punxva

Ok, well i've been looking into buying aftermarket suspension parts for quite some time now, but i wanted to know exactually what i was getting, so i decided to make up this little faq about the basics of the suspension parts on our cars. The examples are mostly from SPLParts, i'm hoping that this may help others know what they are buying before hand, so they get the right type of setup for their personal driving style.



S13 Bushing Diagram

2- TC(tension rod)
4- LCA(lower control arm) front
6- LCA rear
8- Forward link (traction rod)
10- Rear Upper arm
12- Toe link
14- Upright (upper)
15- Upright (lower)
16- Sub-frame (front/lower)
17- Sub-frame (rear/upper)



Spring rate and ride height information
STOCK
Spring Rate - F : 2.0kg/mm (2.2 for sport package?)
Spring Rate - R : 2.0kg/mm (2.2 for sport package?)
Ride Height - F : 0"
Ride Height - R : 0"

EIBACH PROKIT
Spring Rate - F : 1.84~1.92kg/mm
Spring Rate - R : 2.3~2.4kg/mm
Ride Height - F : -1.8" (eibach site) -1" (jnm240 test)
Ride Height - R : -1.6" (eibach site) -.75" (test)

EIBACH SPORTLINE
Spring Rate - F : 1.92~2.0kg/mm
Spring Rate - R : 2.4~2.5kg/mm
Ride Height - F : -2.2" / -1.75" (test)
Ride Height - R : -2.1" / -1.75" (test)

H & R SPORT
Spring Rate - F : 2.0~2.08kg/mm
Spring Rate - R : 2.5~2.6kg/mm
Ride Height - F : -1.3"
Ride Height - R : -1.3"

TEIN S-TECH
(progressive, TEIN only lists the maximal rate)
Spring Rate - F : 3.7
Spring Rate - R : 3.2
Ride Height - F : -1.5"
Ride Height - R : -1.2"

TEIN HIGH-TECH
Spring Rate - F: 3.3 (s13); 3.2 (s14)
Spring Rate - R: 2.9 (s13); 3.1 (s14)
Ride Height - F: -0.9" (s13); -0.7" (s14)
Ride Height - R: -0.6" (s13); -0.4" (s14)

INTRAX SPORT SPRING KIT
Spring Rate - F : (Couldn't get through to tech support)
Spring Rate - R : (Couldn't get through to tech support)
Ride Height - F : -2.25"
Ride Height - R : -2.0"

SUSPENSION TECHNIQUES
Spring Rate - F : 3
Spring Rate - R : 2.66
Ride Height - F : -1.3"
Ride Height - R : -1.3" (?)

WHITELINE CONTROL
Spring Rate - F : S13&S14 = 2.8
Spring Rate - R : S13= 2.36~3.66 S14= 1.91~3.18
Ride Height - F : -1.75"
Ride Height - R : -1.75"

TANABE GF210
Spring Rate - F : 2.9
Spring Rate - R : 2.7
Ride Height - F : -1." to -1.6"
Ride Height - R : -.6" to -1"

RS*R DOWN SPRINGS
Spring Rate - F: 3.0
SPring Rate - R: 3.0
Ride Height - F: -1.6"(s13) -1.0"(s14)
Ride Height - R: -1.2" (s13) -0.6" (s14)

RS*R RACE SPRINGS
Spring Rate - F: 5.0
Spring Rate - R: 4.5(s13) 4.2 (s14)
Ride Height - F: -1.4"
Ride Height - R: -1.2" (s13) -1.0" (s14)

MEGAN RACING LOWERING SPRINGS MR-LS-NS13 (s13):
Springrate F: 6.25kg/mm (350lbs/in)
Springrate R: 4.46kg/mm (250lbs/in)
Ride Height F: 1.75"
Ride Height R: 1.75"

MEGAN RACING LOWERING SPRINGS MR-LS-NS14 (s14):
Springrate F: 6.25kg/mm (350lbs/in)
Springrate R: 4.46kg/mm (250lbs/in)
Ride Height F: 1.75"
Ride Height R: 1.75"

ESPELIR ACTIVE SUPER DOWN -
Front - 3.0kg/mm (168.0 lb/in) ~ drops 1.9"
Rear - 2.4kg/mm (134.4 lb/in) ~ drops 1.1"

KGMM S21 SPORT -
Front - 3.2kg/mm (179.2 lb/in)
Rear - 2.6kg/mm (145 lb/in)

KGMM S21 SUPERSPORT -
Front - 4.6kg/mm (257.6 lb/in)
Rear - 3.8kg/mm (212.8 lb/in)

KGMM DR Race -
Front - 6kg/mm
Rear - 5kg/mm
Ride Height - F: 2.2"
Ride Height - R: 1.2"

5ZIGEN R-RATE -
Front - 2.4 to 5.2kg/mm (134 to 291 lb/in) ~ drops 1.3"
Rear - 1.9 to 5.0kg/mm (106 to 280 lb/in) ~ drops 1.1"

KGMM S21 RACE -
Front - 6.6kg/mm (369.6 lb/in) ~drops ?"
Rear - 5.2kg/mm (291.2 lb/in) ~ drops ?"

Sway bar information
S13
Stock ? (data from Japanparts.com) JDM ?
Front 24mm
Rear 16mm

Suspension Techniques (data from STRacing.com)
Front 27mm
Rear 20.6mm

Whiteline (data from PDMRacing.com)
Front 27mm
Rear 20-22mm

Cusco (data from Japanparts.com)
Front 28mm
Rear 18mm

Tanabe (data from Tanabe-usa.com)
Front 30.4mm
Rear 22mm

Progress
Front 27mm
Rear 22mm

S14
Stock (data from CourtesyParts)
Front 27.2mm
Rear 15.9mm

Whiteline Adjustables (data from PDMRacing.com)
Front 27mm
Rear 20mm (22mm available as well)

Suspension Techniques (data from STRacing.com)
Front 28.6mm
Rear 20.6mm

Cusco (data from Japanparts.com)
Front 30mm
Rear 21mm

Nismo (data from Japanparts.com)
Front 30mm
Rear 23mm

Tanabe (data from Tanabe-usa.com)
Front 30.4mm
Rear 27.5mm

Progress
Front 30mm
Rear 24mm

Spring/shock adjustment guide

Spring Rate Changes (def. important for those who dont pay att. to this)
Modification - Effect on Suspension

Increase front and rear rate - Ride harshness increases; tires may not follow bumps causing reduced traction. Roll resistance increases.

