O.K., Here's most of the project. All that I could get. May not be in the right order, but, you get the idea. Pix would not come up when I C&P'd. If you want to see those, & there's a lot, you will have to google the article.
What kind of magazine would we be, if we had a mail-order makeover theme issue and didn't include Stylin' Concepts? Not a very thorough one. Well, that's not going to happen, so we logged onto Stylin's website and surfed around looking to improve our '94 Chevy truck. We had an idea to build this truck into a G-machine, but we still had to get the basic modifications out of the way first. Who cares how fast it will corner, if it looks like a pile of junk? We do.
The truck was customized back in the day, but somewhere in its life, most of the good custom stuff was taken out, leaving us a truck with a lot of potential. We chose projector beam headlights and LED taillights to bring us into the new millennium, along with a matching set of Crystal Clear turn signal lenses. To lower the truck's center of gravity and make it handle better, we opted for the 2/4 kit Stylin' Concepts offers
Now, this kit is not a slammed truck kit, but it will be a perfect balance between stance, performance, and functionality, or in other words, a daily driver. There are already custom wheels on the truck but in a 15-inch variety, and that will not hold up to our G-machine theme, nor will it give us any street cred. The wheels for said rolling stock are Ultra Wheel's new Hot Schott. These wheels are a Counter Pressure Cast one-piece construction that will provide plenty of rigidity and good looks to boot. Wrapping the Schotts is some high-performance rubber from Nitto. A set of NT-555s, size 295/45ZR18, will give us the 28-inch outside diameter that we need and the fat contact patch we want for traction.
Instead of getting our delicate editor hands dirty, we called in a favor and asked Shaughn Reid at Streetshock Advanced Suspensions in Redondo Beach, California, to install all of our parts. Since he loves us and we bribed him with a greasy cheeseburger lunch, he couldn't say no. So, follow along as we have Shaughn, Brian, Ryan, Lucky, and Sam install the Stylin' package on our future G-machine.
Here is our wheel and tire combo, assembled and ready to go. We chose a 295/45ZR18 tire from Nitto's 555 line because it features a 28-inch outside diameter, which is about the max we could run in front, even with this mild of a drop. By using a racing concept design, Nitto Tire's engineers developed the NT-555 Extreme ZR with a specially formulated compound for excellent grip. The Hot Schott from Ultra Wheels' Platinum line is a Counter Pressure Cast one-piece rim with a nice, easily maintained chrome finish. It's an 18x9-incher with a 10mm offset setup and features five-spoke styling that not only looks perfect on the truck but will also be plenty strong when we start slinging this truck around corners.
In the past couple issues, we have been throwing parts on an ex-'bagged '94 Chevy in the attempts to turn it into a daily driveable G-machine. The first month, we lowered the truck with a Stylin' Concepts 2/4 kit that consisted of coil springs for the front and a shackle/hanger kit for the rear. We also mounted up the kick-ass rolling stock from Ultra Wheel and Nitto Tire. The rims are a Counter Pressure Cast one-piece construction 18x9-inch Hot Schotts with a 10mm offset. Surrounding the Schotts is a set of Nitto 295/45ZR18 NT-555s, which will give us a whole lot of traction, thanks to the fat contact patch and the soft compound. Next, we took a trip over to Energy Suspension to have all the soft factory bushings swapped out with performance-minded polyuretthane bushings.
Energy's special formula Hyper-Flex performance polyurethane components feature a higher durometer (firmness) material that will last longer and deflect less to provide a solid base for our suspension. Now it's time for us to get rid of the excessive body roll in the truck and get this sucker to corner as flat as possible. Since this truck was an ex-'bagger, there were no sway bars to be found when we purchased it, so the body roll was beyond excessive. One name that is synonymous with the science of sway is Hotchkis Performance. The company has been improving the handing of almost every vehicle since 1993, and our truck is no exception, as the company has a front and rear bar kit just for it.
The 1-7/16-inch front Hotchkis bars feature lightweight hollow construction, while the 7/8-inch rears are a solid design. The kit includes greasable polyurethane bushings, endlinks, brackets, and all the necessary hardware to complete the install. The bars are powdercoated for durability, and tested and tuned to ensure the best performance possible. We drove to the Hotchkis facility in Santa Fe Springs, California, to have the crew install these bars, and so we could check out how the bars are made. That's right, they are made in-house.
