Civic Si Lowering Springs Master Guide

shibles

Senior Member
First Name
Seth
Joined
May 12, 2018
Threads
15
Messages
247
Reaction score
159
Location
Athens, GA
Vehicle(s)
2018 Honda Civic Si Coupe
Vehicle Showcase
1
Country flag
When it comes to spring rates and stuff, I am lost. What would be the lowering springs or coilovers that would provide the best ride in terms of comfort for daily driving?
Softer shocks and lower strength springs provide better comfort. Typically coilover swap would be stiffer shocks and springs so not as comfortable driving. Lowering springs are just a cheaper option to coilovers for slightly better handling and lowered look. Also the stock shocks are already pretty good, and a coilover swap would mean removing the adjustable feature with sport mode.
Sponsored

 

letsgoMINAJE

Senior Member
First Name
Minaje
Joined
May 18, 2020
Threads
22
Messages
563
Reaction score
650
Location
In the desert, SoCal
Vehicle(s)
2020 CBP Si Sedan
Country flag
Softer shocks and lower strength springs provide better comfort. Typically coilover swap would be stiffer shocks and springs so not as comfortable driving. Lowering springs are just a cheaper option to coilovers for slightly better handling and lowered look. Also the stock shocks are already pretty good, and a coilover swap would mean removing the adjustable feature with sport mode.
Definitely don't want to lose that. So when searching for springs, because I do want to go lower, what should I be looking for in terms of spring rate? that seems to be the only measurable thing beside height.

And with a softer spring for comfort, what am I giving up? I don't and don't really plan on tracking the car... I do canyon drives here and there. I mostly commute and drive around socal.
 

arpypat

Senior Member
Joined
Jun 29, 2019
Threads
38
Messages
2,661
Reaction score
3,900
Location
⛔️
Vehicle(s)
Civic
Build Thread
Link
Vehicle Showcase
1
Definitely don't want to lose that. So when searching for springs, because I do want to go lower, what should I be looking for in terms of spring rate? that seems to be the only measurable thing beside height.

And with a softer spring for comfort, what am I giving up? I don't and don't really plan on tracking the car... I do canyon drives here and there. I mostly commute and drive around socal.
With a lower spring rate, you'd get more body roll in turns. You'd have less stability after hitting bumps and more weight transfer. Aftermarket spring manufacturers don't generally make springs with a softer spring than stock anyways. And since they're all pretty much lowering springs, the stiffness has to go up or else you'd bottom out and risk damaging your shocks.

Spring rates are given as a force divided by a distance. When you see 300lbs/in, for example, it means it takes 300lbs to compress the spring 1 inch. The higher the number, the more force it takes to compress the spring. Which is why higher spring rate springs make your car feel "stiff". You're not compressing the spring as much as it used to compared to stock, so your suspension travels less. The shock/damper acts as a cushion to absorb the impact and to rebound the spring to keep the tires on the ground.
 

letsgoMINAJE

Senior Member
First Name
Minaje
Joined
May 18, 2020
Threads
22
Messages
563
Reaction score
650
Location
In the desert, SoCal
Vehicle(s)
2020 CBP Si Sedan
Country flag
With a lower spring rate, you'd get more body roll in turns. You'd have less stability after hitting bumps and more weight transfer. Aftermarket spring manufacturers don't generally make springs with a softer spring than stock anyways. And since they're all pretty much lowering springs, the stiffness has to go up or else you'd bottom out and risk damaging your shocks.

Spring rates are given as a force divided by a distance. When you see 300lbs/in, for example, it means it takes 300lbs to compress the spring 1 inch. The higher the number, the more force it takes to compress the spring. Which is why higher spring rate springs make your car feel "stiff". You're not compressing the spring as much as it used to compared to stock, so your suspension travels less. The shock/damper acts as a cushion to absorb the impact and to rebound the spring to keep the tires on the ground.
Thanks for the breakdown. It was very informative.
Just to make sure I am understanding clearly, are you ultimately saying that going lower will sacrifice comfort?

If so, what suspension mods can be done to combat that, if any?
 

