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Lowering - Spring Options, Alignment, Roll Center

11K views 29 replies 7 participants last post by  ProjectVeloN 
#1 ·
Currently, 100% stock suspension and after getting smaller wheels that accentuate the fender gap, I wanna go lower. My main objectives in order of priority are aesthetics, comfort, and retaining good handling. Before anyone mentions it, I'm not interested in the Mando ECS module.

Aesthetically, I don't like to tuck tire and would be happy with Eibach's modest lowering, but I also want to make sure the spring I get are a good match for the stock dampers. In order from least to most lowering the options I've seen are: Eibach, Whiteline, Ark, H&R. Any other brands I'm missing? I've not seen many review threads so if anyone has non-anecdotal opinions based on the springs they bought, I'm all ears.

Secondly, no one has mentioned installing roll center correction kits and with me changing the wheels, I've already slightly changed the handling characteristics and don't want to exacerbate it further by lowering. Anyone install a kit and have any feedback? I don't track or autox but I do hit the canyon roads every now and then.

Lastly, how well do our cars respond to alignments with mild lowering? I'd like to be able to stay within factory specs so if anyone can provide experience if anything was needed to get alignment dialed in, that would be helpful.
 
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#2 ·
I will make a long and lengthy post on this later, there is alos godspeed springs. In short - and to be quick they go like this.

1. Eibach - smallest drop .6 (14-16mm) - progressive springs - highest limit 4.0 kg
2.Whiteline - mild drop 30mm - progressive - firmer in the front that eibach and same in the rear.
3. H and R - 1.4 drop - very stiff - forget comfort
4. Ark - no one knows spring rate - around same drop a whiteline - prob more comfy
5. Godspeed - exactly 15% more stiff than stock at front and rear. 1.5 drop.

It will be a long post in regards of what works best w factory dampers. Progressive springs w our factory dampers would not make the car handle better. More unpredictable when loading up in corners at high speeds. Whiteline and eibach would be more comfy for cruising.

In terms of steering geometry - a lot changes over 1 in 25mm drop. The engineers set up the whole geometry based upon a few factors.

I am not trying to deter you from lowering - I am looking into this myself - but it is complex. Its even more complex when you consider aero mods, warranty, tire and bearing life, etc.

Can you lower it and have it be more comfy - yes.

Will you be able to push the car in the same manner - no. This will only be noticeable dependent upon how willing you are to push you car. However - the engineers chose a linear spring rate because it is predictable and then they varied the damping ratios.

In the inverse it doesnt work the same way - you cant run progressive springs and then simply fix one damping ratio.

To do it right will be expensive and not simply lowering springs if you want the full package.

I am about at hour 100 on research this week alone and have created 4 excel charts trying to understand the way the engineers set up the car.

I will cover all this in a future post.

I hope this helps - I have more to say but I dont want to come across as a know it all, because I do not know it all. My only goal is to help inform you as I am also in the same boat as you my friend.

-JE
 
#3 ·
Thanks for the info! It's a start at least and look forward to seeing what you come up with.

I'm pretty particular with modding and while I'm willing to slightly compromise between comfort, performance, and adding more parts...if it can't be reasonably done short of coilovers then I'll just hold off for now.
 
#7 ·
I do not know for certain they are linear at front and rear. They look linear to me based on photos and me looking at them. I am taking my car apart wednesday for new aero and other mod's and I will look closer. If one was progressive - I suspect it would be the rear and not the front.

The front coils seem pretty evenly spaced throughout.

I dont see how eibach could be a good choice from a spring rate because they F and R start at 2.0 and go up to 4.0. Our car is 3.6F and 4.8R. I feel this would adversely affect dampers and shocks becuase their valving speed has been based on the other OEM rates.

However - to what degree - I have no clue.

-JE
 
#10 ·
From someone who has changed their springs: the OE springs are not linear. Both front and rear have a slight beehive shape to them. The top coil / bottom coil on each have a different size to them vs the main body of the spring.

I had Swift Spec R springs on my Fiesta ST, and it is a shame that they do not yet make a set of springs for our car. They were true linear springs and the car rode amazing. I have whiteline on the VN and I am happy with them, I wouldn't say its ruined the handling because it feels mostly the same to me. I did a track day on stock suspension and a track day on the lowering springs. The car feels more planted on the road and much flatter through the turns. I couldn't tell you if it was actually faster or slower since I don't time, and since I don't race the car for time or anything else, I'm building it for me. Its my daily and there is no reason to not set up your daily to be something you enjoy driving vs all out performance.
 
#11 ·
From someone who has changed their springs: the OE springs are not linear. Both front and rear have a slight beehive shape to them. The top coil / bottom coil on each have a different size to them vs the main body of the spring.

