Audit the drag you can see

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Course: Engineer downforce you can actually use

Module: Trade downforce against drag

Estimated duration: 60 minutes

What you are learning

You are learning to turn visible aero clutter into a disciplined drag audit. The skill is not guessing which part looks ugly. The skill is finding the places where air is being made to separate, turn, enter, exit, or stay turbulent; reducing the suspect list to changes you can reverse; and proving whether the car actually became faster in the parts of the lap where drag matters.

This lesson sits inside the trade-downforce-against-drag module, so keep the boundary clean. The sibling lessons handle induced drag, lift-to-drag ratio, sector trimming, and cases where drag masks a downforce gain. Here you are working one step earlier. Before you decide whether a wing setting, splitter, diffuser, or body device is worth its drag, you audit the drag that is already visible on the car: frontal presentation, exposed add-ons, disturbed cooling paths, body edges, openings, and flow around aero devices.

The lesson is written for an intermediate driver or club racer. You do not need a wind tunnel. The bonded sources support a practical amateur method: visual flow work, basic data logging, pressure measurement where available, disciplined configuration comparisons, and coastdown drag checks. The important habit is evidence. Visible drag is a hypothesis until a tuft map, sector trace, speed trace, coastdown result, or repeatable driver-feedback pattern says it is real.

Principle: visible drag is a suspect, not a verdict

A part that looks exposed may be expensive in drag, harmless, or necessary to keep another airflow job alive. That is why the first principle is simple: do not rank visible drag by appearance alone. Rank it by how strongly it can disturb the flow path, then test the strongest suspect in a way that can survive noise from driver variation, tyre deterioration, weather, track state, yaw, and mechanical resistance.

McBeath gives the practical reason. For an enthusiast aerodynamicist, being able to see what air is doing around a competition car can help you understand the flow and find areas to improve. The important locations named in the corpus are wings, spoilers, diffusers, cooling intakes, cooling outlets, and nearby regions. That is your audit territory. You are not just staring at the nose of the car. You are asking where the air first meets the car, where it is forced through or around the car, where it exits, and where a device is asking the air to stay attached long enough to earn its drag.

The second part of the principle is humility. McBeath warns that it is difficult to generalise in competition car aerodynamics, and that apparently similar cars may not respond the same way. That is not a vague philosophical note. It changes how you work. If a fix helped another car, you still treat it as an experiment on your car. If a part looks bad in the paddock but the data says the car is faster, the data wins. If a cleaner part makes the car slower through the useful sector mix, the cleaner shape did not solve the problem you thought it solved.

The third part is separating aerodynamic drag from total resistance. The coastdown method is widely used for drag measurement, but the corpus is clear that the measured total drag force includes mechanical resistance as well as aerodynamic resistance. That means your audit should use coastdown mostly as a comparative tool unless you have enough information to separate the effects. You are looking for repeatable before-and-after change, not pretending that one simple road test gives a pure aerodynamic coefficient.

Mechanism: how visible drag costs speed

When the car moves, the air has to go somewhere. It can pass cleanly around the body, stay attached over a device, enter a cooling opening and leave cleanly, or separate into messy flow. Visible drag often appears where the car makes the air do unnecessary work. A large frontal presentation asks more air to move out of the way. An exposed obstruction gives the air another object to hit. A poorly managed opening can make air enter the car, lose energy, and exit into a sensitive region. A wing, spoiler, or diffuser can produce useful force but still leave a wake or separated region that costs speed.

For this lesson, define visible drag broadly. It is any visible feature that increases frontal presentation, sticks into the external stream, interrupts attached flow, forces air through the car, dumps air into a poor exit region, or interacts with an aero device. The corpus directly supports the importance of watching flow around wings, spoilers, diffusers, intakes, and outlets. The frontal-area point is also supported by the drag-measurement discussion, where frontal area and vehicle speed are required for a coefficient calculation when the needed data is available. You do not need the coefficient to do the audit, but you do need to respect the role of frontal presentation.

The trap is to confuse visible simplification with faster performance. Removing an obstruction may reduce drag and help terminal speed. It may also disturb cooling, change aero balance, or remove a piece that was helping attachment nearby. The lesson therefore uses three evidence layers. First, see the flow. Second, compare the configuration on track with disciplined runs. Third, sanity-check the drag effect with speed, sector, or coastdown evidence. When all three point in the same direction, you have a useful result.

