PROVEN CHASSIS                         Ron Miller Race Cars
 
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TECHNICAL HELP

INITIAL SET-UP

REAR FRAME HT.(measure from bottom of axle tube to top of chassis tube)(see pg 2 for frame ht. gauge)
RR 4 1/4 in.
LR-4 in.
REAR TRAILING ARMS---TOP LT. 10 DEG UP
                                      TOP RT. 1 HOLE UP FROM LT.
                                      LOWER RT. 7 DEG. DOWN
                                      LOWER LT. 5 DEG. DOWN
REAR SQUARE WITH LOWER FRAME /FRAME KICKOUT TO REAR AXLE 16 ½"
PINION ANGLE 5-7 DEG. DOWN.
5TH COIL 3 TURNS PRELOAD
PANHARD BAR -LEVEL @ 2 ½ IN. BELOW AXLE C/L( if mounted to right side)
J BAR 71/2" C/L ON FRAME MT AND LOWEST HOLE ON PINION MOUNT(if mounted to left side)
L.R. SPRING 225 LB.
R.R. SPRING 200 LB.
BOTH REAR SHOCKS 4 VALVE
5TH COIL SHOCK 3/7 VALVE/350 LB. SPRING (HARD/SLICK 400LB.)

FRONT FRAME HT.(measure from top of lower control arm to bottom of frame rail)
RF 3 ¾ in.
LF 31/2 in.
UPPER CONTROL ARM MOUNTS WILL MOUNT AT 4" ABOVE FRAME TO C/L OF BOLT
R.F. SPRING 400/ 425LB.
L.F. SPRING 500LB.
R.F.SHOCK 76/4 (DRY SLICK)
R.F. SHOCK 76 (HEAVY TRACK or ROUGH TRACK)
L.F. SHOCK 75
R.F. CAMBER-2 ½
L.F. CAMBER+1 ½
R.F. CASTER +3 ½ DEG.
L.F. CASTER+2
TOE-OUT 3/16 "
REAR PCT. W/O DRIVER -1/2 FUEL LOAD-54%
LEFT PCT. W/O DRIVER-53%
DIAGONAL W/O DRIVER 54 ½ -55 ½ PCT.
L.R. BITE WILL BE ABOUT 180LBS. WITH ABOVE PCT.
O STAGGER FRONT
3" TO 4" IN. STAGGER REAR

LR SHOCK BEHIND AXLE WILL PROMOTE BODY ROLL AND TIGHTEN CAR
LR SHOCK IN FRONT OF AXLE WILL ALLOW CAR TO TURN MORE EASILY IN MIDDLE OF TURN BUT WILL SACRIFICE BITE ON CORNER EXIT.
LOWERING THE PANHARD BAR WILL TIGHTEN CAR FROM MID POINT OF TURN THRU EXIT
RAISING WILL LOOSEN AT SAME POINT(when mounted to right)
RAISING J-BAR WILL PROMOTE BODY ROLL AND TIGHTEN CAR IN MIDDLE OF TURN(bar mounted to left)
MORE L.R. BITE (DIAGONAL WT.) WILL TIGHTEN CAR, BUT HIGH AMOUNTS OF LR BITE WILL LOOSEN THE CAR ON CORNER ENTRY.
INCREASING STAGGER WILL LOOSEN CAR ON EXIT AND WILL ALSO DECREASE L.R. BITE.
GOOD TIRES WIN RACES!!!

AFCO NOW MAKES AN RT SHOCK THAT IS DESIGNED FOR ROUGH OR HEAVY TRACKS. THEY ARE FOR USE ON THE REAR AND CAN BE ORDERED BY ADDING THS SUFFIX RT TO THE SHOCK NUMBER

SET-UP STICK DIMENSIONS



(1) TOP LEG 3 ¾ IN (2) BOTTOM LEG 3 ½ IN (3) OVERALL HEIGHT 4 ¼ IN. (outside dim.)

Make Gauge out of 3/8 inch steel dowel rod . Use top leg to measure frame ht. between frame and RF lower control arm. Use bottom leg to measure LF frame ht. at same points. Use overall ht to measure RR frame ht. between bottom of rear and top of rear frame lower bar. The LR ht. will fall between RF gauge and overall ht. gauge. The front height measurements are IMPORTANT, make certain they are correct. The RR ht should remain constant. LR ht. may vary slightly as LR bite changes are made.

