Bump steer tierods on Strano springs?
#1
On The Tree
Thread Starter
iTrader: (1)
Join Date: Jun 2011
Location: Amherst, NH
Posts: 191
Likes: 0
Received 0 Likes
on
0 Posts
Bump steer tierods on Strano springs?
Has anyone found the need to move to bump-steer correcting tierods after installing Stranoparts springs (rated to ~1.2" drop)?
I'm eying all of my front-end as I'm doing new bushings, balljoints, etc. But my outer tierods are relatively new (~ 3 years) and seem in fine shape.
I don't want to sink the $175.00 if I don't have to.
Reference: http://www.summitracing.com/parts/ba...camaro/year/1999
I'm eying all of my front-end as I'm doing new bushings, balljoints, etc. But my outer tierods are relatively new (~ 3 years) and seem in fine shape.
I don't want to sink the $175.00 if I don't have to.
Reference: http://www.summitracing.com/parts/ba...camaro/year/1999
#4
On The Tree
Thread Starter
iTrader: (1)
Join Date: Jun 2011
Location: Amherst, NH
Posts: 191
Likes: 0
Received 0 Likes
on
0 Posts
I know GM High Tech did them in this article here:
http://www.gmhightechperformance.com...k_steer_clear/
Although on this build the drop was a 2" drop, not 1.2".
"On the right, you can see the sorry shape that our factory tie rod end was in. The boot was ripped and you could almost feel the crunch from inside the car. Additionally, our “drop it in the weeds” stance really messed with the stock “instant center” of our wheel, which could introduce bump steer into the suspension if not properly addressed. Luckily, fixing bump steer is as simple as installing a proper set of bump steer specific tie rod ends, like the Baer units you see here (PN BAE-3301011), which we ordered from Summit Racing."
"For 165-bucks, Summit Racing shipped these aluminum beauties right to our door and they will replace our sloppy factory style tie rod ends for a more precise feel, along with improved bump steer control. By simply adjusting the length of the tie rod end pin (using those included spacers you see above and below the tie rod pin) we will be able to compensate for our new ride height and geometry changes, which will quell bump steer and keep us pointed in the right direction, no matter what the front wheels are doing."
I'm probably going to take the car out and try to induce bump steer to see if it's manageable or not. Any time you alter your suspension you need to account for geometrics, but it's good to know if others have come to the conclusion so I don't waste too much time coming to the same result.
http://www.gmhightechperformance.com...k_steer_clear/
Although on this build the drop was a 2" drop, not 1.2".
"On the right, you can see the sorry shape that our factory tie rod end was in. The boot was ripped and you could almost feel the crunch from inside the car. Additionally, our “drop it in the weeds” stance really messed with the stock “instant center” of our wheel, which could introduce bump steer into the suspension if not properly addressed. Luckily, fixing bump steer is as simple as installing a proper set of bump steer specific tie rod ends, like the Baer units you see here (PN BAE-3301011), which we ordered from Summit Racing."
"For 165-bucks, Summit Racing shipped these aluminum beauties right to our door and they will replace our sloppy factory style tie rod ends for a more precise feel, along with improved bump steer control. By simply adjusting the length of the tie rod end pin (using those included spacers you see above and below the tie rod pin) we will be able to compensate for our new ride height and geometry changes, which will quell bump steer and keep us pointed in the right direction, no matter what the front wheels are doing."
I'm probably going to take the car out and try to induce bump steer to see if it's manageable or not. Any time you alter your suspension you need to account for geometrics, but it's good to know if others have come to the conclusion so I don't waste too much time coming to the same result.
Last edited by szalkerous; 05-22-2013 at 12:46 PM.
#5
TECH Senior Member
The 4th Gen F-car lca and tierods are pretty much parallel and the same length... so bumpsteer is very minimal if any (the F-car chassis engineers did their homework)...
if the lca and tierods are parallel and equal length, then lowering the car will not add bumpsteer.
In the GMHTP article I didn't see any drawings showing geometry differences bewteen stock stance and lowered stance.
if the lca and tierods are parallel and equal length, then lowering the car will not add bumpsteer.
In the GMHTP article I didn't see any drawings showing geometry differences bewteen stock stance and lowered stance.
#6
"Well, when you lower a car – any car, be it road race, street, or drag – you change the wheel's "instant center," which is the center point of the arc that it travels. If you lower the car without also changing the arc of the tie-rod end (which is fixed from the factory), you can introduce bump steer, as we did when we dropped the Killer over 2.25-inches."