Increase front rate only - Front ride rate increases. Front roll resistance increases, increasing understeer or reducing oversteer.

Increase rear rate only - Rear ride rate increases. Rear roll resistance increases, increasing oversteer or reducing understeer.

Decrease front and rear rate - Ride harshness decreases; tires follow bumps more effectively, possibly improving traction. Roll resistance decreases.

Decrease front rate only - Front ride rate decreases. Front roll resistance decreases, decreasing understeer or increasing oversteer.

Decrease rear rate only - Rear ride rate decreases. Rear roll resistance decreases, decreasing oversteer or increasing understeer.



Antiroll Bar Changes (aka sway bar)
Modification - Effect on Suspension

Increase front rate - Front roll resistance increases, increasing understeer or decreasing oversteer. May also reduce camber change, allowing better tire contact patch compliance with the road surface, reducing understeer.

Increase rear rate - Rear roll resistance increases, increasing oversteer or decreasing understeer. On independent rear suspensions, may also reduce camber change, allowing better contact patch compliance with road surface, reducing oversteer.

Decrease front rate - Front roll resistance decreases, decreasing understeer or increasing oversteer. More body roll could reduce tire contact patch area, causing understeer.

Decrease rear rate - Rear roll resistance decreases, decreasing oversteer or increasing understeer. On independent rear suspensions, more body roll could reduce tire contact patch area, causing oversteer.

Note - Remember to consider the construction of the sway bar and the endlinks. A solid sway bar has more resistance than a hollow bar of the same diameter. Also the addition of solid or polyurethane endlinks will artificially raise the diameter of the bar in terms of effectiveness.


Shock Absorber Changes (aka your struts)
Modification - Effect on Suspension

Rebound - The dampers resistance when the suspension is de-compressing (when you turn right the right side suspension is in rebound)

Bump - The dampers resistance when the suspension is compressing (when you turn right the left side suspension is in bump)

Increase rebound and bump rates - Ride harshness increases.

Increase rebound rates only - On bumps, tires may leave track surface.

Increase bump rates only - Body roll resisted; outside tire loaded too quickly; car won't stabilize into a turn.

Decrease rebound and bump rates - Ride harshness decreases; car may float over bumps.

Decrease rebound rates only - On bumps, tires follow track surface more effectively; car may continue to oscillate after bumps.

Decrease bump rates only - Body rolls quickly; car is slower to respond to turn-in.


How do I correct my suspension geometry?

Note: Almost every aftermarket arm has a solid rod end which replaces the worn stock rubber bushing. This increases road noise somewhat, but drastically increases the response of the suspension. It also reduces the compliancy of the suspension, which reduces the change in geometry when the suspension is bumped. This creates a much more stable feel in the car especially when cornering.



ADJUSTABLE TENSION RODS

Adjust Caster

Often one of the problem areas found in older 240s with the stock bushings still in place. The tension rod is found at the front of the car running between the front chassis and the lower control arm. It controls the amount of caster in the front suspension. Typically when raising the deg. of negative caster the steering wheel will have a stronger force to return to center when you let go of the wheel, and steering response will be slightly slower. When you lower the deg. of negative caster the steering will be more responsive, this can be beneficial and counter productive at the same time so keep adjustments in moderation.



ADJUSTABLE FRONT LOWER ARMS

Roll Moment Adjustment

Suggested only for those interested in competitive events, and or extensive track/drift usage. The arms have an adjustable shank (balljoint) that allows you to effectively raise and lower the arm, causing a corresponding change in roll geometry.



ADJUSTABLE REAR UPPER CONTROL ARMS

Rear Camber Adjustment

The rear upper control arm is a popular part because it is the only way to adjust the rear camber on the 240's besides the use of eccentric bolts. By accurately adjusting camber you can choose to either save your tires from a camber incited early death, or you can setup the rear camber to maintain the tire patch when the car pitches into the corner.



ADJUSTABLE REAR TRACTION ROD

Rear Bumpsteer Adjustment

When the suspension is lowered, an adjustable rear upper arm is usually installed to reduce the amount of negative camber at the ride height. However, when the rear upper arm is elongated to compensate for the negative camber, this alters the geometry of the rear multiple link and can cause bump-steer. Adjustment of the rear traction rod together with the rear tie rods (Hicas models) or rear toe arm (non-Hicas models), the geometry of the two two arms can be restored to eliminate bump-steer. Typically you want to make the traction rod longer than the OEM unit to reduce bumpsteer. Too much adjustment can cause an unstable change in toe when the suspension bumps. For this reason I suggest that the arm be adjusted minimally.



REAR TOE ARM

Rear Toe Adjustment

Note: HICAS model 240's cannot use these arms.

The stock rear toe adjustment has been found to run out when you have a lowered 240 with adjustable rear upper arms. For this reason the adjustable rear toe arm is made. Rear toe adjustments can change how the car pivots about a corner. Negative toe causes the rear end to want to rotate which can improve cornering but decreases stability. Positive toe works the opposite way, increasing stability but decreasing rear potential for rotation.



ADJUSTABLE REAR LOWER CONTROL ARMS

Rear Roll Center / Axis

Works in the same method as the front lower control arms.



REAR SUBFRAME TILT SPACERS

Rear Subframe Squat / Anti-Squat Properties

Subframe bushing spacers are used to tilt the subframe to change the rear suspension squat/anti-squat characteristic. Increase squat for drag racing or anti-squat for drift.



ECCENTRIC BOLTS

The 240 has eccentric bolts for rear camber and rear toe adjustment. These can cope with stock ride height and slightly lowered suspension geometries.




Well thats all for now, please correct this information, or add to it, thanks alot guys...

