VW WaterCooler Club!

 
Welcome, Guest. Please login or register.

Login with username, password and session length
News:
Pages: [1]   Go Down
  Print  
Author Topic: SuspensionTuning+Alignment 4Everyone  (Read 11212 times)
0 Members and 1 Guest are viewing this topic.
KoNsHaRa
Staff
What da F Member
*****
Offline Offline

Posts: 19579



Email
« on: September 04, 2012, 01:00:48 PM »

มีสมาชิกหลายคน PM มาถามเกี่ยวกับการปรับหรือเซทอัพช่วงล่าง
พอดีผ่านไปเจอนี่มา เห็นว่ามีประโยชน์ เลยเอามาแบ่งสมาชิกที่ชอบซนทั้งหลาย
หลักการเดียวกันหมดไม่ว่าจะเป็นรถขับหน้าหรือขับหลังหรือขับสี่
จัดไป  

Suspension Tuning

Front spring rate increase:
More under steer; increase in proportional weight transfer to the front when rear wheel rate is not increased; reduces front traction when rear rate is not changed.
Usable adjustment: 150-600 lbs/in
Symptoms of too much adjustment: terminal under steer; front of car hops in corners; excessive wheel spin on inside front tire on FF cars.

Front spring rate decrease:
Less under steer; decreases proportional weight transfer to the front when rear wheel rate is not increased; increases front traction when rear rate is not changed.
Usable adjustment: 150-600 lbs/in
Symptoms of to much adjustment: Too much over steer; over steer then under steer if spring is so soft that the car bottoms out on lean, car bottoms out excessively with a jolting ride.

Rear spring rate increase:
More over steer; increase in proportional weight transfer to the rear when front wheel rate is not increased; increases rear traction when front rate is not changed.
Usable range: 100-600 lbs/in
Symptoms of too much adjustment: too much over steer; sidestep hop in corners; twitchy; pretty scary.

Rear spring rate decrease:
Less over steer: decreases proportional weight transfer to the rear when front wheel rate is not changed; increases rear traction when front rate is not changed
Usable range: 100-600 lbs/in
Symptoms of too much adjustment: car under steers; if way to soft car under steers then over steers as car bottoms out on lean; car bottoms out excessively with a jolting ride.

Front anti-roll bar stiffer: more under steer
Usable range: none to 1.25 inches in diameter
Symptoms of to much adjustment: terminal under steer; lifts inside front tire off the ground witch can cause massive wheel spin on FF cars; also not good for most effective tire usage as inside tire is now doing nothing.

Front anti-roll bar softer: less under steer
Usable range: none to 1.25 inches in diameter
Symptoms of to much adjustment: overstate scary; more like fun

Rear anti-roll bar stiffer: more over steer
Usable range: none to 1 inch in diameter
Symptoms of too much adjustment: Big-time over steer. Can cause inside rear tire to lift off the ground.

Rear anti-roll bar softer: less over steer
Usable range: none to 1 inch in diameter
Symptoms of to much adjustment: under steer; slow and boring

Front tire pressure higher: less under steer by reducing slip angels on most tires
Usable adjustment: up to 55psi hot
Symptoms of too much adjustment: no traction- tire crowned so more under steer; adds wheel spin in FF cars; jarring ride; center of tire wears out

Front tire pressure lower: more under steer by increasing slip angles on most tires
Usable adjustment: not less then 20psi
Symptoms of too much adjustment: edges of tire wear quickly because tire is folding over; feels mushy; tires chunk because low pressure means heat build up.

Rear tire pressure higher: less over steer by reducing slip angles on most tires
Usable range: up to 45psi hot
Symptoms of too much adjustment: no traction—tire is crowned so more over steer; bad wheel spin on FR cars; jarring ride; center of tire wears out.