Ummm....no. The arc is defined by the control arm geometry. If you do not change that, the arc does not change. You can only change the control arm geometry by moving the mounting points of the arms or installing different height ball joints. What you CAN do is compound an existing bump steer issue by having the suspension live in an area of the arc where bump steer is bad. With the K member and rack design, once the car is lowered the lca does sit further up but the tie rod already comes with it. It's not as bad as a drag link - pitman arm - idler arm setup on an old car. An alignment to recorrect the toe should be enough if the standard alignment specs can be reached after lowering. I kinda get what they are saying but the tie rod arc does not change, only what area of the arc it might work in.
Ummm....no. The arc is defined by the control arm geometry. If you do not change that, the arc does not change. You can only change the control arm geometry by moving the mounting points of the arms or installing different height ball joints. What you CAN do is compound an existing bump steer issue by having the suspension live in an area of the arc where bump steer is bad. With the K member and rack design, once the car is lowered the lca does sit further up but the tie rod already comes with it. It's not as bad as a drag link - pitman arm - idler arm setup on an old car. An alignment to recorrect the toe should be enough if the standard alignment specs can be reached after lowering. I kinda get what they are saying but the tie rod arc does not change, only what area of the arc it might work in.
Last edited by SSellers; 05-22-2013 at 03:13 PM.
#7
TECH Veteran
iTrader: (1)
"Well, when you lower a car – any car, be it road race, street, or drag – you change the wheel's "instant center," which is the center point of the arc that it travels. If you lower the car without also changing the arc of the tie-rod end (which is fixed from the factory), you can introduce bump steer, as we did when we dropped the Killer over 2.25-inches."
Ummm....no. The arc is defined by the control arm geometry. If you do not change that, the arc does not change. You can only change the control arm geometry by moving the mounting points of the arms or installing different height ball joints. What you CAN do is compound an existing bump steer issue by having the suspension live in an area of the arc where bump steer is bad. With the K member and rack design, once the car is lowered the lca does sit further up but the tie rod already comes with it. It's not as bad as a drag link - pitman arm - idler arm setup on an old car. An alignment to recorrect the toe should be enough if the standard alignment specs can be reached after lowering. I kinda get what they are saying but the tie rod arc does not change, only what area of the arc it might work in.
Ummm....no. The arc is defined by the control arm geometry. If you do not change that, the arc does not change. You can only change the control arm geometry by moving the mounting points of the arms or installing different height ball joints. What you CAN do is compound an existing bump steer issue by having the suspension live in an area of the arc where bump steer is bad. With the K member and rack design, once the car is lowered the lca does sit further up but the tie rod already comes with it. It's not as bad as a drag link - pitman arm - idler arm setup on an old car. An alignment to recorrect the toe should be enough if the standard alignment specs can be reached after lowering. I kinda get what they are saying but the tie rod arc does not change, only what area of the arc it might work in.
I agree with what you're saying, but I'll toss one thing into the discussion. The attachment of the upper control arms, as well as the rack/tie rods are "hard" locations. However, the lower control arms, due to their ability to move in/out for caster/camber adjustment, aren't quite as fixed a location. Even though the movement is minimal, I think that the bumpsteer curve could be altered somewhat, during the front end alignment process.
Therefore, I would think that the adjustable tie rod kit would be beneficial to those looking to get that last .0001% of accuracy in their bumpsteer settings.
Trending Topics
#8
TECH Veteran
iTrader: (23)
You won't encounter any bumpsteer until you reach the limits of the cars ability in a corner or very heavy braking and encounter a bump or dip. And if you do prior to that you won't notice it or care.
Very very few explore that.
On Frrax I never see posts about bumpsteer issues on these cars.
Very very few explore that.
On Frrax I never see posts about bumpsteer issues on these cars.
#9
I agree with what you're saying, but I'll toss one thing into the discussion. The attachment of the upper control arms, as well as the rack/tie rods are "hard" locations. However, the lower control arms, due to their ability to move in/out for caster/camber adjustment, aren't quite as fixed a location. Even though the movement is minimal, I think that the bumpsteer curve could be altered somewhat, during the front end alignment process.
Therefore, I would think that the adjustable tie rod kit would be beneficial to those looking to get that last .0001% of accuracy in their bumpsteer settings.
Therefore, I would think that the adjustable tie rod kit would be beneficial to those looking to get that last .0001% of accuracy in their bumpsteer settings.
Completely agree with you that alignment specs can increase or decrease bump steer. My issue was with the way they implied that lowering the car would change the geometry. You have to change either the control arm pivot to control arm pivot distance or change the balljoint to balljoint distance to do that. They didn't address alignment pre/post lowering. Having a couple of first gens I've gotten pretty familiar with that crap. Had to install tall upper ball joints and tall tie rod ends plus adjustable upper arms just to be able to get a modern alignment without effing up the curves.