Build the visible-drag map

Start with the car clean, safe, and in the condition you actually drive. Photograph it from the front, front quarters, side, rear quarter, and above if possible. Do this at the ride height and setup state you will run. You are not taking vanity pictures. You are building a map of what the air sees and where flow may be forced to detach, enter, exit, or interact.

Divide the map into five regions. The first region is frontal presentation: the parts that meet the air first and define how much air must be displaced. The second region is exposed obstructions: pieces mounted proud of the body, open gaps, brackets, or add-ons that sit in the external flow. The third region is flow-through management: intakes, outlets, grille areas, duct exits, and any opening where air is deliberately or accidentally taken inside the car. The fourth region is aero-device surroundings: the approach and exit flow near wings, spoilers, splitters, and diffusers. The fifth region is body-surface behavior: broad panels, corners, and transitions where tufts or pressure checks may show attached or separated flow.

For each item, write one sentence that states the suspected mechanism. Do not write vague comments such as looks draggy. Write a testable claim, such as this opening may be taking in more air than the cooling system needs, this bracket may be disturbing flow into the wing approach, this outlet may be dumping into a sensitive low-energy region, or this panel transition may be causing separation visible in tufts. The sentence matters because it determines what evidence would prove or disprove the suspicion.

Then add three columns: evidence method, reversible change, and success criterion. Evidence method might be tuft video, pressure measurement, speed trace, sector time, coastdown, or driver aero-balance feedback. Reversible change means tape, temporary cover, removable fairing, alternate duct blanking, a repeatable device setting, or a legal installed part you can remove and reinstall without changing anything else. Success criterion means the exact pattern you will accept: cleaner tuft behavior without cooling trouble, higher terminal speed at the same exit speed, reduced coastdown deceleration in the same speed band, or improved straight-sector time without loss in the high-speed corner where the device matters.

This map keeps the audit honest. It stops you from making five changes at once and then telling yourself a story. It also prevents the most common club-racing mistake: copying a visible clean-up from another car and assuming the same gain will appear on yours.

Sub-skill 1: see the flow before you change the car

The corpus supports flow visualisation as a practical tool for amateur racers. McBeath says there are various ways to see what is happening to air around the car, and many can be used on track during testing or competition when dedicated test time is limited. Edgar's book history points to wool-tuft testing and Magnehelic pressure gauges as techniques now widely used by amateurs, and the Mazda example shows separated and attached flows being determined from tuft testing.

For your audit, tuft testing is the first visual tool because it lets you see attached, wandering, reversed, or separated flow on the actual car. Use it to answer one question at a time. If you suspect a duct exit, put tufts upstream, at the exit, and downstream. If you suspect a body-panel separation zone, put tufts ahead of the suspected separation, across it, and behind it. If you suspect disturbed approach flow to a wing or spoiler, place tufts where the device receives air and where the wake might begin.

Do not over-read one tuft. A single tuft can be disturbed by placement, adhesive, a panel gap, or local swirl. Look for a field pattern. Attached flow tends to show tufts lying in an organized direction. Separated or disturbed flow tends to show tufts lifting, reversing, circling, or disagreeing with neighbors. The useful output is not a pretty video; it is a map of attached and separated regions that tells you where to test a change.

Record video from a fixed mounting location when possible. Use the same speed range, same run direction if you are testing on a road, and same part of the track if you are testing at an event. If the test has to be done during a normal session, do not let the camera task pull attention from driving. The driver drives; the camera records. The analysis happens later.

Sub-skill 2: use pressure evidence where the flow path goes through the car

Tufts are strong for external flow direction and separation. They are weaker when the problem is pressure inside or across an opening. Edgar's background describes Magnehelic gauges used to directly measure aerodynamic pressures and later amateur techniques for panel-pressure measurement. That matters for a visible-drag audit because cooling openings and outlets can look simple while hiding a pressure problem.

Use pressure evidence when the question is not just where the air goes, but whether the air is being driven through an opening in a useful way. A cooling intake, outlet, vent, or panel opening should be judged by the job it performs. If it moves needed cooling air and exits without wrecking a sensitive flow area, it may earn its drag. If it pulls in excess air, leaks into the body, or exits into a place that harms a wing, spoiler, or underbody path, it becomes a stronger suspect.

Intermediate drivers do not need to turn this into a laboratory. The practical lesson is to separate visual cleanliness from functional airflow. A closed opening can improve drag and hurt temperature. An opened outlet can improve cooling and hurt speed. A smaller inlet can reduce visible frontal presentation but starve the system. The evidence method must match the mechanism, so pressure and temperature context belong beside tuft and speed evidence when the suspect is a flow-through part.

