Lower stock 2008

[bigmike06GT]

I have Eibach pro kit springs, 1.5" rear just as you have with the FRPP and 1.3" front with the Eibach's..

My Ford dealership is claiming just the opposite and recommends upgrading to an adjustable panhard bar, as they claim my rear axle is not properly centered and also recommended upgrading from my OEM dampers as well and have since upgraded to Koni yellow adjustable's just this past summer..

Weird, even at my builders he is putting in an adjustable panhard bar for me but told me everything was centered the way it should be. I'm just getting him to put that and the UCA in while he has it at the shop as I plan on putting all new suspension in hopefully in the next year or so and those are the parts I can afford for now LOL

 

[bujeezus]

After dropping your rear by 1.5 inches, did you ever notice any bottoming out issues, as I assume that you didn't replace your stock shocks ?

I'd also like to know if your rear is still properly centered with the factory panhard bar still in place as well..

i didn't notice that big a difference over the factory ride. do bullitt's have the same shocks/struts as gt's? my axle shifted about 3/8" iirc so i did install an adjustable panhard bar.

 

[BMR Tech 2]

Then I'm really stumped here, as I have the Eibach pro kit springs on both front and rear.. The pro springs lowered my front by 1.3 inches and my rear by 1.5 inches.. I had the factory struts replaced this past summer after it felt like my OEM struts would bottom out whenever I'd go over a pavement imperfection.. After bringing this up with both Eibach and my Ford technician, they both claimed it was due to the OEM dampers not being compatible with the lowered suspension height and therefore followed their recommendation and upgraded to Koni yellow adjustable's..

Unless I misinterpreted and they recommended upgrading because of the damping factor ?

You won't bottom the shock or the strut as long as you keep the bump stops installed on the car. That's what they're for. Konis are made to OEM spec, so they're the same length/height as the OEM shocks and struts. They just have better valving so they're able to control more aggressive spring rates better than the OEM dampers. OEM dampers struggle to control higher spring rates, and they will wear prematurely/give you a poor ride. It's not that the springs aren't "compatible", OE dampers are just junk.

 

[07 Boss]

So you mean to say that if the OP intends on lowering his rear section by 1.5 inches, that he'll be fine running his OEM shocks without the possibility of bottoming out ? And are you also trying to say that he won't need an adjustable panhard bar to make certain his rear axle is still properly centered ? Because if you are, then I strongly must disagree..

No, I never said that. We were talking about using different springs and specifically using two different spring rates.

You should get dampners to match the springs. Do you have to? No. Shocks won't prevent you from bottoming out anyways, that's the job of the springs. That is why lowering springs will have a higher spring rate because you have to absorb the same energy with less suspension travel. The shocks are there to keep the springs from bouncing up and down. Take your shocks off and your car will be at the same ride height and need the same amount of force to compress them enough to hit the snubbers on the frame. On that note I suggest cutting half of the jouncer off to give yourself a little more room before bottoming out.

The panhard bar is hit or miss. I've seen some cars not need them because they are off from the factory. I've seen stock suspensions with the rear axle out of line in both directions. I think the factory spec/tolerance is pretty big. I wanna say 3/16", but don't quote me on that. So depending on if your skewed in the right direction from the factory you may or may not need a panhard bar.

If you want me to go deeper I suggest sway bars too if your going to lower the suspension and you want better handling. Depending on the car and it's suspension set up, if you move the roll center farther away from the center of gravity you actually increase body roll. Yes, lowering your car can increase body roll.

This is all good information but I wasn't arguing that lowering springs did not need further suspension changes. Once you mess with the stock geometry you have to make adjustments all the way around to optimize handling. What I am debating is the first line in your post #7 which I highlighted in my response in post #10 about mixing spring rates.

 

[06 T-RED S/C GT]

i didn't notice that big a difference over the factory ride. do bullitt's have the same shocks/struts as gt's? my axle shifted about 3/8" iirc so i did install an adjustable panhard bar.

I'm not really sure if the Bullitt has the same suspension/dampers as the GT or not ? You would think if it had different suspension components ? your axle wouldn't had shifted 3/8" and required installing an adjustable panhard bar..

Therefore it's all just a guess on my part..

