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October 2013


UNDER THE HOOD/////////////////////12

Stopping a Fuel Shortage Solving cranking, no-fuel or insufficient-fuel driveability problems on late-model vehicles can be challenging, especially if you don’t take into account the way that modern fuel systems operate. Discover how fuel systems have evolved and what you need to know to diagnose fuel delivery problems.


UNDERCOVER///////////////////////// 24

Connecting the DOTs on Brake Hydraulics Neglected brake hydraulic systems can cause an expensive warranty comeback or, even worse, a serious traffic accident. Gary Goms explains why it’s important to advise a potential customer of the importance of servicing and repairing worn brake hydraulics.

24 Babcox Blue

ENGINE SERIES ////////////////////////32

Release the Beast Carl Fausett, a member of the Society of Automotive Engineers (SAE) and CEO of 928 Motorsports, LLC, details what it takes to build a Porsche record-setting Bonneville salt flats racer.


FIND US ON facebook. Become a fan at: Did you know you can follow Tomorrow’s Tech on Twitter? Just go to and enter “follow” for news and updates!


October 2013 |

Career Corner: Tips to Gain More Pay in the Shop


Finish Line: Clean Car Competition


Service Advisor: TPMS Tips


TT Crossword


Report Card: Audi’s Nanuk Quattro Attacks Any Road Surface


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Tomorrow’s Technician (ISSN 1539-9532) (October 2013, Volume 12, Issue 7): Published eight times a year by Babcox Media, 3550 Embassy Parkway, Akron, OH 44333 U.S.A. Complimentary subscriptions are available to qualified students and educators located at NATEF-certified automotive training institutions. Paid subscriptions are available for all others. Contact us at (330) 670-1234 to speak to a subscription services representative or FAX us at (330) 670-5335.

4 October 2013 |

Career Corner sponsored by

Money Market:

Tips to increase your pay as an auto technician


he median salary for auto technicians today is roughly $36,000, according to US News. AutoProJobs wants to help techs earn a comfortable living by working smarter. Here’s our advice on how to be as productive as you can so you can earn a bigger paycheck. Continue To Keep Up With Trends: Certifications and attending classes are a great way to keep up-to-date with trends and best practices in the automotive industry. Check out our article on why earning an ASE certified is so important if you’re an automotive technician. ( Network Around the Shop: It’s easy to overlook the importance of networking with other employees around the shop, especially if your pay is commission-based. If you develop good relationships with key people like the service writers, you could see more business come your way. Be Productive: Eat your breakfast at home and leave the coffee sipping to breaks. Your main concern when you get to work is to deal with the morning rush that shops tend to have. If you waste time getting your day started, you’re cutting your earning potential. Be Good at Customer Service: Be personable and approachable. Take time to answer questions from the customer and give out your business card.


October 2013 |

If you don’t have business cards, invest in some. Customers will remember your name and request you next time if you stick out in their mind as someone who takes care of them. Brand Yourself: Branding yourself is really about becoming really, really good at one thing and then becoming the go-to person when people need help. Pick out a certain car part that you’re an expert in, or a certain make or body style. If you love working on German cars, speak up and talk about them. Be the person who gets to talk to all customers with German vehicles. You’ll find a niche that will make you indispensable at the shop. Make a Sale: Your job is to know cars best and predict what will go wrong with them. Use that knowledge to sell to the customer and advise the person to keep up with preventive maintenance. Make the sale by stating the facts: “Your car is getting close to 100,000 miles, its timing belt will soon need to be replaced. Would you like to set up a date and time to replace that belt with me today?” You’ll see more return business come to you if you’re making the sale. Making more money as a technician isn’t about working hard, it’s about working smarter. Be the most productive and the most connected technician in the shop, and you’ll see more business come through your hands than you’ll know what to do with. ■

edited by Tomorrow’s Technician staff Each month, Tomorrow’s Technician takes a look at some of the automotive-related student competitions taking place in this country, as well as the world. Throughout the year in “Finish Line,” we will highlight not only the programs and information on how schools can enter, but we’ll also profile some of the top competitors in those programs. Because there are good students and instructors in these events, we feel it’s time to give these competitors the recognition they deserve.

UW STUDENTS COMPETE IN CLEAN CAR COMPETITION Competitors gain hands-on experience creating a cleaner more efficient vehicle.


coCAR 2: Plugging in to the Future, is a three-year collegiate student engineering competition and the only program of its kind. The competition's mission is a vital one: offer an unparalleled handson experience to educate the next generation of automotive engineers while striving to minimize energy consumption and reduce emissions in the next generation of automobiles. EcoCAR 2 builds on a proud 23-year history of DOE Advanced Vehicle Competitions that exemplify the power of public/private partnerships in providing invaluable experience and training to promising, young minds readying to enter the job market. Representing the University of Washington, the UW EcoCAR2 team consists of engineering, communications and business students competing in the EcoCAR 2 competition. Over three years, the team will have modeled the vehicle and potential drivetrain architecture, built a showroom-quality hybrid vehicle, and launched an exhaustive outreach program intended to educate consumers on green vehicle technology. With the University of Washington's background in environmental science and transportation technology, the team is confident in its ability to excel in this competition. The University of Washington has extensive experience in advanced vehicle technologies. From developing composite materials for Boeing to designing a carbon fiber monocoque for


October 2013 |

Lamborghini, University of Washington engineering students have the tools to succeed in pushing the envelope. However, since this is UW's first time participating in an advanced vehicle technology competition (AVTC), a dedicated EcoCAR program is being built from the ground up. The UW EcoCAR2 team's goal is to create a laboratory for ongoing alternative fuel research beyond the scope of the competition. The UW Advanced Vehicle Works is born.

