StreetLegalTV.com:  “Project No Bucks” – Ultimate Chassis Renovation (May 7, 2010)

In previous installments, this 1991 Camaro, known as “Project No Bucks” has been treated to exhaust and tire upgrades as well as a 75-shot nitrous install and some ignition goodies. Each has had its due impact on the car’s quarter-mile performance, but now its time to update the two decade-old underpinnings of this F-body runner and improve on the archaic suspension pieces with some help from Spohn Performance and Lakewood.

Click here for the complete photo gallery of this build

The 1991 RS Camaro was picked up for an initial outlay of a mere $1500, and a staged project plan was developed for it. None of the individual stages were to cost more than the purchase price, an approach most of us would be taking unless Aunt Millie had passed on and left us a pile of 1957 IBM stock certificates.

Now, regardless how we’ll be enjoying this Camaro in the final stages, the importance of a sturdy chassis is paramount. Drag, autocross, or street performance all rely on the suspension doing its job, and all those years on the road have taken their toll on our Camaro’s underpinnings. This time around, we’re actually going to take on both the front and rear suspension so the $1500 limit is going to be stretched somewhat, but you could easily break it into two installments to budget it over a few more paychecks.

Greater than the Sum of its Parts

Our objective was to increase traction and handling for both street driving and dragstrip duty. While it’s certainly possible to source everything a la carte, we wanted to put together a complete package from one supplier to make sure everything would work together, and that’s exactly what we found from Spohn Performance. From the farm country of Pennsylvania, this father and son operation has developed as solid reputation for quality high performance components.


The complete front suspension, including a tubular K-member and A-arms, manual steering rack, and a coilover conversion including Lakewood struts.

When we talked with Steve Spohn, he was knowledgeable and willing to jump on board with a couple of our project cars. This Camaro is going to benefit from a number of Spohn products, including:

Mild steel tubular K-member – Fitted with coilover upper mounts, motor mounts, and Pinto manual rack mounts, the weight savings available from this piece alone makes it worth doing. Is a tubular K-member for you? We posed this question to Steve Spohn, and he told us, “It depends on how the tubular K-member is built and designed. There are many tubular K-members out there that are built to be as lightweight as possible. That type of K-member is designed to be used a quarter mile at a time. We have built all of our tubular K-members for street-driven applications, as that is our biggest customer base. We use larger OD and thicker wall tubing, heavier gauge brackets and incorporate extensive gusseting throughout. We have never had any durability issues with our K-members. They may weigh 5 or so more pounds than some other units on the market, but they are built for long term durability.”

Manual steering rack kit – Using a Ford Pinto steering gear, the old steering box and Ackerman linkage can be eliminated. Improved response and road feel result from the change and reliability is increased. The weight and complexity of the power steering system are also gone. So, is this going too far for a streetable car? Again, Steve Spohn schooled us on the topic. “The Pinto manual rack is really for the drag-only car or the drag/limited street car. With skinny tires on the front, the steering is still fairly easy. With stock size or larger tires on the front the steering is pretty easy once rolling, but at low speed parking you’ll work a little harder for sure. As I said, it is really for the drag car looking to drop weight.”

Tubular A-arms with Delrin spherical joints – The lower front control arms are going tubular as well. Weight savings is only part of the deal here. Fitted, in this case, with Delrin spherical joints, the suspension will be much firmer and more predictable, without sacrificing too much comfort on the boulevards. Also being completely adjustable, we can adjust for camber with these.

F-body tubular subframe connectors – Solidly linking the car’s front and rear subframes helps to eliminate flex during hard launches and even provides a more confident ride going to and from the track. These Spohn components are welded into the Camaro’s body and feature triangulation for even better results with minimal weight gain.

Front coilover suspension system, with QA1 2.5″ x 12″, 300 lb/in coilover springs – The modern design of a coil over front suspension simplifies movement and provides easy adjustability of ride height. Coupled with the tubular lower arms, the overall arrangement is light, strong and amazingly durable. This will also allow us to set ride height virtually anywhere we want it to be.


The rear suspension incorporates a new torque arm, lower control arms, Panhard bar, and anti-sway bar.

Drag rear sway bar – Power spent twisting the car on its suspension is power wasted, so the new Spohn sway bar uses hefty links and a large diameter bar to keep body roll under control. The axle tube brackets are also much beefier and come with brand new poly bushings.

Full length, adjustable torque arm – Replacing the factory original torque arm with a tubular version improves performance by increasing strength. The adjustability built into this piece gives you the ability to vary pinion angle to control the ‘bite’ of the rear tires.

