Suspension General Knowledge

akirarex

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I wanted to make a post that hopefully creates a knowledge base for 2016/2017 Civics in regards to springs and hopefully shocks. With the intent that it leads to someone being able to calculate motion ratio, wheel rates, and frequencies.
Corrections as needed.
Hopefully someone remembers to weigh and measure distances on their suspension parts when they take them off.

Note for the stock alignment specs:

Caster angle:

2/4-door (Except Si):

5 ° 17 ’±36 ’
5-door (Except Type-R):
5 ° 18 ’±30 ’
Si:
5 ° 24 ’±30 ’
Type-R:
8 ° 00 ’±30 ’

Camber angle:

Except Type-R and Si:
Front:
-0 ° 18 ’±30 ’
Rear:
-1 ° 12 ’±45 ’

Si:
Front:
-0 ° 20 ’±30 ’
Rear:
-1° 20 ’±45 ’

Type-R:
Front:
-1 ° 20 ’±30 ’
Rear:
-1 ° 30 ’±45 ’
(Maximum difference between the right and left side: 0 ° 45 ′)

Rear total toe-in:
2+2-1 mm (0.08+0.08-0.04 in)

Front total toe-in:
0 ± 2 mm (0.00 ± 0.08 in)

Turning angle:

2/4-door (Except Si):
Inward:
40 ° 06 ’±2 °
Outward (reference):
33 ° 00 ’±1 °

5-door (Except Type-R):
Without 18 inch wheel

Inward:
40 ° 04 ’±2 °
Outward (reference):
33 ° 01 ’±1 °

With 18 inch wheel
Inward:
37 ° 02 ’±2 °
Outward (reference):
31 ° 16 ’±1 °

Si:
Inward:
36 ° 53 ’±2 °
Outward (reference):
31 ° 08 ’±1 °

Type-R:
Inward:
34 ° 59 ’±2 °
Outward (reference):
29 ° 51 ’±1 °




2017 Civic Hatchback LX
Curb weight 6MT 2822lbs. / CVT 2888lbs. / CVT with Honda Sensing 2902lbs.
Weight Distribution (front 60/rear 40 for 6MT) CVT is front 61/rear 39

Front fluid filled compliance bushing, LX does not use fluid filled trailing arm bushing in the rear.

Wheel: 16X7 25lbs. 5x114.3 +45mm offset 64.1mm center bore (P215/55R16) (93H) Tire 20lbs.
Front Spring Rate: 126.83 lbs/in [131.6 lbs/in if you use Swift Springs data for Type R]
Rear Spring Rate: 158.53 lbs/in (All normal Hatchbacks use the same rear spring) [146.9 lbs/in if you use Swift Springs data for Type R]
Front Sway Bar: 25.5mm x 4.0mm wall thickness (all Civic Hatchbacks use this except Type R)
Rear Sway Bar: 16.5mm solid = 300 Lbs/Inch (all Civic Hatchbacks use this except Type R)

Front Shock: There are two different front shocks used on normal Hatchbacks. LX 6mt and LX CVT use the same shock, all other versions (LX Sensing, Sport, and higher models) use the other shock.
Rear Shock: There are two different rear shocks used on normal Hatchbacks. LX 6mt and LX CVT use the same shock, all other versions (LX Sensing, Sport, and higher models) use the other shock.
The Hatchback shocks and springs are not used on Sedan or Coupe versions of Civics. They are unique to the Hatchback.



2017 Civic Type R

Curb weight is 3117lbs. Front 61.8/Rear 38.2

As compared to 2017 Civic Hatchback LX
The body/chassis is unique, it is not a normal Civic Hatchback frame
Rear suspension lower arm A +126%
Rear lower arm B +116%
Rear upper arm +109%
Trailing arm +117%
Bushings are over 2x stiffer
42.7 Feet of Structural adhesives = increase of 12% lateral rigidity
3 way active damper system with stroke sensors
Dual axis front strut, aluminum front lower arms and steering knuckles
Front track width is over 2 inches wider than Civic Hatchback LX
Rear track is 1.2 inches wider than Civic Hatchback LX
3/4 inch reduction in steering axis offset (each side) than Civic Hatchback LX