CanadiaegeanBlue

Senior Member
First Name
Humza
Joined
Jul 1, 2017
Threads
17
Messages
874
Reaction score
1,556
Location
Toronto
Vehicle(s)
2017 Honda Civic Si Sedan - Aegean Blue Metallic
Build Thread
Link
Vehicle Showcase
1
Country flag
I've tried the following setups on my Si over the years

- H&R Springs: ride quality matches factory, great drop, some rub on big dips, will require camber kit for alignment correction, but too soft for track use. Used for 1 year.

- K-Tuned Coilovers: Great adjustment range for Height, Dampening, and Camber. However still quite a stiff, clunky somewhat crashy ride, and will throw a code on the dash every time you start up. Used for 1 year, removed last week.

- Whiteline Springs: Relieved to eliminate the crashy ride and not dealing with a code every time. Stiffest front springs offering versus competition, but not crashy - really good turn in, little body roll, and no rub (18x8.5 ET38, 245/35R18 setup). Rear Springs are middle of the range when it comes to weight, and don't require a camber kit but I still installed SPC arms for testing. Purposely went with Whiteline because I was already installing their pretty aggressive 26mm Rear Sway Bar, so I didn't want a combination of super stiff rear sway bar + super stiff rear spring rate like Swift which could make the setup conducive to lift-off oversteer. Really happy so far with about 200 miles of driving on them.
 


KingOfBrussels

Senior Member
Joined
Sep 15, 2020
Threads
3
Messages
171
Reaction score
174
Location
DC burbs
Vehicle(s)
'20 Si sedan
Country flag
- Whiteline Springs: Relieved to eliminate the crashy ride and not dealing with a code every time. Stiffest front springs offering versus competition, but not crashy - really good turn in, little body roll, and no rub (18x8.5 ET38, 245/35R18 setup). Rear Springs are middle of the range when it comes to weight, and don't require a camber kit but I still installed SPC arms for testing. Purposely went with Whiteline because I was already installing their pretty aggressive 26mm Rear Sway Bar, so I didn't want a combination of super stiff rear sway bar + super stiff rear spring rate like Swift which could make the setup conducive to lift-off oversteer. Really happy so far with about 200 miles of driving on them.
I'm leaning towards Whiteline springs myself for similar reasons. What's the handling balance like with the Whiteline 26mm rear bar? I was figuring on the Whiteline 22mm rear bar, and with those relatively stiff front spring rates, setting it on full stiff.

The 26mm seems like borderline too much to pair with the stock front bar. It's intended for the CTR, which has a tubular 29mm front sway bar vs the Si's 27mm, and also its stock springs are stiffer in front vs the Whiteline springs being stiffer in back.

Spring rates (lbs/in)
Si - 144 F; 209 R
CTR - 263 F; 235 R
Whiteline Si - 253 F; 286 R

Without going into an overwhelming amount of detail on how I came up with these numbers (I can explain more if desired) the rear sway bar options are:

Si 18mm tubular - 343 lb/in
CTR 20.5mm solid - 550
Whiteline 22mm 2-way adjustable solid - 732 or 877
Eibach CTR 25mm 2-way adjustable tubular - 1276 or 1492
Whiteline CTR 26mm solid - 1432 or 1664

I've not been able to find any bar rate info on the front sway bars but stock CTR springs/sway is probably a bit more roll stiffness in front than Whiteline front springs + Si front sway, and the Whiteline rear springs are a little stiffer than the CTR rear springs. So...if it were me, I dunno, I'd maybe do at most the Whiteline 22mm on firm or maybe the Eibach 25mm on soft. But getting up into those 1400+ bar rates in the rear just feels like too much increased rear roll stiffness relative to the front.
 

CanadiaegeanBlue

Senior Member
First Name
Humza
Joined
Jul 1, 2017
Threads
17
Messages
874
Reaction score
1,556
Location
Toronto
Vehicle(s)
2017 Honda Civic Si Sedan - Aegean Blue Metallic
Build Thread
Link
Vehicle Showcase
1
Country flag
I'm leaning towards Whiteline springs myself for similar reasons. What's the handling balance like with the Whiteline 26mm rear bar? I was figuring on the Whiteline 22mm rear bar, and with those relatively stiff front spring rates, setting it on full stiff.

