Steeda S550 Mustang Front Roll Center & Bumpsteer Correction Kit (15-19 All)

[Bluemustang]

Leads me to believe they didn't set it up right before...

Yeah me too. The shop says the tie rod is completely parallel to the lateral link. They measured it a few times with a level.

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[Bluemustang]

Leads me to believe they didn't set it up right before...

If true, that could also explain some of my previous bumpsteer complaints.

 

[BmacIL]

If true, that could also explain some of my previous bumpsteer complaints.

Yeah. Exactly parallel isn't necessarily just right, as the steering link and control arm lengths and pivot point widths are different, but it's a very good starting point.

 

[Bluemustang]

Yeah. Exactly parallel isn't necessarily just right, as the steering link and control arm lengths and pivot point widths are different, but it's a very good starting point.

Actually thinking back what he said was it was completely parallel to the "steering rack". Not quite sure what he is referring to.

I don't think they did it by the instructions (jacking down the suspension and measuring toe angle change). I think they just did it a simpler way. May not be totally accurate but I don't think it matters that much. The geometry of the lateral link should help alleviate most of the bumpsteer on its own. I could be totally wrong and it's not setup right. I don't feel any bumpsteer so far though. Definitely a reduction from how it felt before.

 

[Bluemustang]

I'd also add that I think I am feeling more of the effects of the tension link bearing than I am the roll center correction of the lateral links. The bearings up front makes a huge difference. I didn't know how much until actually going through with it and driving it.

IMO the front control arm bearings add more positive effects to the overall experience than the RLCA bearing swap does. Simply because the front steers the car. It makes the front suspension work better by removing the bind, twist and slop from the factory rubber bushings. You can feel this through the steering wheel and promotes better feedback and makes it feels vastly more settled.

Only negative: sharper bumps create more noise (not bothersome) and slightly sharper impacts (again not bothersome). However, all impacts are managed better with a simple up-down motion and that's it.
These are a MUST for any S550 owner who has done a lot of modifications to their suspension.

 

[WhiteyDog]

Hey Bluemustang, I am ready to purchase the same Steeda front suspension items with bearings that you did but I'm having second thoughts with the bumpsteer kit. I'm lowered on an Eibach pro-kit, and have Steeda's front sway bar, their G Trac K Brace, and my front tires are 285/35/20's on 20x10 wheels. (Maybe some of those items don't come into play, but just wanted to mention them in case). I really don't have any issues with the factory bumpsteer other than my steering isn't as responsive as what it was, but I thought maybe it was because of the wider wheel and 285 tire in the front. Do you feel you REALLY needed the bumpsteer kit? As in, can you install the other two items (555-4909) and be fine with the factory bumpsteer set-up? We already spend loads of cash on our cars and a little more definitely won't bother, just want an opinion.

 

[Dr. Norts]

Hey Bluemustang, I am ready to purchase the same Steeda front suspension items with bearings that you did but I'm having second thoughts with the bumpsteer kit. I'm lowered on an Eibach pro-kit, and have Steeda's front sway bar, their G Trac K Brace, and my front tires are 285/35/20's on 20x10 wheels. (Maybe some of those items don't come into play, but just wanted to mention them in case). I really don't have any issues with the factory bumpsteer other than my steering isn't as responsive as what it was, but I thought maybe it was because of the wider wheel and 285 tire in the front. Do you feel you REALLY needed the bumpsteer kit? As in, can you install the other two items (555-4909) and be fine with the factory bumpsteer set-up? We already spend loads of cash on our cars and a little more definitely won't bother, just want an opinion.

I'm not him but I can chime in...

The factory has no bumpsteer setup. Just a one size fits all tie rod end with no adjustment. The factory has no way to mitigate this / adjust to remove bumpsteer.

If your going with the lateral link with the extended ball joint stud, you should be using the bumpsteer kit. If not skip the lateral link or you may have some undesirable results with induced bumpsteer.

If you go with the lateral link with the extended stud it will increase the angle on the lateral link, placing the outboard side closer to the ground. You'll have no adjustment on the outboard end of the steering tie rod and whatever you end up with is what you end up with in regards to their relation to each other (lateral link / steering tie rod).

I would think you'll end up less than optimal and could/will experience bumpsteer and less sharp turning response. You wont be able to drop your tie rod end down with a bumpsteer kit to match the same angle the lateral link is sitting at with the new extended ball stud.

@steeda can chime in, but I asked them the same thing in the spring when I did all my suspension and they said the 2 are recommended to be installed together. They compliment each other.

 

[WhiteyDog]

I'm not him but I can chime in...

The factory has no bumpsteer setup. Just a one size fits all tie rod end with no adjustment. The factory has no way to mitigate this / adjust to remove bumpsteer.