I had Swift Spec R springs on my Fiesta ST, and it is a shame that they do not yet make a set of springs for our car. They were true linear springs and the car rode amazing. I have whiteline on the VN and I am happy with them, I wouldn't say its ruined the handling because it feels mostly the same to me. I did a track day on stock suspension and a track day on the lowering springs. The car feels more planted on the road and much flatter through the turns. I couldn't tell you if it was actually faster or slower since I don't time, and since I don't race the car for time or anything else, I'm building it for me. Its my daily and there is no reason to not set up your daily to be something you enjoy driving vs all out performance.
Thank you for this reply. This is a great response. Do you feel our stock OE springs are (closer to linear) or (closer to progressive)? Other than the top and bottom coil its seems to me like the spacing is constant and even requiring the same amount of force to compress mainly throughout?

Please correct me where I am wrong.

-JE
 
#14 ·
Spoke to Jeff at GenRacer and he says he is "200% sure" the rear is progressive. He cant remember if front is linear or not but he says "it would be weird to have a progressive at the rear and not at the front."

About lowering springs he said "the motion ratio of the rear is around .65 so you can run a stiffer or softer spring and not experience much difference subjectively. " Jeff also stated that if he had to pick a direction he would "go with a spring that lowers the car and has the softest spring rate" because "lowering changes the roll moment and you can get away with a lower spring rate."

This is consistent with what @N_Dorphins said about his car feeling better on whiteline springs even though the rear has a lower spring rate than OE.

Jeff said on their race cars they run pure linear springs because tuning is easier.

When I asked him about the shock valving, timing, and pressure - and the effects of softer springs w OE dampers or stiffer springs w OE dampers - what would he choose? Are there any potential problems to the shock? He said there is a potential problem but he can not give me a "yes or no" answer definitively because the math is too complex and there are other factors in that equation that would have to be specified.

-JE
 
#15 ·
I’m on Eibachs, Enkei 18” TS10s, and using the Mando ECS reprogramming module. Solid setup. If you’re looking to seriously track the car, get the active suspension “cancelers” and go to coilovers. TONS of spring and damper options. As for me, I like to autocross but have to get back to AZ to do that again. The parking lots they have access to are bumpy, and I’ve had the best luck with simple Eibach springs on other cars (mine and those of other competitors). But if you’re on a glass smooth surface (or don’t have less than ideal streets to drive on) I’d go for coilovers.
 
#16 ·
This ^ !!! I believe in this thread the primary issue is comfort, not optimal performance. IMO, If you want a comfortable ride, go buy a comfortable car specifically designed for it. The VN is not designed as a comfort car and lowering springs are going to make it harsher no matter which spring is selected.
 
#18 ·
In the simplest form, it's vastly different in deep braking zones and sustained sweepers.

If you've used N mode (which most people don't, and use Custom mode to soften the dampers but max out everything else) on anything other than a perfectly level surface, you've likely run into a couple issues: skipping/crashing/banging across bumps and undulations when coming to a stop across a rippled surface, and being "tossed" from the outside wheel to the inside when going through a sweeper over 20 MPH.

This happens in any car for a couple reasons:

Excessive spring rate: main springs are what's thought of, but over inflated tires and relatively rigid sidewalls can cause this, along with large/stiff sway bars that are just torsion springs
Excessive compression damping: this is how most inexpensive performance vehicles cover for a "world" spring rate

The 19" wheel coupled with the harsh compression damping (and weak rebound damping) used in the stock programming are the main culprits here. It was pretty obvious what was going on just from an initial test drive, but it was something that can easily be corrected. It just happened to help that the OEM for the adaptive dampers (Mando) put out a programming module that can allow for much wider adjustment of the factory dampers.

NOTE: when changing any of the spring components in the vehicle, the somewhat ironically named "adaptive suspension" will not adapt on its own. This means things like springs, sway bars, and even the wheel/tire size will have significant changes in behavior, but not necessarily for the reasons you'd be familiar with in conventional suspensions. Lowering springs in particular will drop the dampers further into their stroke, and the dampers will ramp up much faster than before, giving an even more "racy" feel but is harsher over bumps.

In my case, I drive the car on streets WAY more than on a competitive surface. And the surfaces I will be able to "race" on will almost never be as smooth as a concrete apron at an airport (those who know, know ;-)) so I needed the car to be livable. I went with Eibach springs, reprogrammed dampers, and 18x8.5 wheels with 245/40-18 tires on them. They're much lighter while having a bit more sidewall to diffuse the shock of expansion joints, while I can program the dampers for low speed compression and rebound (body roll and "handling") to keep the car from wallowing around when too soft, or having sudden load shifts causing under/oversteer unless its desired. The high speed compression and rebound adjustment handle the high speed bumps and can be dialed in to match the springs to alleviate the crashing and skipping over braking zones (with tires and tire size playing a HUGE part in this). I'm waiting for my rear sway bar to arrive so I don't have to keep the relatively harsh "handling" adjustment of the rear end, while I have a collection of Whiteline parts that have finally arrived for the front end. Bumpsteer be gone! ;-)

So, while roll center and spring rates are important considerations, this is a road car. And as such, I defer to brands that I know understand this to help me arrive at the compromise I'm looking for. It just happens that this car has an adjustable suspension which can be reprogrammed to act as mild mannered dampers until you show up in the grid, and then can emulate overly adjusted KYB AGX struts that were all the rage for WRXs back in the day. LOL
 
#19 ·
In the simplest form, it's vastly different in deep braking zones and sustained sweepers.