Rear tire pressure lower: more over steer by incresing slip angles on most tires.
Usable range: not less then 20psi
Symptoms of too much adjustment: edges of tire wear quickly because tire is folding over; feels mushy; tires chunk because low pressure means heat build up

More negative camber front: less under steer because of better lateral traction as tread is flatter on the ground under side load.
Usable range: up to 3.5 degrees negative
Symptoms of too much adjustment: poor braking; car is road crown sensitive; twitchy; front tires wear on inside edge

More negative camber rear: less over steer because of better lateral traction as tread is flatter on the ground under side load. More rear grip
Usable range: up to 2.5 degrees negative
Symptoms of too much adjustment: more over steer; car feels twitchy in back; tires wear out on inside edge; less breakaway warning when limit is exceeded.

Ride height to low (typical beginner mistake): car is twitchy with unpredictable dynamics. Bump steer make you life miserable.
Usable range: usually 1.5-2.0 inches lower then stock unless car has been modified to go lower.
Symptoms of too much adjustment: everything that could possibly go wrong: sudden over/under steer; twitchy due to bump steer; very harsh ride; premature tire wear.

Toe in – front: car is stable going straight. Turn in is average
Usable range: 0-1/8th inch
Symptoms of too much adjustment: car has slow twitchiness under braking; feels odd; kills outside edge of tires

Toe out – front: Car turns in well; works pretty well on FF car as they tend to toe-in under load.
Usable range: 0-1/4 inch
Symptoms of too much adjustment: Car is really twitchy under braking; car wanders on straight road; kills inside edge of tire

 Toe in – rear: car is less likely to over steer when the throttle is lifted
Usable range: 0-1/8th inch
Symptoms of too much adjustment: weird, slow, rocking movement in back; feels slow but still unstable; wears outside edge of tires.

Toe out – rear: Helps car rotate useful in low speed and slalom courses; very common on FF pro rally cars.
Usable range: 0-1/8th inch
Symptoms of too much adjustment: not to good for street driving; causes lift throttle over steer; makes violent side to side rocking motions in the rear; tie wears on inside more.

Positive front caster: helps stability; suspension will get more negative camber when turning; reducing positive caster reduces steering effort. (Negative caster is not usable)
Usable range: 4-9 degrees positive
Symptoms of too much adjustment: can increase under steer especially in cars with wide low-profile tires. Can increase steering effort.

Single adjustable shock stiffer: Better turn in; better transient response; causes slower onset of over/under steer by slowing weight transfer depending on what end of the car is adjusted.
Symptoms of too much adjustment: suspension becomes unresponsive; ride gets harsh; car skips over bumps, loosing traction; Causes a big delay in weight transfer resulting in strange handling like under steer then late corner stage over steer.

Single adjustable shock softer: slower transient response; quicker onset of over/under steer
Symptoms of too much adjustment: car oscillates due to under dampened spring motion, like a boat. Car gets twitchy in turns. Feels unstable.

Have fun tuning your suspention. Use Toe and Camber to your advantage! Even Tire pressure helps.

ปักหมุดไว้เลยก็ดีนะปู
« Last Edit: November 30, 2012, 10:21:19 AM by KoNsHaRa » Logged

wasting money on VW since 1995.
guide267
Staff
Hero Member
*****
Offline Offline

Posts: 1290



Email
« Reply #1 on: September 04, 2012, 01:39:54 PM »

อันนี้สุดยอดเลยอ่ะพี่ หน้าเดียวตอบได้หมดเลย ขอบคุณครับ
Logged
Aq
Staff
What da F Member
*****
Offline Offline

Posts: 20379


Passat B1, Jetta Mk3, Passat B5.5


« Reply #2 on: September 06, 2012, 12:48:12 AM »

 
Logged

visit my gallery
vwc | aq photo
n_mo
Hero Member
*****
Offline Offline

Posts: 1398


vento97 AGG 2.0 8 V borbet A


Email
« Reply #3 on: October 13, 2012, 09:55:56 PM »

แปลสักนิดด คงดีนะค๊ะ  18
Logged

I Love VW
KoNsHaRa
Staff
What da F Member
*****
Offline Offline

Posts: 19579



Email
« Reply #4 on: October 18, 2012, 09:57:03 AM »

ไม่นิดละสิครับ
 18
Logged

wasting money on VW since 1995.
พจน์ 085-519-6955
Hero Member
*****
Offline Offline