Hollow vs. Solid
There are many advantages to using a tubular anti-roll bar rather than a solid bar. The foremost advantage is the weight reduction that can be achieved by using hollow technology. Second is design adjustability, because all you have to do is change the wall thickness of the material to give an incremental change in stiffness. There are many misconceptions floating around about the hollow bar designs. One major one is that a solid bar is stronger than a hollow one. This is only partially correct. If a solid bar and a hollow one of the same diameter are compared, then the solid bar is stiffer than the hollow version. By increasing the outer diameter of the hollow bar, and fine-tuning the wall thickness, you can yield the same performance while reducing weight. How many racing designers try to cut every ounce out of the chassis? They all do! Reducing weight acts like adding horsepower.
The chart displays the results of comparing a 1-inch solid bar to a 1-inch hollow bar with a 0.25-inch wall thickness. Compare the 1-inch solid directly to the 1-inch hollow bar. By removing a 1/2-inch hole from the center of the bar, the stiffness of the bar is reduced by only 6-1/2 percent. Anything less than a 10-percent change cannot be felt by most of the drivers out there. This results in a slight increase in stress by only 5.9 percent. (We assume all bars are manufactured using the same material and subjected to the same 1,000-pound load). Another thing to note when comparing these two bars is that the hollow bar weighs only 8.34 pounds, whereas the solid bar is 11.14 pounds. That's a weight reduction of 25 percent for this part, yet it only loses 5.9 percent stiffness.
Variable
1-Inch Solid
1 x 0.25" Hollow
1.062 x 0.188" Hollow
1.188 x 0.188"
Stiffness
333
312
350
429
%Increase
of Stiffness
-6.5
+5.5
+29
Stress
(KSI)
51
54
51
45
%Stress
Increase
+5.9
0
-12
Weight(lb.)
11.14
8.34
7.35
7.8
%Weight
Increase
-25
-34
-30
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1994 Chevy Truck Adjustable Shock Upgrade - Bad-Ass Shocks
QA1 Shocks and John Hotchkis Get Our Suspension Under Control
From the December, 2008 issue of Sport Truck
By Calin Head
Photography by Calin Head
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1994 Chevy Truck Adjustable Shock Upgrade - Bad-Ass Shocks
QA1 Shocks and John Hotchkis Get Our Suspension Under Control
From the December, 2008 issue of Sport Truck
By Calin Head
Photography by Calin Head
|
We are coming to the end of our transformation of an ex-'bagged '94 Chevy truck into a canyon-carving G-machine. We wanted to create a truck that could rip the corners with the best of them but not be so performance-minded it would be impractical to drive every day. It took some preplanning, good parts, and the hard work of some very talented people to help us accomplish our goal. So, read on, as we recap the prior stories and hopefully teach you what we learned about handling and how a good set of shocks is a must.
Step one, we dropped the truck to give it a lower center of gravity with a 2/4 drop kit from Stylin' Concepts that consisted of a new coil up front and a shackle hanger kit for the rear. Centrifugal force pulls at the center of gravity to lean the truck toward the outside of a curve, but by lowering it we reduced the leverage the centrifugal force has on the truck so we can push the truck harder through the corners. Step two was a wheel and tire combo that could provide the strength and traction we need and look good at the same time. We mounted a 295/45ZR18 Nitto NT-555 tire on an 18-inch Hot Schott rim from Ultra Wheel. This combo gave us enough sidewall to keep the ride smooth and an 11-inch-wide contact patch. This will provide plenty of nice soft rubber on the ground to hold the truck.
Step three was to have the 12-year-old rubber bushings replaced with a set of polyurethane bushings from Energy Suspension that will deflect much less, if at all. When you turn a corner, the bushing is subjected to increased load, and if the bushing deflects, then a lot of things can change, such as caster, camber, and the toe settings. Step four was to remove the lean or body roll the truck has when thrown around a corner. To do this, we installed a set of Hotchkis Performance sway bars, a 1-7/16-inch bar went on the front and a 7/8-inch bar went out back. The sway bars couple the left and right side of the suspension together and reduce body roll. When you go into a turn, the spring of the outside of the turn gets pushed upward or compresses. The arm of the sway bar travels upward with it, applying torsion to the sway bar that is transferred through the bar to the other side of the suspension, causing it to compress, as well. With these installed, the truck body stays relatively flat in the turn and increases our ability to corner faster.