RECORD NUMBER OF STUDENTS CASH IN FOR SCHOLARSHIP AWARDS A record-setting 250 awards totaling more than $260,000 were presented through the Global Automotive Aftermarket Symposium (GAAS) scholarship program for the 2013-2014 academic year. The University of the Aftermarket Foundation funded 115 of the 250 scholarships for 2013. The GAAS Scholarship Fund, supported by attendees at the annual event, its donors and sponsors, funded 69 awards, 10 of which were funded through a grant from the University of the Aftermarket Foundation. State automotive aftermarket groups and other industry organizations funded an additional 76 scholarships. Awards ranged from $500 to $5,000. The full list of 2013 scholarship recipients has been posted to the scholarship website “alumni” page In its 16 year history, the GAAS Scholarship program has presented more than $1.8 million in awards to more than 1,800 students. The site provides “one-stop shopping” for students seeking post high school educations to prepare for a career in the automotive aftermarket, whether at two-year community colleges, ASE/NATEF certified vocational/technical schools, or four-year colleges or universities. Online applications are being accepted now for the 2014 Global Automotive Aftermarket Symposium (GAAS) scholarships, University of the Aftermarket Scholarships, and awards from collaborating organizations beginning now. The application deadline is Monday, March 31, 2014. For details, visit

U OF M LOOKS TO FIRST WORLD CHAMPIONSHIP Students who serve on the University of Michigan's top-ranked Solar Car Team say this could be their year for a world championship. The U-M's team — currently No. 1 in the U.S. — is currently competing against 25 others schools from across the globe in the Bridgestone World Solar Challenge, a weeklong, 1,800-mile trek across the Australian outback.

For the past quarter century, the race has happened every other year, and Michigan has finished third five times. The 2013 vehicle, Generation, makes the best of new regulations that require four wheels and a more upright driver. Like a motorcycle with a sidecar, Generation situates the driver on one side, rather than in the middle of the chassis. The design allows for a sleeker underbelly and a more aerodynamic silhouette. The car weighs less than Do you have an outstanding student or a 600 pounds and has a lithium ion battery and a carbon fiber body. group of students that needs to be recognized To follow the team on facebook, visit: for an automotive-related academic achievement? ■

E-mail us at

10 October 2013 |

Under the Hood

Adapted from Gary Goms article in

Solving the Fuel Shortage Problem How to diagnose fuel systems in modern vehicles


olving cranking, no-fuel or insufficientfuel driveability problems on late-model vehicles can be challenging, especially if a technician doesn’t take into account the way that modern fuel systems operate. Some vehicles, for example, limit vehicle speed by deactivating fuel injectors. In some rare cases, a miscalculation in vehicle speed can cause an insufficient fuel condition. Similarly, shutting off the fuel pump during a collision might be a function of a collision-related module. So, diagnosing a cranking, no-fuel or insufficient fuel condition on modern vehicles can be a challenge. In any case, let’s start with the basics.

Cranking — No-Fuel Condition Let’s begin with the familiar cranking, no-fuel condition. The simplest method of diagnosing a no-fuel condition is to judiciously spray a small amount of throttle body cleaner or propane into the throttle plate as the engine is being cranked. If the engine momentarily starts, the cranking, no-start complaint usually lies with the fuel delivery system. Most Powertrain Control Modules (PCMs) prime the fuel injectors by activating the fuel pump relay for about three seconds as the ignition is turned on. The PCM then deactivates the fuel pump relay and waits for the starter motor to activate. As soon as the starter activates, the

Unless you’re testing a pulse-modulated system, always test fuel pump pressure and volume when diagnosing an insufficient fuel problem.


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Dirty MAF sensors often cause the PCM to miscalculate air/fuel ratios, which can result in insufficient fuel complaints.

fuel pump relay is again activated. Once the engine starts, the crankshaft position (CKP) sensor signal tells the PCM to keep the fuel pump relay activated. In most cases, an activated fuel pump should be audible. If the fuel pump is audible, make sure that the fuel tank contains fuel. If the fuel level sensor is defective, a DTC should be stored in the PCM. If in doubt, add several gallons of gas to ensure that the fuel pump is immersed in fuel. When diagnosing an inactive fuel pump, don’t forget the simple things like checking the fuel pump fuse with a voltmeter. Similarly, check the owner’s manual to see if the vehicle is equipped with an inertia switch that might have accidentally been tripped. If the fuel pump isn’t audible, a standard diagnostic technique is to rap the fuel tank with a soft-faced hammer. If the pump activates, the pump either has a bad connection at the tank or has worn commentator brushes. In this case, the fuel pump should be replaced and the appropriate wiring harnesses inspected for electrical arcing or corrosion.

Check the DTCs With a few systems, if the PCM or immobilizer module can’t identify the ignition key, the PCM simply

won’t activate the fuel pump. Because I’ve had no-fuel conditions caused by something as simple as a resistance chip falling out of the ignition key, I always begin each cranking, no-fuel diagnosis by checking for DTCs. In this situation, a DTC indicating an ignition key identification problem will be stored. In other cases, an immobilizer code might be stored. In general, anti-theft or immobilizer codes must be resolved before proceeding with a cranking, no-start diagnosis.

Fuel Pressure Issues If scan tool data indicates a fuel pump duty cycle value, you might find yourself dealing with a pulsemodulated fuel pump system. Because many pulse-modulated systems use a dedicated module to control fuel pump operation, it’s vitally important to use a scan tool and apply application-specific service information to diagnose these systems. In brief, the PCM helps control the air/fuel ratio on these systems by modulating fuel pressure. Fuel pressure is modulated by changing fuel pump speed. A pressure sensor is located in the fuel rail to monitor the difference between commanded and real-time fuel pressures. When the commanded and realtime values don’t correspond, a DTC 15

When replacing a fuel pump, always inspect the condition of the electrical connector, fuel hose and fuel hose connections.

might be stored in the PCM. All testing on these systems must be done by using a professional scan tool and following the service information. Most of these systems don’t have a Schrader port for a fuel pressure gauge because fuel pressure isn’t a fixed value in these systems. Conventional fuel pump systems incorporate a vacuum-modulated fuel pressure regulator that, at high vacuum levels, modulates fuel pressure to at least 10% less than the key-on, engine off value. Many modern fuel systems integrate a fixed-value pressure regulator into the in-tank fuel pump module. With that said, it’s extremely rare for a fuel pressure regulator to cause an insufficient fuel condition. Testing fuel pressure with a mechanical gauge should include a volume test. While a delivery rate of several pints per minute is a rule of thumb, always check service information for published values. In some cases, the volume is more accurately measured at a disconnected fuel pressure regulator return line. If volume isn’t sufficient, check the fuel filter and fuel lines for restrictions before replacing the fuel pump.