Sub-skill 3: run one-change A/B tests like the result matters

McBeath describes Carroll Smith's practical comparison method for two wings: each configuration was run over five laps, only wing configuration changes were made, lap-time averages were recorded, and abnormal high or low laps were discarded. The important lesson is not the wing itself. It is the discipline. Your visible-drag audit must use the same idea.

Change one thing. Run enough laps for the result to be more than one lucky corner. Keep the driver task consistent. Record sector times, terminal speeds, relevant corner speeds, and driver feedback on aerodynamic handling balance. If you change an obstruction near a wing, do not also change wing angle. If you tape a duct, do not also change tyre pressure. If you remove a bracket or cover an opening, do not move ballast, change alignment, or alter the braking point. If you do, you have no clean answer.

Return to the baseline periodically. McBeath explicitly warns that conditions change and that tyre deterioration can change the baseline. That warning is central to this skill. A visible-drag change might look good because the driver improved. It might look bad because the tyres faded. It might look neutral because wind or track state moved between runs. Baseline returns are how you defend against those false stories.

Use averages, but do not hide the shape of the run. Averages help, but a visible-drag change should often show itself in specific places: a straight where terminal speed improves, a high-speed sector where the car reaches the next braking point sooner, or a coastdown speed band where deceleration changes. If the full-lap average improves but the straight data does not, you may have changed balance or driver confidence rather than drag. That can still be useful, but it is not the same claim.

Sub-skill 4: interpret speed data without forcing the answer

McBeath says indirect measurements of configuration effects on sector times, lap times, and speeds are valuable and often all you need. That is exactly how most club racers should start. You do not need a force balance to decide whether a visible drag clean-up helped on the long straight. You need comparable entry speed, throttle commitment, shift behavior, wind awareness, and a terminal-speed or sector-time pattern that repeats.

Work from the slowest confounder to the fastest evidence. First, confirm the driver left the previous corner similarly. A higher terminal speed means little if the car entered the straight faster. Second, confirm the throttle trace or driver commitment was similar. Third, compare speed gain across the same distance or time window. Fourth, look at the sector split. Fifth, ask whether any high-speed corner or braking-zone stability changed.

This is where the lesson crosses into the siblings without duplicating them. If the car gained straight speed but lost a high-speed corner, you are no longer only auditing visible drag. You are making a lift-to-drag or sector-mix decision. If the car gained speed but the lap got worse because the device had been helping downforce, go to the lift-to-drag and trimming lessons. This lesson gives you the evidence that the visible change altered drag or flow quality. It does not decide every performance trade by itself.

Sub-skill 5: use coastdown as a drag sanity check, not a magic number

The bonded corpus supports coastdown as the common drag-measurement technique. It also gives the constraint: you need a long, straight, flat, smooth road, and the measured total drag force includes mechanical resistance as well as aerodynamic resistance. Treat both statements as rules.

A coastdown check is useful when the change is expected to affect straight-line drag and can be safely tested away from traffic. You accelerate to a repeatable speed, put the car in the defined coast state, and measure how quickly speed decays through a chosen band. Then you repeat with the alternate configuration. The cleaner configuration should decelerate less in the aerodynamic speed range if it truly reduced total resistance. But because mechanical resistance is included, you control tyre temperature, tyre pressure, drivetrain state, brake drag, wind, road slope, and run direction as much as practical.

Do not use coastdown to claim a pure aero coefficient unless you have the missing inputs and a method that separates mechanical resistance. McBeath notes that direct coefficient calculation needs reliable at-the-wheels power, frontal area, available space, gearing, and maximum speed information, and that these elements are rarely all available. For this lesson, coastdown is a comparative audit tool. It helps you decide whether the visible clean-up probably reduced total resistance enough to matter.

Sub-skill 6: include yaw and racing interaction in the audit

A car rarely sees perfect straight-ahead airflow for a whole lap. McBeath includes drag versus yaw-angle comparison in a case-study context, and also notes that aerodynamic interactions are a fact of life when cars are racing. Those two points are enough to keep your audit from becoming too clean for the real world.

If your car runs in traffic, drafts, passes, or gets passed, the visible-drag item may matter differently than it does in clean air. If the track has long yawed conditions from wind, cresting, turning while fast, or running near other cars, a part that looks harmless straight ahead may become costly. Conversely, a visible item that looks crude may be stabilizing or feeding a device under yaw. You do not need to solve every yaw condition in a club test, but you do need to avoid over-claiming from one clean, straight, calm run.