__________________
Slip Gypsies Blog

DrtyRat

Good informative post. I know that some people are gonna say that since this info is readily available on the posted websites that we should just go there. However, I have been to spl's website many times and have never seen the diagram for the s13 bushings. That diagram was very helpful, and I do most of my searching through zilvia, so there's a chance I might not have seen this other than through this post. To others, whom I'm sure will post, give punxva his credit for a very good effort and for using his time to better serve this forum....+1 for you sir

Wiisass

Just a couple things I noticed that were wrong.

Solid sway bars are stiffer than a hollow sway bar of the same diameter. But they are also heavier and if you compare weight to stiffness you are actually better off with a hollow sway bar. The rate of a hollow sway bar depends on the internal diameter of the sway bar.

Solid endlinks will not artificially raise the effectiveness of the bar. Solid endlinks will allow the bar to perform as it was designed. As the bushings get softer more of the load from the arb will be absorbed by the bushing rather than transferred into the bar.

Also with sway bars, a stiffer sway bar will increase lateral load transfer which can be detrimental to handling.

About the shocks, compression damping mainly controls the unsprung mass, while rebound damping controls the body movement of the suspension. With stiffer shocks the car will takes its set quicker. Of course there is a limit for this, if the damper system is overdamped then it will actually take longer for the car to set itself. If the dampers are softer the car will oscillate before taking a set. Say you go into a left turn, the right side of the car will compress past the point that it would be in a steady state turn at the same lateral acceleration.

That might be getting too deep, but since most people have dampers that only adjust rebound or actually adjust rebound and compression at the same time, it's not as important to decouple these effects. So if you're adjusting rebound only, you want to look at the body motion if the car is taking too long to take its set, you want to increase rebound damping. You should increase rebound damping until you are happy with it, but keep in mind that too much rebound damping can lead to an initial loss of traction because of picking up the inside wheel and can also lead to jacking down over a series of bumps. If you're adjusting compression and rebound at the same time, you need to try and find a compromise between controlling the body motion and the motion of the unsprung mass. Compression damping will deal a lot with the ride of the car. Not so much in the low speed region of the shock, but more so in the high speed. When going over a bumper your in the high speed region of the shock, so if the shock is too stiff, these forces will be high and make the ride very harsh.

With all of those correlations, they depend a lot on the situation. I mean depending on what you're using the car for, you'll want different setups. There's a balance for everything and it all depends on if it's a street car or track car. That's a decent guide for adjusting the car when it's setup and everything is dialed in.

About adjusting caster. It's positive caster in the front. Increasing caster will require more force to turn the wheel, it will also increase the amount of camber gain with steer angle. Increasing caster too much can cause the wheel to get stuck at full lock. Decreasing caster will decrease the amount of force needed to turn the wheel and the amount of feedback at the steering wheel. The amount of caster you want depends on desired steer camber characteristics and the amount of mechanical trail. Mechanical trail is the distance from the wheel center to the point where the line connecting the upper and lower ball joint intersect the ground. A tire also generates pneumatic trail based on slip angle. This trail falls off as the slip angle increases. In order to help the driver feel the limit of the tire, the balance between the mechanical trail and the pneumatic trail needs to be determined. More mechanical trail comes with more caster, so by increasing the caster too much the driver will not feel when the front tires are at their limit.

Adjustable lower control arms will help to correct the roll center, camber gain in jounce and roll. With those arms you can also adjust static camber and track width.

The rear traction rod and the rear upper control arm essentially form one arm when considering suspension geometry. Setting up the rear of the car is something that should be done by someone who knows what they're doing. Bumpsteer will need to be measured. It gets difficult becuase of the way the arms are setup.

Bumpsteer should also be accounted for in the front. This can be done using bumpsteer spacers on the tie rod. Usually if you make the tie rod parallel to the lca, your bumpsteer will be better, but it's best if you actually measure it and space everything properly.

The picture your using for the subframe spacers are actually the solid subframe bushings. They will not adjust the angle of the subframe. Adjusting the angle of the subframe will tilt the inboard points of the suspension members will adjust the geometry of the suspension.

Alright, that's about it for now.

__________________
TIP Engineering
R/T Tuning
Drift and RWD Sport
DriftAssNation

punxva

hey, thanks for pointing those out, yea like i said ive just been researcing this stuff so im no expert or anything, if anyone else sees anything, just post it up, im trying to have this be as informative as it possibly can be

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Slip Gypsies Blog

punxva

ok well heres an update, this is just about 3 hours worth of searching and compiling this simple list, im going to actually be adding more to it tomorrow since its 1 am, some things like special features, and other brands/ models and specifications, if you happen to know of any others, please feel free to post them here, and als if you know some specs that i missed or couldnt find like height adjustment specs, please either post them or contact me, thanks alot...

Coilovers

Buddy Club Racing Spec Damper
15 way adjustable, ride height adjustable
Spring Rate - front(8kg/mm)
Spring Rate - rear(6kg/mm)
Height adj. - F(?) inch
Height adj. - R(?) inch

Cusco Comp-S
ride height adjustable
Spring Rate - front(7kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(-75 ~ -50) mm
Height adj. - R(-50 ~ -20) mm

Cusco Zero 1
ride height adjustable
Spring Rate - front(7kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(-90 ~ 0) mm
Height adj. - R(-65 ~ 0) mm

Cusco Zero2
5 way adjustable, ride height adjustable
Spring Rate - front(7kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(-90 ~ 0) mm
Height adj. - R(-65 ~ 0) mm

Cusco Zero2R
5 way adjustable, ride height adjustable
Spring Rate - front(7kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(-85 ~ 0) mm
Height adj. - R(-70 ~ 0) mm

GP Sports G-Master
32 way adjustable, ride height adjustable
Spring Rate - front(8kg/mm)
Spring Rate - rear(6kg/mm)
Height adj. - F(?) inch
Height adj. - R(?) inch

HKS Hipermax DRAG
30 way adjustable, ride height adjustable
Spring Rate - front(4kg/mm)
Spring Rate - rear(3kg/mm)
Height adj. - F(?) inch
Height adj. - R(?) inch

HKS Hipermax II
30 way adjustable, ride height adjustable
Spring Rate - front(7kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(?) inch
Height adj. - R(?) inch