Posts: 2253


Tel.091-872-6813


« Reply #5 on: October 20, 2012, 12:24:40 PM »

ไม่นิดละสิครับ
 18
แปลวันละข้อ เพื่อลูกกระจ๊อกตาดำๆ อย่างผมจะได้มาอ่านนะครับ  15
Logged

Link การแก้ปัญหาต่างๆของVW โดยคุณ aroka17 ครับ
http://www.vwwatercoolerclub.com/webboard/index.php?topic=24028.0
link คู่มือต่างๆ https://www.mediafire.com/folder/woe
คนรักรถ
Instructor
Hero Member
*****
Offline Offline

Posts: 1164

junkle99@hotmail.com
« Reply #6 on: October 20, 2012, 01:58:17 PM »

อ่านแล้วรู้สึกว่าต้องเรียน Suspension 101 ก่อนถึงจะเข้าใจได้ง่ายง่ายโดยไม่ต้องวงเล็บเยอะ
Logged
คนรักรถ
Instructor
Hero Member
*****
Offline Offline

Posts: 1164

junkle99@hotmail.com
« Reply #7 on: October 20, 2012, 02:12:30 PM »

ลองดูก่อนนะ

เพิ่มความแข็งของสปริงหน้า
อันเดอร์สเตียริ่งง่ายขึ้น หน้าแหกง่ายกว่าเดิม เพราะจะไปเพิ่มการถ่ายเทน้ำหนักที่เหมาะสม(ขณะลดความเร็ว น้ำหนักรถจะลงที่ล้อหน้ามากกว่าความเร็วคงที่)
ถ้าไม่เพิ่มความแข็งสปริงล้อหลังด้วย
ล้อหน้าจะยึดเกาะผิวถนนได้น้อยลง (หน้าเลยแหกง่ายไง) ถ้าไม่เปลี่ยนความแข็งสปริงหลัง


« Last Edit: October 20, 2012, 02:55:42 PM by คนรักรถ » Logged
พจน์ 085-519-6955
Hero Member
*****
Offline Offline

Posts: 2253


Tel.091-872-6813


« Reply #8 on: October 22, 2012, 02:53:29 PM »

ลองดูก่อนนะ

เพิ่มความแข็งของสปริงหน้า
อันเดอร์สเตียริ่งง่ายขึ้น หน้าแหกง่ายกว่าเดิม เพราะจะไปเพิ่มการถ่ายเทน้ำหนักที่เหมาะสม(ขณะลดความเร็ว น้ำหนักรถจะลงที่ล้อหน้ามากกว่าความเร็วคงที่)
ถ้าไม่เพิ่มความแข็งสปริงล้อหลังด้วย
ล้อหน้าจะยึดเกาะผิวถนนได้น้อยลง (หน้าเลยแหกง่ายไง) ถ้าไม่เปลี่ยนความแข็งสปริงหลัง



จะรอแปลหัวข้อต่อๆไปนะครับ
ขอบคุณมากเลยครับ  06
Logged

Link การแก้ปัญหาต่างๆของVW โดยคุณ aroka17 ครับ
http://www.vwwatercoolerclub.com/webboard/index.php?topic=24028.0
link คู่มือต่างๆ https://www.mediafire.com/folder/woe
KoNsHaRa
Staff
What da F Member
*****
Offline Offline

Posts: 19579



Email
« Reply #9 on: November 30, 2012, 10:23:57 AM »

เกี่ยวกับการตั้งศูนย์ล้อของ
Golf/Jetta 3-5
Passat B5/5.5
เอาข้อมูลมาแปะไว้ให้
จะได้ไม่ต้องถามกันบ่อยๆ


http://www.myturbodiesel.com/1000q/multi/wheel_alignment.htm

 
Logged

wasting money on VW since 1995.
Aeyvento
Sr. Member
****
Offline Offline

Posts: 380


vento 1.8 T manual


Email
« Reply #10 on: December 26, 2012, 11:23:46 PM »