To avoid a repeat of an insufficient fuel problem, inspect the original fuel pump inlet filter. If it’s clogged with debris, the fuel tank may require cleaning or replacement.

Relaying the Problem In some applications, a professional scan tool can be used to activate the fuel pump relay. Please notice that I said “fuel pump relay” and not “fuel pump.” If this bi-directional feature is available, the activation of the fuel pump relay can be determined by hearing the relay click as it activates or by simply touching the relay to feel the contacts close. If the scan tool can’t command the fuel pump relay on, or if the contacts don’t close, several aftermarket manufacWhen assembling a new fuel pump, make sure that the inlet filter is correctly located in turers offer relay diagnostic tools that allow the relay ter- relation to the pump mounting plate. A pinched inlet filter might cause an insufficient fuel complaint. minals to be tested. In some cases, the terminals can be jumpered with voltage to itself. Keep in mind that the PCM, not the ignition activate the pump. If in doubt, replace the fuel pump switch, operates the fuel pump through the fuel pump relay with new or known good. If it’s a high-mileage relay. In addition, the PCM relay must power up the vehicle, it’s a good idea to replace the relay along with PCM before the PCM can activate the fuel pump relay. the fuel pump. If power and grounds are correct, the PCM might be If the scan tool won’t communicate with the PCM, defective. If communication can’t be established with follow the steps outlined in the scan tool’s help screen the PCM, the PCM itself might be defective. or operator’s manual to test the diagnostic link connecDuct Work tor (DLC) for power and ground to the PCM. If a generWhile it’s a rare condition, a fuel pump can deliver the ic scan tool is available, connect it to verify a no-comcorrect pressure and volume even as the engine lacks munication problem with the PCM. In addition, check the PCM fuses and, as a last resort, sufficient fuel to start and/or run. In this case, inspect the air intake ducting for leakage between the mass air pin-test the power and ground connections at the PCM flow (MAF) sensor and throttle plate. On older vehicles, the fuel pump can be activated by a mechanical switch located in the mechanical air flow meter. In both mechanical and fullelectronic applications, a leaking duct will cause the MAF sensor to starve the engine for fuel during start-up. In equally rare cases, a miscalibrated manifold absolute pressure (MAP) sensor might indicate a much higher intake Tie down loose fuel pump wiring to prevent interference with the fuel level sensor float assembly. In some cases, lower-than-indicated fuel levels can cause driveability complaints.

18 October 2013 |

vacuum than what exists in the intake manifold and cause the PCM to miscalculate the air/fuel ratio. Similarly, the engine coolant temperature sensor (ECT) circuit can be shorted to voltage, causing the ECT data to indicate 300° F engine coolant temperature. Either case will cause an insufficient fuel or cranking, no-start condition.

Setting Codes Insufficient fuel delivery at highway speeds generally results in a P0171 DTC (lean, bank one) and a P0174 (lean, bank two). In either case, a DTC is generally stored when positive long-term fuel trim values approach 25%. In addition, freeze-frame values will be stored along with the DTC. Because only slight differences exist between freezeframe data generated by insufficient fuel delivery and data generated by a sensor-induced miscalculation in fuel delivery, it pays to spend some time looking at the applicable freeze-frame values. If, for example, the freeze-frame values indicate that the DTC occurred at wide-open throttle (WOT) at 3,500 rpm and that the oxygen sensor voltages were less than 500 millivolts when the DTC was stored, it’s possible that the fuel filter

is clogged or the fuel pump delivery rate is marginal. If, on the other hand, the “calculated load” value in the scan tool data stream is less than 80% at WOT, the MAF sensor might be miscalculating airflow into the engine. In most instances of low calculated load values, the MAF is out of calibration or it’s dirty or clogged with debris. I mention using the calculated load value because it’s easier to use than the grams-per-second value. While calculated load values vary among applications, it pays to track those values so that a relationship can be developed between normal and abnormal values. Last, an insufficient fuel condition can be created by the driver filling the fuel tank with E85 ethanol gasoline. If the vehicle isn’t designed for E85, the fuel injectors can’t flow enough fuel to create the desired air/fuel ratio. In other cases, gasoline contaminated with diesel fuel might cause the same effect. And, while we’re at it, it still might be possible that the fuel injectors are partially clogged from using old or inferior-blend gasoline. Clogged fuel injectors are a long shot, but one that must be always considered when diagnosing insufficient fuel problems. ■ For more fuel-related tech tips, visit

Product Release The Ultimate Motorsports Jack System Ranger Products, a division of BendPak, recently unveiled its new QuickJack portable jack system that makes vehicle maintenance on the track and off convenient and lightning fast. The 3,500-lb. capacity lightweight QuickJack can go anywhere and can be easily stowed in the trunk or back seat of most cars. Simply position the lightweight jack frames under the vehicle, push the raise button on the remote hand-held pendant control and in less than 10 seconds the entire car is almost 2’ off the ground. The QuickJack collapses to a low 3” profile. Features open-center design, rugged safety lock bars, remote pendant control on a 20’ cord, quick-connect hoses and a built-in flow divider for precisely equalized lifting. Visit BendPak-Ranger

