CSG and RCE tag-team suspension Q&A thread! Ask us anything!

[NissanGuy]

I'm getting corner-entry understeer on downhill hairpins. Like, it bites hard on initial turn-in and then the front washes out immediately when I'm still 30 feet before the apex. On-throttle or at high speeds the handling is lovely and balanced. Is there something I can alter to reduce this tendency?

My suspension might as well be Scion stock. I've got stiffened drivetrain mounts, rear subframe inserts, 35 minutes front camber and 85 minutes rear camber; 0 front toe and 7 minutes total toe-in rear. My tires are 205/55R16 and soft as all hell even at 46 psi, admittedly exacerbating the problem. I don't particularly want to change the higher-speed or corner-exit handling. Maintaining high-speed understeer is important to me since I crashed my last car due to high speed oversteer.

Any thoughts? I feel like some front-end bracing would help, since a lower control arm brace eliminated this issue with the altima.

[gramicci101]

For those at home, that's 0.58 degrees front camber and 1.42 degrees rear camber. Total rear toe-in is 0.12 (just under 1/8 inch).

Right off the bat, more front camber and better tires wouldn't hurt. If you're plowing coming into the turn, you're coming in too fast for the amount of grip you have.

[finch1750]

What gramicci said. You are on taller sidewall tires which doesn't help. Get some more camber up front and see what it does. Then maybe add a front swaybar to keep things planted. The FRS understeers at the limit so camber is really needed. I run -2.5 for autox on semi sticky tires (potenza S-04) and still push on entry.

[gramicci101]

Try to take the front camber from -35 minutes to -120 minutes (-2.0), and leave the rear alone. See what that does for you. You'll need camber bolts at the very least ($25, here).

You either need to slow down to accomodate the traction you have, or increase your traction to meet the speed you want to go. There are much better ways to increase traction than subframe braces; tires and camber will make the biggest difference to you right now. Then suspension, then swaybars, then strut bars/chassis bracing. Take your time on each step and make sure you get them adjusted as well as possible before deciding that you need to go to the next step.

[NissanGuy]

All of those things would make it oversteer at speed though, excluding front sway bar (which is enticing). Just to be clear, I'm not saying it has too little overall grip. I'm saying the rear won't slide at low speed unless I nail the throttle. Ideally I'd like to enter all hairpins sideways, but not slide at all above like 70mph.

Lol if it weren't a drum-type handbrake I would be able to use that to get it turning

[gramicci101]

It won't oversteer at speed unless you do something to unbalance the car like slam on the brakes or saw back and forth wildly on the steering wheel.

Your goal is to hang the rear end out at low speeds? That's easy enough. If you want to get sideways at low speeds and understeer at high speeds, that's more difficult. A car that's going to exhibit factory levels of understeer at high speeds is going to do the same at all speeds. A car that can twitch the rear end out at low speeds will be even more unstable at high speeds.

I would do more firm suspension all the way around, set the car up as neutral/hint of understeer as possible, and then do some research on various drift techniques beyond hanging on the e-brake. Trailing throttle, power, etc... can be used to induce oversteer without the car being unstable driving in a straight line. A neutral car is very easy to induce trailing throttle oversteer without just randomly spinning around on you, but you have to know what you're telling it to do or it'll bite you in the ass.

[Ultramaroon]

Originally Posted by gramicci101

For those at home,...

lol

[finch1750]

I would say spend a decent amount of money on coils with even or staggered rate (RCE T2, Tien SRC). You basically need a setup that you can initiate overstee/understeer on command. Something as close to neutral as possible should go a long ways to getting there

[Kostamojen]

Originally Posted by NissanGuy

All of those things would make it oversteer at speed though, excluding front sway bar (which is enticing). Just to be clear, I'm not saying it has too little overall grip. I'm saying the rear won't slide at low speed unless I nail the throttle. Ideally I'd like to enter all hairpins sideways, but not slide at all above like 70mph.

You don't want lift-off oversteer at low speeds on this car...

Are you saying you want the car to have a better slip angle or something at lower speeds?

[NissanGuy]

Originally Posted by Kostamojen

You don't want lift-off oversteer at low speeds on this car...

Are you saying you want the car to have a better slip angle or something at lower speeds?

I want lift-off oversteer at low speeds on this car.

Basically, I like how the car handles when driving smoothly or roughly at high speeds, and I like the throttle-on handling at low speed. Pretty much the only problem is that the car can't be made to oversteer into a corner below about 50 mph, a major handicap on the tight canyon roads I prefer. I could just set it up for more oversteer overall, but I'm not comfortable with high-speed oversteer.

The car can most definitely oversteer out of any turn, but that's not helpful when I've missed the optimal braking point by 10 feet and I need to scrub off some speed while turning the car.

I was looking around for kits to reduce anti-dive geometry a la Impreza, but that doesn't seem to be on offer. Forward weight transfer is a wonderful thing, my old car thrived on the ability to do a nose-stand under braking. Stiffer suspension is definitely the opposite of what I want, but the only front springs I could find that are softer than FR-S are also drop springs, which sound like I'd just be all over the bump stops, not to mention steep driveways.

Failing that, I've been trying to look into the effects of increasing caster angle. Greater negative camber at high steering angles (the main effect of increasing caster) seems like it should add plenty of oversteer in tight turns, and not much in wide turns.

I wish I'd saved the link, but I found a simulation online that showed another 3 degrees of caster with 15 degrees SAI (roughly what our cars have, on both counts) would give 1 more degree of camber gain at 20 degrees of steering (more or less a wide hairpin). In practical terms, a Raceseng top hat would give me a healthy dose of camber in hairpins and only a hair of camber in wider turns.

...I think.


EDIT: Also I put front toe 2 minutes out on the front axle. It handles a little better but oh my god it's so annyoing to drive on the freeway. Car goes left, right, left, right... The road goes straight.

[Kostamojen]

Originally Posted by NissanGuy

I want lift-off oversteer at low speeds on this car.

Get a giant rear swaybar and a clutch based differential or something.

I find this car a million times better at entering a corner than any impreza I've had or driven so I dont get what your problem is here.

[LittleBlueGT]

Ordering some RS3s for my track wheels soon.

Should I be wary of getting them from a place that maybe allowed them to be stored in sub freezing temps (from Canada here)? Or are these Hankooks not really susceptible to damage from cold temps?

[BMHumanic]

So i'm having a bit of trouble with the adjustment of my coilovers as the bottom of the threaded sleeve is making constant contact with my sway bar. Basically what I did is installed the coilovers, then set the pretension even and to where I wanted it on all 4 corners, and then lowered them to where I wanted the car to sit. Now looking at these, I cant see how I can adjust it without adjusting the height of the vehicle but im no expert in suspension. I was hoping an aftermarket sway bar would have different mounting points (further back) but I doubt it. Ive asked around and no one can seem to come up with an answer.

For reference these are Godspeed Mono-RS Coils, Whiteline adjustable endlinks, and the OEM sway bar.

[troek]

are you slammed maxed out on your coilovers??