He was responding to my situation; I have a Gendron front sway bar, which comes in three thick versions--very hollow; a little hollow, and solid. I have the "a little hollow" one, and he is advising me to get the solid one, which will be 15% stiffer than what I have.

Why don't they put a good LSD in this wonderful car?

 

Torsens are great diffs as long as you don't pick up a wheel, which you'll never do in an S2000 on street tires.

The alternative is a clutch-type diff, which requires annual rebuilding. I suspect more S2000 drivers would complain about the cost of maintaining a clutch-type diff than would complain about the diff going open when cornering on R-compound tires.

Steve

 

I like the diff, actually.

What would be cool would be a type-r Torsen, which preloads the diff so that if the wheel is down it acts like a normal torsen but if the wheel is up it does not go open.

 

I recently had a track experience with something similar, yet different, from what is described at the beginning of this thread.

On 2 different very tight (decreasing radius) right hand corners, right at mid-corner when I would apply heavy throttle, the car seemed to bog, unable to deliver power, which produced quite a bit of understeer.

Then, as the suspension unloaded itself, I would suddenly get a bunch of oversteer. There did not seem to be gratuitous wheelspin, but there was rear end movement and having to deal with that makes it difficult for me to know for sure if I was spinning a wheel due to power delivery.

This behavior was very repeatable, but I had to be pushing hard for it to happen. So I get a buddy to ride along with me to help diagnose the problem, and it never happens with him in the car (2 different sessions). I suspect that his weight in the passenger side evened out the weight distribution enough to keep the problem from occurring.

Does this sound like the behavior that would be experienced by lifting a wheel with the stock diff?

The car is pretty much stock save proper brake pads and tires (Michelin Pilot Sport Cup).

Thanks,

Clark

 

What I feel when the wheel is off the ground in a tight turn is simply nothing. It seems as if the rear wheels are spinning (I'm giving it a bit of gas, but not getting any response from the drive wheels), but there's no power, and no understeer or oversteer. What's happening, in reality, is that no power is being delivered to the drive wheels, because of the peculiar circumstances. As soon as the car settles a bit, off I go.

 

Hmm, wouldn't no power delivered to the drive wheels = understeer?

In track conditions, when I'm exiting a corner I'm expecting, planning, needing my power delivery to rotate the rear end and help me drift to the exit of the corner. If I do not get this, then I have unplanned understeer.

 

I think what you experienced was fuel starvation. If the engine bogs, it's not making power. It also won't lead to understeer since it's not pushing the car forward. If anything, it's slowing down the rear tires which could lead to oversteer (it's like applying only the rear brakes). Then, as the fuel starts flowing again, the engine starts making power, leading to the rear tires being overpowered and oversteer.

How much gas did you have in the car at the time? Autocrossers frequently run with >1/2 tank of gas to prevent starvation. I think your analysis of having a passenger causing a shift in weight distribution is likely correct, further reinforcing the fuel startvation scenario.

Body roll leading to unloading the inside rear tire and wheelspin wouldn't affect engine bogging (except for the starvation thang again) and probably wouldn't lead to gross oversteer since you're generating enough loading with the tires in the first place...

 

Not necessarily. You certainly can enter the turn in such a way to cause understeer and, hence, need oversteer to balance it out but I suspect that's a slow way to do the turn (in general - maybe specific turns need this technique). A 4-wheel drift looks cool but isn't the fast way through a turn...

 

Definitely not fuel starvation. Been there before and know what that feels like.

When I'm describing oversteer/understeer, I'm not talking about it being actually to the point of the car sliding either end, but rather the weight transfer and balance of the car.

In this case I wasn't getting understeer to the point where I was going to slide off track, but rather I wasn't getting the power delivery to help transfer weight to the rear and start to rotate the car to power out of the corner. I had already gotten the front end turned and pointed though, so I wasn't going to have lift-off type oversteer, particularly since I wasn't getting any power to have lift-off from.

I wasn't in a 4 wheel drift or trying to achieve that, but I certainly needed decent balance mid corner to be as quick as I wanted to be.

 

No.

I'm not getting understeer, in the sense of "push," as our friends in NASCAR would say. I'm just not getting any power. I can steer just fine; I can't throttle steer, but that's not the same thing as understeer, since throttle steer is controlled oversteer. Effectively, when the inside rear wheel is off the ground, it's as if the throttle cable is cut. You can goose the throttle, but nothing's reaching the drive wheels/ground. You can still steer when the throttle cable's cut, you just can't use the throttle effectively.