Penske SPA 7500 Series User manual

Penske Racing Shocks-The Mill House, Packington Hayes, Litchfield,
Staffordshire WS14 9PN
7500 Series Damper
Technical Manual
E-mail: [e-mail]
Tel: [phone]

Address: Penske Racing Shocks-The Mill House, Packington Hayes, Litchfield,
Staffordshire. WS14 9PN Page 1of 11
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Introduction
Thank you for choosing Penske Racing Shocks for your suspension needs!
Every Penske Racing Shock is 100% hand built and dyno tested for the best performance and
customer satisfaction. We stand by our products and routinely assist customers in getting
the best performance from their shocks.
Contents
The 7500 Series..........................................................................................................................2
Terminology:..............................................................................................................................3
To Set Ride Height.....................................................................................................................4
Dyno Graph Overview...............................................................................................................5
Damper Adjuster Guide.............................................................................................................6
Eyelet Adjuster.......................................................................................................................6
Sweep Style Eyelet Adjuster..................................................................................................7
Knob Style Eyelet Adjuster ...................................................................................................7
Compression Adjuster............................................................................................................7
Damper Track Tuning................................................................................................................8
Compression Adjuster........................................................................................................8
Rebound Adjuster...............................................................................................................8
Tuning Symptoms & Suggestions .........................................................................................8
Corner Entry Over Steer/Loose .............................................................................................8
Drag Racing Track Tuning ....................................................................................................9
Troubleshooting.......................................................................................................................10
Warning....................................................................................................................................10
Signs of Fluid.......................................................................................................................10
Loss of Gas Pressure............................................................................................................10
Service Recommendation.........................................................................................................10
Technical Support....................................................................................................................11

Address: Penske Racing Shocks-The Mill House, Packington Hayes, Litchfield,
Staffordshire. WS14 9PN Page 2of 11
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The 7500 Series
Thank you for your purchase of your new Penske Racing Shocks 7500!
The 7500-Series is compact with an internal successful shock line up. This is our most
economical multi adjustment shock, yet it still utilizes all of the standard Penske Racing
Shocks parts that are known for quality and repeatability.
Every Penske Racing Shock is 100% hand built and dyno tested for the best performance and
customer satisfaction. We stand by our products and routinely assist customers in getting
the best performance from their shocks. The same components in the 7500 DA are used all
over the world at the highest forms of Motorsport.
All of the fundamental attributes found in any Penske Racing Shock have been incorporated
into the 7500-DA including:
Standard Penske 55mm bore size which allows use of wide array of piston types.
Low-friction shaft and piston seals.
Hard anodized, 6000 series aluminium bodies and components for superior
durability, performance, and repeatability.
Hard-chromed 4130 main shaft with rolled threads for strength, durability, and low
breakaway friction.
Durable ACME thread body that allows quick adjustment of spring preload (.100” per
turn).
Simple, in-line design for lightest weight and ease of installation.
Winning heritage –Penske Racing Shocks continue to help our customers win races
and championships in all forms of Motorsport.
Hand built and tested for quality in the United Kingdom.

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Staffordshire. WS14 9PN Page 3of 11
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Terminology:
Body
Compression Adjuster
Ride Height Adjuster
(coil-over applications only)
Spring
Spring Retainer
(coil-over applications only)
(
Rebound Adjuster
Inflation Valve
Eyelet
Shaft Bearing
Shaft
Mono-Ball

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Staffordshire. WS14 9PN Page 4of 11
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To Set Ride Height
For coil over applications
Penske Racing Shocks does not set the spring preload on shocks that include coil-over
springs. You must set your ride height AFTER installing the shocks on the car. After your
ride height is set, tighten the 2 Allen screws (3mm Allen) in the spring perch to prevent
loosening. This does not need to be tightened too much –just nip up to prevent damage to
the body threads.

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Staffordshire. WS14 9PN Page 5of 11
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Dyno Graph Overview
When you receive a dyno sheet, it will display your damping curve in “Full Stiff”, “Full Soft”,
and shipped settings “Base Line”. You will notice the (‐) before the setting; this identifies
how many clicks off of full hard the adjuster was set to achieve this curve.
Typically the graph will have a “COMP” for compression and “REB” for rebound before the
setting. For 3-Way dampers Comp will be split into “LSC” Low speed Compression and “HSC”
High Speed Compression. High speed will have a how many clicks off of full soft.
Blow the graph show force against velocity average, this give a good general view of shocks
performance. The top section represents Compression and how lower negative section
represents rebound.