The 26mm seems like borderline too much to pair with the stock front bar. It's intended for the CTR, which has a tubular 29mm front sway bar vs the Si's 27mm, and also its stock springs are stiffer in front vs the Whiteline springs being stiffer in back.

Spring rates (lbs/in)
Si - 144 F; 209 R
CTR - 263 F; 235 R
Whiteline Si - 253 F; 286 R

Without going into an overwhelming amount of detail on how I came up with these numbers (I can explain more if desired) the rear sway bar options are:

Si 18mm tubular - 343 lb/in
CTR 20.5mm solid - 550
Whiteline 22mm 2-way adjustable solid - 732 or 877
Eibach CTR 25mm 2-way adjustable tubular - 1276 or 1492
Whiteline CTR 26mm solid - 1432 or 1664

I've not been able to find any bar rate info on the front sway bars but stock CTR springs/sway is probably a bit more roll stiffness in front than Whiteline front springs + Si front sway, and the Whiteline rear springs are a little stiffer than the CTR rear springs. So...if it were me, I dunno, I'd maybe do at most the Whiteline 22mm on firm or maybe the Eibach 25mm on soft. But getting up into those 1400+ bar rates in the rear just feels like too much increased rear roll stiffness relative to the front.
The 26mm is indeed borderline when pairing it up with the stock Si 27mm tubular. I've been driving with this setup on Soft setting for a month now, and still haven't had the nerves to push it too hard on the street, minus a couple of highway ramps going above 80mph where it felt very planted.

Your calculations seem to be bang on because every bit of the difference I felt going from 18mm Si to 22mm Whiteline, I felt it again going to 26mm Whiteline. It's not twitchy but you can tell it wants to turn in fast, and my rear end feels more solid than the front despite the softer rear springs. Once I get the Anti Lift Kit, and Whiteline 27mm Front Sway Bar installed, it may become more neutral again.

My recommendations are to always have better tires, and an understanding of transferring weight balance before adding a rear sway bar. Second recommendation would be to buy and experience the 22mm RSB first as it's perfect for everyday use - get a 26mm RSB only if you're pushing hard on track, AutoX, or like me testing parts so I can offer real world thoughts to the community :)

My current setup:
BBS RG406 with 245/35R18 Continental ECS
Whiteline Lowering Springs
Whiteline 26mm Rear Sway Bar
Whiteline Rear Toe Control Arms
SPC Camber Kit
Alignment: 0 Toe Front and Rear, -0.8 Camber Front, -1.8 Camber Rear
 

KingOfBrussels

Senior Member
Joined
Sep 15, 2020
Threads
3
Messages
171
Reaction score
174
Location
DC burbs
Vehicle(s)
'20 Si sedan
Country flag
Great info. I'm planning to keep the stock front sway bar but will likely do the anti-lift kit. Probably will stick to the Whiteline 22mm or maybe the Eibach 25 tubular. But that's very much a maybe. I like my cars to have *just enough* sway bar and that might be too much.
 

SuperMotoManDRZ

Senior Member
First Name
Zak
Joined
Sep 29, 2020
Threads
8
Messages
171
Reaction score
243
Location
Alabama
Vehicle(s)
2020 Civic Si Coupe, 2002 Acura RSX Type S, 2017 Suzuki DRZ400SM
Vehicle Showcase
1
Country flag
I am new to this platform and forum and had run into troubles trying to find lowering spring info and options for the 10th gen SI (FC1/FC3) so i decided to create a master thread dedicated to the SI specifically like the one that exists here for the Type R (FK8).
Another good reference thread is here where members have posted pictures of most setups.
All info is from a representative at the company or the companies website itself.
If you found this thread helpful please shoot me a thanks id really appreciate it.:thumbsup:



SI OEM
Front Spring Rate: 144.186 lbs/in
Rear Spring Rate: 208.776 lbs/in

(FK8) CTR OEM for reference
Spring Rate Front: -263.2 lbs/in
Spring Rate Rear: -235.2 lbs/in