Rear lower control arms, with Delrin spherical joints – Combined with the torque arm, the rear lower control arms form a three link structure to correctly maintain the axle position through its full suspension travel. Once again, the choice of Delrin spherical joints eliminates sloppy rubber bushings and improves control, but without sacrificing a kidney in the process thanks to a harsh ride. These are also adjustable for length.

Adjustable Panhard bar, with Delrin spherical joints – While the torque arm and control arms manage the fore/aft and up/down motion of the rear axle, side-to-side control is needed as well. The Panhard bar has only one purpose – managing lateral loads on the rear axle. That way, there is no compromise in geometry or performance. This piece also offers an adjustable joint for proper rear end alignment – something you won’t find in the stock version.

Lakewood Street/Strip Shocks

Also contributing to this stage of Project No Bucks’ development is the Lakewood division of Mr. Gasket. Lakewood shocks are the dampers of choice for many drag racers, having long established a reputation for performance and durability. Getting a solid balance between street and strip performance is important and this tried and true recipe does the trick. Up front, a set of Lakewood 70/30 Street/Strip struts will be pressed into service, while a pair of 50/50 shocks will look after the back end.

Since this is not a dedicated race car, the 50/50’s represent the best all-around choice with their ability to properly load the rear wheels to prevent over-reaction and wheel hop, while the 70/30’s promote rear wheel loading on launch. We asked Paul Grabowski, Marketing guru for Lakewood Shocks, about this arrangement.

“Lakewood Drag Shocks have been precisely tuned for superior weight transfer that remains consistent pass after pass. Additionally, the multistage valving provides more stability and control mid-track as well as reduced brake dive at the big end,” he told us. “90/10 front shocks and struts are intended for track use only and provide the maximum front to rear weight transfer, while 70/30 shocks and struts can be used for street/strip applications.” That’s just what we’re looking for.

Part 1 -Front Suspension Installation


Up on the hoist, you can see the potential weight savings that are available. There’s a lot of metal here, and cutting out the weight is like double-dipping. The car will go faster because it is lighter, plus the front end will be easier to bring up on launch, which gives better traction at the back tires. We might not be putting daylight under the front tires just yet, but weight transfer still helps make the most of the horsepower we already have.


Before going too far, the engine needs to be supported since the engine mounts are attached to the K-member. Once the engine is free of the mounts, wholesale removal of the front suspension can begin. The wheels and tires come off first, revealing the front struts bolted to the spindle assemblies, which also hold the brakes.


An impact gun and large wrench will make short work of this hardware, but you need to support the lower control arm with a floor jack first. This lets you safely drop the LCA when taking out the spring. Some people chain the spring first, in case it binds and pops out, which could be dangerous.


After disconnecting the sway bar link, the LCA can be dropped and the spring removed. Sometimes a little extra persuasion is needed to get it out of the seat. We’re going to take the LCA out entirely, so the brake hydraulic line has to be disconnected and a couple of large bolts removed where the arm connects to the K-member.


The OEM arms are thick stampings clearly designed to be inexpensive to produce in vast quantities, rather than with lightness as a priority. With both sides removed, it’s almost time to pull the factory K-member.


Because we’re upgrading this Camaro to rack and pinion steering, the current steering box and linkage are removed. Before finally unbolting the K-member, it has to be supported from underneath and a transmission jack comes in handy for that.


When all the stock components are off, you’ll have a pile that adds up to about 84 pounds. As you can see, working on an 18 year old car means dealing with fasteners rusted or seized – it’s all just part of working on an older vehicle.

Installing the Spohn/Lakewood Front Suspension Components

Though our Camaro is a California car and didn’t have multiple layers of undercoating or rust stalactites hanging off, we still took the opportunity to clean things up a bit before we started putting our new suspension back on.


This test fitting of the Spohn K-member went perfectly. Here you can see the new Pinto-style rack and pinion gear already installed. The durable powder coating will keep this hardware looking good for years, and because the K-member is designed to bolt up just like the factory piece, it’s actually a very simple swap.


Getting the front suspension together starts with assembling the front coil-over units. The Lakewood struts need a slight modification at the top of their housing in order to allow the threaded coilover spring perches to slip over the body. A moment with a die grinder is all it takes.


With the adjustable spring perch fitted to the strut, the spring goes on and we’re ready to fit it to the replacement upper strut mount.


At this point, the new lower control arm can be installed and the original spindle assembly mounted to the strut on top and to the ball joint on the lower control arm.


