BMR Handling springs installed (revised version)

BmacIL said:

Sounds like you need less rear bar and/or more front. Less rear more likely.

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I'm already at full soft front and rear on the bars. So there's no way of doing that without ditching my BMR sway bars.

Bluemustang said:

I'm already at full soft front and rear on the bars. So there's no way of doing that without ditching my BMR sway bars.

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Go to the stiffest front setting and see how it behaves.

BMR Tech said:

Go to the stiffest front setting and see how it behaves.

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Yep agreed. Going to softer rear will be more effective in the conditions you're seeing it, but going stiff on the front will give you a feel for the overall effect.

Bluemustang said:

The FRPP track pack is a good bit of kit and I had basically created my own FRPP track kit (almost making it a level 2 if you will). I’ll get more into the why later, but it’s mostly because I was looking for a better handling feel.

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Bluemustang... So I'm clear, you had the Ford Racing Track handling springs and dampers/shocks, NOT the regular performance pack setup correct?

Assembled Front Struts and rear shocks M-18000-F
Track Lowering Springs M-5300-Y

And you kept the front struts/rear shocks and replaced only the springs with the SP083's?

I'm about to pull the trigger on my suspension upgrades and I feel as if I've read 100 (or more) posts on this topic.. including the long one started by mustangcollector. I'm leaning towards buying the track suspension package from Levittown Ford and replacing the springs with the SP083's for a mainly street driven car.

Thanks for the writeup and reviews.. appreciate it.

sy1462 said:

Bluemustang... So I'm clear, you had the Ford Racing Track handling springs and dampers/shocks, NOT the regular performance pack setup correct?

Assembled Front Struts and rear shocks M-18000-F
Track Lowering Springs M-5300-Y

And you kept the front struts/rear shocks and replaced only the springs with the SP083's?

I'm about to pull the trigger on my suspension upgrades and I feel as if I've read 100 (or more) posts on this topic.. including the long one started by mustangcollector. I'm leaning towards buying the track suspension package from Levittown Ford and replacing the springs with the SP083's for a mainly street driven car.

Thanks for the writeup and reviews.. appreciate it.

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I would just get the dampers from Levittown Ford and get the SP083s. The springs add enough stiffness to the car that you may not ever need the bars. And yes he had the Track Springs and dampers, not the PP (or "Street" suspension).

sy1462 said:

Bluemustang... So I'm clear, you had the Ford Racing Track handling springs and dampers/shocks, NOT the regular performance pack setup correct?

Assembled Front Struts and rear shocks M-18000-F
Track Lowering Springs M-5300-Y

And you kept the front struts/rear shocks and replaced only the springs with the SP083's?

I'm about to pull the trigger on my suspension upgrades and I feel as if I've read 100 (or more) posts on this topic.. including the long one started by mustangcollector. I'm leaning towards buying the track suspension package from Levittown Ford and replacing the springs with the SP083's for a mainly street driven car.

Thanks for the writeup and reviews.. appreciate it.

Click to expand...

Correct. I am using Ford Racing shocks/struts, NOT the PP ones.

The ride believe it or not feels better and more composed than the FRPP Track (Y) Springs.

I will update more on my impression as I get more seat time and get to push the car.

BMR Tech said:

Go to the stiffest front setting and see how it behaves.

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How might this help? I assume less traction to front vs. the rear and more weight shift to the front vs. the rear?

Just trying to understand the dynamics here.

[MENTION=26233]Rebellion[/MENTION] - you're running almost the same rates and dampers as me?

I forget, do you have aftermarket sway bars too? Have you experienced the scenario I described a few posts earlier?

Bluemustang said:

How might this help? I assume less traction to front vs. the rear and more weight shift to the front vs. the rear?

Just trying to understand the dynamics here.

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The front sway being stiffer will work to force the inside rear down when cornering. There's some interesting kinematics going on, but the way the weight transfer works in that situation is, you'll unload the inside front more, unload the inside rear less, and have less overall roll. It will likely understeer more, but will also respond faster.

These cars tend to like heavier spring, lighter bar in the back. More predictable, keeps the tire planted. You have the heavier spring now. The other aspect is, that compared to Rebellion and I, your rear is lower for the same rate, and the roll couple is larger. This means it'll want to roll more and unload the inside rear just a bit more than mine, all else equal. Because you have the much heavier rear bar (I have the PP rear bar), it exacerbates that unloading, despite reducing roll overall.

BmacIL said:

The front sway being stiffer will work to force the inside rear down when cornering. There's some interesting kinematics going on, but the way the weight transfer works in that situation is, you'll unload the inside front more, unload the inside rear less, and have less overall roll. It will likely understeer more, but will also respond faster.

