Best Shocks for Autocross
#61
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Originally Posted by Naka,Nov 1 2006, 09:10 AM
Those Ohlins seem to be single adjustable only, right? For that money, Penske double adjustables seem to be the better alternative.
#62
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Originally Posted by Orthonormal,Oct 31 2006, 11:43 PM
Plus if you want them for stock class you still need to create an adapter for the spring seat to hold the stock springs, just like you would with the Penskes.
#63
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Originally Posted by Naka,Oct 23 2006, 09:24 AM
In my 85,000 mile car, with street tires, and the Comptech bar at full stiff, I get inside rear wheel spin at half throttle (4000 rpms) coming out of turns. That can't be good. I am blaming it on the shocks. Do you think I'm right, or wrong?
The 01's have a torsen diff right?
Why would he be getting wheel spin on the inside wheel..
The way he explained it in another post sounded like he has an open diff.
Would shocks really help.
Sorry in advance if this is completely retarded..
Thanks
Mac
#64
For a Torsen diff to work, both wheels need to be in contact with the pavement. If you have enough body roll to unload the inside wheel, all the drive will go to that wheel and it'll spin.
#65
Wow i think my brain is officailly fried after reading just half of the stuff in here. But helpfull either way. I too am looking into shocks for my AP1.
My set up now is just V710's and an HKS exhaust (as if that helps..more for audible pleasure) I have no sway bar on the front but plan to add for the next season.
With just this set-up alone i find i am very competitive. I am consistanlty in the top 5 cars at the events i go to. I have also set FTD several times. I have had the car since Augst 05 and hit about 20 events this season.
Chris
My set up now is just V710's and an HKS exhaust (as if that helps..more for audible pleasure) I have no sway bar on the front but plan to add for the next season.
With just this set-up alone i find i am very competitive. I am consistanlty in the top 5 cars at the events i go to. I have also set FTD several times. I have had the car since Augst 05 and hit about 20 events this season.
Chris
#66
Former Moderator
Originally Posted by Conedodger,Nov 1 2006, 07:24 PM
For a Torsen diff to work, both wheels need to be in contact with the pavement. If you have enough body roll to unload the inside wheel, all the drive will go to that wheel and it'll spin.
Thanks
Mac
#67
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[QUOTE=Windscreen,Oct 26 2006, 09:05 AM]That's the crux - the two different shocks, in this case Moton and Penske, do NOT give the same lifting force.
#68
As mentioned before, we're discussing SCCA Solo, Stock category.
Why would there be a precise value for the desired static force? As far as I am concerned, the best value is zero. The only effect of the static force is to raise your static height, which is bad for weight transfer and bad for suspension geometry. You want a Stock car as low as possible given the rules constraints. A "perfectly" set up car is lower than you can achieve in Stock.
Referring to Case 1. Why do you think that a lower internal gas pressure would be more desirable as a goal in itself? Gas pressure has only two practical effects: prevention of cavitation, and static force on the shock shaft. In a case where the gas pressure in two different shocks is such that neither shock experiences cavitation and both shocks have the same extending force, neither can be considered to be "better" based on the internal gas pressure (unless you are worried that one of the shocks will explode as a result).
In Case 2, I don't understand what you think the relationship is between gas pressure and the compression setting. A damping force resists motion. When the piston is moving up, the shock exerts a downward force proportional to the speed of motion. That force is called rebound. When the piston is moving down, the shock exerts an upward damping force proportional to the speed of motion. That force is called compression. When the piston is still, there is no damping force -- no compression, no rebound. Only the static force from the gas. That force is independent of and separate from the compression damping force.
In reality, the Moton is neither clearly superior, nor is it a POS. The higher minimum static force is a drawback, but it 's a relatively minor concern.
Why would there be a precise value for the desired static force? As far as I am concerned, the best value is zero. The only effect of the static force is to raise your static height, which is bad for weight transfer and bad for suspension geometry. You want a Stock car as low as possible given the rules constraints. A "perfectly" set up car is lower than you can achieve in Stock.
Referring to Case 1. Why do you think that a lower internal gas pressure would be more desirable as a goal in itself? Gas pressure has only two practical effects: prevention of cavitation, and static force on the shock shaft. In a case where the gas pressure in two different shocks is such that neither shock experiences cavitation and both shocks have the same extending force, neither can be considered to be "better" based on the internal gas pressure (unless you are worried that one of the shocks will explode as a result).
In Case 2, I don't understand what you think the relationship is between gas pressure and the compression setting. A damping force resists motion. When the piston is moving up, the shock exerts a downward force proportional to the speed of motion. That force is called rebound. When the piston is moving down, the shock exerts an upward damping force proportional to the speed of motion. That force is called compression. When the piston is still, there is no damping force -- no compression, no rebound. Only the static force from the gas. That force is independent of and separate from the compression damping force.
In reality, the Moton is neither clearly superior, nor is it a POS. The higher minimum static force is a drawback, but it 's a relatively minor concern.
#69
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Originally Posted by Orthonormal,Nov 4 2006, 01:37 AM
Why do you think that a lower internal gas pressure would be more desirable as a goal in itself?
Penske shocks: Pressure balancing
It states: "Hysteresis is reduced when overall internal pressures are lowered. Reduction of hysteresis improves response of the damper and therefore enhances grip"
So, I figured (in my simple mind), that between two shocks with the same compression force (which I wrongfully called lifting force), the one with the larger shaft diameter would have the lower overall internal pressure. Which according to the reference above, would help enhance grip.
I guess it's not that simple, huh?
I don't understand what you think the relationship is between gas pressure and the compression setting.
Again, I want to thank everybody for your patience trying to clarify all these concepts. I hope more people, besides me alone, will benefit from this very interesting thread.
#70
I think that's it. The gas pressure is constant, independent of time and (to a reasonable approximation) motion, as is the static/extending/lifting force that results. The dynamic forces (called rebound and compression depending on which direction the shaft is moving) are separate, and result from the resistance to oil flowing through small holes in the piston as the piston moves up or down.
When setting the shocks up for Stock, you're generally going to use the lowest gas pressure that will prevent cavitation. If that minimizes hysteresis, so much the better, although someone would have to explain to me why higher gas pressure results in hyteresis.
When setting up for classes where the perch height is free, racers sometimes use high gas pressure to increase the effective spring rate, which allows them to tune the spring rate to some extent. You wouldn't generally want to do that in Stock though, because a small increase in spring rate is accompanied by a large increase in the static extending force.
When setting the shocks up for Stock, you're generally going to use the lowest gas pressure that will prevent cavitation. If that minimizes hysteresis, so much the better, although someone would have to explain to me why higher gas pressure results in hyteresis.
When setting up for classes where the perch height is free, racers sometimes use high gas pressure to increase the effective spring rate, which allows them to tune the spring rate to some extent. You wouldn't generally want to do that in Stock though, because a small increase in spring rate is accompanied by a large increase in the static extending force.