20 October 2013 |


Adapted from Gary Goms article in

ConneCting the Dot s



uring a service writer’s efforts to sell competitive brake services at the service desk, he or she often focuses on selling “good, better or best” brake friction replacements, while ignoring the added expense of repairing brake hydraulics. Unfortunately, neglected brake hydraulic systems can cause an expensive warranty comeback or, even worse, a serious traffic accident. In any case, it’s important to advise a potential customer of the importance of servicing and repairing worn brake hydraulics. It’s not hard for service writers to evaluate the general condition of Photo 1: The master cylinder should be free of sludge brake hydraulics without assigning a and the brake fluid should appear to be clear tan or technician to remove the wheels. To brown. illustrate, the brake fluid on a vehicle that’s rarely driven will likely be contaminated because DOT 3 and DOT 4 brake fluids are with moisture and normal atmospheric pollution hygroscopic, which means that these brake fluwill likely have deteriorated the vehicle’s rubber ids attract atmospheric moisture. The contamihoses, caliper seals and wheel cylinder boots nated fluid then corrodes the cylinder bores in beyond normal safety margins. master cylinders, brake calipers and wheel High humidity climates are also more cylinders. While DOT 5 silicone-based brake destructive to brake fluid than arid climates fluids don’t attract moisture, DOT 5 fluid isn’t used in anti-lock braking systems (ABS) because of its tendency to foam when the ABS activates. See lit ABS dashboard warning light in Photo 1. Mileage is also an essential criterion for evaluating the condition of brake hydraulics. Keep in mind that, each time the brakes are applied, the master and wheel cylinder piston seals wear. Given time, the rubber cups in master cylinders wear to the point that they will not consistently seal hydraulic pressure. The result will often be a low brake pedal, poor stopping power or an intermittently sinking brake pedal. Wheel cylinder cups and caliper piston seals will also begin to externally leak fluid when they wear out. Assuming normal maintenance and operating conditions, master cylinder, wheel cylinPhoto 2: ABS-equipped vehicles require der and caliper seals generally begin to leak after scan tool diagnostics. the vehicle rolls past the 100,000-mile mark.


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Figuring Out the Configurations Always determine the hardware configuration of the brake hydraulics before recommending an inspection, diagnosis or service. If the vehicle has an orange “ABS” warning light on the instrument panel, it’s equipped with an ABS system. See Photo 2. If not, it’s likely to be a 1990s, pre-ABS system that incorporates a “combination” valve that includes a red brake hydraulic failure warning light, a front disc brake metering valve that delays application of the front disc brakes and a rear brake proportioning valve that limits hydraulic pressure to the rear drum brakes. The hydraulic system warning light indicates a hydraulic failure in either the front or rear hydraulic systems or, in the case of a dualdiagonal system, in the left-front, right-rear or right front, left-rear hydraulic systems. In either case, a

red “Brake” warning light will illuminate. See Photo 3. The front disc brake metering valve allows the rear drum brakes to apply before the front disc brakes. But remember that metering valves can’t be used on dual/diagonal systems. The proportioning valve limits pressure to the rear drum brakes to prevent them from locking up during panic stops. Some light pickup trucks also incorporate a rear brakemetering valve that modulates rear brake hydraulic pressure according to rear suspension height. This valve increases hydraulic pressure at lower suspension heights (loaded condition) and reduces it at higher suspension heights (unloaded conditions). These metering systems were not perfectly engineered when new. In some cases, auto manufacturers attempted to reduce rear drum brake lock-up by installing brake shoes with less frictional

Photo 3: The red brake warning light indicates that the park brake is applied or that a hydraulic failure is present. area or less frictional coefficient. Anti-lock braking systems have, in most cases, functionally replaced the less-than-perfect combination/metering valve hardware configurations.

Photo 4 : Low fluid levels will often activate both the orange “ABS” and the red “Brake” warning lights. 25

A brake fluid test strip will indicate excessive moisture, which can be corrected by thoroughly flushing the brake system. In contrast, oil will generally feel more viscous than brake fluid. If oil is present, the rubber seals on the master cylinder reservoir cap or cover will be swollen and wrinkled. Oil contamination can be corrected only by replacing all rubber parts and thoroughly flushing the brake hydraulic system. See Photo 5.

Looking Over Hoses and Lines Start the engine and turn the vehicle’s front wheels to full lock. Inspect the brake hoses for cuts, cracking and swelling. Remember that brake hoses tend to crack Photo 5: The rubber seal on the master cylinder cap should be in around the metal sleeve that seals the retracted position and seat into the cap’s inner diameter. the hose to the metal fitting. In addition, check the hose itself for Initial Inspection flexibility and correct placement. The hose should The very first step in any brake inspection is to invesnever contact any chassis or suspension component tigate an orange illuminated “ABS” or red “Brake” throughout the normal range of steering and suspenlight by attaching a scan tool and retrieving the assosion travel. The hose should also remain loose when ciated DTCs. Keep in mind that, on most systems, the the suspension is fully extended. See Photo 6. ABS warning light indicates problems specific to the Next, inspect all metal brake lines for rust damage, ABS system mechanics and electronics. particularly where metal clips attach the lines to the Depending upon vehicle year and model, the red chassis and where the placement of the line exposes brake warning light can indicate a low brake fluid it to road salt and moisture. In many cases, the ferrule level, bad park brake warning switch, hydraulic presnut at the wheel cylinder or brake hose will be rusted sure failure or internal piston seal leak in the master to the line. In these cases, the line itself should be cylinder. In some applications, the ABS and brake replaced. See Photo 7. warning lights might illuminate simultaneously if a catWhile inspecting brake hoses and lines, check for astrophic failure occurs. See Photo 4. As for physical inspections, begin with the fluid level. Because disc brake pad wear is compensated for by extending the caliper piston, a low brake fluid level is a good indicator of worn brake pads. Low fluid levels are also indicators of external leakage in calipers, cylinders, metal lines and rubber hoses. If no external leakage is apparent, loosen the master cylinder from its mount on the vacuum booster and inspect it for leakage at the master cylinder rear seal. In some cases, you might discover that the brake booster is filled with brake fluid, which indicates that the booster should be replaced. Fluid condition is also a good indicator of brake Photo 6: Brake hoses usually begin to crack at or hydraulic system condition. While a light coat of residue in the master cylinder reservoir is normal, a near the metal ferrule attaching the hose to the heavy coating of sludge might indicate that the fluid brake caliper. is contaminated with water condensation or oil.

26 October 2013 |

Photo 7: The ABS reluctor should be free of cracks, rust and metal filings. Any of these conditions can cause no-code ABS braking complaints. fluid leakage at the disc brake calipers and at the brake drum backing plates. In some cases, oil leaking from drive axle oil seals will cause similar signs of leakage. Oil or fluid leaking onto brake friction causes the brake to lock up. If oil or fluid contamination is present on brake friction, the friction must be replaced.

