bump steer
- Thread starter sponhower
- Start date
HopnDude
I B Derpin.
Re: bump steer
Him or Her. Theres a decent looking female who does Alighnments here in St Louis for Dobbs, Dobbs is kinda shiesty unless you know someone who works for them. But she did the Alighnment on my daily driver 02 Lancer OZ Ralley, and she did hella good on it!
Any way, comment still stands, have it put on alighnment rack, and spec's shot! Go from there, could also be loose suspension components!
Him or Her. Theres a decent looking female who does Alighnments here in St Louis for Dobbs, Dobbs is kinda shiesty unless you know someone who works for them. But she did the Alighnment on my daily driver 02 Lancer OZ Ralley, and she did hella good on it!
Any way, comment still stands, have it put on alighnment rack, and spec's shot! Go from there, could also be loose suspension components!
JSM
Active member
Re: bump steer
I'd venture to say its probably not camber either.
I would guess you have a toe-in/out issue along with caster problems. Good alignment and put more caster than stock specs show will help. I like 6-7 deg of caster key being both sides are equal amount of caster.
I knew it wasn't bumpsteer as I have only seen 1 person here even come close to knowing how to measure bumpsteer and doing it. Most alignment shops don't even know how to do that measurement.
I'd venture to say its probably not camber either.
I would guess you have a toe-in/out issue along with caster problems. Good alignment and put more caster than stock specs show will help. I like 6-7 deg of caster key being both sides are equal amount of caster.
I knew it wasn't bumpsteer as I have only seen 1 person here even come close to knowing how to measure bumpsteer and doing it. Most alignment shops don't even know how to do that measurement.
HopnDude
I B Derpin.
Re: bump steer
Hmm....I know Caster will not, for sure, cause bump steer. Caster is front to back wheel placement, if correctly alighned will not cause any issue, but would highly advise to get it fixed! This is where one wheels center point is farther forward or backward than the opposing sides.
Toe is the \ \---o---/ / or / /---o---\ \ of the wheel, might cause bump steer, but if only slightly out of alighn will wear the inner/outer edge of the tire over time, and is annoying and not very detectable.
Now if you lowered it, the suspension is a bit more stiffer than stock. And your wheels are now sitting cambered. Your gonna feel this! The wheels are in a bowed up position unless your riding a mexican hydrolic setup on hi, and they camber down (pitched in at the bottom). You'll have to look up pictures of this. I might even be able to find a picture w/ better depictions. But if your camber is out, and your ridinig stiff suspension down the road, hitting uneven pavement, or drops in pavement slabs (highway) then your gonna feel a little pull to one side or another every bump. I can promise you on this!
Hmm....I know Caster will not, for sure, cause bump steer. Caster is front to back wheel placement, if correctly alighned will not cause any issue, but would highly advise to get it fixed! This is where one wheels center point is farther forward or backward than the opposing sides.
Toe is the \ \---o---/ / or / /---o---\ \ of the wheel, might cause bump steer, but if only slightly out of alighn will wear the inner/outer edge of the tire over time, and is annoying and not very detectable.
Now if you lowered it, the suspension is a bit more stiffer than stock. And your wheels are now sitting cambered. Your gonna feel this! The wheels are in a bowed up position unless your riding a mexican hydrolic setup on hi, and they camber down (pitched in at the bottom). You'll have to look up pictures of this. I might even be able to find a picture w/ better depictions. But if your camber is out, and your ridinig stiff suspension down the road, hitting uneven pavement, or drops in pavement slabs (highway) then your gonna feel a little pull to one side or another every bump. I can promise you on this!
HopnDude
I B Derpin.
Re: bump steer
Yeah....I'm pretty sure. I've lowered a few vehicles for friends, went to Hunter Alighnment school as Dobb's paid for it. And I've done hundreds of alighnments....Last alighnment I touched was back in 2007 at Dobbs in Manchester, MO....so Sponhower, go get your shit on a rack and get it checked out!
Yeah....I'm pretty sure. I've lowered a few vehicles for friends, went to Hunter Alighnment school as Dobb's paid for it. And I've done hundreds of alighnments....Last alighnment I touched was back in 2007 at Dobbs in Manchester, MO....so Sponhower, go get your shit on a rack and get it checked out!
HopnDude
I B Derpin.
Re: bump steer
Camber over bumps w/ wide wheels, stiff suspension will cause it to veer left/right when hitting bumps like down roads/highways/etc.
Toe will pull to one side or another when driving down a road. You pull the wheel straight, it goes it's own way even after you correct it.
Caster, just play gay! No dice, you typically cannot notice/feel this. But it will screw w/ your turning radious and impare your handling in emergency situations, veering around a dead animal, pot hole etc. And in rain, can be very bad, all of these if not done properly can cause cerial issues! But get your shit on a rack, have it checked out!
Camber over bumps w/ wide wheels, stiff suspension will cause it to veer left/right when hitting bumps like down roads/highways/etc.
Toe will pull to one side or another when driving down a road. You pull the wheel straight, it goes it's own way even after you correct it.
