KW V3 Settings?

[408Stang]

I recently put KW Suspension V3's on my car. I have corner balanced it and set the compression and rebound to the recommended settings from KW. It handles fine, but basically just like it did before (Saleen Racecraft shocks and springs) . I'm wondering if anybody has ever really "played" with these shocks settings for autoX. I've been reading and reading on what changes to those settings "should do" but I'm wondering if someone has experience with what it "will do".

 

[LS1EATINPONY]

What are the spring rates? what were the racecraft spring rates?

 

[408Stang]

I'll see if I can figure out the spring rates from the manufacturers... The Saleen units came on the car from Saleen and the KW V3 units were a vehicle specific kit. At minimum I should be able to get the KW spring rates.

 

[408Stang]

I called both manufacturers and they said they are progressive rate springs and they can't really specify a rate because it's dependent on the weight of my car and how compressed the springs are at any given time.

However, KW said to run my rear sway bar (Steed adjustable) in the full loose setting and raise my compression / bump shock settings a click or two all the way around. They also said to leave my rebound setting alone or maybe even one click softer.

I've heard that the Mustangs like a loose rear bar but I'm not following the logic for autocross... I thought it basically needed to be as stiff as possible. And I should also mention I'm running a Saleen front bar... I believe it's 35mm... With Whiteline adjustable end links.

I think I have too much adjustability in my suspension frankly... But that's why I'm trying to learn more about it.

 

[Whiskey11]

There is a definite trade off for front to rear grip. I run a soft rear bar on my car but my roll center and rear spring rates are higher than most (don't think the spring rate is higher than the V3's rear springs). I prefer a slight on power push and an off power looseness. I'm pretty close to that setup now.

Anyway, you are going to have to play with damper settings to really figure out what you like. My suggestion is to dial out all the compression damping and deal with just the rebound until you find settings where the car transitions the way you want it. Then bump up compression until the car is too skiddish to drive.

That's just me though.

 

[408Stang]

Talked some more with KW.. They recommended running the Steeda bar full loose and controlling the body roll with the compression and rebound. I tried cranking up the compression once and it slid all over the place. Haven't really played with the rebound, and I haven't run the bar in the softest setting.... Frankly I don't know if I have the tire budget to figure this out... But I like trying.

 

[Norm Peterson]

408 - Let me suggest discussing the bar settings in terms of soft and firm. "Loose" is too easily confused with the exact same word used as slang for vehicle oversteer, which is what you're likely to get when your rear bar is set too firm. I don't know why anybody would use "loose" as a synonym for "soft" anyway. As a synonym for something clunking or rattling around, maybe.

The damping adjustment guides I've seen recommend setting the bump damping first, with rebound damping set full soft.


Norm

 

[Lucky_13]

Hey 408, I run the V3's, albeit with big bars. The settings I tend to run out of track is rebound a click stiffer at both ends than the factory recommended, bump 3 clicks off open in the front, and bump one sweep open on the rears.

My guess is that the Saleen spring rates are actually pretty stiff (stiffer than the KW's) because the Racecraft look similar to BC/Megan etc, purely a guess though.

Here's the info I got from KW about a year ago:

"Michael,

The working rates for the V3s on the Mustang GT are 343 lbs/in front and 200 lbs/in rear.

The Clubsport kit holds linear rates which are 571 lbs/in front and 340 lbs/in rear.

If you have any more questions please let me know."

My thinking would be that the V3's will ride better and generate the same handling with lesser spring rates due to improved valving. The V3's are really not a "track" coilover, they're a very nice street coilover that won't fall on their face out there, but I definitely needed to augment their roll stiffness with sizable bars (38mm BMR front, Eibach rear set to full stiff -- > Likely going to BMR or Whiteline rear).

Since I don't autox and do HPDE, the setup is the best of both worlds for me. For the rapid transitions of autocross, you could set the car "loose" as they suggested (rear bar full stiff), and try dialing in more rebound to get the transition you want.

My +1 click on rebound all around was because the recommended settings felt underdamped and jiggly, and the car had sizable front end lift/rear squat under acceleration out on track and brake dive/rear lift during heavy braking zones. The +1 all around made that behavior far more manageable without totally stinting weight transfer onto the tires.

-Mike

 

[408Stang]

Thanks for the input. I'm trying to fix understeer. And of course increase grip all the way around... I want it all... Lol..

I have a 35mm front bar (no adjustment) and a 32mm rear bar with three positions of adjustment.

When I set the rear bar to full stiff the car drives like it's on marbles... Front and rear. When I set the rear bar to the middle position it gets much better. Which makes me think I should try the softest setting for the rear bar.

Then comes the complications of the rebound and compression settings for the KW's. When I stiffen the settings up (from the recommended ones) , I'm back to driving on marbles. I just can't seem to find the happy medium.

I have about 600 hp on tap at the rear tires so I can power out of most understeer but racing that way is REALLY hard on tires.