If your going with the lateral link with the extended ball joint stud, you should be using the bumpsteer kit. If not skip the lateral link or you may have some undesirable results with induced bumpsteer.

If you go with the lateral link with the extended stud it will increase the angle on the lateral link, placing the outboard side closer to the ground. You'll have no adjustment on the outboard end of the steering tie rod and whatever you end up with is what you end up with in regards to their relation to each other (lateral link / steering tie rod).

I would think you'll end up less than optimal and could/will experience bumpsteer and less sharp turning response. You wont be able to drop your tie rod end down with a bumpsteer kit to match the same angle the lateral link is sitting at with the new extended ball stud.

@steeda can chime in, but I asked them the same thing in the spring when I did all my suspension and they said the 2 are recommended to be installed together. They compliment each other.

Please, chime away. I'm no expert by far with suspensions, so thank you for the response. This clears things up a little better for me. I was figuring going with all three, but just wanted to make sure. Thank you.

 

[Bluemustang]

Please, chime away. I'm no expert by far with suspensions, so thank you for the response. This clears things up a little better for me. I was figuring going with all three, but just wanted to make sure. Thank you.

Yea as Dr. Norts said you will need it. And I think you need the RC correction due to how much you are lowered. You should see a bigger improvement than me because of the Eibach springs. It seems to be the larger the drop the greater the benefit.

 

[SteedaTech]

Hey Bluemustang, I am ready to purchase the same Steeda front suspension items with bearings that you did but I'm having second thoughts with the bumpsteer kit. I'm lowered on an Eibach pro-kit, and have Steeda's front sway bar, their G Trac K Brace, and my front tires are 285/35/20's on 20x10 wheels. (Maybe some of those items don't come into play, but just wanted to mention them in case). I really don't have any issues with the factory bumpsteer other than my steering isn't as responsive as what it was, but I thought maybe it was because of the wider wheel and 285 tire in the front. Do you feel you REALLY needed the bumpsteer kit? As in, can you install the other two items (555-4909) and be fine with the factory bumpsteer set-up? We already spend loads of cash on our cars and a little more definitely won't bother, just want an opinion.

Yes, you would need the Bumpsteer kit with the extended ball joint that's a must.
Thank you,
Steeda Tech

 

[WhiteyDog]

Yes, you would need the Bumpsteer kit with the extended ball joint that's a must.
Thank you,
Steeda Tech

Yea as Dr. Norts said you will need it. And I think you need the RC correction due to how much you are lowered. You should see a bigger improvement than me because of the Eibach springs. It seems to be the larger the drop the greater the benefit.

Thank you all for the responses and insight. And for helping me spend my money.

 

[Bluemustang]

Thank you all for the responses and insight. And for helping me spend my money.

LOL. BUT.. you are going to have more fun after

 

[Bluemustang]

I was discussing the effects of roll center with a friend last night, with a particular focus on MacPherson strut suspension as that is what we have. I was thinking it would be cool to see some actual data on how much the roll couple increases as the lowering amount increases. This might help others to see how important this is.

I am thinking that the extended ball joints are more critical for us to compensate for in our suspension design because the stock camber gain already sucks as it is. And then when you lower the car, the camber gain gets reduced.

I'm also interested in knowing (all other things being equal) how raising the roll center back up affects the handling balance of the car - in theory. Would it promote more understeer or oversteer? I would assume if front grip increases and rear grip does not, it would lean more towards oversteer without anything else being changed. However, the raising of the roll center decreases roll and usually a decrease in roll means less grip on that end of the car - at least that's how it is with springs and bars. The roll center correction is different though than springs and bars because it actually decreases leverage on the suspension. Less weight transfer goes into the springs, and therefore allows the springs and bars to be more effective at combating roll. Maybe the front grip increases due to having a more ideal contact patch as the camber gain improves.

So I'm a little confused because there are a lot of factors here. Regardless, my guess is this would still be beneficial for anyone with a lowered car even if it necessitates a change in sway bar to keep the balance where you want it.

@SteedaTech - what would you say raising the roll center does to the handling balance?

 

[BmacIL]

Raising the roll center will typically reduce grip on that end of the car from the reduction in roll couple, similar to what an anti-roll bar does. However, because of the strut suspension design, raising the roll center will often increase camber gain enough to improve overall front grip more than the reduction in roll couple would.

 

[Bluemustang]

Raising the roll center will typically reduce grip on that end of the car from the reduction in roll couple, similar to what an anti-roll bar does. However, because of the strut suspension design, raising the roll center will often increase camber gain enough to improve overall front grip more than the reduction in roll couple would.

Thanks @BmacIL that is what I was thinking. Nice to confirm that. Based on this assumption I think it was right for me to go to a softer rear bar prior to this to compensate for the increase in front grip.

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