 
Logged
KoNsHaRa
Staff
What da F Member
*****
Offline Offline

Posts: 19579



Email
« Reply #11 on: December 16, 2013, 06:18:20 PM »

Eibach Motorsport Catalog 2013
ตามไปโหลดเก็บไว้เป็นข้อมูล

http://performance-suspension.eibach.com/sites/devperformance-suspension.eibach.com/files/catalogs/ERS_18_US.pdf

เผื่อใครอยากจะ ปรับแต่งการทํางานของช่วงล่าง
ให้เหมาะสมกับสไตล์การขับของแต่ละคน
ซึ่งค่า K และความยาวของขดสปริงที่มากับ Coilover
ยังไม่เป็นที่ถูกใจเรา

 
Logged

wasting money on VW since 1995.
KoNsHaRa
Staff
What da F Member
*****
Offline Offline

Posts: 19579



Email
« Reply #12 on: January 06, 2014, 09:54:13 AM »

High-Performance Handling Handbook
คร่าวๆ

http://books.google.co.th/books?id=i2ZmgxbTS3AC&printsec=frontcover&dq=high+performance+handling+handbook&hl=en&sa=X&ei=IhvKUtzxIKGriAe1vYHADA&ved=0CDIQ6AEwAQ#v=onepage&q=high%20performance%20handling%20handbook&f=false

 
« Last Edit: January 06, 2014, 09:57:07 AM by KoNsHaRa » Logged

wasting money on VW since 1995.
porche360
Full Member
***
Offline Offline

Posts: 112


JDM! B5 1.8T (AEB)- B5.5 TDI -2.0TSI PASSAT CC


Email
« Reply #13 on: May 16, 2014, 11:19:13 PM »

 
Logged
KoNsHaRa
Staff
What da F Member
*****
Offline Offline

Posts: 19579



Email
« Reply #14 on: July 12, 2016, 10:05:20 AM »

Suspension 102

Understanding Vehicle Dynamics:

Friction circle: This is basically a vehicles performance envelope. It's expressed in lateral G’s, accelerating and braking G’s. When graphed, the friction circle looks like an egg with the X axis lateral G’s and the Y access braking and accelerating G’s.

Understeer: This is when, at the limit of vehicle traction, the front of the car slides first before the rear. Race car drivers call this "push". This is the way that many cars come set up to behave from the factory as it is the most predictable for average drivers. The crash mode for understeer is that when the limit of adhesion is exceeded, the car will plow strait ahead off the road nose first. This is not the fast way to have your car set up but if you are a dork mode driver. When the car understeers you should regain control if you let off the gas, unless of course you run out of road first. That is what air bags are for. Even my uncoordinated evil twin sister could get that right, maybe. It is not efficient for extracting maximum lateral G’s because the car will dynamically use the front tires excessively for turning, overloading them while the rear tires basically just hold the back of the car up. Front wheel drive cars like ours tend to exhibit understeer as the final terminal mode of balance.

Oversteer: This is when, at the limit of vehicle traction, the rear of the car slides first before the front. Race car drivers call this "loose". The rest of us call this "spinning out", "spinning a shitty", "doing a brodie" or even crashing. The final crash mode of oversteer is backwards, tail first into the woods or in the worst case spinning round and round with the driver as a helpless passenger. Since the infamous days of Ralph Nader and the Corvair, most auto manufactures avoid oversteer like the plague. Oversteer is difficult for a dork to handle because recovery requires judicious use of countersteering and throttle feathering to control; fine motor skills that only some of us can deal with. Although oversteer looks neat and macho it is really a slow way to drive except in pro-rally on the dirt which I don’t know too much about. Oversteer is slow on the pavement because hanging the tail out bleeds off a great deal of speed going through a corner. Conserving the momentum is the fast way around as turn.

Neutral: This is the fast way around a turn where all four wheels slide evenly. Since the total friction circle traction of each tire is being used, all the available grip that the tires have is being put to the ground. Racers call this "drifting". This not to be mistaken for the idiotic Japanese Option Magazine video stuff which makes a mockery of proper driving technique. Neutral is the fast way around a corner most of the time. Neutral is also the hardest handling mode to achieve for the suspension tuner.