Weird, even at my builders he is putting in an adjustable panhard bar for me but told me everything was centered the way it should be. I'm just getting him to put that and the UCA in while he has it at the shop as I plan on putting all new suspension in hopefully in the next year or so and those are the parts I can afford for now LOL

Mike ! Here's what I don't understand.. If your rear axle is centered the way it should be, then why even bother upgrading to an adjustable panhard bar to begin with ? If everything is centered properly, then what is the purpose for doing the upgrade at all..

And why even bother putting in all new suspension components, if the OEM/stock suspension is compatible with lowering springs..

I definitely agree with you 100%.. As it's weird alright lol.


-Rocky

 

[BMR Tech 2]

And why even bother putting in all new suspension components, if the OEM/stock suspension is compatible with lowering springs..

-Rocky

Because the ride quality and performance with OEM shocks and struts is severely lacking compared to a good aftermarket set up.

Why did you change your shifter? Why did you change your gears? Why install a supercharger? Everything you removed worked just fine

 

[06 T-RED S/C GT]

You won't bottom the shock or the strut as long as you keep the bump stops installed on the car. That's what they're for. Konis are made to OEM spec, so they're the same length/height as the OEM shocks and struts. They just have better valving so they're able to control more aggressive spring rates better than the OEM dampers. OEM dampers struggle to control higher spring rates, and they will wear prematurely/give you a poor ride. It's not that the springs aren't "compatible", OE dampers are just junk.

I didn't say that the springs weren't compatible, but rather the OEM dampers aren't compatible.. However I still don't understand what you mean by the OEM's damping sucks, so are your referring to the valving that sucks or the length/height ?

I also kept the OEM bumpstops installed on the car and still use them after upgrading to the Koni yellow adjustable struts.. So could it be it's the OEM bumpstops that are causing what it feels like bottoming out when going over bumpy road pavement ? But after you brought up about Koni's being made to OEM spec and also have the same length/height, you would think the OEM bumpstops wouldn't be an issue at all.. But I thought I'd just ask to make certain anyhow..

Because the ride quality and performance with OEM shocks and struts is severely lacking compared to a good aftermarket set up.

Why did you change your shifter? Why did you change your gears? Why install a supercharger? Everything you removed worked just fine

Great points indeed Dylan

No, I never said that. We were talking about using different springs and specifically using two different spring rates.

You should get dampners to match the springs. Do you have to? No. Shocks won't prevent you from bottoming out anyways, that's the job of the springs. That is why lowering springs will have a higher spring rate because you have to absorb the same energy with less suspension travel. The shocks are there to keep the springs from bouncing up and down. Take your shocks off and your car will be at the same ride height and need the same amount of force to compress them enough to hit the snubbers on the frame. On that note I suggest cutting half of the jouncer off to give yourself a little more room before bottoming out.

The panhard bar is hit or miss. I've seen some cars not need them because they are off from the factory. I've seen stock suspensions with the rear axle out of line in both directions. I think the factory spec/tolerance is pretty big. I wanna say 3/16", but don't quote me on that. So depending on if your skewed in the right direction from the factory you may or may not need a panhard bar.

If you want me to go deeper I suggest sway bars too if your going to lower the suspension and you want better handling. Depending on the car and it's suspension set up, if you move the roll center farther away from the center of gravity you actually increase body roll. Yes, lowering your car can increase body roll.

This is all good information but I wasn't arguing that lowering springs did not need further suspension changes. Once you mess with the stock geometry you have to make adjustments all the way around to optimize handling. What I am debating is the first line in your post #7 which I highlighted in my response in post #10 about mixing spring rates.

So it appears that we both misinterpreted what was intended in post # 7 and for that, I should had clarified my intentions rather than took what you posted in the wrong way as meaning that lowering springs did not need further suspension changes and I suppose that's how I also misinterpreted your definition of mixing spring rates as well lol.

As for the panhard bar, It appears I'll need to find out the exact measurements for being within OEM specs.. If I'm still within factory OEM specs ? Then I won't even bother upgrading to an adjustable panhard at all..

