We have Direct Lift two- and four-post hoists in the Car Craft shop. The two-posters are a
Norman Willis; Dawson, IL: With This Guy's Garage, you have done a good job presenting a page that most aspiring car crafters definitely pay attention to. I find the car lifts quite affordable these days and personally have an interest in the one featured in the Nov. '10 issue (Tom Owens' garage). If you could interject in your articles some info on garage lifts, I think readers would find that helpful in planning and use in their garages. Thank you for the fine job.
Jeff Smith: Above-ground car hoists can be separated into three basic configurations of two-post, four-post, and scissor lifts. Let's start with the popular two-post style. This hoist places the car between two outside posts using arms that swing under the car after the vehicle is in position. This requires the operator to place the four arms under the car in the proper places. The most popular two-post hoist is the overhead style, using a beam that connects the two posts together at the top. The baseplate-style lift places a panel on the floor between the posts. It is less convenient for using undercar accessories such as a trans jack or tall stand supports since the plate is often in the way. Baseplate two-post lifts are most often used with low ceilings because the overall height of the lift is shorter. There is normally a beam or connector between the posts that connects the lifting cable or chain across both uprights.
Within the two-post hoist is the variable of symmetrical or asymmetrical arms. The most popular version is the asymmetrical: The front arms are shorter than the rears. With the arms folded back, the operator drives the car between the posts, and because the front arms are shorter, only 30 to 40 percent of the vehicle is placed ahead of the posts. This allows more room to open the door to exit the vehicle. It also allows the uprights to be placed closer together for space considerations. Because symmetrical hoist front arms are longer, they require the vehicle to be centered between the uprights. This reduces the clearance for opening the vehicle door to exit, requiring the posts to be farther apart. One disadvantage to the two-post hoist is that it is time consuming to properly set the four lift points on some vehicles such as medium-duty trucks because of their kick-up frame sections. There are also portable two-post hoists for small shops with limited floor space that can be stored when not in use. Garage Equipment Supply sells a portable Dannmar medium lift called the MaxxJax that will lift 6,000 pounds about 4 feet in the air. This independent-two-post hoist design uses compressed air instead of hydraulic pressure to lift the vehicle. Each post employs wheels that allow it to be moved when not in use.
The four-post-style lift is also called a drive-on lift, using two ramps that are supported by the posts. This simplifies placing the vehicle on the hoist but hinders work on tires and suspension because the car must then be lifted off the ramps with a second hydraulic or pneumatic jack. Four-post hoists also tend to cost more than two-post versions because of the extra material and mechanics. But an advantage is that many four-post hoists only require a 115-volt power supply. All the two-post hoists we looked at require a 220-volt, single-phase power supply with a minimum of a 30-amp circuit. Keep in mind that most home garages are not equipped with 220-volt service, which will add to the cost of installation. Another advantage to four-post lifts is that some versions offer optional casters that make the hoist portable within the shop.
There are safety labels on all hoists. This is my favorite: generic man scooting out of th
Four-post hoists are most often used when additional vehicle storage is desired. Even with an 8-foot ceiling, it is possible to stack two cars (depending on their combined height). Keep in mind that while the post height will probably clear an overhead garage door when open, the upper vehicle must also be able to clear the door. If you happen to own a GT40 (that's only 40 inches tall) or any low vehicle like a Corvette, then placing it on top would be an advantage. The typical muscle car is somewhere between 50 and 55 inches tall. Unless you are one of the few car crafters in the world with a vehicle that doesn't leak, you'll also want to invest in a drip pan (or two) to protect the lower car.
The third version of vehicle lift is the scissor hoist. This style can either be a drive-on- or four-arm-style hoist. The scissor lift is most commonly used as a midlift-style hoist that is mainly used for wheel service in which full-height access underneath the car is not required. There are also scissor-style hoists that can lift the car high enough to work underneath while standing upright.
If you are at a point in life where you no longer want to work on cars lying on your back, struggling to get that automatic trans back in place, then there are some important questions to answer about fitting a hoist in your garage. Do you have sufficient ceiling height to accommodate a 72-inch undercar height? Garage rafters may have to be modified or moved to make this happen. Do you want a two- or four-post hoist? Is the concrete in your garage floor thick enough? The minimum requirements are generally 4 inches thick using 3,000-psi concrete with no cracks within 36 inches of the baseplates. Will your hoist require 115- or 220-volt power, and do you have sufficient power in your garage to run this hoist at the same time that perhaps your compressor is running? And finally, do you have enough friends who will help you unload a brand-new Dannmar machine from the truck when it shows up? A four-post, drive-on hoist can weigh 1,700 pounds or more. You won't be moving that by yourself unless you own a forklift.
