[91TB78]

Originally Posted by stretch

I think the, "How stiff is too stiff?" question is much easier to answer: if you find yourself skipping over broken pavement, your suspension is too stiff for the road you are on. The object of a suspension is to keep your tire on the road at all times, and any time it is not doing so will result in a loss of grip. This limit, of course, varies depending on what road you are on. :P

Sadly then, my near stock suspension is too stiff for some of the roads and turns in Minneapolis.

[Mykl]

Originally Posted by 91TB78

Sadly then, my near stock suspension is too stiff for some of the roads and turns in Minneapolis.

That's actually what I was thinking. I can feel my front suspension bouncing off of some of the older, rougher sections of interstate here. I know it's because the dampers are too stiff.

[evilSTi7]

i think this thread is sticky worthy (very much in thanks to Adam).

[91TB78]

Originally Posted by Mykl

That's actually what I was thinking. I can feel my front suspension bouncing off of some of the older, rougher sections of interstate here. I know it's because the dampers are too stiff.

Some of that is due to the dampers being over damped and the springs not matching up to the valving perfectly. This is the same reason we have the "bobble head" effect in the STi...well, that and a short wheelbase, but off topic.

[Z1 Performance]

^ not to mention the stock STi tires....I bet if you put some all seasons on there, it would be nice and comfy, though the confidence inspiring handling, turn in respnse, etc would go out the window. It is the perpetual balancing act

[stretch]

Originally Posted by Mykl

That's actually what I was thinking. I can feel my front suspension bouncing off of some of the older, rougher sections of interstate here. I know it's because the dampers are too stiff.

On my last car, I pumped up the rebound dampening in the rear to get the car a little more stable as the rear stepped out. It worked great, until I crested a hill.

The rebound on the shocks was so stiff that the rear tires would not extend back towards the ground- at least not quickly enough. The front tires stayed planted, while the rear of the car had no weight on it. Naturally, this led to massive oversteer. It was as if the rear of the car went airborn mid-turn. When gravity did its thing and the rear settled, the rear tires suddenly had a lot of load on them, and they let out a loud chirp and settled back into place. I lost a lot of time because of this.

So yeah, that's what too stiff is. Those shocks felt great firmed up on flat ground, but as soon as I hit a hill, they were too stiff. I noticed the same behavior later while hitting a large bump in a road mid-turn. For the most part, though, the shocks were digressive enough that bumps were absorbed without upsetting the car's balance. (They were Koni yellows.)

That's another term worth Google'ing if you're not familiar- search for "digressive shocks". The more digressive, the better, and generally more expensive too!

[wdb]

Originally Posted by Z1 Performance

^ not to mention the stock STi tires....I bet if you put some all seasons on there, it would be nice and comfy, though the confidence inspiring handling, turn in respnse, etc would go out the window. It is the perpetual balancing act

Been there, done that -- except that I went from stockers to dedicated winter tires. I don't know if I would call the ride "nice and comfy!" But there definitely is an improvement, especially over small, sharp bumps and edges.

Like you found with your Z, hard sidewalls have some big tradeoffs on the street. When my RE070's run out I will probably ease up on the sidewall stiffness for daily use. My big question now is, do I want to go wider or not...

[GTWORX.com]

Originally Posted by stretch

I think the, "How stiff is too stiff?" question is much easier to answer: if you find yourself skipping over broken pavement, your suspension is too stiff for the road you are on. The object of a suspension is to keep your tire on the road at all times, and any time it is not doing so will result in a loss of grip. This limit, of course, varies depending on what road you are on. :P

Obviously, too stiff on a rough road just isn't gonna work. And obviously, you want damper rates that match your spring rates.


But even on a glass smooth road, 9k or 10k springs that are properly damped without the right tires (i.e. don't use all seasons, not even RE92's ) isn't gonna work either. Sure you may not be bouncing around because it's a smooth road, but all that spring rate is NOT ideal. It might feel pretty good, but you really should be on R-comps when you're getting up in that range. Even RE070s can't really generate the lateral g's necessary for that kind of spring rate.



- Andrew

[T3h_Clap]

very nice info here guys.

so, assuming a car was the following.

Daily Driven on 255 Max Performance Street rubber (AD07/RT615/ect.)
Autox'd on 275 V710s
Track'd on 255 RA1s

is there a happy medium to fit all three of these tires?

would it be logical to have a spring/damper combo that was too stiff for the street tires but decent for the autox/track tires?

or would it be more logical to have a proper spring/damper combo for the street tires and suffer on autox/track tires?

this isn't on a nationally campaign'd car.

[RaceComp Engineering]

For your situation, it seems to make more sense to use a bit lower spring rate combined with larger sway bars. I assume your car is a daily driver...if so, you will be kicking yourself if you go with really high rates because they will beat you up on the street, not to mention the loss of grip with street tires, especially on bumpy surfaces. For your situation, it sounds like the KW Variant 3's would be pretty much perfect. The wide range of adjustability will allow you to set up the car exactly as you like for street, auto-x, and track use. Plus their rates (445F, 380R) are right in the middle, not too high to be comfortable and not too low to be effective during track/auto-x use.

-Dan

[T3h_Clap]

Originally Posted by RaceComp Engineering

For your situation, it seems to make more sense to use a bit lower spring rate combined with larger sway bars. I assume your car is a daily driver...if so, you will be kicking yourself if you go with really high rates because they will beat you up on the street, not to mention the loss of grip with street tires, especially on bumpy surfaces.

It is daily driven currently, but It isn't my only vehicle.

Originally Posted by RaceComp Engineering

For your situation, it sounds like the KW Variant 3's would be pretty much perfect. The wide range of adjustability will allow you to set up the car exactly as you like for street, auto-x, and track use. Plus their rates (445F, 380R) are right in the middle, not too high to be comfortable and not too low to be effective during track/auto-x use.

-Dan

My largest concern with running the big bars is lifting a rear wheel, I really don't want to do that. The rear springs are Progressive on the V3's no?

I'll be waiting to see how 91TB78 likes his V3s.

[GTWORX.com]

Yes, the rears are progressive. As for the bars, that's why it's tough to find an ideal setup for all applications. If you go with adjustable sways (which most are anyways) you can easily change the effective diameter for different events. All it takes is 10-15 minutes and some ramps and basic hand tools.

-Dan

[91TB78]

Clap,
I just got my V3s in by UPS today!!! Install will probably be tomorrow morning. I'll let you know once I get an alignment and corner balance my impressions.

The rears are progressive, but after speaking with KW direct they assured me they are valved with a range in mind and for a little bit more I can purchase a different mount for a fixed rate spring and the rates I'm looking for. Plus, with Hypercoil and Swift, there are a ton of options to hit my "ideal" spring rate.

[T3h_Clap]

Originally Posted by 91TB78

Clap,
I just got my V3s in by UPS today!!! Install will probably be tomorrow morning. I'll let you know once I get an alignment and corner balance my impressions.

The rears are progressive, but after speaking with KW direct they assured me they are valved with a range in mind and for a little bit more I can purchase a different mount for a fixed rate spring and the rates I'm looking for. Plus, with Hypercoil and Swift, there are a ton of options to hit my "ideal" spring rate.

that's what i like to hear.

I'm liking the KWs more and more.

I appreciate the help from the guys at RCE and Z1.

[GTWORX.com]

Glad to help

-Dan