The work that remains up front is to repeat the same steps on the other side, then connect the steering rack’s input shaft to the column and the rack’s tie rod ends to the spindles.

Part 2 – The Rear Suspension

Out back, our primary goal is to trade the heavy, nonadjustable rear components for lighter, stronger pieces that will let us dial in the suspension. The combination of the torque arm and the lower control arms make for an unequal-length suspension like the kind you’ll find in the front of some cars, but in this case it’s turned sideways. The three arms provide longitudinal location of the rear axle, as well as controlling the vertical movement to minimize pinion angle changes on the axle.

The sole function of the Panhard bar is to control lateral movement of the axle. Having an adjustable bar allows us to center the axle housing in the car for a given ride height, because the axle will shift slightly from side to side with changes in ride height.


With the car up on the hoist and the rear axle supported, it takes just a few fasteners to remove the factory torque arm, which is bolted to the differential housing and pivots in a bushing attached to the tail of the transmission.


The original torque arm pivot mounted to the transmission housing has been replaced with a heavy duty Spohn unit. The OEM clam shell mount gets reused, though you will need to remove the old rubber bushing and backing to make room for the new polyurethane piece. The replacement torque arm is set in place and connected to the existing bracket on the axle housing, re-using the stock bolts.


The Spohn torque arm has a turnbuckle-style adjuster that allows you to set pinion angle without removing the torque arm from the car.


The lower control arms are just as straightforward to replace as the torque arm. Getting the old fasteners apart is likely to be the most time consuming part. Before we installed them, we set them to the same length as the stock pieces to have the proper baseline for alignment. Because they’re adjustable, it’s easy to square the axle to the car.


Before tightening down the front ends of the lower control arms, we have to connect one end of the tubular subframe connectors. These are going to add a lot of chassis structure and reduce twisting of the unit body during hard launches.


After preparing both the braces and the Camaro’s body metal, the connectors are welded into place. If you’ve never felt the difference subframe connectors can make, you’ll be hugely surprised at the result. The next step is to install the rear lower control arms and put the suspension back together.


What remains is mostly bolt-together work which includes installing the springs, shocks and rear sway bar. Everything’s designed to be easy to install using the stock mounting points, and to be easy to maintain for longevity in season after season of racing use.


Outside, you can see that we set the car to the same ride height as stock for the time being. This helps aid in our sleeper look.

A quick road manners check confirms that this Camaro is ready for just about anything. The Camaro is now lighter and stiffer thanks to Spohn and Lakewood. It not only rides better, but there is also a night-and-day difference in the reaction from a stop. The Camaro now transfers weight over the rear wheels and hooks solidly. Keep an eye out for future installments when we take our F-body to the track to show exactly how much these pieces helped.

Sources:

Spohn Performance
Phone: 1-888-365-6064
Web: www.spohn.net

StreetLegalTV.com:  “Project No Bucks” – Ultimate Chassis Renovation (May 7, 2010)


Frequently Asked Questions about Polyurethane:

What is Polyurethane?

Polyurethane is a term used to describe a wide ranging family of elastomers (any compound exhibiting the characteristics of natural rubber; stretchy and elastic.). Poly meaning “many” and “urethane” the classification of the chemical structure. Polyurethane or urethane for short, is used as a solid cast material (bushings). Polyurethane can be as soft as a rubber band or as hard as plastic.

Is there a benefit over rubber?

Many advantages can be found over rubber. Depending on the formulation, urethane has a higher load-bearing capacity, greater tear strength, better compression set, greater abrasion resistance, tolerant to greases, oils and ozone and allows for more unique designs.

What’s the difference between rubber and urethane?

Rubber is the sap of trees found mostly in tropical climates. The sap is altered by mixtures of carbon (why it’s black) and mineral oils and various fillers. Polyurethane is completely chemical or man-made. Because rubber is a biodegradable product it is affected by ozone and will over time dry rot and degrade, while urethane will keep going and going.

How are urethanes rated?

There are approximately 20 categories in which urethanes are rated based on physical properties. The most common is hardness. Others include: abrasion resistance; compression set; tensile strength; tear strength; etc.

How are bushings manufactured?

Most all urethane bushings and mounts are manufactured from a two part liquid cast system. It basically constitutes a polyol or prepolymer and a curative. Much like epoxy, when the two are mixed together, they begin to harden and form a solid material. This mixture is poured into molds where it forms the bushing, mount or pad when it turns a hard solid.Other ways include injection of melted urethane pellets. This is accomplished much like plastic injection moldingwhere the pellets are melted and forced through a small opening into a closed mold cavity. Another way is to cast a solid round bar and then machine it to the desired shape.