Consider, too, that once you own a hoist, the fun has just begun. You're also going to need a high-quality hydraulic trans jack and some way to get that monster 4L80E up on the trans jack. You'll also need at least two tall, sturdy, adjustable stands to support the rear axle or exhaust system while you work under your hoist. Finally, you're going to need a nice, big dry-erase calendar where all your friends can choose dates and times when they'll want to use your hoist. The good (or bad) news is you will quickly become the most popular car guy in the neighborhood. This might demand a small waiting room with a couch, a refrigerator, and HDTV for the throngs of hoist hopefuls. Tell 'em they have to buy their own cold drinks, chips, and salsa.
Direct Lift; Madison, IN; 866/347-5438; www.DirectLift.com
Garage Equipment Supply; Moorpark, CA; 800/261-7729; www.GESusa.com
Greg Smith Equipment; Indianapolis, IN; 800/262-1950; www.GregSmithEquipment.com
High-Tech Data Logging
Chris Sommerfeld; Edmonton, Alberta, Canada: Can you please tell me which data-acquisition tools and procedures you use to record slalom, skidpad, and braking distance? I would like to record my own testing of the typical magazine tests to track progress on my car, but I can't find which systems will do what I need.
Jeff Smith: I would love to tell you that Car Craft has this very sophisticated and expensive data-acquisition system with a team of engineers dressed in white lab coats to help us with the testing. But frankly, what we do is barely one step above using a stopwatch. Let's go over some of the simpler ways to measure performance and then you can come up with ways to spend the money to do more if you so desire. There are some very cool systems out there.
Let's start with skidpad numbers, how to measure them, and what they really mean. The skidpad is generally a 200- or 300-foot circle that the vehicle negotiates as quickly as possible. The lap time is then converted to a lateral acceleration number that is commonly referred to as the g number. Keep in mind that this is an average g number. Typical vehicle-mounted accelerometers will produce much higher peak numbers. These peak g numbers can be far above an average g number created on the skidpad. We've seen street cars that can pull a peak g number well above 1 g, but it's tough for that same car to come close to that on an average g. When testing on a given circle, it's important to straddle the circle with the center of the vehicle. Testers will often cheat by placing the outboard tire on the circle, reducing the diameter of the circle by a couple of feet, which improves the lap time and increases the average g number. Here's the formula: lateral acceleration = 1.227 x (radius of circle/time2). Let's say we have a 200-foot circle and our best lap is 11.5 seconds. We plug these numbers into the formula: lateral acceleration = 1.227 x [100/(11.5 x 11.5)] = 0.927 g.
The skidpad is an indication mostly of tire traction since the suspension is already loaded, so the shocks are not contributing much to vehicle performance. This is more a test of spring rate, front or rear suspension design, and tuning and how well each end of the car works in relationship with the other. The g-force is limited to the speed at which either the understeer or oversteer is manageable. Ultimately, a better suspension and stickier tires will increase the speed and therefore the average lateral g number.
A better evaluation of the entire suspension is the slalom test in which several cones are spaced a given distance apart and the vehicle is driven as quickly as possible through them to achieve its highest average speed. Our slalom tests are done with seven cones spaced 70 feet apart with the course length at 420 feet. The higher the average speed through the course, the better the car handles. Testing with a stopwatch is a low-tech way to accomplish this but is fraught with inconsistencies because the timer must be accurate with his reactions. We use a Brower Timing Systems portable, wireless system with sensors that trigger when the car enters and exits the slalom and send the data to a handheld receiver. This is a relatively simple, wireless system that eliminates timing inaccuracies. The biggest drawback to this particular test procedure is that there is no standard distance or number of cones that must be negotiated. Each magazine or test organization has its own procedure and slalom distance, which makes comparisons difficult.
However, this type of test gives us a great baseline from which to do evaluations on modifications to the suspension and is a great tool for vehicle response to dynamic suspension loading. Basically, it consists of a series of aggressive lane changes, which loads the suspension harder as the car nears the end of the course. Often, this results in severe oversteer or understeer situations. Of course, hitting a cone results in a time penalty and negates the run. An onboard electronic accelerometer can accompany this type of testing to evaluate instantaneous g-loads and would be of some benefit, but the elapsed time is the most valuable test, since that represents that car's ability to maintain a high average speed throughout the entire course.
