How to tech a used car for the track

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Update by Tom Suddard to the Volkswagen Golf GTI project car
Dec 6, 2022 | Volkswagen, track day, Volkswagen Golf GTI

We zeroed in on our ideal Volkswagen Golf GTI–a 2017 Sport with a DSG transmission–and successfully purchased one from Carvana. Time for the race track, right?

Not so fast. Before we take any used car on track, we give it a thorough tech inspection.

The reality is this: Even in a fairly modern, fairly safe, fairly slow car like this Golf GTI, death is a possibility when you go on track. And even if you don’t die, do you really want to have an incident because of a mechanical issue that could have been avoided?

Let’s get the GTI up on the lift and see what we really bought.

Wasn’t this car certified?

Carvana, like most used car dealers, offers some vehicles as “certified pre-owned cars.” At Carvana, this means our car passed a 150-point inspection and hadn’t had any accidents.

We do find some value in these programs–among other things, Carvana promises its certified cars will have suitable brake pad and tire life remaining, along with a fresh oil change–but we’ve noticed two things: These inspections almost always focus on each component’s presence rather than its condition, and they’re conducted by the same dealers selling cars.

There’s a huge financial incentive to have a positive inspection, so we followed the adage: Trust but verify.

I thought tracks teched your car for free?

It’s true that almost every organization makes you pass a tech inspection before going on track, but we won’t bet our lives on it.

A 2-minute tech line inspection isn’t actually a thorough evaluation of your car’s condition. We prefer to go beyond the minimum.

Tech Inspection Process

We’ve covered the reasons why you should tech a used car, so now let’s cover the process. And it’s worth noting that an inspection like this isn’t a unique or rare operation. The corner garage might not be up to it, but any shop that works on race cars will have no problem inspecting your car for a nominal fee, even if your car is a bone-stock Volkswagen like this.

We like to do our tech inspection in stages, starting with general and moving toward specific. That way, we can catch issues that may not be on a specific checklist and remember to go back to our list after any detours.

So let’s start with the first step.

Step 1: General Condition

What do we mean when we say “general condition?”

Simple: Park the car and walk around it three times from 5 feet away. Then put it up on a lift or jack stands and do the same thing underneath.

The goal here isn’t to look at anything in particular, but rather to look at nothing in particular and let your eyes wander.

Is that piece of trim loose? Is that tailpipe hanging? Should there be water under that part of the car?

If anything doesn’t look showroom fresh, it’s time to investigate. Our GTI passed this stage with flying colors–after all, it’s a nearly new car with 19,000 miles.


Step 2: Interior, Seatbelts, Egress

Next, we move on to the interior. Are there any loose items? Is the driver’s seat bolted down and secure? Do the seat belts latch securely?

Did the previous owner leave a bowling ball on the floor to roll around? Does the steering column move around because the adjuster is broken? Is that floor mat going to interfere with the pedals?

These are all common checks, but some people forget the importance of getting out of the car.

Pretend the car is smashed and burning. Can you exit it with your eyes closed?

Do the seat belts release reliably every time? Can you find that release without looking? A few minutes of practice in the garage could save a few seconds in an emergency, and seconds matter when there’s fire.

This was the first inspection our Volkswagen failed. When put into drive, the car automatically locks its doors. Then, when you put it in park, it unlocks them.

Why is this a problem? Because you can’t guarantee that you’re going to remember to put the car in park if you crash–or even that there will be power to unlock the doors if you do. We changed this setting to ensure corner workers would always be able to open the door and get to us.


Step 3: General Underhood Inspection

Moving right along, we popped the hood and looked over the engine bay.

Any significant leaks, aftermarket parts, missing bolts and similar issues get added to the list for further investigation. This is a great time to look for big missing parts. Is there an air deflector missing from the radiator opening, for example? If so, your car may overheat on track until it’s replaced.

Missing exhaust heatshield? Items that would never melt on the street can suddenly be vulnerable when you push the car hard.


Step 4: Brakes

Okay, now things are getting serious: We pulled the wheels off for a thorough inspection of the brakes.

Are the rotors cracked or thin? Do the pads have plenty of life and even wear? Are the bolts all present and tight?

Our GTI passed this inspection, as the front and rear pads looked like they’d barely been used.

But then we moved on to the brake fluid, which we always change on every used car we buy. Why? Because it absorbs moisture over time, and this absorbed moisture lowers its boiling point.

What’s wrong with boiling brake fluid? Steam is compressible, meaning your pedal effort compresses steam in the brake lines instead of moving the brake pads. This is a minor issue on a street car where long-term corrosion is the biggest concern, as it’s rare to get the brakes really warm. But on track, with frequent hard stops, it’s imperative that brake fluid has as little moisture (and as high a boiling point) as possible.

Generally, the older the car, the more you need to worry about moisture absorption. Modern cars have systems that are far better sealed, but old fluid can still be contaminated by slowly dissolving the parts it’s in contact with.

We use BrakeStrip, a simple test developed by Phoenix Systems, to measure the amount of dissolved copper present in the fluid. This concentration is a reasonable proxy for the age of the fluid, and the story it told about our GTI wasn’t great: This was old fluid, and it needed to go.

Using our Motive Power Bleeder, we flushed out the old fluid and replaced it with Wilwood EXP 600 Plus. This fluid is DOT-approved, so you can legally use it on the street, but it also boasts a dry boiling point of 626 degrees Fahrenheit.


