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Questions after this weekends DE - for 993 owners

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Old 06-27-2011, 10:48 PM
  #16  
Larry Herman
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Originally Posted by bavarian06
There were two sections where the car would fly over the bumps of the road, literally propelling us out of our seats. I was always white fisted going through these sections, ready to correct the steering wheel if the wheels came back down differently then how they left the ground; from you excerpt: “The racecar has only ¾ of an inch compression on its outside spring, so it loses ALL grip momentarily. Imagine going from generating 1.2~1.5 G’s of side loading to zero for an instant? It will take a fast and large correction of the steering wheel to keep the car balanced and on course. This is what makes it so much harder to drive. It really requires an innate sense of exactly what the car is going to do, along with the experience to make the right corrections to be able to drive this car at its limit.” We were experimenting if I was better off lifting, semi throttle, or go flat out (I didn’t have the ***** so I would occasionally have to lift from a semi throttle input) going through these sections.

So my question, if I was to swap out my street tires to a RA-1, would this:

1) improve
2) worsen
3) stay roughly the same

the car’s handling characteristics over these two sections? The springs aren't expensive but the labor associated in getting swapped out, car realigned, then corner balanced again IS. I rather opt for new tires depending on what your reply is.
Because the RA-1s typically run at a lower hot pressure than most street tires do, it will provide a little more compliance and could help the problem a little.

I'd like you to expound a little on "the car would fly over the bumps of the road, literally propelling us out of our seats". Does the car lose grip when it hits the bump, or does it lose grip after it goes over the bump? There is a big difference between the two, and knowing which it is will determine possible solutions.
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Old 06-28-2011, 01:23 PM
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bavarian06
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Unfortunately I'm not versed enough to know the difference. But I assume it loses grip after it hits the bump?

On the street that I live on, where the street merges to the main road, there is a dip for the rain channels/curbs. If I approach this too quickly, it would make my car hop. I suspect the suspension travel isnt enough to factor in uneven surfaces or something is too stiff to soak it up. Another example, when I drive up my driveway (have to angle slant it up), the front outside wheel would pick up from the ground.

The front springs are 6" long 2.25" diameter thick, the tenders are 1.75" long (but almost fully compressed at standstill). I'm at RS ride height, possibly even higher in the front.



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