end (you're on the other side of the pivot). In the case of a straight line you're mostly just adding weight to the car that you then have to accelerate, which just takes some extra power obviously.

Gen_Crunchytoes

Ah I see. Didn't think about the location of the motor in relation to the front axle line.

Yardjass

Correct me if I'm wrong, it has been a while, but are you not still adding that weight closer to the front wheels? The "moment arm" from the CG of that weight to the rear wheels will be longer than that of the front wheels, which the weight would almost be directly over. From a statics standpoint, that would mean the front wheels are bearing significantly more of that load, which should affect your cornering stiffness and make it tend more towards oversteer. To what degree, I'm not sure but I assume you would want it as close to stock weight distribution as possible, and as close to stock loading on the springs, or you would want to make some changes in the springs and dampening to account for that (which I guarantee none of these idiots are doing). I'm not sure what an F20C weighs, but I imagine it is about 100 lbs lighter than a dressed LS1 and then, even lighter than a steel block v8.

Anyway, I would imagine it would be a good idea to address all of this, especially with the AP1 and its already existing tendency for snap oversteer.

JacKal

Yes it's more weight but its weight in a small nimble car. I agree it's basically a camaro at his point but it's more attractive. If it will preform the same way why does the 200lbs give it take it adds an issue?

Gen_Crunchytoes

It won't perform the same way, that's the issue. Best way I can describe it is putting a second stock motor in the engine bay. It won't behave the same way

If it were an ls1 in a miata it'd be different since the lighter subframe used for that swap allows for the weight if the ls without altering weight distribution.

JacKal

Right but with the longer front end and the weight distribution we've already discussed if we're boosting and realize that 500hp is what we want, then why does the heavier iron block matter? I'm just arguing the point of saving money and not really sacrificing very much. Is 200lbs really gonna make much difference? I doubt it. If I built one Id save money an snag a 4.8 iron. That's my opinion.

Gen_Crunchytoes

If its an iron block in a circuit style car, it will affect the way the car behaves in turns. It being heavier will also impact exit speed in turns

If its a drag car, its more weight to move down the track. I could see 60ft times being affected by this

Doesn't matter what the application is, heavier is never better

Fabrik8

Yes, you're absolutely correct. The addition engine weight will affect the front wheels more because the engine is closer to them. Whether it will oversteer or understeer depends on a lot of things, but all are related to how the extra weight affects the existing geometry and weight transfer. Sometimes the extra front weight will make it an understeering pig, even though you're moving the front/rear weight distribution to the point that it should oversteer more readily.

JacKal

I don't know I'm not mathematically inclined enough to figure all the points out to show where it would or wouldn't affect it enough to offset the $1k difference. It looks like a fun street car to me. I know in the past I've seen super light cars like this have issues because they weren't heavy enough. IE miata with 500hp. I think the only aspect here that actually relates is his price. He's way off but an aluminum LSX would've helped him get closer to a figure like he wants. All in all this is still not worth what he wants and was a under planned build. I wasn't intending to get into the geometric never ending discussion of weight/power/understeer/etc I was simply saying that having an iron block in it isn't necessarily a mistake. If you want to make X power, with X amount of dollars, in X amount of time there's nothing wrong with an iron 4.8L junkyard truck motor. I know plenty of guys running them without issue and I wouldn't consider the vehicles running those setups to be lacking anything That a tiny little car with a monster powerplant normally produces. I've ridden in two cars like what we are discussing and steering is a non issue, now keeping it straight under medium to heavy acceleration is a full body experience.

95FDmang

Not to jump off topic here, but I wonder with the v10 swap if that would affect the weight distribution drastically or barely notice a difference?