Eibcah PRO-KIT Performance Springs
2017- 2020 Civic Si Sedan/Coupe
Part # E10-40-036-02-22
Drop Front: .9"
Drop Rear: 1.1"
Spring Rates (Progressive)
Front: 137-177 lb/in
Rear: 83-256 lb/in
$230
Best price found here


Eibach SPORT LINE
2017-2020 Civc Si Sedan/Coupe
Part # E20-40-036-02-22
Drop Front: 1.7"
Drop Rear: 1.8"
Spring Rates (Progressive)
Front: ?
Rear: ?
$261 Everywhere



D2 Racing Lowering Springs
2016-2020 Honda Civic/2017-2020 Civic Si
Part# D2R D-SP-HN-25-3
Front Drop (Coupe/Sedan): 1.7"
Rear Drop (Coupe/Sedan): 1.9"
Progressive Spring Rate
Spring Rates "20% Stiffer than stock" need to verify
$170
Best price found here


Swift Spec R
17+ Civic Sport/SI
Part# 4H918R
Front Drop: 1.1"
Rear Drop: 1.1"
Spring Rate (Dual)
Front 229.5 lbs/in
Rear 319.2 lbs/in
$298
Best price found here


Skunk 2
'16-'18 Civic
Part# 519-05-1775
Front Drop: 1.375"
Rear Drop: 1.25"
Drop varies by chasis not specifically listed as SI compatible
$173
Best price found here


K Tuned
16+ Civic (Coupe/Sedan/Hatchback) - DOES NOT FIT TYPE R
Part# KTD-K1S-FC3
Drop Front: 0.9"
Drop Rear: 1"
Spring Rate (Front): 173.6 lb/in
Spring Rate (Rear): 252 lb/in
$270
Best price found here


Whiteline
Listed as compatible with all 10th gen
Part# WSK-HON017
Drop Front: .8"
Drop Rear: .8"
Spring Rate (Progressive)
Front 253 lb/in
Rear 286 lb/in
$233
Best price found here


Tein S Tech
FC1/FC3/FK7
Part# SKHH6-AUB00
Front Drop 1.2"
Rear Drop 1.0"
Spring Rate Front 146 lb/in
Spring Rate Rear 174 lb/in
$172
Best price found here


RS*R
2016+ Honda Civic Coupe / Sedan
Part#: H057D
Drop for Coupe:
Front 1.0in to -1.2in
Rear 1.4in to -1.6in
Drop for Sedan:
Front 1.0in to -1.2in
Rear 1.2in to -1.4in
Spring Rates
Front 148.40 lb/in
Rear 188.71 lb/in
$245
Best price found here


H&R Sport Springs
2016-2020 Honda Civic (Confirmed compatibility with SI)
Part# H&R 51892
Front Drop ~1.25"
Rear Drop ~1"
Spring Rate (Progressive)
$233
Best price found here



Fell free to post pictures of your setups just be sure to list what springs youre running.
If any of this info is incorrect please let me know or if you have something to add and ill continue to update this post.
I'm going for the Tein H Tech springs, which aren't mentioned here. Supposedly only a 0.6" drop for the 2020 Civic Si Coupe.. these I think will be a good option for keeping similar suspension dimensions/geometry and running bigger tires and or rims.. I have yet to install them with factory wheels and tires. I will be doing that at the end of this month.. will post before and after pics and all the specifics for them at that time. I'll keep everyone posted and see how they will eventually do with different wheel/tire sizes..
 


BoostinIX

Senior Member
Joined
Jul 23, 2020
Threads
8
Messages
370
Reaction score
298
Location
Laurel, MD
Vehicle(s)
2020 SI Sedan
Country flag
Great info. I'm planning to keep the stock front sway bar but will likely do the anti-lift kit. Probably will stick to the Whiteline 22mm or maybe the Eibach 25 tubular. But that's very much a maybe. I like my cars to have *just enough* sway bar and that might be too much.
What use case? Autox? Daily driven? Living with the 22 rear is definitely enjoyable on a daily.