If you are looking for high-tech gadgets that will give you information it would take a week of analysis to decipher, there are plenty out there. On the affordable side, there's a company called Tesla Electronics that makes a windshield-mounted accelerometer that with the drag racer model (DR) will give you 0-60-mph, eighth-mile, quarter-mile, 0-100-0 runs and calculate torque and horsepower based on the acceleration rate and weight of the vehicle. Tesla also makes the G-Tech Pro EGS (expandable gauge system), which is a tachometer that is expandable to offer inputs like air/fuel ratio. There is also an accelerometer that can deliver acceleration and stopping distances. During the El Toro Pro Touring race last year, Baer Brakes used an older G-Tech Pro system to measure the overall acceleration and braking runs that effectively were 0-100-0 runs. To record a full run, the system requires the driver to maintain consistent braking pressure throughout the run. If you lift off the brakes, the system thinks the run is over and stops recording. The G-Tech Pro road race (RR) model is a little more money but will track g-force in both longitudinal (acceleration and braking) and lateral (left and right) directions plus rpm and it will generate a friction circle. The friction circle is a round graph that represents all four acceleration modes with a cross-hair (the math geeks call this an X-Y coordinate) in the center. With the vehicle at rest or not accelerating, the indicator is centered. If you accelerate, the indicator will track down. If you brake, the indicator will track up. If you turn left, the indicator will move to the right (force of acceleration) and the opposite direction when you turn right. A combination of braking and turning left will place the indicator in the upper righthand corner of the friction circle to indicate the combined forces of that action. Concentric circles placed outward from the center of the X-Y centerline will indicate 1 g and (depending on the accelerometer) perhaps as much as 2 or even 3 g's (for race cars). Did you know, for example, that Indy 500 cars at the Speedway regularly pull as much as 4 g's in the turns? The RaceTech Pro RR is affordable at only $299 for as much data as it delivers, but there are other data loggers out there.
The hottest thing right now is the combination video cameras/GPS/accelerometer data recorders. There are several units, such as Motorsports Camera, Stack DVR, SmartyCam, and Chase Cam models that deliver video and audio input from one or sometimes two cameras while displaying configurable on-screen graphics with data such as rpm, a real-time friction circle, throttle percentage, a brake indicator, vehicle speed, lap number, position on track, and lap times. Perhaps the biggest bang for the smallest buck is the Motorsports Camera unit, which offers a windshield-mounted camera along with GPS location for track mapping and a three-axis g-meter for $315, including shipping. Prices for the other models vary from around $500 up to $1,100 and more. The more expensive models obviously do more, and it may seem like a hefty investment for a little feedback as to how well your car handles. But most of these units are best used for reference and study after the race to compare changes with the suspension and to improve driver skills. With driving classes costing $3,000 and up, an investment of $1,500 is a comparatively good deal.
AIM (SmartyCam); Lake Elsinore, CA; 951/674-9090; www.AIM-Sportline.com.
Brower Timing Systems; Draper, UT; 801/572-5540; www.BrowerTiming.com.
Chase Cam; San Diego, CA; 858/397-1777; www.ChaseCam.com.
Motorsports Camera; Tucson, AZ; www.MotorsportsCamera.com.
Tesla Electronics; Pacific Palisades, CA; 310/230-0040; www.GTechPro.com.
In The Clutch
I was talking with Will Baty of Centerforce the other day, and he gave me some great information on seating a brand-new clutch and why this is so important. If you think about it, a clutch operates in many ways like a disc brake. We have a friction material (the clutch disc or brake pad) that is pushed in direct contact (pressure plate clamp load or disc brake clamp force) with a rotating friction surface (a flywheel or disc brake rotor). New brake pads should be properly bedded to obtain the maximum coefficient of friction performance, and the same is true with a clutch disc. Will used the example of a typical Centerforce 101/2-inch-diaphragm clutch for a small-block Chevy. Centerforce has a machine that will measure the actual clamp load of a given clutch in lb-ft of load. Using this machine, the company has determined that a brand-new 101/2-inch clutch assembly right out of the box will hold 400 lb-ft of torque. If the clutch disc friction material is properly seated (bedded) to the flywheel and the pressure plate, the load capacity increases to 520 lb-ft. That's an impressive increase of 30 percent. If excessive heat is applied to the clutch and the disc becomes glazed, then clamp load capacity drops to barely 310 lb-ft, which is less than its out-of-the-box capacity. This illustrates why it's so important that the clutch be properly seated.
