S2000 roll center discussion
02-04-2011, 07:53 PM
#21
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Originally Posted by ZDan,Feb 4 2011, 10:18 PM
26.5" seems WAY high for c.g. height, most of the major masses are ENTIRELY below that! Gotta be more like 22", maybe 20".
I've used that method for calculating c.g. heights of motorcycles/scooters, and I was never able to get precise or repeatable values.
Not saying others can't get good results, but there's just no freaking WAY the c.g. is at 26.5"!
I've used that method for calculating c.g. heights of motorcycles/scooters, and I was never able to get precise or repeatable values.
Not saying others can't get good results, but there's just no freaking WAY the c.g. is at 26.5"!
02-04-2011, 08:02 PM
#22
Originally Posted by nmrado,Feb 4 2011, 05:41 PM
Had a chance to update my initial estimate using the corrected track width numbers.
Also, the complexity of what we are trying to figure out is why WinGeo exists. Keep that in mind as we analyze the estimated data.
02-05-2011, 08:29 AM
#23
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Originally Posted by robinson,Feb 4 2011, 11:02 PM
Measure track from the hub mounting surfaces, not the middle of the tire.
Also, the complexity of what we are trying to figure out is why WinGeo exists. Keep that in mind as we analyze the estimated data.
Also, the complexity of what we are trying to figure out is why WinGeo exists. Keep that in mind as we analyze the estimated data.
I agree that WinGEO is probably the tool to use. However, a CAD model should produce the same results, for simple stuff like this. Once we start looking at roll (and maybe even transient response?) I doubt the CAD model will be as useful.
02-07-2011, 03:25 PM
#24
Thread Starter
Let's also remember that we want to know all 3 CGs: overall, sprung-mass only, and unsprung-mass only.
The unsprung CG is typically taken as the axle height (~12 in.?). I've guesstimated unsprung weight at about 300lb: 40wheel/tire + 15 brake + 15 susp + 5hub/axle = 75 per corner).
With overall CG (measured via scales) and unsprung CG, we should be able to calculate sprung CG.
The unsprung CG is typically taken as the axle height (~12 in.?). I've guesstimated unsprung weight at about 300lb: 40wheel/tire + 15 brake + 15 susp + 5hub/axle = 75 per corner).
With overall CG (measured via scales) and unsprung CG, we should be able to calculate sprung CG.
02-07-2011, 05:30 PM
#25
Originally Posted by nmrado,Feb 5 2011, 11:29 AM
Isn't track width a function of wheel dimensions, relative to the mounting face of the hub? The track width of a car can change when you use different offset wheels, though the hub face-to-hub face distance remains constant. Maybe all of us need to come to some consensus about the terms & definitions we're using here.
I agree that WinGEO is probably the tool to use. However, a CAD model should produce the same results, for simple stuff like this. Once we start looking at roll (and maybe even transient response?) I doubt the CAD model will be as useful.
I agree that WinGEO is probably the tool to use. However, a CAD model should produce the same results, for simple stuff like this. Once we start looking at roll (and maybe even transient response?) I doubt the CAD model will be as useful.
05-11-2011, 12:01 PM
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05-11-2011, 12:54 PM
#29
Honestly I don't really think so. Looking to pickup that last tenth of a second to give you the lap record at your local track maybe but overall I think it's low on the list of importance.
I personally ran the J's RCA up front on my last s2k and noticed no difference at all in how the car felt or handled. I got them mostly to serve as camber joints the RCA was just a bonus. I'm also no pro or track regular so that might also explain why I didn't notice so a huge change.
I'm very interested to see what the data points to though. I'll be keeping an eye on this thread.
05-14-2011, 06:03 AM
#30
I think the consensus is that it makes little difference that the driver can feel. However considering the Js s2k is very low this may be a good mod for those who want to be low and handle well. Not sure if this is true though. To me what makes sense though is that the RCA kit "lowers" your suspension, thus you won't need to drop your coils as much to get the same ride height equaling in longer suspension travel which is good. Does this makes sense? Is the RCA kit better suited for the slammed guys?