Making an Evaluation When we road test a brake performance complaint, we must

always be aware that we’re driving a potentially unsafe vehicle. For that reason, always begin by checking the master cylinder reservoir fluid level and by testing brake pedal height. For example, a low pedal might indicate poorly adjusted rear service or park brakes. It might also indicate that the disc brakes have a loose wheel bearing or that the disc rotor is catastrophically worn. Similarly, always check the holding power of the park brake. If the

Photo 8: A loose or inoperative parking brake usually indicates that the parking brake friction is worn or that the service brake self-adjusting mechanism needs repairs.

pedal or lever exhibits excess down movement, the linkage, cables, the low pedal height could be caused by the service/park brakes needing adjustment or replacement. See Photo 8. If the brake pedal sinks when the brakes are suddenly applied at rest, the cause could be a leak in the brake hydraulics. Never assume that a full master cylinder reservoir indicates a sound hydraulic system. Remember that jamming on the brake pedal will tend to conceal, rather than reveal, a worn master cylinder. So, if we’re investigating an intermittent sinking brake pedal, begin by gradually applying light pedal pressure to the pedal. If the master cylinder cups are severely worn, the pedal will gradually sink to the floor. If the brakes lock up after a hard application, the master cylinder piston isn’t returning to a seated position in the cylinder bore and releasing fluid pressure. In some cases, the brake booster pushrod might be too long or, in other cases, the brake light switch mounted on the brake pedal might need adjustment. See Photo 9.

Photo 9: At least ½ inch of “free pedal” is required to fully release the brakes and turn off the brake light switch.

Last, a short test-drive or stopping sequence around the parking lot will usually reveal most catastrophic hydraulic, mechanical or friction failures. If a master cylinder failure is suspected, it’s always best to recommend replacement accompanied by a thorough flushing of the hydraulic system using the OEM-specification brake fluid. During any inspection or service, always perform a complete “bumper-to-bumper” inspection of the brake hydraulic and friction systems. Whatever the case, it’s always better to be safe than sorry. ■

Engine Series

Carl Fausett and his team at 928 Motorsports had already built a 650-hp engine for the Pikes Peak International Hill Climb where it netted a podium finish in the Open Division and was the fastest 2WD car in the class. But for Bonneville, 650 hp wasn’t going to get it done. Every system in the engine would need attention to make the hp needed and survive long enough to repeat it. Some of the parts would have to be engineered and fabricated from scratch.


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Getting 900 HP from a Porsche 928 V8 Adapted from Carl Fausett’s article in View additional notes on this engine at

The task I had given myself was to see if I could get enough hp out of a Porsche 928 V8 to break one or more world land-speed records. We would build for the Blown Gas Modified Sports (BGMS) class where the record is currently 231.5 mph. Another record we were after was the Porsche marquee record for the 928 of 205.6 mph. Our math told us that – because we knew our final drive ratio, tire diameters and engine redline; and if our estimates for vehicle frontal area and coefficient of drag were correct – we would need 750 hp at the tire just to meet the current record. With a 15% drivetrain loss, this meant we would require 900 hp at the engine to net the 750 we needed at the tire. (Remember, the class is Blown Gas Modified Sports cars – there is a “Fuel” class as well and they get to run anything they want in their tanks such as alcohol, nitro methane or whatever.) Cars in the Gas class must run the event gas provided – everybody gets the same event gas right there at trackside and then your filler neck is sealed by the officials. Using just straight gas, making 900 hp from this small V8 would be a little more challenging. Also, we didn’t have to make 900 hp once, but repeatedly and for a long time. Unlike a dyno pull of 6 seconds or so, we would be at wide-open throttle and full load for almost 2 minutes each run – and have to do that several times to get our Bonneville 200 mph license and (hopefully) establish a new world record. The stresses on the engine during these runs are staggering. Over the last decade I have carefully modified and built each engine in my race car and have learned the “do’s and don’ts” peculiar to supercharging the Porsche 928 engine. I had already built a 650 hp motor for my race car and it had performed admirably at the Pikes Peak International Hill Climb where it netted us a podium finish in the Open Division and made us the fastest 2WD car in the class. But for Bonneville, 650 hp wasn’t going to get it done. Every system in the engine would need attention if we were to make the hp needed and survive long enough to repeat it. Some of the parts I would need existed, but had to be adapted or modified to the task. Many others didn’t exist at all and would have to be engineered and fabricated from scratch. 33

Unlike a dyno “pull” of 6 seconds or so, the 900 hp Porsche 928 32v V8 will be at wide-open throttle and full load for over a minute each time – and have to do that several times to get its Bonneville 200 mph license and (hopefully) establish a new world record. The stresses on the engine during these runs are staggering, but like all racing, you cannot win if you do not finish.

Compression Ratio and Displacement When designing the engine for this event, I had a choice of displacement options and compression ratios. The displacement decision was made easy by looking at the current Bonneville land speed records. The engine size with the lowest mph record was the lowest hanging fruit on the tree, so we felt it was ripe for a change. This meant I would build for the “B” engine class – engines from 6.11L to a maximum of 7.19L. By boring and stroking the 928 it landed squarely in the middle of the “B” engine class at 6.54L. Compression ratio is another matter. When building for boost, there are two schools of thought: build with higher compression and run low boost, or build with lower compression and run higher boost. In theory, both engines can produce about the same horsepower, but I am a member of the group that believes that the lower CR motor will be safer and less difficult to tune. With lower compression, I have a larger cylinder volume to fill with air/fuel mixture, a safer burn, and (arguably) higher outputs. We decided on a 8.5:1 compression ratio, and

about 15 to 18 psi of boost. The custom pistons were made for us with molybdenum-coated skirts and ceramic crowns.

Doing the Math After a little engine math we, learned that 900 hp would require the capacity to move 320 cfm into each cylinder and 260 cfm out at ambient pressure (1 bar); or an average of 2,560 cfm for the complete V8 engine.

