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Old 10-06-2002, 08:16 PM
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Richard Hudgins Richard Hudgins is offline
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Join Date: Jun 1999
Location: Fallbrook, CA USA, CA
Cobra Make, Engine: Porsche 928 S4
Posts: 739
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Scott and a427sc,

.Sorry Guys, a brain fart.

I miss-read the post. I had reversed the numbers in my head. (It is a habit for me to always speak of front numbers first and rear numbers second)

However, the numbers indicate a even bigger dynamic inbalance in the chassis as they are. This could really be just Scott's method of driving (BIG RIGHT FOOT), too small a rear tire, wrong compound, or rear bump rates too high.

I do not know the valving on pro-shocks, but from your numbers ("The pro shocks were set at 5 and 7 out of a 1 to 8 range" Note: I am assuming 5 front and 7 rear and equal bump/ rebound adjustment per click) I think that you might have the rear set too high in bump and the front may be too high in rebound.

And your statement "My cobra does not behave under trail breaking. It behaves much better with early brake, earlyier throttle in the corner" indicates too light a bump in front and too light rebound in the rear. That aside, In a high horsepower to weight ratio/short wheelbase car, your method of driving has proven to be the fast way around. (So stop giving yourself a bad time about your talents. You would be real surprised at how few drivers can even tell understeer from oversteer.)

However, it is fairly normal in a high horsepower car to see the numbers that you are seeing. There is only so much that can be done with the dampers to bring temps into balance. (The dampers control the transients remember, and therefore the loads the tire sees over a given amount of time. If the bump rate on the rear is too high, the weight transfer is too slow, therefore allowing the tire to spin due to improper transfer timing.)

The next step if the dampers are right and you continue to have high rear temps is to split compounds. (You must take temps before you look at compound changes) I do not know if Goodyear has a slightly harder rear compound in your rear sizes, but you may need to go a bit harder in the rear to handle the output of your motor.

a427sc. Dampers are a subject that we can use every bit of bandwidth available on this forum to discuss and debate and still not truly understand the effects on a given chassis. that is why all good race teams have a engineer that does nothing but dampers and he/she spends all of their time on a damper dyno in the truck all weekend. (PS: they get paid real well to know how to make them work. Just go to a NASCAR race, you will notice a really big trailer that says PENSKE SHOCKS on the side. this is the busiest trailer in the paddock. The same in all the series, the damper truck gets all the attention from the race engineers.)

Scott, Sorry to tell you this, but you are at the point that you need to go to proper race dampers. Penske etc. I know the numbers are big, but you will not get that thing where you want it until you have proper dampers. (Just ask Boris.)

Sorry for my Sunday stupidity. I need to read better
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Richard Hudgins
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