As for the sway bars, I do plan on upgrading sometime this upcoming spring/summer and I'm also debating as to whether or not a bumpsteer kit would be considered a necessary upgrade being as my front is lowered just between 1.2 and 1.3 inches.. I also asked my Ford tech's advice about this and he claims that it's not necessary as long as I'm within 1-1.5" drop..

In the meantime, my apologies for the misinterpretations on my part and hope we're both now on the same page

 

[bujeezus]

I'm not really sure if the Bullitt has the same suspension/dampers as the GT or not ? You would think if it had different suspension components ? your axle wouldn't had shifted 3/8" and required installing an adjustable panhard bar..

Therefore it's all just a guess on my part..

not really following what you're trying to say here. it's geometry as far as the panhard bar goes. if you change the height, you're axle is going to shift. how much is within spec? i don't know.

 

[06 T-RED S/C GT]

not really following what you're trying to say here. it's geometry as far as the panhard bar goes. if you change the height, you're axle is going to shift. how much is within spec? i don't know.

I was responding to your question about whether the Bullitt has a different suspension over the standard GT.. I responded by saying that I don't know the answer.. I also stated that I didn't know how much the panhard bar would still be within factory specs after changing the height..

Therefore once again, I'm unable to provide an answer.. So is 3/8" shift still within factory specs ? I have no idea, as some have stated their rear axle was still properly centered after being lowered by 1.5" which really doesn't make much sense to me, as I fully agree that once you change the height, your rear axle is most definitely going to shift..

 

[bigmike06GT]

Mike ! Here's what I don't understand.. If your rear axle is centered the way it should be, then why even bother upgrading to an adjustable panhard bar to begin with ? If everything is centered properly, then what is the purpose for doing the upgrade at all..

And why even bother putting in all new suspension components, if the OEM/stock suspension is compatible with lowering springs..

I definitely agree with you 100%.. As it's weird alright lol.


-Rocky

All the stock components on my car have 100K miles on them now and I have had the lowering springs for around 30K of that. Our roads up here are nasty and rough as hell as well as I drove the car through our harsh winter for the first 3 years I had it and our roads are covered in salt all winter so the suspension is getting a bit weak and noisy. As for the Panhard and UCA I figured while things are apart "why not" They were recommended by my builder as parts that I would probably need or want down the road. Then when things get changed and replaced that will be one less thing I have to think about. If I had the money I would do all of it now but my engine is running up a pretty big number as more and more stuff under the hood is getting replaced.

 

[06 T-RED S/C GT]

All the stock components on my car have 100K miles on them now and I have had the lowering springs for around 30K of that. Our roads up here are nasty and rough as hell as well as I drove the car through our harsh winter for the first 3 years I had it and our roads are covered in salt all winter so the suspension is getting a bit weak and noisy. As for the Panhard and UCA I figured while things are apart "why not" They were recommended by my builder as parts that I would probably need or want down the road. Then when things get changed and replaced that will be one less thing I have to think about. If I had the money I would do all of it now but my engine is running up a pretty big number as more and more stuff under the hood is getting replaced.

With 100K miles on your car, I can certainly understand your reasons Mike.. Therefore it's definitely in your best interest to upgrade your suspension components without a doubt for safety reasons to begin with anyhow..

I also understand how it is when your on a budget and don't have the money for doing all the upgrades you would like to do, as I'm pretty much in the same boat in which I can only afford to do a couple of mods at a time as well

 

[bigmike06GT]

With 100K miles on your car, I can certainly understand your reasons Mike.. Therefore it's definitely in your best interest to upgrade your suspension components without a doubt for safety reasons to begin with anyhow..

I also understand how it is when your on a budget and don't have the money for doing all the upgrades you would like to do, as I'm pretty much in the same boat in which I can only afford to do a couple of mods at a time as well

Need the price of oil to go up so the OT comes back, then the car can get the full treatment LOL. Has held up pretty well considering but I also had it in getting serviced at the dealer every 5K and they did good inspections each time, to bad the broken cat didn't get along with the supercharger LOL. Gonna be LT's and no cats from now on.

 

[UMI Sales]

Then I'm really stumped here, as I have the Eibach pro kit springs on both front and rear.. The pro springs lowered my front by 1.3 inches and my rear by 1.5 inches.. I had the factory struts replaced this past summer after it felt like my OEM struts would bottom out whenever I'd go over a pavement imperfection.. After bringing this up with both Eibach and my Ford technician, they both claimed it was due to the OEM dampers not being compatible with the lowered suspension height and therefore followed their recommendation and upgraded to Koni yellow adjustable's..