Fausett says there are two schools of thought when building for boost: higher compression and low boost, or lower compression and higher boost. In theory, both engines can produce about the same horsepower, but he believes that the lower CR motor will be safer and less difficult to tune.

Then, if we ran about 2 bar of manifold pressure, we should hit our numbers. I began at the combustion chamber and worked outward from that point on every component and system all the way to the air filter on the intake side and to the exhaust tips on the other. Every part of every system had to have as much capacity as the next and none less than 2,560 cfm.

Cylinder Heads Usually, porting a set of heads is up to the skill of the tool operator as each intake and exhaust port is hand-milled to open them up. In many cases, this is the only way it can be done. But no matter how expert the operator, making the intake and exhaust ports match from cylinderto-cylinder is just about impossible. And with that irregularity, variables from cylinder-to-cylinder are being built in that will negatively affect the engine’s smoothness, power and longevity under high loads. To get more cylinder-to-cylinder consistency, we developed a CNC milling program on a 5-axis mill for optimizing the 928 heads. This digital milling process guarantees not only maximum flow, but repeatability from cylinder-to-cylinder.

seat bounce at 7,000 rpm, yet avoid valve spring stack with our high-lift (.442˝) camshafts. The solution was a custom set of valve springs made from chrome-vanadium wire, shot-peened, heat-treated and stress-relieved. Titanium retainers and clips were found and used to hold them in place.

Camshafts Of course the large valves and porting alone won’t move the right amount of air without the cams to lift them. Unique to the Bonneville application, we needed our max

Valve Sizes and Seats In concert with our CNC porting job, we upgraded from stock 36 mm to special 39.5 mm intake valves, and also larger 33 mm exhaust valves. We opted for stainless steel as the material for our valves which allowed us to have the same valve weight as stock, even though the valves were larger. Titanium is also available for high-rev engines but we didn’t think we needed it as we would be staying under 7,000 rpm. Special beryllium-copper valve seats were used to improve the thermal conductivity of the seat and to reduce valve bounce at closing.

Valve Springs At 15 pounds of boost, our 65.2 gram intake valve with a head diameter of 1.899 will have a virtual weight (physical weight plus air pressure loading) of 28.63 pounds. This meant stronger springs were required to close the intake against the boost pressure. Other challenges also included controlling valve float from cam lobe toss and 35

hp to come in at 7,000 rpm where we will have our greatest aerodynamic resistance. A combination of special cams and intake runner lengths were used to tune the power band to make this happen. Here we have a certain disadvantage compared to our friends running pushrod motors. Because a pushrod motor can use a 1.4:1, 1.5:1 or even 1.6:1 rocker arm ratio, they can throw their valves open further and faster than a OHC, OHV setup like that in the 928 engine. I had a special cam grind made with absolute maximum lift that would still fit within the 32v Porsche 928 heads.

Intake Runner Development Owing to the size and type of injectors available to Porsche when the original manifold was designed, a fairly large intrusion into the intake runner exists to make room for the old Generation II injectors. The advent of the modern thin-body Generation III injector allows us to reduce this intrusion into the runner and permits more air to travel though. In addition, we canted the runner away from the injector slightly, which had several benefits. It further reduced the intrusion of the injector into the runner wall, it smoothed the transition from the runner into the head, opened the radius of the turn, and guaranteed proper aim of the atomized fuel plume at the back of the valves.

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There are two methods of “natural supercharging,” that is, increasing the velocity of the air at the back of the intake valve. The first is the Helmholtz Effect, (using proper inlet bells to reverse the pressure wave in combination with intake runner length to time the pulse so it arrives at the back of the valve just as the valve opens); and the second is runner taper. Even though we would be boosted, these fluid dynamics still apply and needed to be factored in to achieve maximum engine output. The inner diameter of the runner at the head was set once the head was fully ported. Working up from the finished ported head, we established the diameter and taper desired in the intake runner, the length of the runner, the injector angle and fitment, and the mounting surface for the plenum. Computer Aided Design (CAD) of these intake runners were a must. Here I had the assistance of an excellent Solid Works designer named Ryan Silva. CAD modeling the intake runners gave us the opportunity to try many iterations, and make changes to transitions and radiuses rapidly. We “hit our marks” on the third manufacturing model, and went right to pressure and thermal testing the runners. Changes and adjustments to fitment were made via Rapid Prototyping and fed back into the computer model. The material we chose was SLS glass-filled nylon for the intake because of its many fine properties and low single-

928 Motorsports selected a Vortech V7 YSI supercharger, capable of 1,600 cfm at 30 psi. They say it is big enough to feed a 1,200-hp engine. The only issue they had was that neither an 8-rib or 10-rib belt drive could pull the V7 YSI without belt slip or breakage. So a new cogged crank pulley and tensioner system had to be made to handle the load. unit cost. But the finished intake needed testing under heat and pressure to make sure they would not fail in the field. The runners were bolted to 928 heads and heated to 200 degrees F, then put through 8,640 pressure cycles (0 to 40 psi to 0 = 1 cycle) without failure, and with only .002˝ deflection. They would hold our 20 psi without a problem, and more if we needed it.

Plenum Development After the finished intake runners were mounted to the heads, the plenum floor was put in place. The inlet bells that make up the top of the intake runners were set at the proper height off the plenum floor, and at the proper dis-

tance from the back of the valve. Even though the top of the runner would be completely encased within a pressurized plenum, the bells are still necessary to benefit from the Helmholtz effect. We did the math on both a large single-plane plenum and smaller twin plenums with a balance tube between them, and opted for the twin plenums as the finished volume was closer to the ideal volume for us. The sides, floor and roof of our plenums were made from 0.25˝ 6061 aluminum. That’s thicker than most would use, but we were designing for up to 30 psi of boost, and that’s the reason for the extra stiffness. Then the plenum sides were added, as well as the inlet tubes at the rear of each plenum. A “balance tube” is often only 3/4˝ in diameter, just enough to balance out plenum pressures. This one is a full 3.0˝ in diameter and does more than that. Because of the firing order of the 928 (1-3-7-2-6-5-4-8), this balance tube will actually feed and equalize the forward-most cylinders (cylinders 1 and 5) with air from the opposite plenum on every cycle. The finished plenums were strong enough to handle 30 psi of boost, and move enough air to support 900+ hp, and still fit under the hood of the 928. Even though the intake manifold is done at this point, we kept following the airflow outward and forward all the way to the air filters! A restriction at any point will negate all the other work and choke off the engine. We opted for a single pressurized 4.0˝ ram tube to supply the two plenums with a dead-head design to keep the pressure up and equalized in the two plenum chambers. The ram tube is fed by a large 4.0˝ throttle body, which is sized to provide best throttle response as well as maximum airflow. Bell Intercooler was brought in to design and build us a new aftercooler. We gave them the dimensions of the 37