Wheel: 20x8.5 22lbs. (245/30ZR20 XL) (90Y) Tire 23 lbs.
Front Spring Rate: 253.65 lbs/in (2.0 times stiffer over Civic Hatchback LX) [263.2 lbs/in if you use Swift Springs numbers]
Rear Spring Rate: 253.65 lbs/in (1.6 times stiffer over Civic Hatchback LX) [235.1 lbs/in if you use Swift Springs numbers]
Front Sway Bar: 29.0mm x 5.0mm wall thickness (1.7 times stiffer over Civic Hatchback LX)
Rear Sway Bar: 20.5mm solid = 721 lbs/In (2.4 times stiffer over Civic Hatchback LX)


2017 Civic Hatchback Sport
Curb Weight (6MT 2871lbs / CVT 2937lbs) (Sport Touring CVT Honda Sensing is 3010lbs)
Weight Distribution (front 60/rear 40 for 6MT) CVT is front 60.8/rear 39.2 (Sport Touring CVT Honda Sensing is front 60.7/rear 39.3
Front fluid filled compliance bushing
Rear fluid filled trailing arm bushing

Wheel: 18X8 32lbs. 5x114.3mm +50mm offset (P235/40R18) (91W) Tire 22lbs.
Front Spring Rate: 126.83 lbs/in ?? Same as LX?? [131.6 lbs/in if you use Swift Springs data for Type R] Confusing with part numbers. SPORT 6mt has a different part number than the other Hatchbacks. SPORT CVT has 2 options, one that is the same as all other Hatchbacks and the other is the same as SPORT 6mt. Could be a manufacturer difference though. Tried two different Sport VINs, a CVT and 6mt, and it returned a part number that is only used on those to versions of Hatchbacks. It's possible that the Sport 6mt and Sport CVT use a front spring that is slightly stiffer. Hard to tell.
Rear Spring Rate: 158.53 lbs/in (same as all normal Hatchbacks) [146.9 lbs/in if you use Swift Springs data for Type R]
Front Sway Bar: 25.5mm x 4.0mm wall thickness (same as all normal Hatchbacks)
Rear Sway Bar: 16.5mm solid = 300 Lbs/Inch (same as all normal Hatchbacks)


2017 Civic Si

Curb weight: 4 door Si is 2906lbs. Front 60.3/Rear 39.7
(2 door SI is 2889lbs. Front 61.4/Rear 38.6)

Front solid compliance bushing uses Type R compound
Rear solid trailing arm bushing uses Type R compound
Rear upper control arm uses Type R compound
18% stiffer front upper damper mounts than Civic EX-T model
2 way Adaptive Damper System- does not have stroke sensors
Front ADS shock body is about .050" to .070" larger diameter than Civic Hatchback Sport shock (will not fit in knuckle)
Rear ADS shock has overall fitment interchangeability with other Civics
ADS System is complicated and interlinked into many systems of the vehicle (F CAN data) - would not swap over easily
The unpowered state of the shocks is to run in the middle of the range/sport mode, not comfort

Wheel: 18x8 28lbs. (P235/40ZR18) (91W) Tire 23lbs. for Goodyear Summer Tire
Front Spring Rate: 144.186 lbs/in (+7% stiffer than Civic EX-T model)
Rear Spring Rate: 208.776 lbs/in (+32% stiffer than Civic EX-T model)
Front Sway Bar: 27.0mm x 4.5mm wall thickness (+7% increase over Civic EX-T)
Rear Sway Bar: 18.0mm solid = 457 Lbs/Inch (+26% increase over Civic EX-T)


2017 Civic EX-Touring 4 Door
Curb weight: EX Touring CVT 2923lbs. Front 61.4/Rear 38.6
Curb weight: EX-T 6mt 2849lbs. / CVT 2899lbs. / CVT with Honda Sensing 2905lbs.
(2 door EX-T 6mt is 2830lbs. Front 61.1/Rear 38.9)
(2 door EX-T CVT is 2889lbs. Front 62/Rear 38)