JIC FLT-A1
5 way adjustable, ride height adjustable
Spring Rate - front(7kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(0.5 ~ 0.25) inch
Height adj. - R(0.5 ~ 0.25) inch

JIC FLT-A2
15 way adjustable, ride height adjustable
Spring Rate - front(7kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(0.5 ~ 0.25) inch
Height adj. - R(0.5 ~ 0.25) inch

Ksport Kontrol Pro
36 way adjustable, ride height adjustable
Spring Rate - front(7kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(?) inch
Height adj. - R(?) inch

KTS Coilovers
15 way adjustable, ride height adjustable
Spring Rate - front(8kg/mm)
Spring Rate - rear(6kg/mm)
Height adj. - F(?) inch
Height adj. - R(?) inch

Megan Racing Coilover Kit
32 way adjustable, ride height adjustable
Spring Rate - front(8kg/mm)
Spring Rate - rear(6kg/mm)
Height adj. - F(?) inch
Height adj. - R(?) inch

Silk Road RM/A8
8 way adjustable, ride height adjustable
Spring Rate - front(8kg/mm) or (8kg/mm)
Spring Rate - rear(6kg/mm) or (7kg/mm)
Height adj. - F(?) inch
Height adj. - R(?) inch

Stance
15 way adjustable, ride height adjustable
Spring Rate - front(8kg/mm) or (9kg/mm)
Spring Rate - rear(6kg/mm) or (7kg/mm)
Height adj. - F() inch
Height adj. - R() inch

Tanabe Sustec Pro DD
4 way adjustable, ride height adjustable
Spring Rate - front(8kg/mm)
Spring Rate - rear(6kg/mm)
Height adj. - F(-0.5 ~ -2.5) inch
Height adj. - R(-0.5 ~ -2.5) inch

Tanabe Sustec Pro SS
4 way front and 4 or 8 way rear adjustable, ride height adjustable
Spring Rate - front(8kg/mm)
Spring Rate - rear(6kg/mm)
Height adj. - F(-0.5 ~ -2.5) inch
Height adj. - R(-0.5 ~ -2.5) inch

Tanabe Sustec Pro SS Type II
4 way front and 4 or 8 way rear adjustable, ride height adjustable
Spring Rate - front(8kg/mm)
Spring Rate - rear(6kg/mm)
Height adj. - F(-0.5 ~ -2.5) inch
Height adj. - R(-0.5 ~ -2.5) inch

Tanabe Sustec S-OC
? way adjustable, ride height adjustable
Spring Rate - front(8kg/mm)
Spring Rate - rear(6kg/mm)
Height adj. - F(-0.5 ~ -2.5) inch
Height adj. - R(-0.5 ~ -2.5) inch

Tanabe Sustec S-OC Type II
? way adjustable, ride height adjustable
Spring Rate - front(8kg/mm)
Spring Rate - rear(6kg/mm)
Height adj. - F(-0.5 ~ -2.5) inch
Height adj. - R(-0.5 ~ -2.5) inch

Tein Basic Damper
ride height adjustable
Spring Rate - front(6kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(-1.0 ~ -2.5) inch
Height adj. - R(-1.1 ~ -2.9) inch

Tein Super Street
16 way adjustable (compression and rebound combined), ride height adjustable
Spring Rate - front(6kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(-0.7 ~ -2.2) inch
Height adj. - R(-0.1 ~ -2.5) inch

Tein Super Drift
16 way adjustable (compression and rebound combined), ride height adjustable
Spring Rate - front(10kg/mm)
Spring Rate - rear(8kg/mm)
Height adj. - F(-0.2 ~ -3.2) inch
Height adj. - R(-0.3 ~ -2.6) inch

Tein Type FLEX
16 way adjustable (compression and rebound combined), ride height adjustable
Spring Rate - front(5kg/mm)
Spring Rate - rear(4kg/mm)
Height adj. - F(-0.1 ~ -2.5) inch
Height adj. - R(-0.8 ~ -2.4) inch

Zeal Function B6
6 way adjustable, ride height adjustable
Spring Rate - front(6kg/mm)
Spring Rate - rear(5kg/mm)
Height adj. - F(?) inch
Height adj. - R(?) inch

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Slip Gypsies Blog

punxva

Alignment Measures -(Courtsey of Yokohama Tires)


Wheelbase
Refers to the distance between the front and rear axles measured at the hub centers. This distance should be equal on both sides of the car. If not, some suspension components are worn, bent or damaged.


Tracking
Relates to the distance of each wheel to the vehicle's centerline. Each wheel should be equidistant from this centerline so that, as the vehicle moves straight ahead, wheel tracks are parallel to the vehicle's centerline (e.g., the axle should not be cocked).


Caster
To determine caster, first draw an imaginary line through the upper and lower ball joints. The angle made by this line (the steering axis) with another imaginary line drawn perpendicular to the ground (the centerline) is the caster. If the angle between the steering axis and centerline is toward the front of the car, caster is negative. If toward the rear of the car, caster is positive. Measured in degrees, caster plays a large role in determining both steering feel and high-speed stability. The goal of proper caster alignment is to achieve optimal balance between low-speed steering effort and high-speed stability. An increasingly positive caster enhances high-speed stability, but increases low-speed steering effort. An increasingly negative aster decreases low-speed steering effort and high-speed stability. For cars with power steering, an increase in low-speed steering effort increases the rate of wear in the power steering system. With most suspension designs, there is a trade-off between caster and camber angles at the extreme limits.


Camber
Viewed from in front of the vehicle, camber describes tilt of the tire from vertical. A tire has negative camber when its top inclines toward the vehicle. Positive camber occurs when its top tilts away from the vehicle. Camber is measured in degrees, and varies by car model and year. A wheel's camber angle should be adjusted to maximize a tire's contact with the road's surface under given loaded cornering conditions. Because a tire's camber changes slightly as its suspension moves during travel, the static angle at which the camber is set will depend on driving habits. If a driving style entails hard cornering, outside tires (heavily loaded) will need to have a statically set negative camber. If driving is on highways where tires are mainly subjected to lightly loaded cornering conditions, the static camber setting should be zero or slightly positive. Camber plays a large role in determining both the overall handling feel of a vehicle and how a tire wears across its treadface. A tire wears most at the point(s) where the majority of the vehicle's load rests. A properly set camber maximizes a tire's contact patch, leading to even wear. Excessive negative or positive camber has an adverse effect on treadlife by causing premature outer or inner shoulder wear.