Is there a difference between colors?

No. In most cases the color of the part has no relation to the hardness or other physical characteristic. The pigment used to color our urethane components is a paste-like product that is mixed into the urethane in quantities of about 2-4%. You have your choice between red or black colors.

Does urethane squeak?

In a word, no. Squeaking is caused by high frequency vibrations that can be heard rather than felt. It is usually caused by lack of lubrication, poor installation, incorrect part, urethane that may be too hard for the application. In sway bar mount applications, most squeaking comes from not cleaning the sway bar prior to installing the bushings and not using our “squeak proof” grease! Additionally, all our dynamic application bushings feature grooves or splines to hold in our waterproof, highly adhesive, high temperature and pressure grease.

Does urethane ride really hard (harsh)?

The original rubber bushing or mount was fairly soft which helped to attenuate noise and vibration that is generated by the tires and road surface. Increasing the hardness of the bushing either with harder rubber, urethane or even bronze, will allow more transmission of noise and vibration. Some manufacturers formulate the hardness and design to reduce this effect. A softer urethane bushing allows the vehicle to perform better without the harshness, even over the same hardness rubber piece.

Are all urethane bushings the same? Same material, same hardness?

No, no and no. Each manufacturer has their own idea as to the best way a bushing should be designed. We select materials based on physical performance and choose the right hardness for each application.

Can urethane be used for all types of vehicles?

Urethane can be formulated for anything from an MG to a Cadillac to a rough and ready 4X4 or lowered Honda street car.

Do I need special tools to install?

No. Installing urethane components requires no special tools. However, if unique tools and equipment are required due to the type of vehicle, you will need them in order to do a correct job.

Will I need to reuse my metal shells?

We have a complete shell program for most popular applications. Many of our control arm bushing kits come complete with a new shell. On some applications you will need to reuse the metal shell, so be very careful when removing it from the vehicle. The shells themselves are not a replacement item. If you do damage a shell during the removal procedure, you have a few choices: Obtain a used piece from a repair shop or salvage yard or purchase a new shell with rubber bushings from your local parts store.

Spohn Performance offers a complete selection of direct fit polyurethane bushings for a variety of car and truck applications as well as performance suspension components. Visit us on the web at www.spohn.net.


Tech Article: Suspension Alignment Settings Explained

Posted by Spohn Performance | 04/12/10 | Tagged 4. Technical Articles

In our new series of technical articles we will address some of the most common questions our technical support group receives on a regular basis. Please leave your comments below this post with any suggestions you’d like to see us cover in future technical articles. These articles are being written to benefit you, so your input is greatly appreciated. Remember that you can always find our technical resources in the future very easily through our searchable online FAQ/Knowledgebase located at http://support.spohn.net.

Tech Article: Suspension Alignment Settings Explained

Camber:

Front End Camber Explained

Camber is the tilting of the wheels from the vertical when viewed from the front of the vehicle. When the wheels tilt outward at the top, the caster is positive (+). When the wheels tilt inward at the top, the camber is negative (-). The amount of tilt is measured in degrees from the vertical. Camber settings influence the directional control and the tire wear.

Too much positive camber will result in premature wear on the outside of the tire and cause excessive wear on the suspension parts. Too much negative camber will result in premature wear on the inside of the tire and cause excessive wear on the suspension parts.

Unequal side-to-side camber of 1 degree or more will cause the vehicle to pull or lead to the side with the most positive camber.

Caster:

Front Caster Explained

Caster is the tilting of the uppermost point of the steering axis either forward or backward, when viewed from the side of the vehicle. A backward tilt is positive (+) and a forward tilt is negative (-). Caster influences directional control of the steering but does not affect the tire wear. Caster is affected by the vehicle height, therefore it is important to keep the body at its designed height, or correct the caster setting when altering the vehicle’s height. Overloading a vehicle or a weak or sagging rear spring will affect caster. When the rear of the vehicle is lower than it’s factory ride height, the front suspension moves to a more positive caster. If the rear of the vehicle is higher than it’s factory ride height, the front suspension moves to a less positive caster.

With too little positive caster, steering may be touchy at high speed and wheel returnability may be diminished when coming out of a turn. If one wheel has more positive caster than the other, that wheel will pull toward the center of the vehicle. This condition will cause the vehicle to pull or lead to the side with the least amount of positive caster.

