FRTP sway bar setup

[dmann]

Your installer is trying to kill you

Run the rear bar on a softer setting, the car will oversteer less easily and should feel a lot more planted. If you want more rear grip, soften the rear bar. If you want more front grip, soften the front bar.

Only go as stiff as you need to meet your goals for flat handling and weight transfer speed. Softer means more grip in general.

I know right lol
Thanks for the always solid advice.

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[BmacIL]

If you want more front grip, soften the front bar.

I've really not found this to be true on this car (unless you go way overboard compared with the tire grip you have).

 

[NightmareMoon]

I've really not found this to be true on this car (unless you go way overboard compared with the tire grip you have).

I’ve tried multiple swaybar setups and settings on my car at the track and autox and the Mustang responds just like any other RWD car to swaybar changes, some bar at either end seems to help overall /handling/, and if your car is riding the bumpstops adding some swaybar may help the situation but...

Stiffer front bar means a bit more understeer and a stiffer rear bar yields oversteer. That’s the same thing as gaining and loosing grip. If a stiffer front bar gained front axle grip, the car would oversteer when you run stiffer front bar settings, which it absolutely doesn’t do. Same on the rear, increasing stiffness just give more oversteer (less grip), which has been my exact experience on my car.

 

[BmacIL]

I’ve tried multiple swaybar setups and settings on my car at the track and autox and the Mustang responds just like any other RWD car to swaybar changes, some bar at either end seems to help overall /handling/, and if your car is riding the bumpstops adding some swaybar may help the situation but...

Stiffer front bar means a bit more understeer and a stiffer rear bar yields oversteer. That’s the same thing as gaining and loosing grip. If a stiffer front bar gained front axle grip, the car would oversteer when you run stiffer front bar settings, which it absolutely doesn’t do. Same on the rear, increasing stiffness just give more oversteer (less grip), which has been my exact experience on my car.

Yes I know the theory and how it works, but the experience has been different. I experienced a significant increase in front axle grip in pretty much all situations and phases of the corner going from the stock front bar to the BMR front bar on the middle setting. The reduction in roll is keeping the front geometry better constrained and subsequent contact patch improved. The car was vastly more competitive in autocross with that change, a change that should've made the car understeer. It didn't.

 

[NightmareMoon]

Yes I know the theory and how it works, but the experience has been different. I experienced a significant increase in front axle grip in pretty much all situations and phases of the corner going from the stock front bar to the BMR front bar on the middle setting. The reduction in roll is keeping the front geometry better constrained and subsequent contact patch improved. The car was vastly more competitive in autocross with that change, a change that should've made the car understeer. It didn't.

Yeah, its better for quickly turning in, the weight transfers faster so your outside tire can grip harder, earlier in the process. Once the weight has shifted, its maximum grip however isn’t higher. Thats what I mean by handling versus grip.

Continuing to stiffen that front axle, but setting it on hard versus medium would not continue to improve your autox results overall though. We need to consider all 3 phases of the corner and not just corner entry.

 

[BmacIL]

Yeah, its better for quickly turning in, the weight transfers faster so your outside tire can grip harder, earlier in the process. Once the weight has shifted, its maximum grip however isn’t higher. Thats what I mean by handling versus grip.

Continuing to stiffen that front axle, but setting it on hard versus medium would not continue to improve your autox results overall though. We need to consider all 3 phases of the corner and not just corner entry.

Ok, yes it's early and I phrased it wrong. The change in balance in the entry and middle of the corner is better utilizing the front grip available and creating less/no understeer when not overdriven. This also allows for getting on the power sooner/more, finishing each section/corner faster. The overall handling going to the stiffer front was improved such that it has the feeling of improving front axle grip.

I am actually going to try the stiff setting to find the limits of this. Most of the popular motorsports-focused coilover setups (MCS, Cortex, JRi, etc) have front spring rates in the 450-600 range, with rear in the 1200-1400 (if divorced spring/damper, or equivalent wheel rate if true coilover). That's a massive increase in front axle roll stiffness compared with what you or I have relative to the rear, but it does work. I struggled with that for a long time, because it shouldn't work on track, but it does. Heavy+front heavy+RWD needs a focus on getting the car rotated to the apex and then powering out to create the yaw necessary to exit quickly.

 

[Rebellion]

I’ve tried multiple swaybar setups and settings on my car at the track and autox and the Mustang responds just like any other RWD car to swaybar changes, some bar at either end seems to help overall /handling/, and if your car is riding the bumpstops adding some swaybar may help the situation but...

Stiffer front bar means a bit more understeer and a stiffer rear bar yields oversteer. That’s the same thing as gaining and loosing grip. If a stiffer front bar gained front axle grip, the car would oversteer when you run stiffer front bar settings, which it absolutely doesn’t do. Same on the rear, increasing stiffness just give more oversteer (less grip), which has been my exact experience on my car.

I've struggled with this paradigm for some time, mainly my refusal to mount a front bar with the reasoning of it adding understeer. I'm sure that at certain point it does, but so far (BMR front on middle and 350R rear bar) it hasn't. Seems like there is a balance to be achieved with 2 effects: 1) reduction of front roll, which causes understeer, and 2) reducing front compression, therefore preventing or delaying the "inflection". The effect of the McPherson strut going from negative camber to zero and then positive as compression increases is what I call inflection.

So far, with my bar settings, the balance has been towards grip...and I'm pretty sure it will depend on roll stiffness (2x spring plus bar rate) and roll tendency due to geometry (static center of gravity, roll center and migration). The car doesn't understeer more than usual, if anything it's being biased towards oversteer (indicating more front grip) but not quite past neutral. I'm sure it's still on the understeer spectrum, just significantly closer to neutral.

This effect might or might not happen to an arbitrary setup, there are so many factors at play...but at least in some setups, it is possible to add more grip via front sway bar.

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