Step five involved removing the slop from the steering system and reducing the amount of movement we had to make to the steering wheel to get the truck around a corner. An AGR performance steering box with matching pump cut about a full turn from our lock-to-lock ratio. Also, the feel of the wheel is much better; it is firmer without being tiring and allows us to make turns without removing our hands from the wheel. Step six of our buildup will go over the installation and tuning of QA1's kick-ass Stocker Star double adjustable shocks. These bad boys feature 24 positions of compression adjustment and 24 positions of rebound adjustment, providing 576 possible combinations to allow you to set them perfectly to your driving demands. Compression and rebound are controlled independently; when the compression knob is adjusted, rebound does not change, and vice versa. The shocks are constructed with a forged aluminum body, which we know is stronger than billet and a 5/8-inch hard chrome-plated piston rod. So the shocks will last longer, the engineers have developed a three-step sealing system that has a double-lip seal with wiper to keep the fluid in and the dirt out. Before the shocks are sent to you, they are 100-percent dyno-tested, and in the event something bad happens, the shocks are re-valveable and rebuildable by an authorized dealer, so you just go to the QA1 website to find one near you.
Because, as much as we would like to think so, we are not experts in shock tuning and these QA1s have so much adjustability we brought in a ringer to help. John Hotchkis has years of racing experience and suspension tuning under his belt, so when we asked, "Could ya give us a hand?" he simply replied, "OK." We went to his shop in Santa Fe Springs, California, to get the shocks bolted in place and have him tune them for overall street performance. We say street, because to tune them for the track is possible, but this truck will spend most of its life on city streets and highways that are way more inconsistent than a smooth track surface. Ever seen a speed bump or pothole on a track? We didn't think so. Read on, as we show you how they go in and how a professional gets the settings right.
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Driving the truck around John's makeshift route takes us over just about every obstacle you might come across in your daily drive. There is a set of raised railroad tracks, a few speed bumps, and numerous dips. John says, "This is the route I test all of my suspension kits on," so if it's good enough for him, it will work for us. Driving the route the first time showed us the shocks were just too soft; the truck did ride like an early Caddy but had almost no control when we hit the railroad tracks. It was time to turn the dials and really see what they could do to control the bounce. See sidebar for our notes concerning shock adjustment for this particular truck and how it reacted with each adjustment.
THE TEST DRIVE
John stated the best way to tune in a set of adjustable shocks is to start with the compression settings first and then move on to the rebound. Then, you can go back and make any minor adjustments to either, once you have a good base line. John also recommended we see what the range the shocks have, so that is why the first two adjustments will be 12 clicks (half way) and then 24 clicks (full).
Adjustment
Setting
Effect
1
C-F&B- 12 clicks
Less nose dive on braking - morereactive on the steering response.
2
C-F&B- 24 clicks
Can feel every imperfection inthe road. John stated, "You could feel a nickel if you ran it over,right now" The rear jumped out over tracks, meaning the tires left theground, which is not good. Tight steering response, which means yourbody bounces all over inside the truck.
3
C-F&B- 18 clicks
Responsive steering with nochatter over bumps. Comfortable ride, not too
sensitive, but not slushy - this works well.
4
R-F&B- 12 clicks
Stiffened up the ride - wordused harsh. Feels bouncy, John says, "That is the front and rear of thetruck fighting each other."
5
R-F&B- 24 clicks
Bouncy and hard on the abs, nota good ride at all for a street truck.
6
R-F&B- 8 clicks
Back feels good - feels likethere is not enough rebound in the front.
7
R-Fonly - 12 clicks
Perfect ride for the front.Tires are in control, with not a lot of bounce and great steeringresponse. Back now feels like it has too much compression.
8
C-Bonly - 14 clicks
Pleasant ride but bottoms outtoo easy.
9
C-Bonly - 16 clicks
No bottom-out but a littlebouncy.
10
C-Bonly - 15 clicks
Perfection, no bottom-out, andnot quite as harsh.
Key: C=Compression; R=Rebound; F=Front; B=Back
Final Settings:
Front:
C-18
R-12
Back:
C-15
R-8
In the past couple of issues, we have been throwing parts at an ex-'bagged '94 Chevy truck in the attempt to make it a G-machine. We started off by lowering the thing with a drop kit from Stylin' Concepts that consisted of a drop coil up front and a shackle hanger kit in the rear. That got the truck down enough to make the 18-inch Ultra Wheel/Nitto Tire combo visually work. The rolling stock features the new Hot Schott rim that is wide enough (9 inches with a 10mm backspacing) to hold the 295/45ZR18 Nitto NT-555 that will give us about an 11-inch-wide contact patch. This should be plenty of rubber on the ground to hold the truck, but we would have to get everything else up to par. So, we trekked over to Energy Suspension to have the 12-year-old rubber bushings replaced with a performance-minded set of polyurethane bushings that will deflect much less if at all.