2001 5 BAR CHASSIS

THE 5TH BAR IS USED TO TAILOR THE AMOUNT OF LR BITE THAT IS GAINED BY THE CHASSIS DURING BODY ROLL. THE 5TH BAR AT OR NEAR THE TOP OF THE ADJUSTER WILL PROVIDE THE LARGEST AMOUNT OF LR BITE DURING CHASSIS ROLL. INCREASING LR BITE WILL TIGHTEN THE CAR FROM THE MID-POINT THROUGH THE EXIT OF THE TURN. THE 5TH BAR ALSO SENSES REAR ROLL STEER RAISING THE TOP TRAILING ARMS OR RAISING THE RT LOWER TRAILING ARM WILL INCREASE REAR ROLL STEER.
HIGH CORNER SPEED TRACKS SEEM TO PREFER THE 5TH BAR AT THE MID-POINT OF ITS ADJUSTMENT. SHORT/ STOP AND GO TRACKS SEEM TO LIKE THE 5TH BAR UP AS WELL AS THE TRAILING ARMS.


TO TIGHTEN CHASSIS ON CORNER EXIT

RAISE 5TH BAR
LOWER RT LOWER 4 BAR TO LOWEST HOLE
LOWER TOP 4 BARS TO 3RD HOLE FROM TOP
RAISE J-BAR ON CHASSIS
USE EASY UP SHOCK ON RF (6/4)
LOWER J-BAR ON REAR END
INCREASE LR SPRING RATE
INCREASE RF SPRING RATE
INCREASE LR BITE
DECREASE STAGGER

TO LOOSEN CAR FROM MIDPOINT THROUGH EXIT OF TURN

LOWER 5TH BAR
RAISE RT LOWER TRAILING ARM
RAISE TOP TRAILING ARMS
LOWER J-BAR ON THE CHASSIS
RAISE J-BAR ON THE REAR END
DECREASE LR SPRING RATE
DECREASE RF SPRING RATE
INCREASE STAGGER
DECREASE LR BITE
INCREASE STAGGER

TO TIGHTEN CAR ON CORNER ENTRY

ADD DAMPER SHOCK ON TOP OF REAR
INCREASE LR BITE

TO LOOSEN CAR ON CORNER ENTRY

REMOVE DAMPER SHOCK FROM TOP OF REAR END
USE TIE-DOWN SHOCK ON LR (3/7)
DECREASE LR BITE

NOTICE THAT CHANGING BITE AND STAGGER ARE LISTED LAST. THESE ITEMS CAN SIGNIFICANTLY CHANGE SEVERAL HANDLING CHARACTERISTICS AND SHOULD BE DONE AFTER THE PRECEDING REMEDIES HAVE BEEN TRIED.

 

 

SHOCKS

Shock valving can be used to affect the racecar at different points in the race track.

The following chart will show shock changes, when they should be made and in what order.

Stage one: Early Entry
This is when you are off the gas and start applying the brakes, also you are starting to turn into the corner. How fast the transition from straight-aways to apex of corner will determine the effects of the LR shock, wide turns will require less rebound in the LR.

Shocks most affected :
RF-Compression
RR- Rebound
LR- Rebound
LF-Compression

How to tighten car:
RF- Compression (Dec)
RR- Rebound (Dec)
LR- Rebound (Inc)
LF-Compression(Inc)

How to loosen car up:
RF- Compression (Inc)
RR- Rebound (Inc)
LR- Rebound (Dec)
LF- Compression(Dec)

Stage two: Primary Entry
This is when you are decreasing the pressure on the brakes and increase the steering input into the corner
.
Shocks most affected:
RR-Compression
RF-Compression
LF-Compression

How to tighten car:
RR-Compression (Inc)
RF-Compression (Dec)
LF-Compression (Inc)

How to loosen car up:
RR-Compression (Dec)
RF-Compression (Inc)
LF-Compression (Dec)

Stage Three: Middle of Corner
This is the stage where the car takes a set, you start applying throttle and continue with steering input.
Shocks most affected:
RF-Compression
RR-Compression
LF-Rebound
LR-Compression
RF-Rebound

How to tighten car:
RF-Comp ression(Inc)
RR-Compression (Dec)
LF-Rebound (Inc)
LR-Compression (Dec)
RF-Rebound (Dec)

How to loosen car up:
RF-Compression(Dec)
RR-Compression(Inc)
LF-Rebound (Dec)
LR-Compression(Inc)
RF-Rebound (Inc)

Stage four: Middle of corner to exit of corner
This is the stage where steady power is being applied and steering has been reduced.In a lot of cases increasing the compression on the LRshock has tightened the car. Example: dry slick tracks.

Shocks most affected :
RF-Rebound
LR-Compression
LF-Rebound
RR-Compression

How to tighten car:
RF-Rebound (Dec)
LR-Compression(Dec)
LF-Rebound (Inc)
RR-Compression(Dec)

How to loosen car up:
RF-Rebound (Inc)
LR-Compression(Inc)
LF-Rebound (Dec)
RR-Compression(Inc)


The Important thing to remember is that you have to know the low and high speed valving of your shocks. Using Industry standards will not tell you what you need to know. Ex. 50# of force at 3" per second or 210# of force at 10" per second.

 

 

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