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Damper Adjuster Guide
Do not over-tighten the adjusters. When making adjustments, they will have a positive
stop. In order to close off the bleed, you do not need to continue to turn the knob for it to
seal.
Eyelet Adjuster –There are several options for the eyelet adjuster as displayed above.
This adjusted can be used for a 1-way rebound, compression and a combined rebound
compression adjuster. This eyelet adjuster is used for rebound as stander across most shock
models. It will be specified to you if this eyelet adjuster changes other damping
characterises
Turn the adjuster Clockwise will increase damping/ Stiffer, Turning it Counter-clockwise will
reduce damping softer. (Clockwise = stiffer, Counter-clockwise = softer)
A. Sweep Adjuster, operated by pick or pin. - 20 sweeps of adjustment. A sweep
is one radial movement of a pick or pin engaged in the adjuster the full throw
of the window
B. Hex Adjuster, operated by 4mm or 5/32 Alan-key. 48 “clicks” of adjustment.
C. Knob Adjuster, hand operation. 2 options 35 or 80 “clicks” of adjustment.
D. Stud eyelet / Shaft pin Alan-key fitting 3/32 Allen-key –4 ½ “revolutions” of
adjustment. We recommend making adjustments using ¼ turns. This is done
by inserting a 3/32 Allen Wrench down the centre of the shaft mount

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Staffordshire. WS14 9PN Page 7of 11
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Sweep Style Eyelet Adjuster
1.) Turn knob or screw clockwise to full stiff.
2.) Turn adjuster back “counter clockwise” to
desired settings. Typically this is shown as a
negative (-) settings. Example: Compression -5
clicks, Rebound -10 clicks/sweeps.
3.) During discussions on handling, if you were to
be instructed to “soften rebound by 5 clicks” it
would mean to adjust your rebound
counterclockwise by 5 clicks or sweeps,
depending on your adjuster.
Knob Style Eyelet Adjuster
This knob adjuster is hand operated, tuning it to (+)
making will increase damping making it stiffer. Twisting
it to (-) will reduce damping making it softer. 2 options
Compression Adjuster
Compression Adjuster uses the 4mm or 5/32 Alan-key this is located in the body cap. It
allows for 40 different positions of compression adjustment. The range of the adjustment is
dependent on what compression stack is used. A typical “B” compressions stack will have
about 150 lbs of adjustment range.
Clockwise = Stiffer

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Damper Track Tuning
Compression Adjuster
This adjuster is typically used when looking to improve the car over bumps. If your vehicle is
hitting a certain bump that is causing the vehicle to “unload” the tire, simply soften the
compression adjustment. This will allow the shock to absorb the bump, there keeping the
vehicle more stable and making the car more controllable.
You can also use this adjuster to help in controlling the “platform” of the car, or the body
roll. Example- If you are entering a corner and under braking the front of the car is diving to
quickly or the weight being transferred from the back to the front is too much, simply close
the compression adjuster on the front to slow that weight transfer down.
Rebound Adjuster
The rebound adjuster is a great tool for tuning body roll. This is a much more driver sensitive
adjustment than the compression. If you want to slow the pitch of your car from the back to
the front, simply close the rebound off, this will slow the weight transfer.
When you are accelerating off a corner, getting weight transfer to the rear tires is very
important for grip or “forward bite” as its referred to sometime. By softening the front
rebound, this will allow for quicker weight transfer to the rear tires, resulting is better rear
grip. Be careful though, by allowing to much weight transfer to the rear, you may cause a
loss of front grip, resulting in an “under steer” or “tight” condition.
Important!! You can over adjust. Always have a baseline to go back to!!!
Tuning Symptoms & Suggestions
Corner Entry Under Steer/Push
This typically is a result of too much front compression. Soften compression -5 clicks. Soften
the compression until you lose platform in the front of the car, or the front feels under
supported, then go back +2 clicks.
b. Soften rear rebound. Sometimes too much rear rebound will not allow weight to transfer
to the front which can cause and under steer condition.
Corner Entry Over Steer/Loose
Add rear rebound. You don’t want to take grip away from the front if you don’t have to. So
first work on the end of the car with the grip issue, in this case is the rear. Stiffen rear
rebound, if the rear is too soft, it will allow too much weight to transfer to the front too
quickly. By slow this, you will keep more weight on the rear, generating more grip, longer
into the corner.
Mid Corner Under Steer/Push
First try and determine if the chassis is taking a set, then going into under steer, or if it
under steers before taking a set.