Things were really coming together, and the truck was already feeling better, but there was still way too much body roll when we turned into a corner. We called John Hotchkis from Hotchkis Performance and picked his brain about what would be the proper sway bars for the truck. He recommended his company's 1-7/16-inch bar for the front and a 7/8-inch bar out back. Those results almost immediately made the truck handle flat and gave us a lot more confidence in the truck's cornering capabilities.
We were going to install a bitchen set of adjustable QA1 shocks and do the final testing on the rig, but the steering box was just worn out. No matter how good the truck could corner, we couldn't move the wheel fast enough to make use of it, plus with everything else being so tight now the steering wheel feel was just crappy. We decided to tackle the steering box issue first, and we knew the perfect company to call. AGR has been making quick ratio steering boxes for musclecars for a long time, and we have used the company's products on a few personal cars. The results were great back then, and when we logged onto the AGR site and noticed a quick ratio performance steering box for our truck, the click was made and the order was shipped.
What makes AGR's box better than a stock replacement? The first thing is the option on ratios. The company sells quick ratio boxes, not just replacements. The second selling point would be the steps AGR takes to make the boxes bulletproof and highly efficient. On top of all that, AGR also sells matching pump units for a total performance steering system.
The box features a newly designed total bearing control system that incorporates a specially machined casting, with a triple roller bearing arrangement that supports the sector shaft at both ends, eliminating excess side-play. The bores are mechanically polished to a fine-micron finish, and high-temperature seals are used throughout. AGR whittles out heavy-duty billet aluminum, finned end caps and the four-bolt top covers to provide better sealing properties and enhance the look as well. Internally, you will find oversize stainless guide balls, specially designed valves, and some special conversion work on each gear to improve performance and endurance. After all of that, each gear is 100-percent dyno-checked for pressure, balance, and returnability. Finally, each gear undergoes a fluorescent leak test, so you know your box is ready to install.
AGR also sells matching power steering (P.S.) pumps that have been put through the same steps the gearboxes received. Also, the company performs custom porting to ensure strong fluid flow, while providing a long and cool life. The bearings are custom-sized for maximum performance at any rpm, and each pump is 100-percent dyno-checked for pressure, response, and flow at varying speeds.
Combined with all that technology, you will have a steering wheel that feels like it's hooked to a true performance machine, not just a truck. When it's time to install the parts, be aware you will need to pull the power steering pump down to bare bones and unhook the steering arm. If you don't have the proper pullers and installing tools, you might want to either get some loaners or have a professional do it. The Sport Truck shop doesn't have those fancy pullers and such, so we went over to Streetshock in Redondo Beach, California, one more time and had Shaugn, Brian, and Ryan knock it out for us. These guys rock when it comes to anything suspension. The only complaint we have is the choice of tunes on the stereo. Two hours of Color Me Bad? Really? Next time, we are bringing music! All joking aside, if you are tired of moving the wheel a mile just to change lanes, then read on.
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There are a few procedures to properly bleed out the air from a power steering system, and AGR gives you a step-by-step breakdown in the instructions, but here is the gist of it. With either the front wheels off the ground or the steering arm removed (like ours), fill fluid reservoir to "full cold" level and leave the cap off. While an assistant is checking the fluid level and condition, turn the steering wheel lock to lock at least 20 times. While turning the wheel, check fluid constantly to ensure proper level and that no bubbles exist. If you see any signs of bubbles, recheck all connections then repeat the steps above. Once you have completed the lock-to-lock turns, start the engine and top off the fluid level. Reinstall the reservoir cap and return the steering wheel to center.
The Final Word
The steering of the truck is noticeably quicker and more responsive. We cut almost three fourths of a turn off the lock-to-lock ratio. Also, the feel of the wheel is much better, it is firmer without being tiring, and gives us the confidence to really throw this truck around some corners. Besides the seats and pedals, the steering wheel is what we as drivers are hooked to when we drive, and this upgrade has made it great. Check back next month, because we have a bitchen set of QA1 shocks to install and tune.