These cars tend to like heavier spring, lighter bar in the back. More predictable, keeps the tire planted. You have the heavier spring now. The other aspect is, that compared to Rebellion and I, your rear is lower for the same rate, and the roll couple is larger. This means it'll want to roll more and unload the inside rear just a bit more than mine, all else equal. Because you have the much heavier rear bar (I have the PP rear bar), it exacerbates that unloading, despite reducing roll overall.

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Interesting. So the unloading of the front will make the rear unload less. That makes sense now that I think about it. More weight off the ground on the front forces the weight of the rear to keep the tire down.

This is a good idea. So you agree with Kelly about going full stiff on the front bar? And I guess if that doesn’t work 100%, I could try getting a softer bar for the rear like the PP bar that you have. Good stuff man.

Basically I need the front to have more roll control and the rear to have less. That rolling action in the rear will make the body move but should help keep the tire itself from coming off the ground.

Bluemustang said:

Interesting. So the unloading of the front will make the rear unload less. That makes sense now that I think about it. More weight off the ground on the front forces the weight of the rear to keep the tire down.

This is a good idea. So you agree with Kelly about going full stiff on the front bar? And I guess if that doesn’t work 100%, I could try getting a softer bar for the rear like the PP bar that you have. Good stuff man.

Basically I need the front to have more roll control and the rear to have less. That rolling action in the rear will make the body move but should help keep the tire itself from coming off the ground.

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Kind of. You got a lot more roll control in the rear with the spring change. The front springs are probably not far off from each other. It's more about the contribution the sway bar makes in the total roll stiffness. Right now you have too much in the rear. Adding some in the front will help plant that tire and give you a sense of what the effect is. I think the best idea long term will be to go to a softer rear bar and leave your BMR front in the soft or middle position, so you have some adjustment capability.

BmacIL said:

Kind of. You got a lot more roll control in the rear with the spring change. The front springs are probably not far off from each other. It's more about the contribution the sway bar makes in the total roll stiffness. Right now you have too much in the rear. Adding some in the front will help plant that tire and give you a sense of what the effect is. I think the best idea long term will be to go to a softer rear bar and leave your BMR front in the soft or middle position, so you have some adjustment capability.

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Thank you BmacIL. This is very helpful. I think you are correct.

In fact I was a little afraid of this happening due to the large increase in spring rates, particularly in the rear.

I do not need more front bar, just less rear bar. Maybe you and I can do some data analysis of sway bar rates to determine the optimum combination when it comes time. Til then I will get used to the car in its’ current form - then stiffen front bar - then maybe soften front bar and get a PP bar to swap in the rear at the same time. A PP bar should be pretty cheap me thinks.

Bluemustang said:

Thank you BmacIL. This is very helpful. I think you are correct.

In fact I was a little afraid of this happening due to the large increase in spring rates, particularly in the rear.

I do not need more front bar, just less rear bar. Maybe you and I can do some data analysis of sway bar rates to determine the optimum combination when it comes time. Til then I will get used to the car in its’ current form - then stiffen front bar - then maybe soften front bar and get a PP bar to swap in the rear at the same time. A PP bar should be pretty cheap me thinks.

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Very. They're like $30. Cheap experiment.

Bluemustang said:

[MENTION=26233]Rebellion[/MENTION] - you're running almost the same rates and dampers as me?

I forget, do you have aftermarket sway bars too? Have you experienced the scenario I described a few posts earlier?

Click to expand...

Same dampers, 10lbs less on the front, same on the rear but with spring spacers (about 1/8 drop approx on rear). Front sway is base, rear is 350R.

I would listen to [MENTION=10281]BmacIL[/MENTION], this is the tuning with sways part that I told you about...done at the very end of your setup to fine tune the behavior.

Frankly, I don't recall experiencing what you said, but both of my sway bars are softer that yours. I believe that the sway bar rates per se are not so important by themselves but the relationship between sway rates, spring rates, and geometry.

In your case, seems like your front compliance is comparatively higher than the rear (roll resistance is inverse to compliance, so to speak). This is the opposite situation of what I had when I did the spring spacers...I was rolling way more on the rear, which led to the front unloading. I hope this makes sense, it's the relative compliance/roll between front and rear.

Bluemustang said:

Thank you BmacIL. This is very helpful. I think you are correct.

In fact I was a little afraid of this happening due to the large increase in spring rates, particularly in the rear.

I do not need more front bar, just less rear bar. Maybe you and I can do some data analysis of sway bar rates to determine the optimum combination when it comes time. Til then I will get used to the car in its’ current form - then stiffen front bar - then maybe soften front bar and get a PP bar to swap in the rear at the same time. A PP bar should be pretty cheap me thinks.

Click to expand...

On the topic of a softer rear sway, if you happen to have the bar from the FRPP kit, you can try that. I really don't know how they compare to BMR, just a freebie idea.