Caster, just play gay! No dice, you typically cannot notice/feel this. But it will screw w/ your turning radious and impare your handling in emergency situations, veering around a dead animal, pot hole etc. And in rain, can be very bad, all of these if not done properly can cause cerial issues! But get your shit on a rack, have it checked out!
JSM
Active member
Re: bump steer
Google works well it appears. Now that we have the definitions down of what they are, do you really know HOW they react?
Alignment schools are going to teach you how to read a computer screen and adjust a car to get in the "green zone". They won't teach you WHAT each does and how it affects things.
If you so desire though my background does include an engineering degree, and as part of that I took a 400 level college course on suspension design where we had to design are own complete vehicle suspension from scratch. http://vri.etec.wwu.edu/
On top of that I just may have designed a coil over suspension for the syty's a few years ago, produced many sets with probably way over a million miles on MY design. O yea, my own typhoon is all custom front to rear, I've raced it at the drag strip, open road course topping over 140mph, autocross, heck I am doing a road course/autocross in 2 weeks in it.
I know exactly what all 4 items of discussion are and how they affect how a vehicle handles. More so than "my lowrider go bumpty bump over the bumps"
Google works well it appears. Now that we have the definitions down of what they are, do you really know HOW they react?
Alignment schools are going to teach you how to read a computer screen and adjust a car to get in the "green zone". They won't teach you WHAT each does and how it affects things.
If you so desire though my background does include an engineering degree, and as part of that I took a 400 level college course on suspension design where we had to design are own complete vehicle suspension from scratch. http://vri.etec.wwu.edu/
On top of that I just may have designed a coil over suspension for the syty's a few years ago, produced many sets with probably way over a million miles on MY design. O yea, my own typhoon is all custom front to rear, I've raced it at the drag strip, open road course topping over 140mph, autocross, heck I am doing a road course/autocross in 2 weeks in it.
I know exactly what all 4 items of discussion are and how they affect how a vehicle handles. More so than "my lowrider go bumpty bump over the bumps"
Flyin Ryan
hated cuz he drives fords
Re: bump steer
These trucks typically don't have bump steer issues and I know with mine i've expierenced what the op is talking about which is when the truck grabs any type of groove in the road and wants to follow it.In my case it's because I have 275's on the front.. I swapped to 245's to see what would happen and bam issue totally cured. Went back to 275's since the truck doesn't see highway use much
These trucks typically don't have bump steer issues and I know with mine i've expierenced what the op is talking about which is when the truck grabs any type of groove in the road and wants to follow it.In my case it's because I have 275's on the front.. I swapped to 245's to see what would happen and bam issue totally cured. Went back to 275's since the truck doesn't see highway use much
SyTy Militia
Noob Welcome Committee
Re: bump steer
Man, what is that word that defines this interaction between a seasoned syty guru and a noob that apparently doesnt even own a syty....
Oh wait, wait, wait, I got it...........
OWNED.
Man, what is that word that defines this interaction between a seasoned syty guru and a noob that apparently doesnt even own a syty....
Oh wait, wait, wait, I got it...........
OWNED.
13.robb
New member
Re: bump steer
Dont know where this thread is going, but i dont beleive you are getting a bump steer, its more of a when you lower the front end on an independant (ifs) vehicle and the wheels tuck in @ the top they tend to chase ruts. If you have any excess wear on the steering components it gets real bad at times. The best way to fix is either raise the front back up or go with a coil over setup w/aftermarket upper control arms. Been down this road, getting ready to go up an inch on mine to clear my 19's and wont miss chasing ruts.
Dont know where this thread is going, but i dont beleive you are getting a bump steer, its more of a when you lower the front end on an independant (ifs) vehicle and the wheels tuck in @ the top they tend to chase ruts. If you have any excess wear on the steering components it gets real bad at times. The best way to fix is either raise the front back up or go with a coil over setup w/aftermarket upper control arms. Been down this road, getting ready to go up an inch on mine to clear my 19's and wont miss chasing ruts.
JSM
Active member
Re: bump steer
Now that I have been a bit sarcastic, here is some specific advice as it relates to sytys.
I have no doubt our trucks have SOME bumpsteer, in fact I know they do EVERY suspension that exists will have some. I do not believe it is a problem for anybody in this thread.
One thing that concerns me greatly with the few guys that have installed a rack in pinion (yes I looked into this many years ago, talked to manufactures of racks at Sema about it, etc.) is bump steer MUST be calculated. Grabbing any old rack off the shelf that fits underneath doesn't work. The pivot points of the ends must be in line with the suspension travel points in more than just 1 plane.
I own 2 typhoons right now. They drive TOTALLY different.
My white typhoon is all stock, 197k miles, front suspension has stock balljoints and shocks. It needs rebuild o about 100k miles ago. Tires on the front are 275's, rear are the same. It drives horrible. It will find ruts 2 lanes over to grab. I probably look drunk driving it, just not had time to rebuild front yet. Yes tires are getting ate up on outside edge also.
My black typhoon; It is all custom coilover front, 4 link rear, 275 front, 315 rear, coilovers on all 4 corners, ZQ8 box and guess what it was aligned by ME. I didn't need a fancy hunter machine, and in fact don't trust the monkeys at the shops if they did it for free.