Use this as a caution when interpreting marginal gains. If a change barely improves a coastdown on a calm road but makes the car nervous in a high-speed passing situation, you have not found a useful race setup. If a change improves a clear-air straight but hurts the car in traffic, the audit result is conditional. Record it that way.

The practical sequence at your next event

Start with a baseline run in the current configuration. Gather lap time, sector time, terminal speed on the longest straight, relevant corner speeds, and driver notes on balance and stability. If you have a camera or logger, make sure it is installed and calibrated well enough to give useful results. The data-logging chunk in the corpus emphasizes buying, installing, calibrating, and extracting useful information from a system; that reminder matters because bad logging can make a clean test look noisy.

Next, run the visual-flow pass. Use tufts or other flow-visualization methods on the strongest suspect area. Keep the driver task normal and safe. Do not chase lap time during a tuft pass if the camera placement or tufts require caution. The output is a flow map.

Third, choose one reversible change. It must be safe, legal for the session, and isolated. If the suspect is an opening, the reversible change might be a controlled cover or alternate exit arrangement. If it is an obstruction, the reversible change might be a removed bracket, temporary fairing, or repositioned item. If it is a disturbed approach to a device, the reversible change might be a local cleanup ahead of that device. Do not change ride height, wing angle, tyre pressure, and ducting in the same pass unless your goal is confusion.

Fourth, run the A/B comparison. Use the same driver task, same fuel range if practical, same tyres, same warm-up state, and enough laps to average. Watch for abnormal laps and keep the notes. Then return to baseline. If the result survives baseline return, the evidence is much stronger.

Fifth, decide what the result means. A strong result has multiple aligned cues: cleaner tuft behavior, better straight speed or sector time, no unacceptable temperature or balance penalty, and a repeated pattern after the baseline return. A weak result has only one cue, a tiny change, or a change that appears only when the driver also changed the run. A failed result makes the car slower, less stable, hotter, or less repeatable.

Calibration cues: how you know the audit is improving

You are improving when your suspect list gets shorter and more specific. Early on, drivers write broad guesses. With practice, you will write mechanism-based claims: flow separates behind this outlet, approach flow to this device is dirty, this opening may be taking more air than the system needs, or this exposed item is likely adding straight-line drag without helping another job. That is progress.

You are improving when your tuft maps become readable. The first tuft session may be messy. Better work produces consistent camera angles, known speed ranges, and tuft placement that answers a question. You are not just collecting footage; you are learning to distinguish attached flow, separated regions, and changed flow after a modification.

You are improving when your data questions get narrower. Instead of asking whether the car is faster, you ask whether speed from the same corner exit to the same braking marker improved, whether the longest straight showed a repeatable terminal-speed change, whether the high-speed sector gained or lost, and whether returning to baseline brought the old pattern back.

You are improving when you stop celebrating unverified cleanliness. A smooth-looking part that does not improve the relevant sector is just a nice-looking part. A crude-looking part that keeps the flow attached, manages cooling, or supports a device may be worth keeping. The car teaches you through evidence, not through style.

Failure modes and recovery

The first failure mode is changing too much at once. It feels efficient because you leave the paddock with a cleaner-looking car. It is inefficient because you cannot say which change mattered. Recover by returning to baseline and testing one suspect at a time.

The second failure mode is confusing driver improvement with drag reduction. A driver often gets faster during a session. That can make the second configuration look better even if it did nothing. Recover by returning to baseline and by comparing speed traces from similar exits, not just lap time.

The third failure mode is ignoring tyres and conditions. McBeath notes tyre deterioration as a changing baseline, and weather or track condition can also move the target. Recover by recording run order, tyre state, wind awareness, and baseline returns.

The fourth failure mode is treating coastdown as pure aero. The source is explicit that total drag includes mechanical resistance. Recover by using coastdown comparatively, controlling mechanical state, and avoiding over-precise claims.

The fifth failure mode is removing useful flow management. A visible piece may look like an obstruction but may feed cooling, protect attachment, or manage flow into or out of a device. Recover by checking the job before deleting the part, especially around cooling openings, wings, spoilers, and diffusers.

The sixth failure mode is ignoring race context. Aerodynamic interactions are real when cars are racing. A clean-air gain that hurts stability in traffic may not be a useful setup. Recover by labeling the result as clean-air only until you have race-context evidence.