If you decide later to change, you'll likely have an easier time offloading the 22 than the 26.

Incremental upgrades vs full ham ;)
 

KingOfBrussels

Senior Member
Joined
Sep 15, 2020
Threads
3
Messages
171
Reaction score
174
Location
DC burbs
Vehicle(s)
'20 Si sedan
Country flag
What use case? Autox? Daily driven? Living with the 22 rear is definitely enjoyable on a daily.

If you decide later to change, you'll likely have an easier time offloading the 22 than the 26.

Incremental upgrades vs full ham ;)
DD with the occasional back road and infrequent autocross or track day. The only reason I was thinking of going more than the Whiteline 22mm rear bar is the relatively stiff front Whiteline springs. But the jump up from the Whiteline 22mm solid to the Eibach 25mm tubular is pretty significant. I don't need snap oversteer and lifting an inside wheel in turns.
 

rhino

Senior Member
First Name
jacob
Joined
Jul 15, 2019
Threads
5
Messages
5,313
Reaction score
6,620
Location
Weeb land!
Vehicle(s)
2015 sr5 access cab, 98 civic hx ej7, 2003 KLX400s
Vehicle Showcase
1
Country flag
Hey everyone,
Currently on Eibach Sportlines. They’re great so far but had an alignment done recently and the shop brought this to my attention. Is it normal for the coils in the rear to be stacked so tightly? Should I contact Eibach? The rear does feel harsher on impact than the front...
A13265F3-B0DD-406D-AC67-0D0F3A1D4F49.jpeg
im new to the whole lowering cars thing but man that dont look right to me did eibach ever get back to you?
 

si@vegas

Senior Member
First Name
JT
Joined
Feb 25, 2019
Threads
17
Messages
96
Reaction score
61
Location
NV
Vehicle(s)
2019 Civic Type R
Country flag
I've tried the following setups on my Si over the years

- H&R Springs: ride quality matches factory, great drop, some rub on big dips, will require camber kit for alignment correction, but too soft for track use. Used for 1 year.

- K-Tuned Coilovers: Great adjustment range for Height, Dampening, and Camber. However still quite a stiff, clunky somewhat crashy ride, and will throw a code on the dash every time you start up. Used for 1 year, removed last week.

- Whiteline Springs: Relieved to eliminate the crashy ride and not dealing with a code every time. Stiffest front springs offering versus competition, but not crashy - really good turn in, little body roll, and no rub (18x8.5 ET38, 245/35R18 setup). Rear Springs are middle of the range when it comes to weight, and don't require a camber kit but I still installed SPC arms for testing. Purposely went with Whiteline because I was already installing their pretty aggressive 26mm Rear Sway Bar, so I didn't want a combination of super stiff rear sway bar + super stiff rear spring rate like Swift which could make the setup conducive to lift-off oversteer. Really happy so far with about 200 miles of driving on them.

Hi, Do you get any additional negative camber from the whiteline springs by themselves vs. stock? I'm looking to get the SPC ball joints for -1 degree camber, but wanted to see if the whiteline springs add more to it.
 

racerguy180

Senior Member
First Name
Erik
Joined
Jan 25, 2020
Threads
7
Messages
265
Reaction score
228
Location
San jose
Vehicle(s)
1995 Acura Integra GS-R 2001 Acura Integra GS 2014 Acura MDX Advance
Country flag
I'm going for the Tein H Tech springs, which aren't mentioned here. Supposedly only a 0.6" drop for the 2020 Civic Si Coupe.. these I think will be a good option for keeping similar suspension dimensions/geometry and running bigger tires and or rims.. I have yet to install them with factory wheels and tires. I will be doing that at the end of this month.. will post before and after pics and all the specifics for them at that time. I'll keep everyone posted and see how they will eventually do with different wheel/tire sizes..
I'm interested in the h.tech springs as well. not looking for more than an inch drop so these seem to fit my needs. tend drive my car more like a rally car than anything so the more suspension stroke available the better.
Sponsored

 


 


Top