Centerforce recommends a typical street clutch be driven for 500 miles before it is used in a drag race-style load application. This mileage figure might be a bit high, but the idea is to use the clutch in normal street operation without applying full load until the clutch has a chance to transfer some of the friction material from the disc to both the flywheel and the pressure plate. This is exactly the same idea behind bedding brake pads in which a portion of the friction material is transferred to the brake rotor to improve the overall coefficient of friction. According to Will, even 200 to 250 in-town miles will do a good job of transferring material to the friction surfaces and allow the clutch to properly seat.
Earlier, we mentioned glazing, which is what happens to a clutch disc (or a brake pad) when excessive heat is applied to the friction material. Will says most street Centerforce clutches like to operate in the 180- to 220-degree-F heat range. He says the friction material is stable up to around 350 degrees, but its ability to hold torque is reduced at higher temperatures. The clutch's friction material is happiest and enjoys its highest coefficient of friction in the 200-degree-F range. This figure will change with different friction materials. As the temperature increases, the resins that help bond together the different compounds begin to melt, causing the resins to leach to the surface of the clutch disc. You can actually see the result of the resin melting on a clutch disc because the friction surface will become shiny and much more reflective. At that point, the disc is ruined and must be replaced.
The friction material is the key to how well a clutch works. The best street clutch uses a friction material that increases the torque capacity while still allowing smooth operation with minimal chatter or harsh feedback during normal street use. The other variable when designing a clutch (or a disc brake) is surface area and/or clamp load. One way to increase torque capacity is with a twin-disc clutch, which has become very popular lately as an easy way to increase torque capacity while maintaining a comfortable pedal effort. Adding a second clutch disc while maintaining the same friction and clamp load effectively doubles the torque capacity. So this is what allows Centerforce to claim that the company's dual-disc clutch can hold up to 1,200 lb-ft of torque. In an abbreviated format, that is the essence of clutch operation and why properly breaking in a clutch will pay off in terms of far better performance. That's why you spend the money for good parts.
More Info; Centerforce; Prescott, AZ; 928/771-8422; www.Centerforce.com
Low-Tech EFI Pump and Return Solutions
Mac Miller; Portland, OR: Another solution to the return fuel line question posed by Michael Dalton in the Nov. '10 issue is to run the return line to the fuel tank filler tube. I did this on my '66 El Camino when installing an Edelbrock EFI system. I removed the fuel filler tube from the car, installed a return line fitting low in the tube in an unexposed position, and sealed the fitting with MarineTex epoxy, a readily available adhesive made for fuel and vibration environments. After reinstallation, I drove the car for years with no problems. This is a pretty low-tech solution, but it was convenient, safe, and kept the return flow of fuel as far from the fuel pump intake line as possible.
Cristian Klinefelter; Bloomington, MN: Michael Dalton wrote about his '82 Chevy pickup and a fuel system for adding TPI. I installed a TPI in my '78 K20, and while researching the fuel delivery system, I learned that '86 C/K trucks offered FI available with an in-tank fuel pump. The TBI pump only runs on 10 to 15 psi, but the stock TPI F-body pump has the same dimensions and fits in the C/K TBI sending unit. I used a new tank and sending unit for the '86, installed the '88 F-body TPI fuel pump, and used the vapor line as my return. It has worked fantastically for the last seven years. Just thought I could help a fellow car crafter.
Jeff Smith: This just shows the resourcefulness of Car Craft readers. Great job, guys.
Here is a Trosley cartoon of our upcoming Dodge Demon project. We don't know whose mummy that is.
This is dangerous. The slicks on Ted Toki's '55 were old and starting to crack. Then we noticed the word blem stenciled on the side. We were lucky it didn't detonate at 600 rwhp. Don't try this at your dyno day-the operator will likely expel you.
We spotted this Carrillo fastener on an engine parked at Westside Performance waiting for final assembly. A 7/16-inch rod bolt like this one has infinite torquing capacity if you use a stretch gauge, a 285,000-psi tinsel strength, and costs $50. That's $800 in rod bolts for your small-block Chevy.
This is the left-side timing chain tensioner and guide from the 4.6L Ford in John McGann's Crown Victoria. There should be no hole in the guide, and the yellow plastic coating should reach the end of the guard. Over 166,000 miles, the chain ate through the guide and began wearing the tip of the tensioner piston.
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