Wheel: 17x7 26.3lbs. (P215/50R17) (91H)
Front Spring Rate: 134.75 lbs/in
Rear Spring Rate: 158.16 lbs/in
Front Sway Bar: 26.5mm x 4.5mm wall thickness
Rear Sway Bar: 17.0mm solid


Normal= NOT Si, NOT Type R
Note: all normal Civic Coupes use 25.5mm front stabilizer bar (2 door LX uses 25.0mm)
Note: all normal Civic Sedans use 25.5mm front stabilizer bar (4 door LX uses 25.0mm and Touring uses 26.5mm)
Note: all normal Civic Coupes use 16.0mm solid rear stabilizer bar
Note: all normal Civic Sedans use 16.5mm solid rear stabilizer bar (4 door Touring uses 17.0mm)
Note: all normal Civic Hatchbacks use 25.5mm front stabilizer bar and 16.5mm rear stabilizer bar
Note: all Civics use bonded bushings on the stabilizer bars, they are not replaceable. If you need new bushings, you have to buy a new bar.
Note: the rear stabilizer bars across all versions of Civics appear to be interchangeable. The Type R uses different bushing brackets which are required to mount the bar.
Note: the front stabilizer bars appear to be interchangeable, I do not know if the Type R front will work on any other version of Civic. Changing the front stabilizer bar requires dropping the sub frame and removing the steering gearbox.

Notes on normal Civic Coupe (compared to normal Civic Sedan):
Coupe FRONT:
The LX-P trim and above have increased front roll stiffness to balance the additional weight of the sunroof and resultant increased inertia. Furthermore, a small increase in damping force controls that inertia and maintains ride quality. The Civic EX-T Coupe and above trims have front springs with a rate 15 percent stiffer than the LX and LX-P trims and the damping force is increased by 20 percent for more direct, agile handling response and body control. Due to the lighter alloy wheels on the Touring trim, the damping rates are specifically tuned for the reduced unsprung weight, increasing road isolation and providing a premium, direct feel.
Coupe REAR:
The EX-T and above trims also have 20 percent stiffer rear springs and the damping force is increased by 90 percent to deliver high levels of body control and direct agile handling response. All Civic Coupe trims use a solid rear stabilizer bar for improved crisp turn-in and body roll control. As with the front suspension, the rear damping rates are specifically tuned for the reduced unsprung weight of the lighter Touring trim wheels.



Eibach Pro-Kit
Front 157 lbs/inch
Rear 120-183 lbs/inch

Eibach Sportline
Front 148 lbs/inch
Rear 103 lbs/inch linear spring in rear?

Megan Racing Performance Lowering Springs
Front 162 lbs/inch
Rear 190 lbs/inch

RS-R H058D
Front 148.39 lbs/inch
Rear 188.71 lbs/inch

Conversion of kilogram/millimeter to pound/inch:
1.7k = 92.5lb
1.8k = 100.8lb
1.9k = 106.4lb
2.0k = 111.9lb 3.0k = 168.0lb 4.0k = 224.0lb 5.0k = 280.0lb 6.0k = 336.0lb
2.1k = 117.6lb 3.1k = 173.6lb 4.1k = 229.6lb 5.1k = 285.6lb 6.1k = 341.6lb
2.2k = 123.2lb 3.2k = 179.2lb 4.2k = 235.1lb 5.2k = 291.2lb 6.2k = 347.2lb
2.3k = 128.8lb 3.3k = 184.8lb 4.3k = 240.8lb 5.3k = 296.8lb 6.3k = 352.8lb
2.4k = 134.4lb 3.4k = 190.4lb 4.4k = 246.4lb 5.4k = 302.4lb 6.4k = 358.4lb
2.5k = 140.0lb 3.5k = 196.0lb 4.5k = 252.0lb 5.5k = 307.0lb 6.5k = 364.0lb
2.6k = 145.6lb 3.6k = 201.6lb 4.6k = 257.6lb 5.6k = 313.6lb 6.6k = 369.6lb
2.7k = 151.2lb 3.7k = 207.2lb 4.7k = 263.2lb 5.7k = 319.2lb 6.7k = 375.2lb
2.8k = 156.8lb 3.8k = 212.8lb 4.8k = 268.8lb 5.8k = 324.8lb 6.8k = 380.8lb
2.9k = 162.4lb 3.9k = 218.4lb 4.9k = 274.4lb 5.9k = 330.4lb 6.9k = 386.4lb
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360glitch

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Great information, I will pin this up top. :thumbsup:
 

Hatchy

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There seems to be some confusion over spring rates. Has anyone found published numbers? The sway bar sizes appear correct.

