Suspension Explained
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Hi cannga,
Thx for the great information on suspension for our turbo.
Power is deinitely enough for our cars but just need to improve on handling.
I've decided to go with kwv3 instead of bilstein
Question. What's the difference in effect of increase/reduce compression & rebound in terms of handling.
Thx for the great information on suspension for our turbo.
Power is deinitely enough for our cars but just need to improve on handling.
I've decided to go with kwv3 instead of bilstein
Question. What's the difference in effect of increase/reduce compression & rebound in terms of handling.
The problem is 2 folds. First, the factors are not independent of each other: for example when you turn down rebound dampening for comfort, you will influence the handling dynamics - a mushy under-damped system. The back and forth adjustment process in these adjustable coilovers could be maddening, cause doubts ("do I really have the best now?") unless you have a good setup man and you yourself are an advanced level driver who could give the setup man concise feedback as to what you feel in corners, does the car push or is it loose, on entry (deceleration)?, on exit (acceleration)?, etc.
Second, you have the front and the rear suspension interacting with each other, what you do on either end affects front to rear balance and therefore understeer/oversteer behavior. This part is needless to say tricky and best done by professional drivers at the track (this is what TPC does with their Bilstein - they have professional driver involved in tuning the TPC-Bilstein system HERE).
The short answer is this: You could get away with a good general installer, but to have the best, get the best setup man possible who knows 911 and the specific coilover (in this case KW) when it comes to suspension tuning. There are multiple factors and components involved: the sway bar, the tires, the spring rates, etc., and an experienced setup man is the key.
Last edited by cannga; Sep 13, 2012 at 02:04 AM.
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Sorry it's been a while so I don't have the link where I got this algorithm (for a coilover with independent bump/rebound adjustment), but it is from Bilstein and I will post it here as an example of how complicated suspension tuning is. It illustrates the points above, that bump and rebound (obviously) interact, and more importantly, front AND rear interact to influence understeer/oversteer behavior. Pro's will do this in their sleep, but for us amateurs, it could be a hopeless quagmire.
Take the rebound setting for example, say it has a scale of 1 to 10, 1 being softest. 1 will make the car soft and mushy, 10 will make the car lose traction over bumpy surfaces, somewhere in between there is a setting that will result in "best" traction, and it would be up to your setup person to find this sweet spot for you. Note that the point of max traction doesn't frequently coincide with the point of max comfort - another decision for you to make.
This is the reason that IMHO for the majority of amateur drivers, the plug and play Bilstein Damptronic is a much better solution than the manual-setting Bilstein PSS10. The pros have done the dirty work for you when you have the Damptronic. The best analogy is that when my wife needs to take a picture, I give her the small Point-and-Shoot Panasonic camera, and not my Canon 1D DSLR with the manual Contax-Zeiss lens. Complexity in the wrong hands tend to cause complex complications! :-)
Take the rebound setting for example, say it has a scale of 1 to 10, 1 being softest. 1 will make the car soft and mushy, 10 will make the car lose traction over bumpy surfaces, somewhere in between there is a setting that will result in "best" traction, and it would be up to your setup person to find this sweet spot for you. Note that the point of max traction doesn't frequently coincide with the point of max comfort - another decision for you to make.
This is the reason that IMHO for the majority of amateur drivers, the plug and play Bilstein Damptronic is a much better solution than the manual-setting Bilstein PSS10. The pros have done the dirty work for you when you have the Damptronic. The best analogy is that when my wife needs to take a picture, I give her the small Point-and-Shoot Panasonic camera, and not my Canon 1D DSLR with the manual Contax-Zeiss lens. Complexity in the wrong hands tend to cause complex complications! :-)
Last edited by cannga; Sep 14, 2012 at 04:16 PM.
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Sorry I've been away from this thread for a long time. Thanks Cannga. Taretts have been installed and Ira @ Tarett is a pleasure to work with (highly recommend the company). Not much additional noise or stiffness but the drop links definitely look sturdier compared with the stock ones.
Hi DB, first congrats on the very well modded car, starting with the Akra Titanium exhaust 
! Second, my apology that I haven't followed the forum that closely and therefore missed this thread, which has some question about my posting in the past.
Third, about the Tarett drop links: My fault for not emphasizing this, but every comment on stiffness of any suspension component should be taken in context of the rest of the system this component is paired with. At the time, I most likely had Pirelli Corsa R Comp tires on, and was trying on very stiff springs. In that context, and used as a daily driver, the system as a whole was noisy and stiff and hence my reservation. But really the stiffness was caused more by very stiff springs that I was experimenting with and the stiff tires, not just the drop links.
Currently with Michelin Pilot Super Sport and the more normal spring rates, the "final" version of my car's suspension has the Tarett drop links as a permanent fixture and I recommend the Tarett Drop Links very, very highly: stiffer, more precise, more planted than the stock rubber links. The effect *is* considerable for something that is so easy to put on and off (ie totally reversible if you don't like it), and cost so little: Rear Drop Link . I have **no doubt** about this because I've done the comparison between stock and Tarett numerous times - the links can be installed at home so I don't need to wait for my tuner.
! Second, my apology that I haven't followed the forum that closely and therefore missed this thread, which has some question about my posting in the past.Third, about the Tarett drop links: My fault for not emphasizing this, but every comment on stiffness of any suspension component should be taken in context of the rest of the system this component is paired with. At the time, I most likely had Pirelli Corsa R Comp tires on, and was trying on very stiff springs. In that context, and used as a daily driver, the system as a whole was noisy and stiff and hence my reservation. But really the stiffness was caused more by very stiff springs that I was experimenting with and the stiff tires, not just the drop links.
Currently with Michelin Pilot Super Sport and the more normal spring rates, the "final" version of my car's suspension has the Tarett drop links as a permanent fixture and I recommend the Tarett Drop Links very, very highly: stiffer, more precise, more planted than the stock rubber links. The effect *is* considerable for something that is so easy to put on and off (ie totally reversible if you don't like it), and cost so little: Rear Drop Link . I have **no doubt** about this because I've done the comparison between stock and Tarett numerous times - the links can be installed at home so I don't need to wait for my tuner.
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