If you've used N mode (which most people don't, and use Custom mode to soften the dampers but max out everything else) on anything other than a perfectly level surface, you've likely run into a couple issues: skipping/crashing/banging across bumps and undulations when coming to a stop across a rippled surface, and being "tossed" from the outside wheel to the inside when going through a sweeper over 20 MPH.

This happens in any car for a couple reasons:

Excessive spring rate: main springs are what's thought of, but over inflated tires and relatively rigid sidewalls can cause this, along with large/stiff sway bars that are just torsion springs
Excessive compression damping: this is how most inexpensive performance vehicles cover for a "world" spring rate

The 19" wheel coupled with the harsh compression damping (and weak rebound damping) used in the stock programming are the main culprits here. It was pretty obvious what was going on just from an initial test drive, but it was something that can easily be corrected. It just happened to help that the OEM for the adaptive dampers (Mando) put out a programming module that can allow for much wider adjustment of the factory dampers.

NOTE: when changing any of the spring components in the vehicle, the somewhat ironically named "adaptive suspension" will not adapt on its own. This means things like springs, sway bars, and even the wheel/tire size will have significant changes in behavior, but not necessarily for the reasons you'd be familiar with in conventional suspensions. Lowering springs in particular will drop the dampers further into their stroke, and the dampers will ramp up much faster than before, giving an even more "racy" feel but is harsher over bumps.

In my case, I drive the car on streets WAY more than on a competitive surface. And the surfaces I will be able to "race" on will almost never be as smooth as a concrete apron at an airport (those who know, know ;-)) so I needed the car to be livable. I went with Eibach springs, reprogrammed dampers, and 18x8.5 wheels with 245/40-18 tires on them. They're much lighter while having a bit more sidewall to diffuse the shock of expansion joints, while I can program the dampers for low speed compression and rebound (body roll and "handling") to keep the car from wallowing around when too soft, or having sudden load shifts causing under/oversteer unless its desired. The high speed compression and rebound adjustment handle the high speed bumps and can be dialed in to match the springs to alleviate the crashing and skipping over braking zones (with tires and tire size playing a HUGE part in this). I'm waiting for my rear sway bar to arrive so I don't have to keep the relatively harsh "handling" adjustment of the rear end, while I have a collection of Whiteline parts that have finally arrived for the front end. Bumpsteer be gone! ;-)

So, while roll center and spring rates are important considerations, this is a road car. And as such, I defer to brands that I know understand this to help me arrive at the compromise I'm looking for. It just happens that this car has an adjustable suspension which can be reprogrammed to act as mild mannered dampers until you show up in the grid, and then can emulate overly adjusted KYB AGX struts that were all the rage for WRXs back in the day. LOL
Hahahahahahhaa “emulate overly adjusted KYB!!!!”

Thanks for you article my friend for helping all of us out in the community! I appreciate your openness to share.

I am glad you are happy with the car and you went with a name (EIBACH) you felt you could trust.

-JE
 
#26 ·
That’s one thing I have noticed about this car - not one spring sits the same on two cars! Hahaha

On Instagram there are two users I know with Eibach and it doesn’t look this flush or sexy, but still looks better than stock IMO.. The pictures shared here look like my two friends who have Whiteline.

Social media away to conduct experiments!

-JE
 
#30 ·
Pulled the trigger on Whiteline Lowering Springs and Whiteline Roll Center/Bump Steer Correction Kit. I was hesitant to go with whiteline based upon the spring rates given on their US WEBSITE. I contacted someone in AU to see if this was correct because it seemed low and they informed me the US site was wrong and needs to be updated.

The website reads as such. "Whiteline Springs deliver improved vehicle performance whilst maintaining safety and ride quality characteristics. This kit contains 2.4kg/mm (134lb/in) front rated springs that provide a 25mm drop while the 2.0kg/mm (112lb/in) rated rears deliver a desirable 25mm to the vehicle. By lowering the vehicles centre of gravity, the unique and progressive rate coil design not only improve performance but enhance overall appearance. Developed and manufactured in Europe from the highest quality materials, coating and to the finest tolerances guaranteeing exact fitment. Whiteline Springs are engineered for optimal balance with OEM and aftermarket shocks. For total grip activation match with Whiteline Sway Bar and Essentials kit for unrivalled handling and optimal vehicle performance."

The spring rates are F3.6 and Rear 4.0 progressive but they would not give me the final numbers and it lowers the vehicle 30mm in front and rear.

For aesthetics I wanted Godspeed or H&R as they are 1.4 drop and also stiffer but these Texas roads are just too bad in my area to go that low.

So it was left to EIBACH, ARK, or WHITELINE. I filled out a form on Whiteline's website to see if they would sponsor me. I figured if they did sponsor me Ill take it as a sign from God to go through with it.

They wrote back and did indeed sponsor me so I a now an ambassador and get 35% off everything.

I am pumped about having a lower COG, corrected roll center geometry, as well as no wheel gap!

Blessings,
-JE
 
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