Cross-references

Use the induced-drag lesson when the suspect is drag caused by producing downforce rather than a visible obstruction or body-flow problem. Use the lift-to-drag lesson when the part clearly adds both grip and drag and you need to decide whether the exchange is worth it. Use the sector-trim lesson when the result changes one part of the lap but hurts another. Use the drag-masking lesson when a slower straight may be hiding a better cornering package. This lesson feeds those decisions by giving you a cleaner audit of the drag you can see.

Worked example: the Mazda tuft map

Edgar's bonded chunk describes a Mazda drawing that showed separated and attached flows as determined from tuft testing. That is exactly the kind of output you want from a visible-drag audit. The valuable result was not a claim that every Mazda-shaped car has the same problem. The valuable result was the method: put visible indicators on the car, observe the actual flow, distinguish attached from separated regions, and turn the observation into a development map.

Apply that pattern to your car. Suppose the rear quarter and outlet region look messy in photographs. Do not start by cutting a vent or taping a hole shut. Start by placing tufts across the suspected region and far enough upstream and downstream to see the flow develop. Run the car in the speed range where the drag concern matters. Review the video for field behavior, not one tuft. If the tufts upstream are organized but the tufts at the outlet lift, reverse, or swirl, you have a stronger suspect. If the downstream tufts settle after a revised outlet or cover, you have evidence that the visible change affected the flow. Only then should speed, temperature, and sector evidence decide whether the cleaner flow is useful.

Worked example: a disciplined wing-adjacent cleanup

McBeath's discussion of Carroll Smith's wing comparison gives you the template for testing a visible cleanup near an aero device. Imagine you suspect a visible obstruction ahead of a rear wing or spoiler is dirtying the device's approach flow. The wrong test is to remove the obstruction, change the wing angle, drive harder, and call the car faster. The disciplined test is narrower.

Run the baseline for a fixed number of laps, recording lap times, relevant sector speeds, terminal speed, and driver comments on aero handling balance. Make only the obstruction cleanup. Run the same number of laps. Discard laps with obvious traffic, mistakes, or abnormal times, but keep a note that they occurred. Then return to the baseline. If the cleaned configuration improves straight speed and the same pattern disappears when the obstruction returns, the result is credible. If the car becomes faster only when the driver also changes corner exit, the test is not finished. If the cleaned configuration gains terminal speed but loses stability or high-speed corner confidence, move the decision into the lift-to-drag or sector-trim lessons rather than pretending the drag audit alone has answered it.

Worked example: coastdown on a straight, flat, smooth road

The coastdown example is useful because it makes the drag claim concrete. The corpus says you do not need a racetrack, but you do need a long, straight, flat, smooth piece of road. It also says the coastdown technique measures total drag force, including mechanical resistance. Those two facts shape the whole exercise.

Pick a safe legal test location and a speed band that matters to the car. Warm the car consistently. Check that brakes are not dragging, tyres are at the intended state, and the car is in the same configuration except for the visible-drag suspect. Run in both directions if practical to reduce wind and grade bias. Compare the speed decay through the same band. If the cleaned configuration repeatedly loses speed more slowly, the change likely reduced total resistance. Do not turn that into a pure aerodynamic coefficient unless you have the needed power, frontal area, speed, and mechanical-loss information. For most Tracky drivers, the honest conclusion is enough: this visible cleanup did or did not produce a repeatable resistance change worth taking back to the track.

Common mistakes

Mistake 1: ranking by ugliness. The bad version is pointing at the most awkward-looking part and assuming it is the biggest drag source. The good version is writing a mechanism and choosing an evidence method. Around wings, spoilers, diffusers, intakes, and outlets, the flow job matters more than appearance.

Mistake 2: making a batch of tidy changes. The bad version is taping openings, removing brackets, trimming edges, and changing a device setting in one session. The good version is one reversible change, one reason, one success criterion, and a baseline return.

Mistake 3: treating lap time as the whole answer. The bad version is accepting a faster lap as proof that drag fell. The good version checks the part of the lap where drag should show up: terminal speed, straight-sector gain, speed trace from the same exit, and any high-speed balance penalty.

Mistake 4: ignoring cooling and pressure. The bad version is closing or reducing an opening because it looks cleaner. The good version asks whether the opening is doing a required flow-through job and checks pressure, temperature, tuft, and speed evidence together.

