SR20 Forum banner
1 - 8 of 8 Posts

·
LoSe-R
Joined
·
908 Posts
Discussion Starter · #1 ·
Too high rate springs and not so spunky dampers are bad. To spunky of shocks and not so high rate springs is not very good either. But is there anyway to match them perfectly. What decides whether the spring is to stiff for the shock or the other way. Is it just left up to a well educated guess or what? Is this what a shock dyno is used for?
 

·
Registered
Joined
·
1,199 Posts
You "dial in" by driving a lot of events and making methodical changes. I have yet to embark on this phase of tuning for my autox car.

For tuning dampers to springs you want to perform transient maneuvers such as slaloms, chicanes, esses. Or a rougher method would be to go and drive over some big bumps. What your dampers do is control the oscillation of your springs on rebound and control the unsprung weight like your wheels & brakes on compression. You want to look for too little rebound which manifests in a "bobbing" feeling where the springs oscillate too much. Too much compression will feel like super stiff springs or even somewhat like riding on your bumpstops where little bumps will cause the car to rattle.

With single adjustable struts don't worry about too much compression as the rebound is more important and you have to change both at once. With double adjustable struts you can change rebound and compression independently.

Note that I am regurgitating this all out of book and articles I have read on suspension tuning. Adjustable suspensions usually means you've got more chances to get things wrong than right. If you go messing around with too much stuff at once you're pretty much stumbling around blind. Make small changes and try to record them. That's my new autox year's resolution btw.. :p
 

·
employment whiplash, NC
Joined
·
3,646 Posts
Congratulations. You have just discovered why it is so important to have adjustable shocks. In addition, if you have a coilover system, you can fairly easily swap springs with different rates.

Now, you can get shocks that only adjust the rebound (Koni), shock that adjust both rebound and compression at the same time (AGX), or shocks that can adjust both independantly (any custom shocks should do this).

Now, if you really want to get serious, you can get shocks that change the high speed (bumps) and low speed (turning into a corner) caracteristics of both the rebound and compression.

Matt, with GC coilovers and AGXs.
 

·
LoSe-R
Joined
·
908 Posts
Discussion Starter · #4 ·
goodness gracious... all these options will only show my lackluster tuning skills oh well im glad i still got one way adjustables :D

i still want to know what a shock dyno is good for... is there not a better way than the seat of the pants impression?
 

·
Registered
Joined
·
1,199 Posts
A shock dyno is obviously a great tool for tuning your shocks, but keep in mind that the car won't be driven by the dyno. It ultimately comes down to the driver, and if the driver goes faster with a different setting than the shock dyno recommends you do what the driver wants.
 

·
LoSe-R
Joined
·
908 Posts
Discussion Starter · #6 ·
i remember reading in a european car a while back that some company(cant remember) matched some excellent dampers to eibach springs for the Mrk4 volkswagens. They acted like it takes lots of development and tons of hours on a shock dyno to deliver good performance. Well im starting to get the impression its more like you need to "dial" in you setting to fit YOU! That article has stayed in the back of my mind for a while. Well i guess dialing in is not so easy and is what sets apart the good from the great, NO? I just wish making a car handle was like making power. I guess if some is good more is not always better !!!
 

·
Registered
Joined
·
1,199 Posts
Black93 said:
They acted like it takes lots of development and tons of hours on a shock dyno to deliver good performance. Well im starting to get the impression its more like you need to "dial" in you setting to fit YOU!
For OEM applications I would think development has to be a lot more detailed since the driver is "factored out". They want the car to handle a certain way in ideal conditions and that's that. If they do an excellent job (Type-R & M3 for instance) then the car is easier to drive fast.

Tuning a adjustable suspension to the driver/course/conditions is a different process and is more rooted in real-world performance than theoretical ideals. I do think that data crunching and experiential tuning can overlap though and they certainly complement each other.
 

·
employment whiplash, NC
Joined
·
3,646 Posts
Suspensions are so tough because there are so many variables. Everything acts like a spring. The sidewall of the tires has a spring rate. The bushings in the control arms have a spring rate. The wheels even have a spring rate!! Then you can get into the whole chassis rigidity thing.

This is the area that most race teams spend the most time and money on.
 
1 - 8 of 8 Posts
Top