Toe
If you were able to view the front tires of a vehicle from above the car, you would expect them to look exactly parallel to each other. In fact, they rarely are. The difference in distance between the front edge of the tires and the rear edge is called toe. Toe describes how close to parallel the two tires are, and whether they are toed-in (closer at the front of the tire) or toed-out (closer at the rear of the tire). The goal of toe is to provide proper tire wear through various driving conditions. The amount of toe your suspension is set to varies by the drive layout of your vehicle, driving preference, and car's handling characteristics. On a rear-wheel-driven car, acceleration forces on the tire tend to push the front tires back slightly in the wheel well. Static toe-in will result in a zero-toe situation at speed. For a front-wheel-driven vehicle, the front wheels will pull themselves forward in the wheel wells under acceleration. This happens because as the (driven) front wheels claw for traction, hey pull themselves forward, dragging the rest of the car along. For this situation, static toe-out will result in a zero-toe condition at speed. Assuming that the rest of the suspension is correctly aligned and maintained, and the tires properly inflated, toe-in will result in additional understeer for the car. In a corner the inside front tire will turn at less of an angle than the outside tire. Additionally, excessive toe-in will result in premature tire wear through feathering, and increased fuel consumption. Conversely, toe-out will result in additional oversteer for the vehicle. This occurs as the inside front tire turns at a greater angle than the outside tire. Thus, in a corner, the inside tire is trying to turn even more than the heavily-loaded outside tire. Excessive toe-out will also result in premature tire wear due to feathering, and increased fuel consumption.

__________________
Slip Gypsies Blog

dorisil80

just to help out even more (for newbeeees .on the alignment part a few things to mention is what happens when the car is lowed on a... s13 for example if the car is lowed and measured at the factory height check points(not eye or fender looks)the rear tends to toe in and the front toe out imagine this in ur head WOW!! looks crazy what is really going on is the rear has a stability setting and the front has a more agrressive turn in. generally toe out in the front inducess quicker turn in but u lose high stability as for the reaR toe in more stability(also mimicks a stiffer rear like stability bars with out them and toe out loosens the rear ( this setting is most desired for drifting) remember also that since its rear wheel drive the rear toe when accellerating will toe in because of the torque(torque pulls in the wheels in ward) so keep in mind that the differential plays a big part as well the majority of my customers that i do suspension tuning(this is what i do for a living i set the rear to toe out 2degrees(power plays a role) on mild sr20 if they have more power such as 270hp or so plus i will increase toe out since more torque will want to pull the rear wheels in( this is for drifting set up with 2way diff)i cant really give an example for auto-x because its more indeep than drifting set-ups. their is ALOT more but i will post little by little what i call CTC caster toe camber the 3 magic works that make a world of a diff!!! hope this helps a bit!!!!

g6civcx

This is a very difficult topic. Big thumbs up for trying to teach the rest of us.

exitspeed

This is always super helpful. Especially for newbs.
http://www.rsracing.com/tech-wheel.html#fitting
And also a wheel offset calculator...
http://marksink.com/tire_wheel_offset/offset.html


How to Measure Bolt Patterns


How to Measure Wheel BackSpace
Items required to measure wheel backspace: Tape measure
Straight edge
Wheel w/o tire (preferred)

The easiest way to measure backspace is to lay the wheel face down onto the ground so the backside of the wheel is facing up. Take a straight edge and lay it diagonally across the inboard flange of the wheel. Take a tape measure and measure the distance from where the straight edge contacts the inboard flange to the hub mounting pad of the wheel. This measurement is backspace. The above photo shows three wheels with 2",3", & 4" backspace.

Measuring Wheel Offset
To calculate offset you'll need the following measurements:

Wheel backspace
Wheel Width
Wheel Center line (outboard flange to inboard flange measurement / 2)

Subtract:

Wheel center line from Wheel backspace to get offset. If backspace is less than the wheel centerline the offset is negative
If backspace is greater than the wheel centerline the offset is positive


Tip:

To convert from inches to mm multiply by 25.4
To convert from mm to inches divide by 25.4


Backspace to Offset Conversion Chart
The table on the right is q quick reference for finding offset, pick the rim width and follow the row over to the backspace of your wheel.


Determining Vehicle Fitment
Fitting a wheel and tire package is different for each vehicle, but by following these guidelines your chances for success will be much greater. In most cases you'll have to use the physical dimensions of the current wheel/tire package to determine the dimensions of the new wheel/tire package.
Items which are potential trouble spots:

Tie Rod Ends
A-arms
Brake Calipers
Shocks and Shock Mounts
Inner & Outer Fenders (esp. front tires turned to lock)


In the drawing on the left, we've made two measurements Front Side Clearance
Back Side Clearance

These measurements when used with:

Tire Section Width
Tire Diameter
Rim Width
Rim Backspace

Help determine if wheel/tire clearance is adequate for the new wheel/tire package you've selected


Suggestion: Start your search for new wheels by picking the tires first. Get the tire manufacturer's rim width recommendations and physical dimensions for the tires you want. Pay close attention to Section Width and Measured Rims specs., these are important numbers to be used when selecting rims and determining vehicle fitment.


Determine Wheel Caliper Clearance
Ensuring proper caliper clearance inside the wheel is important. The following chart should enable you to have the dimensions required by most wheel manufactures.
A. Caliper Overhang Distance Used to determine if wheel dish is adequate (in some cases a spacer is required for clearance)

B. Diameter of Hub Center Required if wheels are hub centric

C. Wheel Stud Diameter Required along with bolt circle

D. Height of Hub Center
E. Length of Lug and Thread Type (Fine or Coarse) Required to determine if longer studs are necessary

F. Distance from CL of Hub to Caliper Used with A to determine if a spacer is required for proper fitment

G. Width of Caliper Used with F to determine if wheel ID is adequate to clear rotor/caliper package

H. Diameter of Hub Mounting Face Used to determine if hub is adequate to support wheel/spacer



Typical Lug Nut Torque Specifications
Lug Size Ft/Lbs Torque
7/16" 55-65
1/2" 75-85
9/16" 95-115
5/8" 135-145
12mm 72-80
14mm 85-95

IMPORTANT NOTICE: As with all types of wheels retorque lug nuts after the first 25 miles & at 100 mile intervals until lug torque is maintained.
Note: Always refer to Owner's Manual for proper factory specifications that take precedence over the listed recommendations.