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i. If it takes a set, then under steers, add compression to the front. This will support and
slow the weight transfer just enough to eliminate or help the condition.
ii. If the chassis doesn’t feel like it is taking a set, or feels like you not into the track, soften
the compression, this will make the chassis more compliant, allow weight transfer a little
quicker to the front tires and help increase grip.
Mid Corner Over Steer/Loose
a. Determine if it’s off throttle or on throttle. If over steer is induced when getting back to
throttle, soften rear rebound.
b. If over steer is coming off throttle, add rear rebound.
Corner Exit Under Steer/Push
a. Add front rebound, try and hold weight on the front tires longer increasing grip.
b. If it is still over steering, increase rear compression. This will balance out the chassis by
taking some grip away from the rear.
Corner Exit Over Steer/Loose
a. Reduce rear compression. This will allow quicker weight transfer to the rear tires, creating
more grip.
b. Reduce front rebound. This again will transfer more weight to the rear tires resulting in
more grip
Gas Pressure
Gas pressure is like spring rate. This is more used for a fine tuning adjustment. 50psi is
similar to 5-10lbs of spring rate. Adding more gas pressure is a common adjustment for
qualifying, when you need to get your tires to max operating temp very quickly. If you do
this, remember to reduce PSI before racing or shortened tire life may result.
Drag Racing Track Tuning
Normal adjustment steps for Drag Racing: Compression: Adjust 5 clicks at a time.
Rebound: Adjust 2 sweeps at time.
To Increase Bite: Soften compression or stiffen rebound. Example: hot and greasy track /
bald spots on starting line.
To Decrease Bite: Stiffen compression or soften rebound. Example: Track conditions are at
their best / starting line is covered with good rubber.
When using a pneumatic (air) bleed off eyelet: As each chassis and track is different, we
recommend consulting a Penske technician for help with the setting of timers and other air
bleed-off mechanisms.

Address: Penske Racing Shocks-The Mill House, Packington Hayes, Litchfield,
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Troubleshooting
Warning
Penske Racing Shocks recommends running no lower than 50 psi depending on piston and
shims being used. Lack of nitrogen pressure could result in “cavitation” which can result in
loss of immediate damping and rider feel.
We also do not recommend using pressure higher than 300 psi. This could result in stress
fractures in main mounting components which may lead to seal or other failures.
Always check with Penske Racing Shocks technicians on recommended pressures for your
application and use.
Signs of Fluid
If the area around the shaft bearing and shaft exhibits a small amount of moisture, this is
normal. In order to reduce friction in the system, seal squeezes are slightly relaxed which
serves the purpose to allow a small amount of fluid to be wicked onto the shaft when the
shock operates. If you see excessive amount of fluid that may “pool” on the top of the shaft
bearing, you may have a seal problem. Contact Penske Racing Shocks UK representative at
once.
Loss of Gas Pressure
If the shock for some reason loses its gas charge, a tell-tale sign of reduced or no gas
pressure is that the shock (without a spring) when compressed, will not return to its fully
extended position, or gradually gets much slower when reaching full extension. If you have
experienced a loss of gas pressure, Contact Penske Racing Shocks UK representative at once.
Service Recommendation
Pre-Race –Inspect for oil leak, Check nitrogen pressure
30 Hours of Track Time or Yearly - Change oil, Replace O-rings, seals and valve shims.

Address: Penske Racing Shocks-The Mill House, Packington Hayes, Litchfield,
Staffordshire. WS14 9PN Page 11 of 11
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Tel: [phone]
Technical Support
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[e-mail]
Open:
7:30 AM –4:30 PM Monday –Thursday
7:30 AM –1:30 PM Friday
Tel:
01543 434 580
Address:
Penske Racing Shocks
The Mill House
Packington Hayes
Litchfield
Staffordshire
WS14 9PN
Web:
www.penskeshocks.co.uk
www.spa-uk.co.uk