space envelope, the layout and the cfm and pressures, and they did the rest. They always do a great job. The new intercooler was smaller and yet moved more air with less pressure drop than the last one we had been using. A pressure test on the dyno showed 17 psi going in and 16 psi coming out – only a 1 psi pressure drop. Our old aftercooler was giving us a 4 psi drop, and when you’re averaging more than 25 hp per pound of boost – finding 3 psi more in the system is like finding 75 hp. For the supercharger, we selected a boost head that would feed this beast from Vortech. Their V7 YSI is capable of 1,600 cfm at 30 psi, which they said was big enough to feed 1,200 hp. The only issue we had was that neither our 8-rib or 10-rib belt drives could pull the V7 YSI without belt slip or breakage. So a new cogged crank pulley and tensioner system had to be made to handle the load.

Rounding It Out The finished engine required special support systems to perform as intended. These were: crankcase ventilation, engine management and cooling system modifications. Crankcase windage was handled by modifying our existing crank scraper and windage system to fit the longer throws of the stroker crank. Directional screening is used below the baffles so that once the oil drops down, it stays down, and out of the rotating assembly. Special deflectors were needed to redirect the drain oil

38 October 2013 |

coming out of the heads away from the spinning counterweights as well. Outside the engine, twin pan-o-vacs in the exhaust system were routed through a 12-quart Patterson dry sump oil separator, and then to the engine. The oil extracted from the crankcase cloud was returned to the engine by a Tilton pump. We noticed a restriction in the water bridge/thermostat housing of the 928 and took it to task. We would be making more heat than ever before with this engine and keeping those heads cool was a must. The restriction was cut out, the passage opened, and a new plate welded in to improve coolant flow through the heads.

Final Results Horsepower: 760 at the tire, 900 at the engine; Torque: 701 at the tire, 825 at the engine. To find out more about Carl’s record run at Bonneville, visit an enhanced version of this story on and see a video of his run at Carl Fausett is a member of the Society of Automotive Engineers (SAE) in Horicon, WI, and CEO of 928 Motorsports, LLC. His products and racing team have been featured at Pikes Peak, Road America, the Bonneville Salt Flats and other top venues. Carl is available through his website ■

Âť Spotlight


Bridgestone Firestone

Service Advisor



he first step in any diagnostic strategy is to figure out whether or not your customer's vehicle actually has a TPMS problem. Any number of things can cause the TPMS warning light to come on or flash. The light should illuminate when a tire is low, and should eventually go out after the low tire has been inflated to its recommended pressure. If the light remains on after checking/inflating the tires, or if it flashes and remains illuminated, it may signal a TPMS problem that will require further diagnosis.

TPMS problems can include any of the following: • A tire pressure sensor that has stopped functioning because the battery has died. • A tire pressure sensor that is working intermittently

By Larry Carley

due to a weak or failing battery. • The TPMS module is not receiving a signal from one or more sensors because of an antenna or wiring fault. • The TPMS module itself is not functioning properly or has failed because of a voltage supply, wiring or internal electronics fault. • The tires were serviced or rotated recently and the relearn procedure or was not done correctly. • The vehicle owner does not understand how their TPMS system works.

Tooling Around One of the diagnostic mantras that is preached by service experts today is "Test Before Touch." Basically, you should always use a TPMS tool to activate and check the response signal from each tire pressure sensor in each wheel before you do anything else. This will tell you: (1) whether or not each sensor is capable of generating a signal; and (2) if the sensor is generating a signal whether or not the pressure reading is accurate. The pressure reading from a sensor can be easily verified by checking the actual pressure in the tire with a gauge. If the pressure value displayed on your TPMS tool from a sensor reads 32 PSI (or whatever), you should find 32 PSI when you check the pressure with a gauge. A key point here is that your tire pressure gauge MUST be accurately calibrated. Those cheap spring-loaded stick-style tire pressure gauges often vary up to 5 PSI or more! The most accurate gauges are the electronic digital ones because many have a self-calibrating feature that compensates for changes in ambient air temperature.

Age Factor Something else to watch out for is corroded or damaged TPMS valve stems. The valve stem on each wheel should be visually inspected for corrosion or other damage that might affect the integrity of the valve stem. Consider the age and mileage of the vehicle when doing your diagnosis. The average life of the battery inside a brand new factory TPMS sensor is around 7 to 10 years, depending on use. The more the vehicle is driven, the more often the TPMS sensors generate their signals and the faster they use up their remaining battery life.


October 2013 |

TPMS Tips If you find a tire pressure sensor that is not functioning or reading accurately, the natural assumption is that the sensor is the problem and that replacing the sensor will fix it. Usually it will. But until you check the rest of the TPMS system, there's no guarantee a bad sensor is the only problem that may be affecting the operation of the system. If all of the sensors appear to be working normally, and all of the tires are inflated to the recommended pressure, but the TPMS warning light is remaining on or flashing, you'll have to dig deeper to uncover the fault. For the next step, you'll need a TPMS tool or scan tool that can communicate with the TPMS system via the OBD II diagnostic connector under the instrument panel. After plugging in your tool, read out any fault codes that are found and write down the code(s) so the information isn't lost when you clear the module's memory. You might find a code indicating one or more bad tire pressure sensors because there is no signal coming from the sensor. But if you already checked each sensor with

your TPMS tool and didn't find any problems, you know the problem isn't the sensor. Consequently, the only explanation is that the sensor signal is not getting through to the TPMS module. The problem could be a damaged or shorted antenna near the wheel, or a wiring fault between the antenna and the TPMS module. If you suspect the TPMS module is not receiving a good signal from one or more sensors, check the antenna wiring for continuity and problems such as shorts, opens or high resistance. A voltage drop test across any wiring connections should read 0.10 volts or less. If you find a higher voltage drop reading, it indicates excessive resistance that is affecting the quality of the signal. On some vehicles, the signals to the TPMS module are shared or go through the keyless entry system so a wiring problem that affects the keyless entry system could cause a problem with the TPMS system. The TPMS module may be working fine but is not getting the right information from the keyless entry system. That's why you should always look up the OEM service information for the vehicle you are working on to see how the TPMS system operates — especially if you are having difficulty figuring out a problem. You should also check for any Technical Service Bulletins (TSBs). â– 41