Wheel Terminology

Bolt pattern or lug pattern or bolt circle is determined by the number of bolt holes and the bolt circle diameter.

Hub Diameter or center bore is the hole at the center of the wheel.

Rear spacing or back spacing is the distance from the backside of the wheel mounting pad to the outside of the rim flange.

Offset: The distance from the centerline of the wheel to the mounting surface of the wheel.

Negative offset: When the back of the bolt pad is closer to the inside of the wheel; when mounting surface is inboard of the rim centerline.

Positive offset: When the back of the bolt pad is closer to the street side of the wheel; when the mounting surface is outboard of the rim centerline.

Bead-Loc A device which captures the tire bead between it's flanges, usually secured by bolts to keep tire bead from dismounting. Usually used in dirt circle track or off road applications where low tire pressures are used and hitting ruts or other vehicles are common. Left: An example of a Bead-Loc wheel


Modular Wheel Inspection and Maintenance
Two & Three piece modular wheels require periodic maintenance. You'll want to work out your own maintenance schedule, but here's an example of what the manufacturer recommends. Each Season disassemble, thoroughly inspect, clean, re-seal, and re-torque each wheel:
Replace wheel bolts each season
Wheel Bolt Torque: 1/4" bolts 15 ft/lbs. or 180 in./lbs
5/16" bolts 20 ft/lbs.

After thoroughly cleaning all mating surfaces with an appropriate cleaner, add a thin skim coat of silicone sealant to these surfaces, assemble wheel and torque bolts to recommended torque
Install a new valve stem
Add a thick coat of silicone sealant to the drop center area of the wheel and let it cure for 24 hours before initial use


Below is an example of cracking which can occur on wheels which don't support the back rim half with the center. This wheel happens to be a Dura-lite wheel. Modular Wheel Leak Detection

So your tires keep going flat, before you blame those leaky slicks, check your wheels for leaks.

Inflate the tire/wheel combination to 40psi
Spray a solution of soapy water onto the wheel
Mark areas where bubbles appear with a tire crayon
If leaks in the wheel are found follow the maintenance procedure above to reseal the wheel

The most common cause for leaking modular wheels is; the tire changing person has stuck their tire spoon into the silicone seal and damaged it during a tire mount.




Last Modified on:03/01/2002 09:17 AM Phone: (515)462-3432

©2004 R & S Racing Inc.

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punxva

Differentials - Courtsey of DoriftoSlut

There are various types of LSDs. For our cars, there are Viscous, which uses a fluid filled sac that expands with heat (Fritction) to lock the output shafts, and then there are mechanical. Mechanical means that the LSD in engaged or not due to interaction between 2 (or more) set, mechanical parts. This category includes CLUTCH and HELICAL type LSDs.

For road racing, Helical type is more desirable, because it acts like an open diff while turning in and such. If I am not mistaken, it does not lock the two output shafts to spin at the same rate, but rather it biases torque to the wheel with more grip up to 80%.

Ok, other type of Mechanical LSD, clutch type. Clutch type LSDs use a center cam that moves under torque changes within a casing. The casing is 2 parts (L and R) and is symetrical in that sense. However, the cuts in the casing making the notches for the cam to slide in are not. That determines 1, 1.5, or 2 way LSD. As the cam slids in the notch it pushes the casing outward, which engages a series of clutch discs, some attached to the casing, some to the output shafts. When engaged, both output shafts will rotate at the speed of the casing, making both axles, and subsequently, wheels, rotate at the same speed.

Now back to the notches:

A 1 way notch is cut like an upside down triangle. While the cam can push backward against the tapered edges, expanding the casing, it cannot push forward against the flat surface. Therefore under acceleration torque (cam rotating backwards) it will lock, and under deceleration torque, when the cam is forced to rotate forward due to forces from braking, engine braking, etc.. it will just contact a flat "wall" and the casing will not expand.

A 1.5 way notch is like an upside down triangle with a half trangle on top of it. During acceleration it will expand the casing at one rate, and during deceleration, it will still expand the casing, but due to the cuts' higher angles, it will require more force to move the casing apart. Therefore, only during Very hard braking will it have enough force pushing it forward to expand the casing.

Need it be said that a 2 way then is shaped just about like a diamond? Where it requires almost the same amount of acceleration or deceleration to force the casing apart. Usually, the top cuts are slightly more dramatic, making the 2 way still require slighlty more deceleration force to push the cam to expand the casing.

Ok, there is more. The more the casing expands, the more clutches contact each other, and the more the output shafts get locked into the same rotation. Now there are adjustable diffs where you can set a breakaway torque. That means that the cluch discs get moved closer together or further apart to dictate the SOFT, MED, or HARD setting. The closer the clutch plates are to each other, the sooner the output shafts, and thus the wheels, will spin in sync.

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GSXRJJordan

great thread!

I know there have been some posts (or mentions in other posts) about optimal suspension settings for our cars... I personally wrote down what a few F-D drivers had their S13s set to (as far as degrees caster/camber, tire sizes vs horsepower numbers, etc) but have lost the paper lol. Would anyone like to step in here with suggested settings to start from, and possibly an expansion on which parts to mess with to get desired effects?

Also, anyone know which of the above coilovers have separate rebound and compression settings? Do they all, except the Teins that were listed as combined? (I doubt it...)

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punxva

well, im in the process of compiling more information about actual setups, like in-depth parts lists and settings, including variables that might make yours different than their setups, so keep an eye out for this thread to have more information added sometime soon

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GSXRJJordan

dorisil80 - I've heard that 1.5* - 2* or rear toe out is ideal, thanks for backin that up.

some popular s13/s14 CTC settings would be fantastic ~

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chmercer

this isnt really specific to any topic, more just general info ive picked up along the way.