Unless I misinterpreted and they recommended upgrading because of the damping factor ?

I think someone was blowing smoke up your butt when they told you your oem struts failed from a stiffer spring rate.

Springs absorb the energy of a bump or pothole,Shocks work to dampen the springs natural tendancy to oscillate.

In simple terms when you hit a pothole with factory rate springs your spring compresses at a much easier and faster rate than a stiffer rate spring would.
If you have bump stops this is where all the energy would be applied when it bottoms out, if you don't have them then the shock will take the "hit" causing shock failure. If you have adjustable shocks you could stiffen up the compression setting which essentially helps control the rate at which the spring compresses.

In most all applications you don't go with a "lowered" shock until you get in the neighborhood of 2 1/2" lower(every application is different)or you have removed the bump stops.

I think what the guys you talked to are saying is that you need higher quality shocks with curves that will be able to help control the stored energy of the stiffer springs as well as having the ability to adjust both compression and rebound

Craig

 

[06 T-RED S/C GT]

I think someone was blowing smoke up your butt when they told you your oem struts failed from a stiffer spring rate.

Springs absorb the energy of a bump or pothole,Shocks work to dampen the springs natural tendancy to oscillate.

In simple terms when you hit a pothole with factory rate springs your spring compresses at a much easier and faster rate than a stiffer rate spring would.
If you have bump stops this is where all the energy would be applied when it bottoms out, if you don't have them then the shock will take the "hit" causing shock failure. If you have adjustable shocks you could stiffen up the compression setting which essentially helps control the rate at which the spring compresses.

In most all applications you don't go with a "lowered" shock until you get in the neighborhood of 2 1/2" lower(every application is different)or you have removed the bump stops.

I think what the guys you talked to are saying is that you need higher quality shocks with curves that will be able to help control the stored energy of the stiffer springs as well as having the ability to adjust both compression and rebound

Craig

It appears that you misinterpreted part of my post.. So just to clarify, my OEM struts didn't fail.. My reason for replacing them was out of concern for bottoming the OEM struts after upgrading to the Eibach lowering springs..

I also retained the OEM bump stops, therefore I have no idea what could be causing the issues I've described when hitting a bump/pothole..

What I do know, is since I upgraded to the Koni adjustable struts.. I don't seem to notice it as bad as with the OEM's but it's still there.. Perhaps the bump stops are just too long and need shorter stops

 

[07 Boss]

It appears that you misinterpreted part of my post.. So just to clarify, my OEM struts didn't fail.. My reason for replacing them was out of concern for bottoming the OEM struts after upgrading to the Eibach lowering springs..

I also retained the OEM bump stops, therefore I have no idea what could be causing the issues I've described when hitting a bump/pothole..

What I do know, is since I upgraded to the Koni adjustable struts.. I don't seem to notice it as bad as with the OEM's but it's still there.. Perhaps the bump stops are just too long and need shorter stops

Ding, Ding, ding, ding........If you are bottoming out you are hitting your bumpstops on the frame rail. Look above the bumpstops and you can see where it is hitting. Just chop off the first nub and go from there.

 

[UMI Sales]

I agree with 07 Boss^^^

The Koni's have more aggressive valving so you won't be hitting quite as hard on the stops as you were on the oem's

 

[06 T-RED S/C GT]

Ding, Ding, ding, ding........If you are bottoming out you are hitting your bumpstops on the frame rail. Look above the bumpstops and you can see where it is hitting. Just chop off the first nub and go from there.

Sounds like a plan to me.. In the meantime, thanks once again

 

[06 T-RED S/C GT]

I agree with 07 Boss^^^

The Koni's have more aggressive valving so you won't be hitting quite as hard on the stops as you were on the oem's

I also agree with you both as well ^^^

 

[duststang]

I ordered SR adjustable panhard bar from American Muscle when I installed my springs and my rear end did need adjusting. I used camber kit on fronts and I have 19 wheels and after my alignment tires are wearing perfectly even all four corners.