Step 5: Tires and Wheels

While the wheels were off, we inspected the front and rear of each wheel as well as each tire.

They seemed nearly new, measuring between 7/32 and 9/32 inch of tread depth. We also made sure the wheel bolts were the right profile for the wheels–we’ve often purchased used cars with conical lugs attaching wheels with a ball radius seat.

Ten of our wheel bolts were rusty, so we replaced them with new ones before reattaching the wheels. Would the rust have been a problem? Likely not, but we didn’t want to risk a stuck or broken bolt at the track. We torqued every wheel to spec and set the tire pressures to factory specs–that’s our starting point for our first lap. (Each tire was underinflated by 10 psi.)

Oh, and we balanced our wheels. As delivered, our GTI shook around like it had thrown a wheel weight or two, so we spun each and every wheel on our tire balancer. Shockingly, every single wheel was out of balance, some by nearly 2 ounces.

We balanced the tires correctly, then taped the weights in place to ensure they’d stay put on track. And yes, Carvana’s 100-day warranty should have covered this, but taking the car to our local tire shop would have cost a $200 deductible, and Carvana’s approved repair facility was a 1-hour round trip from home. It was quicker and easier to just balance the wheels ourselves.

[Invest in tire mounting and balancing equipment, save money?]

What about that Carvana inspection? Honestly, we’d be shocked if their technicians ever pulled the wheels off this car. It took us nearly 10 minutes to hammer the wheels off our GTI thanks to rusty hubs, and the wheel bolt holes themselves were full of rust that fell on the floor when the wheels were removed. These aren’t major problems, though, and we solved them with a little anti-seize.


Step 6: Suspension and Bearings

While the wheels were off, we looked over every bushing for condition and wear patterns indicating excess compliance, then wiggled every ball joint with a pair of pliers to check for play that would warrant further inspection. We also checked for leaking shocks and springs not seated in their cups–we’ve found both in past used cars.

Next, we took a hard look at the front suspension to see if we could add some negative camber, as we know from experience that adding it to an otherwise stock street car on street tires improves lap times and tire wear. Sadly, we couldn’t find any provision for front camber adjustment.


Step 7: Plastic Undertray

It may not seem important, but the OEM undertray can be a pretty vital part of your car’s aerodynamic package.

Undertrays often decrease front aerodynamic lift and improve cooling airflow, so we always check for it before going on track. And even if they don’t help aero, one can cost you a session if it falls off or starts flapping around. 

After comparing the underside of our car to photos online, we decided everything was secure, present and accounted for.


Step 8: Battery

What’s the most common reason for failing tech? Improper battery hold-downs.

We checked to confirm that the GTI’s battery was secured and that its terminals were tight. If you can’t shake the entire car by pushing on the battery, then add hold-downs until you can.


Step 9: Air Filter

A dirty air filter costs power, and a missing air filter can cause problems. We checked to make sure ours was present and not too filthy.


Step 10: Fluids

We checked every fluid in the car and noticed the oil looked filthy. (The oil filter turned out to be gross, too.)

We won’t comment on Carvana’s guaranteed oil change on certified cars–visual condition isn’t a good way to assess an oil’s age or quality–but we wanted to change it anyway. Modern Volkswagens are picky about oil grade and type, so we didn’t want to go on track with whatever random oil the last mechanic had sitting on the shelf.

We ordered an oil change kit from FCP Euro. For $107, we got 6 liters of the proper Liqui-Moly 5w-40 oil, a new filter, a replacement oil drain plug, an oil drain plug removal tool, and a fancy filter that screws right into the oil cap.

Sure, we spent a little more than we would have at the local parts store, but we’ve struggled to find Volkswagen 502-spec oil locally in the past, and the extra tools will be handy for future changes. And while we’re tempted to complain about single-use drain plugs and special tools, we will say that this was the quickest, cleanest oil change we’ve ever done.


Step 11: Actual Tech Inspection

After every tech inspection, we run down the checklist provided by the organization we’ll be racing with–in this case, the FIRM.

These lists are almost always available online in advance, and they’re a great way to make sure you didn’t forget anything. We’d looked at every single item on the list, so we pulled the car out of the garage, threw our helmet in the seat and headed to our first test day. We’ll cover that in the next installment.

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View comments on the GRM forums
GCrites80s Dork
12/5/22 9:07 p.m.

I had never thought about auto-locking doors being a problem on track. Even my IROC's alarm does that even though I swapped over to a manual. When it's in neutral the car thinks it's in park so when I select a gear they lock shorty thereafter. Hmm

Tom Suddard
Tom Suddard GRM+ Memberand Director of Marketing & Digital Assets
12/5/22 9:25 p.m.

In reply to GCrites80s :

Yeah, it's a super common feature and I'm surprised people don't talk about it more. Theoretically your window is open for HPDE so a locked door wouldn't be the end of the world, but why make it harder for workers to reach you? It's usually easy to turn off in the settings menu.

And yes, in theory most modern cars will unlock if a crash is detected, but I'd rather not rely on them to detect the crash and have 12v power to unlock doors. 

David S. Wallens
David S. Wallens Editorial Director
12/6/22 1:36 p.m.

I'd add that most/all of this can apply to a car primarily used for street, too.

Just bought a new/used car? Can you easily remove the wheels, or are they rusted in place? I'd rather find out in the garage than on the side of the highway. 

Good info here. 

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