[token-negro]

Anyone currently running or have ran this spring rate combo? Wondering how it would affect the handling of the car.

[Mykl]

I'm running 450/400 with Cobb swaybars. The ride is a bit stiff, but these rates match a set of sticky 245 width street tires quite nicely.

I would go with higher rates if race tires were involved.

[mgsm666]

On what struts? And with what purpose?

A lot of your ride quality is gonna come from good valving on the struts. T2 guys often run 450/500 iirc.

As a daily driver they're gonna be quite stiff, but on the track / autoX course, with a set of sticky tires, they'll probably be quite nice


Jesse

Ps - as a daily driver with light autoX I just ordered. Set of 350/300 to go with GC/koni inserts. I'll update in about a month when I install them.

[mug23]

I used to run 500/400 on RCE T2's and were ok as I mainly used for the track. It was still a little bit soft for the track so now I'm using 700/600.

[token-negro]

KW V3's are what my buddie has, but we wernt sure how a spring combo thats rated that close together would handle, there seems to be a ratio that follows between front and rear. RCE, 500/400 stock but added the extra 50lb in the rear will stiffen it up some, and have what kind of affect?

Originally Posted by mgsm666

On what struts? And with what purpose?

A lot of your ride quality is gonna come from good valving on the struts. T2 guys often run 450/500 iirc.

As a daily driver they're gonna be quite stiff, but on the track / autoX course, with a set of sticky tires, they'll probably be quite nice


Jesse

Ps - as a daily driver with light autoX I just ordered. Set of 350/300 to go with GC/koni inserts. I'll update in about a month when I install them.

[Mykl]

Originally Posted by token-negro

KW V3's are what my buddie has, but we wernt sure how a spring combo thats rated that close together would handle, there seems to be a ratio that follows between front and rear. RCE, 500/400 stock but added the extra 50lb in the rear will stiffen it up some, and have what kind of affect?

With -3.0 camber front and -2.0 rear, my car is overall neutral.

On turn entry I can coax the rear end out if I'm gentle, but otherwise I get very mild understeer. Mid turn balance depends on how much throttle you give it, too much and the rear will slide, just right and the entire car drifts wide, not enough and it understeers. Let off the throttle mid turn and the front tucks in neatly and the car rotates predictably. Track out depends on how far the steering wheel is turned when I step on it. If it's turned too far the car will oversteer, just right and it goes exactly where you point it.

I came up with 450/400 by taking the weight of the car and assigning a number to the front and rear axles based on the car's weight balance. Then I divided by two to assign each corner a number. Then I divided by two again and ~450/400 were the numbers I ended up with.

Certainly not the most precise way to determine rates, but it worked out and is a good starting point.

[mgsm666]

valving, valving, valving... With the kw's u should be good, depending on your ride height.

Jesse

[ButtDyno]

I run 450/500 on my Koni/GC rig - I could DD the car if I didn't have a better DD.

The rest of my setup makes a bigger difference on handling than the rates though, in terms of bars, alignment, pressures, etc.

[modaddict]

thinking about linearitying the rear springs on my kwv3's. (vs. progressively springy's i have)

we'll see though. How good ARE those swifts?

[scotty20bsp]

I run 600/500 on my '04 with custom valved Whiteline struts/shocks and its a little stiff, as a dd I'm used to it and I'm a geezer!

[Lutfy]

Originally Posted by Mykl

With -3.0 camber front and -2.0 rear, my car is overall neutral.

On turn entry I can coax the rear end out if I'm gentle, but otherwise I get very mild understeer. Mid turn balance depends on how much throttle you give it, too much and the rear will slide, just right and the entire car drifts wide, not enough and it understeers. Let off the throttle mid turn and the front tucks in neatly and the car rotates predictably. Track out depends on how far the steering wheel is turned when I step on it. If it's turned too far the car will oversteer, just right and it goes exactly where you point it.

I came up with 450/400 by taking the weight of the car and assigning a number to the front and rear axles based on the car's weight balance. Then I divided by two to assign each corner a number. Then I divided by two again and ~450/400 were the numbers I ended up with.

Certainly not the most precise way to determine rates, but it worked out and is a good starting point.

Mykl,

This is exactly what I am aiming or (behaviour wise) at the track. What size bars are you running and at what setting?

TIA

Lutfy

[Mykl]

Originally Posted by Lutfy

Mykl,

This is exactly what I am aiming or (behaviour wise) at the track. What size bars are you running and at what setting?

TIA

Lutfy

I'm running Cobb bars with the rear set to full stiff. I imagine 24mm Whiteline bars adjusted to match would offer the same spring rate split between the front and rear.

Other setup notes...

My car is raked forward, center of hub to fender measurement front and rear is the same. I have ~-2.9 degrees camber front, and -1.9 degrees rear. Toe is as close to 0 as strings can get me, it's actually about 1mm off front and rear, but it's hard to get closer than that in my garage.