"so you want to run donker wheels like good ol charlie"

i see about 50 million cars every day on zilvia that have widebody but dont need it and/or install it wrong. widebody comes with a lot of things you need to consider to get proper wheel fitment, but not much of anyone does. they just rivet the panels to their car and roll. this is not the right way to do it.

i wont talk too much about the physical installation of these since that has already been covered, but i will say, when you are cutting out the metal from your rear fenders, cut it out wayyyyy higher than you think you need. you should at LEAST be cutting into the body crease. your radius cut should get very close to the fuel filler door. you never want to have to take these panels off cause you lowered your car and now your chopping into the tire.

as for actual wheel fitment. if you put these panels on without the wheels on the car, it wont fit. plan and simple. your shit will be sunk. if you let some body shop install them, shit will be sunk.



this is the goal.

ok so lets jump ahead, youve got your fenders cut out big enough to fit 22s if you want. also before you do this, make sure your car is at the ride height and alignment specs that you want it at. because it will be tricky to change these things properly after you install your fenders. now comes the actual placement of the fenders, which has the biggest effect on the appearance of your car. i cant really tell you a step by step on how to do this since it depends on how agressive your wheels are and such, but heres some general stuff.

before you start doing this, you want to disconnect your rear shocks from the spindle so that the car will go as low as possible.

a good way to start out is first line the panel up with the body crease and screw your panel in on the top corners. this way you have the alignment with the body crease while still being able to manuver the panel around the wheel.

so your car is max low to simulate full suspension compression, and your fender is loosley mounted. now you want to get the fender as close as possible to the tire/wheel. since you are at the bottom of the suspension curve at this point there is no danger in it rubbing while being super flush. if you have a hard time getting the fender like 2mm away from the tire at all points, a good technique is to put maybe a quarter inch thick pad of newspaper in between the wheel and the fender, and then bolt the fender down. the paper will compress to very thin, but it will still cause a gap to be formed.

also, the wider your wheels, the higher up the fender arch will be (since you are pulling the fender outwards and upwards so that its wider), so the lower your car will have to be to acchieve the same look.

another thing - on the fenders, you can bolt them down to the car in multiple ways. my preferred way is to screw it down all the way up against the wheel well, cause it makes more tire stick out and gives you that "shoehorned" look, but if you want more of a full widebody look, you can skip the holes along the edges of the sideskirts (you do have aero right? this is 2006) which will cause the fender to bubble out all around the wheel well, instead of just the top.

maybe ill put more later

Siizzzoooo

just some pictures of to support your idea




if you cut it up to the body line, your fenderwell SHOULD be pretty much flat all the way across, I think most will be safe cutting to this height

and like your man just said, DO NOT install your widebody and work your wheels around them...you should buy your wheels and work your widebody around them.

this is what your after:

buy wheels and tires


fit wheels on stock body


cut fenders, fit wheels and work your widebody panel around your wheels


paint and rivet panels in

punxva

thank you both for your contributions

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Wykydtron

Definately an excellent read. Thank you sir!

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punxva

heres a guide of rims for each the s13 and s14 and body mods needed

car: s13
Wheel: 280zx turbo swasticas
Wheelsize: 15x6 +12
Tire size:
fitment modifications:
Coilovers: yes
Brakes: no
****************************
car: s13
Wheel: r33 gtr rims
Wheelsize: 17x9 +30
Tire size: F: 215/40/17 R:215/45/17
fitment modifications: rolled/ light pull
Coilovers: only with 5mm spacer
Brakes: yes
****************************
car: s13
Wheel: 5 zigen FN01RC
Wheelsize: 17x9 +15
Tire size: F: 215/40/17 R: 225/45/17
fitment modifications: rolled / light pull
Coilovers: yes
Brakes: yes
****************************
car: s13
Wheel: Borbet Type-T
Wheelsize: 16x7.5 +35
Tire size: 225/50/16
fitment modifications: none
Coilovers: stock shocks clear by 1 cm
Brakes: should
****************************
car: s13
Wheel: Riken Mesh
Wheelsize: 15x7 +0
Tire size:
fitment modifications:
Coilovers: yes
Brakes: no
****************************
car: s13
Wheel:
Wheelsize: 15x7 -2
Tire size:
fitment modifications:
Coilovers: yes
Brakes: no
****************************
car: s13
Wheel: FN01RC
Wheelsize: 17x8 +35
Tire size: 225/45/17
fitment modifications:
Coilovers:
Brakes:
****************************
car: s13
Wheel:
Wheelsize: 16x7 +0
Tire size: F: 205/45/16 R: 215/45/16
fitment modifications:
Coilovers: yes
Brakes: no because of mesh
****************************
car: s13
Wheel: kosei k1
Wheelsize: 15x7 +27
Tire size: 205/55/15
fitment modifications: no
Coilovers: yes
Brakes: yes
****************************
car: s13
Wheel:
Wheelsize: 15x7.5 +17
Tire size: 205/55/15
fitment modifications:
Coilovers: yes
Brakes: w 30 mm spacer
****************************
car: s13
Wheel: ssr longchamp xr-4 REAR ONLY
Wheelsize: 15x7.5 +5
Tire size: 205/55/15
fitment modifications:
Coilovers: yes
Brakes: no
****************************
car: s13
Wheel: blitz type 03
Wheelsize: 17x8 +28
Tire size: 215/45/17
fitment modifications:
Coilovers: no
Brakes: no
20mm spacer was also used in this app
****************************
car: s13
Wheel: *Front only
Wheelsize: 16x8 -15
Tire size: 205/55/16
fitment modifications: demon camber
Coilovers: yes
Brakes: yes
****************************
car: s13
Wheel: fno1rc
Wheelsize: 17x9 +15
Tire size: 215/45/17
fitment modifications:
Coilovers: yes
Brakes: yes
Rubs fenders when really low
****************************
car: s13
Wheel: nismo lm-gt2
Wheelsize: F: 17x8 +35 R: 17x9 +38
Tire size: 215/45/17
fitment modifications:
Coilovers: (finger fits between tire/spring. not with bigger tire on front) rear: yes
Brakes: yes
****************************
car: s13
Wheel: Riken mesh
Wheelsize: 15x7 +15
Tire size:
fitment modifications:
Coilovers:
Brakes:
****************************
car: s13
Wheel: bbs rs
Wheelsize: F: 17x8 +35 R:17x9 +35
Tire size: F: 235/45/17 R: 255/40/17
fitment modifications: (rear needs camber or roll to fit?)
Coilovers: F: yes with 5mm spacer R: yes
Brakes: yes
****************************
car: s13
Wheel: Volk racing ce28n
Wheelsize: F: 17x7.5 +25 R:17x8.5 +30
Tire size: F: 215/45/17 R: 245/40/17
fitment modifications:
Coilovers: yes
Brakes: yes
****************************
car: s13
Wheel:
Wheelsize: 17x9 +15
Tire size:
fitment modifications: widebody fenders
Coilovers:
Brakes:
****************************
car: s13
Wheel: daytons
Wheelsize: 14x6.5 -10
Tire size:
fitment modifications:
Coilovers:
Brakes:
****************************
car: s13
Wheel: Hoshino Impul RS3
Wheelsize: F: 17x8 +30 R: 17x9 +35
Tire size: F: 235/40/r17 R: 265/40/r17
fitment modifications:
Coilovers: w 5mm spacer or 225 tires
Brakes: yes
****************************
car: s13
Wheel:
Wheelsize: 15x7 +5
Tire size: 205/55/15
fitment modifications: mucho camber or roll fenders f+r
Coilovers: yes
Brakes: not even stock in front
****************************
car: s13
Wheel:
Wheelsize: 16x8 +36
Tire size: 205/55/16
fitment modifications:
Coilovers: yes but need 5mm spacer up front
Brakes: yes
****************************
car: s13
Wheel: m2 dt05r
Wheelsize: F: 17x8.5 +25 R: 17x9.5 +30
Tire size: F: 225/45/17 R: 245/45/17
fitment modifications: roll rear fenders/ remove front liner
Coilovers: yes
Brakes: yes
****************************
car: s13
Wheel: m2 dt-05r
Wheelsize: F: 17x8.5 +25 R: 17x9.5 +30
Tire size: F: 215/45/17 R: 235/40/17
fitment modifications:
Coilovers: yes
Brakes: yes
****************************
car: s13
Wheel:
Wheelsize:
Tire size:
fitment modifications:
Coilovers:
Brakes:
****************************