Mistake 5: over-claiming coastdown. The bad version is announcing a precise aerodynamic drag number from a simple coastdown. The good version remembers that total drag includes mechanical resistance and uses the method mainly for controlled before-and-after comparison.

Mistake 6: forgetting the car races near other cars. The bad version is optimizing only for calm clean air. The good version records whether the result is clean-air evidence, traffic evidence, or both, because aero interactions during racing are part of the real environment.

Drill: the three-session visible-drag audit

Session 1 is the map. Before the event, photograph the car and choose three visible-drag suspects. For each suspect, write one mechanism, one reversible change, and one success criterion. At the track, run the car in baseline condition and collect terminal speed, sector time, and driver balance notes. Success for Session 1 is not a modification. Success is a ranked suspect list with evidence targets.

Session 2 is the flow pass. Put tufts or another visual method on the highest-ranked suspect area. Run enough laps or passes to capture the speed range where the suspected drag matters. Review the video after the session and mark attached, disturbed, and separated regions. Success for Session 2 is a readable flow map that either strengthens or weakens the suspect.

Session 3 is the A/B proof. Make one reversible change only. Run baseline, changed, and baseline again if session time allows. Use at least three clean laps per state when possible, and five is better when the schedule and tyres allow it. Compare the evidence against the original success criterion. Success for Session 3 is a written decision: keep, reject, or retest. Keep requires aligned flow and performance evidence with no unacceptable cooling, balance, or race-context penalty. Reject requires reverting the change and recording why. Retest means the evidence was too noisy, not that you get to call it a win.

When this principle breaks down

The visible-drag audit breaks down when the visible part is only a symptom of a hidden flow problem. A messy tuft pattern near an outlet may be caused by upstream pressure, not the outlet shape itself. A straight-speed loss may be caused by added downforce, mechanical drag, tyre state, or driver exit speed rather than the visible part you changed. A clean coastdown result may not transfer to yaw or traffic. These are not reasons to quit. They are reasons to narrow the claim.

When the evidence points beyond visible drag, move to the right neighboring skill. If the part changes downforce and drag together, use lift-to-drag. If the best setup depends on where the track rewards speed, use sector trimming. If the car is slower on the straight but better in fast corners, investigate whether drag is masking a gain. The visible audit is the front door. It should make the next decision better, not pretend to replace every aerodynamic decision.

Author Review

No quiz questions are attached to this lesson.

Sources

#	Document	Chunk	Pages	Score	Collection
1	Competition Car Aerodynamics 3rd Edition McBeath Simon	2abb3a1a-1abc-3549-8f79-9fce704061d6	334	1	uio_books_raw_v1
2	Competition Car Aerodynamics 3rd Edition McBeath Simon	c0cd0f54-6d9c-7f08-e9af-37c31b3421d3	345	1	uio_books_raw_v1
3	Competition Car Aerodynamics 3rd Edition McBeath Simon	c87c89fe-58c4-8968-6248-4a307e39f9e2	346	1	uio_books_raw_v1
4	uio julian edgar car aero testing	8a8a57a0-d10b-6d9e-7ee7-a345aca95a3c	4	1	uio_books_raw_v1
5	uio julian edgar car aero testing	b1e5656b-dd3a-c641-4556-06c2a28ae0e2	21	1	uio_books_raw_v1
6	Competition Car Aerodynamics 3rd Edition McBeath Simon	9f0edfc1-9e8c-3a96-a48d-b0d658513db3	385	1	uio_books_raw_v1
7	Competition Car Aerodynamics 3rd Edition McBeath Simon	6edca499-2988-7702-ccc8-3d17b516edff	385	1	uio_books_raw_v1
8	Competition Car Aerodynamics 3rd Edition McBeath Simon	c7d0125c-8080-dbcc-df83-3b96d0b84bab	477	1	uio_books_raw_v1
9	Competition Car Aerodynamics 3rd Edition McBeath Simon	4b5e1aa7-14cf-aacf-908a-c47094ea7ba5	504	1	uio_books_raw_v1
10	Car Aerodynamic Testing for Road and Track Julian Edgar	04bbb790-fd87-b387-5838-a750ea68d9df	2	1	uio_books_raw_v1
11	Competition Car Aerodynamics 3rd Edition McBeath Simon	d788f877-dfdc-2c41-96e0-e6a0de38e907	412	1	uio_books_raw_v1
12	Competition Car Aerodynamics 3rd Edition McBeath Simon	5f8f0fe1-ae71-b849-97d2-d63df40bb83b	423	1	uio_books_raw_v1