Also, the key to that kind of turn in behavior is to ensure that the suspension stays off the bumpstops (I don't have any). So you'll need to taylor your spring rates based on your tires. I'm running 245/45-17 RE-01R's. If you run stickier or wider you'll need stiffer spring rates.

I have Koni 8611 dampers. The rears are set a hair stiffer than the fronts in both compression and rebound, but I don't actually think this is having much of an effect. Setting the rears the same as the front seems to drive about the same.

The last detail is tire pressures. At the track I run 38 psi hot all around. A little less in the rear should provide more rotation. Different tires may like different pressures of course.

I need to get a tire pyrometer so I can fine tune the settings. But overall this setup feels very nice at the track. Very easy to drive, stable but willing to dance.

[Lutfy]

Originally Posted by Mykl

I'm running Cobb bars with the rear set to full stiff. I imagine 24mm Whiteline bars adjusted to match would offer the same spring rate split between the front and rear.

Other setup notes...

My car is raked forward, center of hub to fender measurement front and rear is the same. I have ~-2.9 degrees camber front, and -1.9 degrees rear. Toe is as close to 0 as strings can get me, it's actually about 1mm off front and rear, but it's hard to get closer than that in my garage.

Also, the key to that kind of turn in behavior is to ensure that the suspension stays off the bumpstops (I don't have any). So you'll need to taylor your spring rates based on your tires. I'm running 245/45-17 RE-01R's. If you run stickier or wider you'll need stiffer spring rates.

I have Koni 8611 dampers. The rears are set a hair stiffer than the fronts in both compression and rebound, but I don't actually think this is having much of an effect. Setting the rears the same as the front seems to drive about the same.

The last detail is tire pressures. At the track I run 38 psi hot all around. A little less in the rear should provide more rotation. Different tires may like different pressures of course.

I need to get a tire pyrometer so I can fine tune the settings. But overall this setup feels very nice at the track. Very easy to drive, stable but willing to dance.

Mykl,

I have the front and rear bars set to full soft (27mm front, 22,24,26 Whitelines) with the same camber settings as yours (1/32 toe in at the back). Running Nitto NT01s with 38 hot temps.

Turn in is fine. I get a lot of mid corner understeer and with the throttle down, the car just plows. I added the ALK with little or no effect.

I will crank up the rear bar to medium and take it from there. Just having a hard time with the STi (came from an E36 M3).

Thank you so much for the feedback.

Regards,

Lutfy

[Mykl]

It might be the 27 mm bar up front that could be causing the mid corner push? Does the car rotate fine when you lift or does it continue to plow?

For me at the track most of the time I apex so late there really is no mid corner. I try to time it that I go full throttle at the same moment that I dive in towards the apex. Around the corners that require speed maintenance I'm usually going so fast at turn in that I don't dare go full throttle mid corner because the extra velocity will cause the entire car to go sideways off the track. In that case I feed in as much throttle as I can, and lift if I need rotation.

On the old Little Talladega GP layout there was most of a skidpad on the track (been there?). If I stomped on it while set in the corner the rear end would slide around some, but the car would pick up too much speed and just slide wide. It wouldn't push, and it wouldn't spin... I guess it was the definition of neutral.

[Lutfy]

Originally Posted by Mykl

It might be the 27 mm bar up front that could be causing the mid corner push? Does the car rotate fine when you lift or does it continue to plow?

For me at the track most of the time I apex so late there really is no mid corner. I try to time it that I go full throttle at the same moment that I dive in towards the apex. Around the corners that require speed maintenance I'm usually going so fast at turn in that I don't dare go full throttle mid corner because the extra velocity will cause the entire car to go sideways off the track. In that case I feed in as much throttle as I can, and lift if I need rotation.

On the old Little Talladega GP layout there was most of a skidpad on the track (been there?). If I stomped on it while set in the corner the rear end would slide around some, but the car would pick up too much speed and just slide wide. It wouldn't push, and it wouldn't spin... I guess it was the definition of neutral.

The front bar is set on full soft. Part of the reason I let the front spring rates low (400) since the bar its quite big. The car does rotate fine when lifted. I feel the rear bar being full soft may be the culprit. I am going to put it in center setting and eventually full stiff to test it out.

With the steering yanked into the corner and lifting (trailing throttle over steer) and then getting back on the gas gradually I still have understeer. even when I floor it during mid corner, I get massive understeer. Can never get the car to power oversteer PERIOD.

I have not been to LT however been to Barber a few times. In my Stock Classed E36 M3 I was running 1:46s. In the STi I was running the same times with MASSIVE push all over the board (full stiff front bar, rear full soft). Looseing the front bar helped quite a bit but not enough. Now rear to mid setting and will report next week when I hit Dubai Autodrome (moved to DXB and got the car with me here).

Cheers,

Lutfy