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punxva

S14
Fn01r-c 5zigen's 17*8 +35
*****************
****************************
car: s14
Wheel: work wheels
Wheelsize: F: 18x8.5 +32 R: 18x10 +40
Tire size: F: 235/40/18 R: 265/35/18
fitment modifications:
Coilovers: Clears agx w rsr springs
Brakes:
****************************
car: s14
Wheel: Stern Face II Beast
Wheelsize: F: 18x8.5 R: 18x9.5
Tire size:
fitment modifications:
Coilovers:
Brakes:
****************************
car: s14
Wheel: Volk Gramlight 57s
Wheelsize: 17x9.5 +22
Tire size:
fitment modifications: demon camber
Coilovers:
Brakes:
****************************

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punxva

S14
Fn01r-c 5zigen's 17*8 +35
*****************
****************************
car: s14
Wheel: work wheels
Wheelsize: F: 18x8.5 +32 R: 18x10 +40
Tire size: F: 235/40/18 R: 265/35/18
fitment modifications:
Coilovers: Clears agx w rsr springs
Brakes:
****************************
car: s14
Wheel: Stern Face II Beast
Wheelsize: F: 18x8.5 R: 18x9.5
Tire size:
fitment modifications:
Coilovers:
Brakes:
****************************
car: s14
Wheel: Volk Gramlight 57s
Wheelsize: 17x9.5 +22
Tire size:
fitment modifications: demon camber
Coilovers:
Brakes:
****************************

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BOROSUN

http://www.ikeya-f.co.jp/en/product_...oot_works.html

ikeya formula site has great pics from basic alignment/bumpsteer/rollcenter and r34 & s15 charts/data

Matej

Sorry for the dumb question, but what's the best way to achieve 3-4 degrees of negative camber in the front, since most coilovers only allow up to 2 degrees of adjustment?
Someone please post some demon camber tips and information.

vqboodah

i hope some one could help me also. i just put an SR in my 240 last summer and i have a huge wheel gap up front right now since the SR is alot lighter then the KA. would any springs solve the problem or do you need to get a certain spring rate/ brand or whatever?

punxva

dont make the same mistake i made, by getting some springs and struts, i went with eibach sportlines and agx's. Just go ahead and get yourself a nice set of coilovers, which will allow you to make your wheel gap any size you want

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vqboodah

im definitely getting coilovers soon but i just had to spend my money on bills. i was looking for the cheap alternative but guess thats gonna have to wait. so i wont waste money on springs then. i'll just sport the 10 inch wheel gap for a bit hahaha

babyzilla

Post Moved...

Jonnie Fraz

Somthing that I picked up in Grassroots Motorsports.

"The approximate stiffness of a solid anti-rollbar can be calculated using this equation:
K = 1,178,000 x (D4/LA2)
K = bar rate in lbs./in
D4 = daimeter of the bar, to the 4th power, measured in inches
L = center length of the bar, measured in inches
A2 = lever arm length, squared, measured in inches
and 1,178,000 = the rigidity modulus consistant of spring steel."


Ok it is alot of calculations, but with this you could figure how much the rate would change if you had an adjustable bar or if you had an aftermarket anti rollbar adjuster like these JIC magic adjustable end links

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wurm

how do you measure ride height?

Jung918

If you are referring to where to measure. I measure the shock body.
I have seen others measure from the floor to the fender.
Not exactly sure which is the correct or best method.
I figure since the body is not always correct, measuring the coilover is a better estimate.

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S14 Rear Valences

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punxva

not to be or sound like an asshole but with a tape measure...

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