Lead / Pull:

At a constant highway speed on a typical straight road, lead/pull is the amount of effort required at the steering wheel to maintain the vehicle’s straight path. Vehicles will tend to lead/pull in the direction of the road slope as part of normal operation. Lead/pull is usually caused by the following factors:

  • Road slope
  • Variability in tire construction
  • Wheel alignment (front cross caster and camber)
  • Unbalanced steering gear
  • Electronic Power Steering (EPS) steering position and torque sensors not calibrated correctly, if equipped.

Memory Steer:

Memory steer is when the vehicle wants to lead or pull in the direction the driver previously turned the vehicle. Additionally, after turning in the opposite direction, the vehicle will want to lead or pull in that direction.

Scrub Radius:

Ideally, the scrub radius is as small as possible. Noramlly the SAI angle and the centerline of the tire and the wheel intersect below the road surface, causing a positive (+) scrub radius. With struts, the SAI angle is much larger than the long arm/short arm type of front suspension. This allows the SAI angle to intersect the camber angle above the road surface, forming a negative (-) scrub radius. The smaller the scrub radius, the better the directional stability. Installing aftermarket wheels that have additional offset will dramatically increase the scrub radius. The newly installed wheels may cause the centerline of the tires to move further away from the spindle. This will increase the scrub radius.

A large amount of scrub radius can cause severe shimmy after hitting a bump. Four wheel drive vehicles with large tires use a steering damper to compensate for an increased scrub radius. Scrub radius is not directly measurable by the conventional methods. Scrub radius is projected geometrically by engineers during the design phase of the vehicle’s suspension system.

Setback:

Setback applies to both the front and rear wheels. Setback is the amount that one wheel may be aligned behind the other wheel. Setback may be the result of a road hazard or a collision. The first clue is a caster difference from side-to-side of more than 1 degree.

Thrust Angles:

Thrust Angles Explained

The front wheels aim or steer the vehicle. The rear wheels control tracking. This tracking action relates to the thrust angle. The thrust angle is the path that the rear wheels take. Ideally, the thrust angle is geometrically aligned with the body centerline.

In the above illustration, toe-in is shown on the left rear wheel, moving the thrust line off center. The resulting deviation from the centerline is the thrust angle.

If the thrust angle is not set properly the vehicle may “dog track”, the steering wheel may not be centered or it could be perceived as a bent axle. Thrust angle can be checked during a wheel alignment.

Positive thrust angle means the thrust line is pointing to the right hand side of the vehicle. Negative thrust angle means the thrust line is pointing to the left hand side of the vehicle.

If the thrust angle is out of specification, moving the axle to body relationship will change the thrust angle reading. If the vehicle is out in the positive (+) direction, moving the right hand side forward and/or the left hand side rearward will move the thrust angle towards 0 degrees. If the vehicle is out in the negative (-) direction, moving the right hand side rearward and/or the left hand side forward will move the thrust angle towards zero degrees.

Toe:

Toe Settings Explained

Toe is a measurement of how much the front and/or rear wheels are turned in or out from a straight-ahead position. When the wheels are turned in, toe is positive (+). When the wheels are turned out, toe is negative (-). The actual amount of toe is normally only a fraction of a degree. The purpose of toe is to ensure that the wheels roll parallel.

Sample Front End Alignment Specifications:

2010 Chevrolet Camaro SS

Camber: -0.8* (+/- 0.75*)
Cross Camber: (L-R): 0.00* (+/- 0.75*)
Caster: 6.6* (+/- 0.75*)
Cross Caster: 0.00* (+/- 0.75*)
Total Toe: +0.20* (+/- 0.20*)
Steering Wheel Angle: 0.00* (+/- 3.50*)


The World Car Design of the Year award is one of the most prestigious automotive awards given out and is meant to highlight new vehicles with innovation and style that push established boundaries. A design panel consisting of five highly respected world design experts asked to first review each candidate, and then establish a short-list of recommendations for the jurors. The original list consisted of 30 different cars.

The three design finalists were the Chevrolet Camaro, Citroën C3 Picasso, and Kia Soul.

Congratulations to Chevrolet on a great design and a very fun 2010 Camaro!


Spohn G8 & 2010 Camaro Rear Suspension on LSXTV.com

Posted by Spohn Performance | 03/29/10 | Tagged 1. News Releases

LSXTV.com LogoLSXTV.com put up a nice write up on the Spohn Performance 2008-2009 Pontiac G8 and 2010 Chevrolet Camaro rear suspension components. To check out their article click here.