Sedan: link
Coupe: link
Si: link
Hatchback: link
Type R: link

The Si front spring rate listed in the above post is 7% stiffer than the Touring sedan rate, and ~14% stiffer than what was called "regular." The press kit is vague on this point. Those numbers might align with the lower and higher coupe trims having 15% different front rates. That makes more sense than especially soft springs on lower trim coupes. Rear springs also appear to be a % relative to sedan. High trim coupes might be tuned sportier than we're giving them credit for.

Type R and Hatchback spring rate multipliers line up nicely.

Si springs could be a worthy upgrade for hatchbacks, most sedans, and low trim coupes at 15% stiffer front and 32% rear, not just 7% front as is often quoted. High trim coupes would likely not notice the small change of ~10% in the rear.

Eibach lists the OE front rate as 141 on their product page for non-Si springs, which would be within measuring accuracy of the Si factory springs. Does anyone know what car they used for their testing? Was it a high trim coupe?
 
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Lunarsilver17

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anyone know the spring rates of Eibach pro-kit for the si?
 


lurker_j

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anyone know the spring rates of Eibach pro-kit for the si?
Eibach PK Front: 28 N/mm (157 lbs/in)
Eibach PK Rear: 21-32 N/mm (120-183 lbs/in) - These are progressive springs in the rear so the spring rate will change with load changes
 

Lunarsilver17

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Eibach PK Front: 28 N/mm (157 lbs/in)
Eibach PK Rear: 21-32 N/mm (120-183 lbs/in) - These are progressive springs in the rear so the spring rate will change with load changes
Where do you see those numbers listed? I saw on prl website those numbers are for the base civic, can't find si rates anywhere.
 

absolude

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Thanks for putting all this info together.
I was looking for a shock that matches the Si springs better than my LX ones. Do the EX-T and above Coupe shocks have the highest damping rate of all? Off course excluding the adjustable ones.
 


nrchaytor

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Would the coupe shocks directly fit our LX hatch?
 

FogEater

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Notes on normal Civic Coupe (compared to normal Civic Sedan):
Coupe FRONT:
The LX-P trim and above have increased front roll stiffness to balance the additional weight of the sunroof and resultant increased inertia. Furthermore, a small increase in damping force controls that inertia and maintains ride quality. The Civic EX-T Coupe and above trims have front springs with a rate 15 percent stiffer than the LX and LX-P trims and the damping force is increased by 20 percent for more direct, agile handling response and body control. Due to the lighter alloy wheels on the Touring trim, the damping rates are specifically tuned for the reduced unsprung weight, increasing road isolation and providing a premium, direct feel.
Coupe REAR:
The EX-T and above trims also have 20 percent stiffer rear springs and the damping force is increased by 90 percent to deliver high levels of body control and direct agile handling response. All Civic Coupe trims use a solid rear stabilizer bar for improved crisp turn-in and body roll control. As with the front suspension, the rear damping rates are specifically tuned for the reduced unsprung weight of the lighter Touring trim wheels.
I just got my first Civic and I dont know what half of this means but it feels true when I drive...
 

Alphaskoom

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@FogEater stiffer springs and anti roll bar = more sporty, glued to the road feeling. Think of an old 70's cadillac with worn out suspension.. these cars are the opposite of that. Lighter wheels means the wheel / tire combo has a tendency to bounce more when going over rougher terrain, so the suspension being stiffer counteracts that and pushes down the wheels harder to prevent the bouncing tendency basically.
 

remusrm

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Does anyone have the weight of the stock sedan LS steelies? I am looking for offset and weight!
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