Polar Moment of Inertia: Or PMI as we will refer to it, is a description of how a cars mass is distributed along the length of the vehicle. A car with a high PMI is like a rear engine, rear drive car like a Porsche 911 or a front engine, front wheel drive car like our beloved GTI, same thing only the poles are different, so to speak. A car with a low PMI would be a mid engine car like a Boxster. Low PMI cars have most of their mass about the middle, high PMI cars have the mass at one end or another. Low PMI cars are the easiest to get a neutral balance out of due to the balanced, centralized mass. High PMI cars like to oversteer, in the case of the 911 or understeer like our cars. To get a feel for this phenomena, hold a bowling ball in one hand and rotate it back and forth by twisting your wrist. Now get a set of dumbbells of the same weight, grab the middle of the bar and do the same thing. Bet the bowling ball wants to rotate easier right? Guess what type of car will be easier to get neutral!

Slip Angle: This is the wonderful thing that allows us to tune our cars suspensions despite the design limitations caused by the PMI. Proper manipulation of slip angle is the great equalizer and is what suspension tuning is all about. Slip angle is the difference in which a cars wheels are pointed vs the angle that the tires contact patch is placed on the road. The main thing that affects slip angle is the manipulation of the individual load placed on each wheel while cornering. This is the key for suspension tuning. A front wheel drive car has most of the weight on the front wheels. So the front wheels run at higher slip angles and develop understeer. Conversly the same for a rear wheel drive, rear engine car developing oversteer. That is also a reason why a mid engine car with equally loaded tires will be more or less neutral. Slip angles, weight distribution and PMI are the main factors in how a vehicle will handle.

Because our cars are front heavy, front tire overloaded, front wheel drive cars, does that mean that we are condemned to econobox hell for driving fun? Heck no! By design we can not change the basic layout of our cars to significantly change the PMI or weight distribution but we can sure tweek the slip angles of the tires to achieve world class handling out of our killer econo transportation units.

The easy way to tweek the slip angles are with anti-sway bars and springs. Shock absorbers, going against what people think that they do, are not really for changing the handling balance. Shocks mostly act as spring dampers and affect understeer/oversteer balance mostly only in transient (which is big word for a change from straight line travel to turning) maneuvers like initial turn-in and zig zaging around slalom cones.

Changing to heavier springs changes the slip angle differential by resisting the cars tendency to roll on the end of the car that they are installed on. The resistance of the heavier spring to compression causes more weight to be transferred to the outside wheel of the end of the car that they are installed on as the car tries to lean over in a corner. This causes that wheel to proportionally run at a higher slip angle than it normally would. If you put heavier than stock springs in the rear of your GTI while not changing the spring rate of the front, the car would tend to understeer less.

Antisway bars work in much the same way. Antisway bars are torsion bars attached to the cars chassis and are linked to the right and left control arms. Antisway bars offer resistance to independent side to side wheel movement. This is how these bars limit sway in the turns and hence their name. While limiting sway, the antisway bars also cause weight transfer to the outside wheels. By altering the diameter of the antisway bars or installing them where there were none before adds yet another chassis tuning element. If you were to increase the size of the rear antisway bar on an GTI you would be increasing the amount of weight transfer to the outside rear wheel, thus causing it to run a bigger slip angle. This would give you more oversteer.

Tire pressure also can affect the slip angle. Higher pressures reduce the slip angle and lower pressures increase it. A great deal of suspension tuning can be done for free by adjusting the tires pressure.

Alignment also has a great deal of effect on a vehicles handling balance. Caster and camber affect how a tires contact patch is positioned on the ground by compensating for a tires tendency to flex and lift the inside tread while cornering, By helping keep the tread flat, these settings can increase or decrease the available friction circle traction on an end of a car thus affecting balance. Toe in or out can affect balance also by changing how a vehicle turns in.

SUS 102 พอแค่นี้ก่อนนะจ๊ะ
Logged

wasting money on VW since 1995.
Pages: [1]   Go Up
  Print  
 
Jump to: