What is a "bump steer" kit?

929PhoenixSquid · 09-16-2002, 12:41 PM

I guess the question should be what exactly does a bump steer kit DO? How does it effect the handling of a lowered car with castor camber plates? Is it neccessary? How much does the installation usually run?

Thanks for the info!!!

Conman · 09-16-2002, 01:58 PM

the geometry of the suspension is very complex. The A-arms and steering tie-rods have a relationship so that the wheels are pointed forward. When you hit a bump the suspension moves and this relationship changes causing the wheels to steer in or out a little bit depending on how it is setup. I don't know specifics on the mustangs and what is included in the kit. This relationship can get thrown out whack by lowering your car so for a corner carver you would definately want to correct this but for a daily driver I think the main problems associated with lowering a car can be corrected with caster/camber plates.

Chevyguy · 09-16-2002, 04:46 PM

The bumpsteer kits fall into two categories I have seen,

Offest rack bushings

Adjustable tie rod ends.

Since Mustangs have a strut front end, you can't really use drop spindles which is the best way to lower a car, that maintans the proper geometry.

When you lower a car with springs, this squats the car lower on the A arms as there is only one pivot point for the suspension. Using caster/camber plates allows the caster to be set properly at the new ride height.

Bump steer is related to the geometry of the steering linkage in relation to the spindle, which is set to be in the middle of the arc from the spindle to the rack. The lowering process changes the length from the rack to the spindle. So when you hit a bump, the wheel can get pulled inward, causing "bump steer" The Offest rack bushings raise the rack, or the adjustable tie rod ends lowers the attaching point to the spindle.

At least that's what I understand about the issue.

P.S. My Notch was a virgin too. Isn't it kinda cool when you find the silencer still there!! Of course I had original everything, plugs wires PCV Cap&Rotor struts and shocks all 99K miles 11 years old

lx5091 · 09-16-2002, 09:26 PM

steeda has a new balljoint also, the x2, it raises the spindle relative to the balljoint pivot point, which supposively raises the roll center back into the correct range.
I don't know what you can use in conjunction with what. like, can you use these balljoints with bumpsteer kits or maybe they work on there own?

srv1 · 09-16-2002, 10:50 PM

Quote:

Originally posted by 929PhoenixSquid
I guess the question should be what exactly does a bump steer kit DO? How does it effect the handling of a lowered car with castor camber plates? Is it neccessary? How much does the installation usually run?

Thanks for the info!!!

Matt, do you have Nov. Issue of 5.0 Mustang and Super Fords? if not get it. Page 107. alot of info on setting up the suspension and it tells you what bumpsteer is.

here are some pics of what a bumpsteer kit looks like:

what you really want to have is the inner tie rod end to pivot exactly where your lower control arm pivots. the closer you are to the lower pivot point, less bumpsteer. it is not a "bolt-n-go" procedure either. to correctly do it, you need to take out the front springs and lower the rack or use the bumpsteer kit, and measure the difference in travel of the arc of the lower control arm and the tie rod end. theoretically, they should both move parallel to each other and move in the same arc, meaning same travel. here is what i mean:

is that what you wanted to know?

929PhoenixSquid · 09-17-2002, 07:58 AM

Okay, I think I have a "vague" (and I do mean VAGUE) idea of what is going on here.

I suppose my next question is, in order to keep the drive geometry optimal, do I need to add offset bushins WITH a bump steer kit or is the bump steer sufficient along with castor camber plates (aftermarket)???

Also, I did notice that Steeda's X2 balljoints claim they are for '94-2002 mustangs. Are there any aftermarket balljoints for Fox bodys and are they really beneficial?

09-16-2002, 12:41 PM	#1
929PhoenixSquid Registered Member Join Date: Oct 2001 Location: Joosey Shore Posts: 358	What is a "bump steer" kit? I guess the question should be what exactly does a bump steer kit DO? How does it effect the handling of a lowered car with castor camber plates? Is it neccessary? How much does the installation usually run? Thanks for the info!!! __________________ 1988 5.0 notch: Previously never modified!! SN95 block front and rear seats, Mac catback, BBK off-road H-pipe, Steeda castor camber plates, Steeda lowering springs, Tokico shocks/struts, Alpine/MBQuart/PPI audio mods...

09-16-2002, 01:58 PM	#2
Conman Registered Member Join Date: Apr 2002 Location: Kingston, Ontario Posts: 351	the geometry of the suspension is very complex. The A-arms and steering tie-rods have a relationship so that the wheels are pointed forward. When you hit a bump the suspension moves and this relationship changes causing the wheels to steer in or out a little bit depending on how it is setup. I don't know specifics on the mustangs and what is included in the kit. This relationship can get thrown out whack by lowering your car so for a corner carver you would definately want to correct this but for a daily driver I think the main problems associated with lowering a car can be corrected with caster/camber plates. __________________ '88 lx, Black on Black, check it out here Spent all my money on school, what a dumb mistake I'm old enough to know better, but still too young to care.

09-16-2002, 04:46 PM	#3
Chevyguy Backyard Mechanic/Chemist Join Date: Feb 2001 Location: Acton MA USA Posts: 435	The bumpsteer kits fall into two categories I have seen, Offest rack bushings Adjustable tie rod ends. Since Mustangs have a strut front end, you can't really use drop spindles which is the best way to lower a car, that maintans the proper geometry. When you lower a car with springs, this squats the car lower on the A arms as there is only one pivot point for the suspension. Using caster/camber plates allows the caster to be set properly at the new ride height. Bump steer is related to the geometry of the steering linkage in relation to the spindle, which is set to be in the middle of the arc from the spindle to the rack. The lowering process changes the length from the rack to the spindle. So when you hit a bump, the wheel can get pulled inward, causing "bump steer" The Offest rack bushings raise the rack, or the adjustable tie rod ends lowers the attaching point to the spindle. At least that's what I understand about the issue. P.S. My Notch was a virgin too. Isn't it kinda cool when you find the silencer still there!! Of course I had original everything, plugs wires PCV Cap&Rotor struts and shocks all 99K miles 11 years old __________________ 2001 Crown Vic Maurader Airbox/MAF, DR chip Edel IAS shocks Single exhaust :wtf: 93 P-71 Vic interceptor Backup car now 90 5.0 LX Notch SOLD 74 Chevy Laguna type S-3 454 under construction Currently apart undergoing bodywork.

09-16-2002, 09:26 PM	#4
lx5091 Registered Member Join Date: Nov 2001 Location: Fall River, MA Posts: 467	steeda has a new balljoint also, the x2, it raises the spindle relative to the balljoint pivot point, which supposively raises the roll center back into the correct range. I don't know what you can use in conjunction with what. like, can you use these balljoints with bumpsteer kits or maybe they work on there own? __________________ '02 Explorer XLT 4.0L --Nice Vehicle '97 Saturn SL1--Soon to be ditched for a Ford!

09-17-2002, 07:58 AM	#6
929PhoenixSquid Registered Member Join Date: Oct 2001 Location: Joosey Shore Posts: 358	Okay, I think I have a "vague" (and I do mean VAGUE) idea of what is going on here. I suppose my next question is, in order to keep the drive geometry optimal, do I need to add offset bushins WITH a bump steer kit or is the bump steer sufficient along with castor camber plates (aftermarket)??? Also, I did notice that Steeda's X2 balljoints claim they are for '94-2002 mustangs. Are there any aftermarket balljoints for Fox bodys and are they really beneficial? __________________ 1988 5.0 notch: Previously never modified!! SN95 block front and rear seats, Mac catback, BBK off-road H-pipe, Steeda castor camber plates, Steeda lowering springs, Tokico shocks/struts, Alpine/MBQuart/PPI audio mods...