I_Call_D.I.B.s

I am planning on lowering my 2013 V-6PP. I plan on doing some autocross for fun as well once the weather gets better.

I already have a Fays2 Watt's Link installed and Koni Yellows waiting to be installed. I will be getting Steeda Ultralite springs (1.25"/1.5" drop front/rear) and MM caster/camber plates.

I've been reading up on how lowering the Mustang changes the LCA angle and how that contributes to wheel hop and roll understeer, so I was going to get Whiteline adjustable LCAs and LCA relocation brackets. However, I read from a prominent vendor on another forum that the brackets are unnecessary. The OP on that thread wanted a street/strip setup, IIRC. Should I still consider LCA brackets since I'm more concerned with street/autocross? If not, will most adjustable LCAs extend enough to bring the LCA angle back to stock on a lowered car? For now, I would like to return the LCA angles to stock once the car is lowered.

eolson

As I understand it, for road racing, having the trailing arms slightly sloping down to the front of the car is better for accelerating in and out of corners, where as drag racers want the torque transfer to have the arms sloping down toward the rear of the car.

Autocross probably level with the ground, I'm sure Sam Strano knows. Erik

Norm Peterson

At autocross you don't get any real choice about LCA inclination until you're playing in C-Prepared or higher.


Norm

corruptor

There is no benefit in any situation of having the control arm point downwards towards the front of the car. This creates more understeer.

If you're dropping the car with 1.5" lowering springs, you will need relocation brackets. I

Norm Peterson

There is a difference between understeer due to rear axle steer and understeer due to roll stiffness distribution and while there might be a few low speed situations where axle steer in the vehicle oversteer direction is useful, it's a less stable method of freeing up the handling. The S197 only has minimal axle steer at OE ride height, a little under 2.5% with a 180-ish lb driver aboard.


Agreed - about the same drop in axle side pivot height as the rear of the car is lowered will retain a stock-ish amount of axle steer which is pretty darn good to begin with.

Meanwhile noting that by doing so you can forget about autocrossing in Stock, Street Touring, Street Prepared, or Street Modified. Say hello to
C-Prepared.


Norm

UPRSharad

Norm makes a valid point about class rules. If you're not worried about winning your class, you may still consider the relo brackets, but it's not a decision I'd make lightly.

I'm thinking about trying some UPR relo brackets on my car... but not without welding them on and welding the axle tubes to the center section.

I_Call_D.I.B.s

As long as I have the Watt's link installed I'm stuck in C Prepared anyways. If I'm reading the rules correctly I'm only allowed to use stock or aftermarket Panhard bars to be eligible for Street Touring, and can only use the factory Panhard bar in Stock. Good to know about the relocation brackets and classing. I'm exploring other clubs besides SCCA to run with anyways, some of them only run PAX indexes or have looser classing structures.

I haven't done any racing in a while and am looking at a-x to get back in the groove and get used to the Mustang. I would like to move up to track days with it and I haven't ever driven the Mustang in anger.

Murphdog

Trying not to hijack this thread but I'm curious about this....

I currently have sitting in my garage the Sport springs, which are not as much of a drop as the Untralights. My car is a daily driver. Is relocating the LCA a requirement because it physically won't work in it's stock location after being lowered, or are you suggesting that it's a requirement for that specific auto-x ? If relocation brackets are required. I certainly need to put it on my "to be purchased" list.


I wasn't quite prepared to do this upgrade, but due to unforeseen circumstances (read my other recent topic) I've decided to upgrade the majority of the suspension. I've got or will have in my possession soon, the following...

Koni Yellows, Steeda Sport Springs, UPR bumpsteer kit, Steeda Upper Strut mount. Adjustable panhard bar.

Will find out this week whether or not I need to replace my k-member or a-arms in the front.

Thanks
Murphy

Norm Peterson

It will physically work, but will make the car's understeer somewhat worse and sudden lane change swerves or similar avoidance maneuvers might be a little sloppier than if you corrected the LCA inclination.

At -1.5" you might have just a little more resistance to wheel hop, if that's a consideration.


Norm

UPRSharad

Relocation brackets are never a "requirement". Personally, I'm not a fan, but I can't deny that the BOSS 302R cars are running them, so it's time for me to give them a shot.