I drove it last night testing the new computer. That truck drives very straight and true, steering is very quick, its a blast to drive.
Here is the trick to our trucks and wide tires, even the stock 245 is a wide tire.
Increase the caster to 6-7 degrees. Some trucks you can get more than others. Key is both sides are the same. Don't let the shops get close, it must be exact. Don't let them put more on 1 side vs the other to compensate for crown of the road unless they can certify every road you drive on is crowned and crowned the same. (obviously they can't do that).
Caster is the angle of the upper ball joint in relation to the lower ball joint. The more caster you have the straighter the vehicle will go, and the more it will want to return to straight after you turn. If one side has more than the other it will pull that direction.
Camber is how straight up and down the tire sits. Lower rider guys think its cool to have the tires look all bow legged like a worn out cowboy. What you want here is the tire to remain flat with as much contact patch as possible. This includes going through corners and suspension travel and will get into the roll center of the truck, and how the trucks rolls in addition to suspension geometry as designed by GM. It by itself won't cause a truck to want to dart all over the road unless it is extreme. I like to put 1/4-1/2 deg negative in. This favors the inside a tadd, and anybody around syty's long will notice most trucks wear outside edge, hence why I try to favor inside some.
Toe-In: Key here is through the suspension travel you do NOT want any toe out. A toe out vehicle will become very darty. A vehicle with excessive toe in will wear and cup tires. 1/8" Toe in is a good number I have found.
Now if you have worn balljoints, pitman arms, idler arm (most syty idler arms are worn out BTW)., etc. The alignment will not stay and no matter what specs you put nothing will help.
So recap, use at your own risk but having designed and built my first coilover suspension ~8 years+ ago now, installed many, driven even more these numbers work well for me and customers I give them too have been happy.
CASTER: +7deg (both sides must be the same)
CAMBER: -1/4 to -1/2 Degree
Toe-In: 1/8"
Now that I have been a bit sarcastic, here is some specific advice as it relates to sytys.
I have no doubt our trucks have SOME bumpsteer, in fact I know they do EVERY suspension that exists will have some. I do not believe it is a problem for anybody in this thread.
One thing that concerns me greatly with the few guys that have installed a rack in pinion (yes I looked into this many years ago, talked to manufactures of racks at Sema about it, etc.) is bump steer MUST be calculated. Grabbing any old rack off the shelf that fits underneath doesn't work. The pivot points of the ends must be in line with the suspension travel points in more than just 1 plane.
I own 2 typhoons right now. They drive TOTALLY different.
My white typhoon is all stock, 197k miles, front suspension has stock balljoints and shocks. It needs rebuild o about 100k miles ago. Tires on the front are 275's, rear are the same. It drives horrible. It will find ruts 2 lanes over to grab. I probably look drunk driving it, just not had time to rebuild front yet. Yes tires are getting ate up on outside edge also.
My black typhoon; It is all custom coilover front, 4 link rear, 275 front, 315 rear, coilovers on all 4 corners, ZQ8 box and guess what it was aligned by ME. I didn't need a fancy hunter machine, and in fact don't trust the monkeys at the shops if they did it for free.
I drove it last night testing the new computer. That truck drives very straight and true, steering is very quick, its a blast to drive.
Here is the trick to our trucks and wide tires, even the stock 245 is a wide tire.
Increase the caster to 6-7 degrees. Some trucks you can get more than others. Key is both sides are the same. Don't let the shops get close, it must be exact. Don't let them put more on 1 side vs the other to compensate for crown of the road unless they can certify every road you drive on is crowned and crowned the same. (obviously they can't do that).
Caster is the angle of the upper ball joint in relation to the lower ball joint. The more caster you have the straighter the vehicle will go, and the more it will want to return to straight after you turn. If one side has more than the other it will pull that direction.
Camber is how straight up and down the tire sits. Lower rider guys think its cool to have the tires look all bow legged like a worn out cowboy. What you want here is the tire to remain flat with as much contact patch as possible. This includes going through corners and suspension travel and will get into the roll center of the truck, and how the trucks rolls in addition to suspension geometry as designed by GM. It by itself won't cause a truck to want to dart all over the road unless it is extreme. I like to put 1/4-1/2 deg negative in. This favors the inside a tadd, and anybody around syty's long will notice most trucks wear outside edge, hence why I try to favor inside some.
Toe-In: Key here is through the suspension travel you do NOT want any toe out. A toe out vehicle will become very darty. A vehicle with excessive toe in will wear and cup tires. 1/8" Toe in is a good number I have found.
Now if you have worn balljoints, pitman arms, idler arm (most syty idler arms are worn out BTW)., etc. The alignment will not stay and no matter what specs you put nothing will help.
So recap, use at your own risk but having designed and built my first coilover suspension ~8 years+ ago now, installed many, driven even more these numbers work well for me and customers I give them too have been happy.
CASTER: +7deg (both sides must be the same)
CAMBER: -1/4 to -1/2 Degree
Toe-In: 1/8"