My understeer is usually at the beginning of the turn which also makes me think alignment... Perhaps I need more camber and perhaps a little toe-out. Right now I'm running - 1.5 camber / +7.5 caster /. 10 tie-in. I'm thinking of changing to - 2.0 camber / +6.5 caster / zero toe... The problem for me is that I only do 1-3 AutoX's in a year and about 2000 miles of street driving, so I'm trying to strike a balance and not kill tires.

As a general rule it seems that going stiffer with either the bars or the shocks on either the front or rear causes that axle to lose grip. This seems opposite to me from what is supposed to happen. Increased stiffness should increase grip... Right? ... To a point, I understand.

So if I soften the rear (bar and shocks) in theory the front should gain traction, or the perception of more traction, because the rear will feel looser?

I guess now I'm getting confused as to what the above post meant by increasing rebound to help the transition. If I "increase" / more power the rebound wouldn't it make the shock / slower to rebound... vs. Decreasing the rebound power / resistance to make it rebound quicker?

Same for compression... Right? Increasing the power / stiffness makes it harder to compress the shock / strut, thus increasing the cars resistance to body roll or pitch. While decreasing the compression setting / lowering the power would allow the body to roll and pitch more.

Do I have that right?

KW told me that the Mustangs like to roll a little to "dig" for better traction. I also have a friend who raves HPDE a lot and he purposely has about 1/2" play in his front sway bar end links to allow it to roll a little bit before encountering sway bar resistance. My thought on this is that I'm trying to hard to make the car corner flat, when it really needs to roll a bit.

Somebody straighten me out please!

 

[csamsh]

One thing that you have to keep in mind- the "stiffer reduces grip and softer increases grip" really only holds true if your suspension is already optimized and your tires are already happy. If you have noodle springs on the front, a stiff swaybar will help keep the contact patch reasonable, as opposed to taking away grip. With my setup (800# front springs) yes, the stiffer the front bar, the less grip there is. For autocross, I recently did a test and tune and was fastest with the bar on full soft. The timers don't lie.

There is an elephant in the room in this thread- what is your wheel anf tire setup? Until you get that straightened out, none of the rest of anything really matters

 

[Lucky_13]

One thing that you have to keep in mind- the "stiffer reduces grip and softer increases grip" really only holds true if your suspension is already optimized and your tires are already happy. If you have noodle springs on the front, a stiff swaybar will help keep the contact patch reasonable, as opposed to taking away grip. With my setup (800# front springs) yes, the stiffer the front bar, the less grip there is. For autocross, I recently did a test and tune and was fastest with the bar on full soft. The timers don't lie.

There's a lot to sort through here, but this +/x1000. Most of the internet wisdom you'll come across regarding vehicle dynamics is only pertinent to race cars, which are already at a certain point of optimization.

To echo what Cs is asking, are you running a staggered wheel/tire setup?

 

[408Stang]

I'm running a staggered set up, but barely: 275/35/20 front and 295/35/20 rear. Michelin Pilot Super Sports

 

[csamsh]

I'm running a staggered set up, but barely: 275/35/20 front and 295/35/20 rear. Michelin Pilot Super Sports

Well that's part of the problem. Right there you are already biasing the car towards understeer. You have a smaller tire on the heavy end of the car, and a bigger tire on the light end. Even with a square setup it wants to push unless a lot of stuff is done right.

What size are your wheels? I'd highly recommend square 18x10's or 18x11's.

 

[408Stang]

When I get the $$$$ I'd like to get 18x9 Enkei PF01's and Hoosier A6's... But for now the car will have to keep the staggered 20" tires and wheels.

 

[csamsh]

When I get the $$$$ I'd like to get 18x9 Enkei PF01's and Hoosier A6's... But for now the car will have to keep the staggered 20" tires and wheels.

There's cheaper and wider out there too!

 

[408Stang]

I "want" those Enkei's, but my budget will probably force me to get some American Muscle wheels or some factory 18's from EBay. I just can't afford it this year.

 

[neema]

I "want" those Enkei's, but my budget will probably force me to get some American Muscle wheels or some factory 18's from EBay. I just can't afford it this year.

Nothing wrong with saving up. SVE drifts are the go-to budget race wheel. 18x10s for $600 shipped (or less if you dig up a coupon).

The guys in this thread will steer you in the right direction. like csamsh recommended, go with something wider unless you're sticking to class specific rules

you played with compression but don't write off rebound. It has a profound effect.

 

[SlowJim]

American Muscle and Late Model Restoration have fairly decent sales on almost every holiday. That's how a bunch of us picked up the 18x10 AMR's for under $400 shipped a while back.

 

[LS1EATINPONY]

Keep in mind that Enkei released two new versions of the PF01..... Mwa hahahahaha

PF01 EVO

PF01SS

 

[csamsh]

you played with compression but don't write off rebound. It has a profound effect.

This x100. Rebound way more important than bump.