Learned some very interesting Moton info at PRI
12-17-2009, 10:42 AM
#17
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Moving back from pictures to shocks, I have a couple of comments...
Just to be correct - and this is important because if we don't speak the same language with suspension, there is little hope of understanding what experts are saying and what we are saying to each other - the number of clicks does not equal 'way'. If a shock has only one adjustment (compression or rebound) that is a single adjustable or 1 way shock. Compression and rebound is double adjustable or 2 way. 5 adjustments - compression and rebound with different speeds are 5 way. I think that you will find that every major shock manufacturer uses this phrasing, as do suspension engineers. This is not just a comment about this thread, but a general one as I often see discussions in other threads where number of clicks is referred to a 'ways'.
Increasing the number of clicks may or may not be a benefit. If they are expanding the range of adjustability of the shock, then that is probably a good thing. If all they are doing is making the clicker a finer adjustment (15 clicks over the same range that used to be 7 clicks) it is probably of no benefit at all. The reason I say no benefit is that very, very few people can feel the difference between 2 or 3 clicks so adding more clicks in the same range has no impact.
Just to be correct - and this is important because if we don't speak the same language with suspension, there is little hope of understanding what experts are saying and what we are saying to each other - the number of clicks does not equal 'way'. If a shock has only one adjustment (compression or rebound) that is a single adjustable or 1 way shock. Compression and rebound is double adjustable or 2 way. 5 adjustments - compression and rebound with different speeds are 5 way. I think that you will find that every major shock manufacturer uses this phrasing, as do suspension engineers. This is not just a comment about this thread, but a general one as I often see discussions in other threads where number of clicks is referred to a 'ways'.
Increasing the number of clicks may or may not be a benefit. If they are expanding the range of adjustability of the shock, then that is probably a good thing. If all they are doing is making the clicker a finer adjustment (15 clicks over the same range that used to be 7 clicks) it is probably of no benefit at all. The reason I say no benefit is that very, very few people can feel the difference between 2 or 3 clicks so adding more clicks in the same range has no impact.
12-17-2009, 10:42 AM
#18
Team Owner
Thread Starter
IMO, 7 is a lot, but they arte relatively coarse adjustments...meaning, each adjustment makes a very noticeable difference to the experienced drover. Sometimes, the ideal setting would be between one of the 7 positions, but not being able to get there means "fixing" the handling in one corner causes a major degradation in another. In addition, there will be slightly more rebound adjustment available...
The Motorsports model has always offered more fine, subtle adjustments where this trade-off is less likely. Now this is also part fo the CS model line as well.
Sunday is correct about terminology...
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12-17-2009, 01:31 PM
#22
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Last edited by DanR; 12-17-2009 at 01:47 PM.
12-17-2009, 01:57 PM
#23
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12-17-2009, 05:55 PM
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12-18-2009, 08:24 PM
#27
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I have some information that many of the GT something teams in ALMS, LMS, etc. are using a more compression-biased damper setup (as opposed to the rebound-bias that has been the norm for a long time). It would be interesting to know if the architecture of these units support that setup without excessive hysteresis (ie. cavitation).
A rebound biased setup will use less stroke (allowing the car to be lowered; lower CG), and a more even 'split' between bump and rebound will minimize contact patch load variation.
A rebound biased setup will use less stroke (allowing the car to be lowered; lower CG), and a more even 'split' between bump and rebound will minimize contact patch load variation.
12-19-2009, 12:26 AM
#28
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Huh?
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Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
12-19-2009, 10:13 AM
#29
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The relationship between spring stiffness and damping coefficient has an optimal value at the vehicle heave mode frequency, such that the damping stiffness is slightly greater than the spring stiffness.
We can (hopefully) agree that the time the CPL spends below its mean value should be minimized after an event, such as going over curbing or a depression or bump in the track surface. The characteristics required for this condition include a high ratio of spring stiffness to unsprung mass (yielding a high unsprung mass acceleration), and a high ratio of spring stiffness to damping force (giving a high terminal unsprung mass velocity). This suggests that a compression biased damping setup will minimize CPL variation about the mean, use less stroke, though at the expense of ride quality (perceived harshness), which is irrelevant to us.
We can (hopefully) agree that the time the CPL spends below its mean value should be minimized after an event, such as going over curbing or a depression or bump in the track surface. The characteristics required for this condition include a high ratio of spring stiffness to unsprung mass (yielding a high unsprung mass acceleration), and a high ratio of spring stiffness to damping force (giving a high terminal unsprung mass velocity). This suggests that a compression biased damping setup will minimize CPL variation about the mean, use less stroke, though at the expense of ride quality (perceived harshness), which is irrelevant to us.
12-19-2009, 10:16 AM
#30
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Last edited by Veloce Raptor; 01-17-2010 at 10:26 AM.