CrossWord PuZZle Tomorrow’s Technician October Crossword

ACROSS 1. Sealing device between engine parts 4. Steering-system element (3,3) 9. Valve-seat deterioration 10. Non-rubber brake lines 11. Snowmobile, slangily 12. Brake-fluid reservoir mark (4,4) 14. Under-dash lever (4,7) 18. Interstate passing zone (4,4) 19. One of 12 in auto electrics 22. Word following drive and crank 23. Engine-shaft protrusion (3,4) 24. Erases a car loan 25. Tire profile, a.k.a. ____ ratio


Solution at

1. Chassis lube 2. Oil-burner's output 3. Interstate egress opportunity 5. Vaned water-pump part 6. Service-bay tasks 7. Recessed-center wheel description 8. Worrisome underhood sound (6,5) 13. Corvette or Harley, some say (5,3) 15. See 3-Down clue 16. Fifth word in right-side-mirror message 17. Urban thoroughfare 20. Emissions-affected atmospheric layer 21. Cold cranking ____ battery rating

Hot Rodders Of Tomorrow Races to Final Round The Hot Rodders Of Tomorrow Engine Challenge build competition will hold its 2013 National Championship during Race Industry Week at the 26th Annual Performance Racing Industry Trade Show, December 10-14, 2013, in Indianapolis, IN. Each year hundreds of automotive technology students from high schools across the country take part in regional competitions to determine which teams can disassemble and reassemble a small-block Chevrolet engine with aftermarket components in the fastest time, with the top scorers advancing to the National Championship. In 2013, a select group of teams with the best time will be invited to compete for scholarship money and industry recognition at the PRI Trade Show in Indianapolis, site of the world’s largest annual gathering of hardcore racing parts and professionals. In addition to the established engine challenge events, the 2013 Hot Rodders Of Tomorrow National Championship will feature an expanded competition format with three new contests: • Carburetor Rebuild Competition • Ring and Pinion Challenge • Cylinder Head Challenge Since its inception in 2008 at the Race and Performance Expo in St. Charles, IL, the Hot Rodders Of Tomorrow Engine Challenge has seen explosive growth in the number of competing teams. In the first year of competition, five teams with 25 students competed. By the end of the 2012 season, there were 112 teams with 560 students competing. The competition has been seen by more than 760,000 people, and has raised over $6 million in scholarship money donated by Ohio Technical College (OTC), School of Automotive Machinists (SAM) and University of Northwestern Ohio (UNOH) over the last four years. For more information about Hot Rodders Of Tomorrow, visit


October 2013 |

Report Card

Audi developed the Nanuk Quattro concept show car in collaboration with the designers from Italdesign Giugiaro. Displayed earlier this year at the 2013 Frankfurt Auto Show in Germany, the sports car was built for any stage of life and for any surface – equally at home on the race track, the highway or a winding country road as it is off-road in the sand or in the snow. Its crossover concept combines the dynamics of a mid-engine sports car with the versatility of a sporty recreational vehicle. The two-seater is powered by a newly developed V10 TDI installed longitudinally in front of the rear axle. The powerful 5.0L diesel engine produces more than 544 hp and delivers 737.56 lb-ft of torque to the crankshaft from just 1,500 rpm. Its twin-turbo register charging unit is controlled via the Audi valvelift system (AVS). The common rail system operates at an injection pressure of 2,500 bar. A beefed-up seven-speed Stronic, located behind the engine, transfers the torque to a specially designed quattro drivetrain. The Audi Nanuk Quattro concept has a curb weight of around 4,188


lbs, yet is able to sprint from 0 to 62 mph in 3.8 seconds with a top speed of 189 mph. The innovative thermal management with its separate cooling loops and the steplessly regulated oil pump contribute to the excellent fuel consumption of about 30.16 mpg on average. Double wishbones guide the show car's 22-inch wheels, which are shod with 235/50-series tires up front and 295/45 at the rear. The carbon fiber, ceramic brake discs can withstand high temperatures and are extremely abrasionresistant. The adaptive air suspension with electronically controlled dampers features the next generation of technology from Audi. The driver can manually adjust the ground clearance of the Audi Nanuk Quattro concept in three stages: normal, 1.18-in. lower or 1.57-in. higher. The system also controls the level of the body itself based on driving speed and the

October 2013 |

predictive route data supplied by the navigation system. On the highway, for example, the body remains lowered even when the Audi Nanuk Quattro concept is moving slowly. It is automatically raised when turning onto a gravel road. Another technological highlight of the show car is the integral steering, which resolves the classic conflict between dynamic handling and stability. The system combines the proven Audi dynamic steering at the front axle, which among other things can intervene at the cornering limit for enhanced stability, with supplemental steering for the rear wheels. Separate actuators activate the two active track rods. Although plans to build the Nanuk Quattro for the general public is undecided, consumer excitement for such a performance vehicle could steer Audi executives in the right direction. View more on the Audi Nanuk at: PQ-w9xmxXLk â–

2013 School of the Year finalists

View videos from all of the top School of the Year finalists. Just go to:

Tomorrow's Technician, October 2013  

Tomorrow’s Technician delivers technical information about servicing today’s vehicles to a target audience of 17-to-25-year-old automotive v...