Budget Transmission Part 2: How I Chose a Road Racing Final Drive

Introduction

In my last post, I discussed the first upgrade for my budget transmission-- moving from a helical limited slip differential to a clutch-type differential.  If you didn't read that yet, I suggest you go back and take a look.

A pic from my Instagram of Damien and I at New Jersey Motorsports Park (Photo by Windshadow)

The second of two transmission modifications allowed in the National Auto Sport Association's (NASA) Honda Challenge H4 class is a final drive gear with a different gear ratio from stock.  

So, what does a final drive do?  In this post, we'll delve a little into that and we'll discuss how you should choose one for the road course.

What is a Final Drive?

The final drive is basically the last gear between the transmission and the drive axles.  By altering the final drive gear ratio, you alter the amount of wheel rotations per rotation of the selected gear.

So, a 4.2:1 final drive will rotate the driven wheels 4.2 times for each rotation from the transmission and a 4.7:1 final drive will rotate the driven wheels 4.7 times for each rotation from the transmission.

Understanding a Final Drive

If we select a "shorter" final drive, we are saying we want a final drive with more rotations at the wheels per rotation at the gear.  This gives us more torque at the wheels and more acceleration, which we gain in return for a loss in top speed.  We call this a "shorter" final drive because the amount of time between gear shifts is now not as long as it once was.


2 Fast...

On the flip side, if we choose a "longer" final drive, we are trading straight line torque and acceleration for top speed and a potential gain in fuel economy.  The longer final drive gives less rotations at the wheel per rotation in the selected gear.  It takes more time between shifts, so we call it "long."

Why Should I Change My Final Drive?

In a drag racing car, we can go faster by turbocharging our cars or modifying the engines to generate more torque and horsepower.

However, if the stock final drive is too short, one disadvantage is a loss of top speed.

If the stock final drive is too long, one disadvantage is a loss of torque at the wheels.

So, drag racers must find the proper balance between torque to the wheels and top speed by selecting the correct final drive.  Many other factors play a role in this phenomenon, but they're beyond the scope of this article.


A Camaro at the strip

In road racing cars, the sessions are typically longer, the tracks have corners and elevation changes, and horsepower isn't as important as cornering speed in most amateur classes.

So, to go faster we can't rely on adding power at the cost of reliability, choose a final drive that will give us the best straight line speed, or choose the final drive with the best acceleration.  We must consider other factors.


Ken, Kallie, and Brian at New Jersey (Photo by Windshadow)

How to Choose a Final Drive

There are five steps outlined in this article for choosing a final drive.

Step 1: Find the Powerband

Step 2: Find your Corner Speeds

Step 3: Compare Final Drives for Each Corner for Each Track

Step 4: Repeat Step 3

Step 5: Test

Step 1: Find the Powerband

Let's take a look at the stock, 94-01 Acura Integra LS/RS/GS-- a popular Honda for road racing due to its suspension geometry and operating costs.

The stock Integra that loaned its motor to my race car

The powerband for a car is a colloquial term which refers to the engine's RPM range at which it operates most efficiently.  If you're low on money and have a relatively stock motor and no dyno sheet, a great way to find your car's powerband is through the internet.

Wikipedia states that the stock 1998 Acura Integra generates peak torque at 5,200 RPM and peak power at 6,300 RPM.  So, we will conservatively assume that the powerband is from ~5,000 to ~6,500 RPM, allowing for shifting inaccuracy and any changes in engine efficiency due to age and use.

Pulling a stock Integra motor from #TrashTeg

So, we know where the car's RPMs need to be to remain happy, but how do we apply this to the track?  You may be racing Summit Motorsports Park Main with a 0.55-mile-long straight or Lime Rock Park which is a Miata track.  You may be racing somewhere with anywhere from ten to twenty-five corners, all with different average speeds and elevations.

Some corners are extremely important and can lose races if the car and driver are not fast through them and out of them-- like Turn 1 at Watkins Glen.  Some corners are not important at all and are referred to as "throw-away corners,"

So what do we do?

Turn 1 at Watkins Glen International Raceway

Step 2: Find Your Corner Speed

Disclaimer:  This is where we must analyze our cornering speeds-- it is an art and our conclusions may not always be the same.  However, i'm going to do my best to break it down so you can make your own decisions in the end.  The most important thing is that you trust your gut and supplement that with real-world data.

Using an AiM Solo or an equivalent lap timer, take a look at all of the tracks you race in a typical season in your area.  For each track there will be several key corners where exit speed is critical because momentum is lost.  For example, below you'll find a trace of one of my fast laps at NJMP Thunderbolt last year with a 4.2 final drive:

Data from an AiM Solo

There are three graphs drawn versus track distance in the above figure.  In order from top to bottom they are: lateral G's, longitudinal G's, and speed.  We use the longitudinal G and lateral G graph as a reference point and the speed trace to see what our corner speeds are.

In this figure, I have highlighted several corners where a lot of momentum is lost due to braking which is required to make the tight-radius corners.  Those corners are 1, 2, 5, 7, and the exit of the octopus.  Below you'll find a track map and video for reference:

NJMP Track Map

A lap of Thunderbolt in my old single cam HPDE setup

Looking at the AiM data, we can see the following corner exit speeds for a 4.2:1 stock final drive in an H4 Acura Integra:

Approximate minimum speed per corner at NJMP Thunderbolt

Watching video and using common sense, I can look at these speeds and remember what gear I'm in while on track, which is third gear for every. single. corner!  Why is this useful again?

Step 3: Compare Final Drives

The internet doesn't just have the powerband for a stock B18B1, it also has calculators that allow you to look at the RPM vs Speed trace for a stock Integra transmission.  The calculator I like to use for Hondas is from Zeal Autoworks.  It's been around since forums were hot and it's still in use-- so you know it's good.

You can choose the Honda transmission you're interested in and alter gear ratios as well, comparing two at a time.  Tools for other cars are likely to exist on the internet as well.

Zeal Autoworks Transmission Speed Calculator...Stock 4.266:1 Final Drive in an Integra

The screenshot above shows the max MPH for each gear using a stock 4.266 final drive in an Acura Integra.  Using this calculator, we can also get the values for a transmission with a different final drive.  For our example, we'll look at a comparison between a stock 4.2:1 and an aftermarket 4.7:1 final drive.  Trans 1 uses a 4.2:1 final drive and Trans 2 uses a 4.7:1 final drive:

We can see that the RPM increases much quicker for a given change in speed with the 4.7:1 when compared to the 4.2:1.  However, you'll also note that the top speed in 5th gear is much lower with a 4.7:1 final drive than it is with a 4.2:1.  This reinforces what we stated above, that a longer final drive has less acceleration ability, but a higher top speed, and vise-versa.

Now, we know the corners we want to optimize our car's final drive for, we know the minimum speed through the corners, and we know the power band for our car.  All that's left is to compare graphs of RPM vs. speed for different final drive ratios to find the most optimal for your car.  For the sake of simplicity, we'll analyze the comparison between a 4.2:1 and 4.7:1 transmission further.

Dame and I going at it at Lime Rock Park

Below you'll see the graph we looked at previously, but this time I've overlaid two y-axis lines and several x-axis lines.  The y-axis lines are in red and they represent the powerband and the x-axis lines are the minimum speeds for the corners we deemed most important at NJMP Thunderbolt.

Overlaying pertinent powerband and track corner speed data on the RPM vs speed trace for different transmission gearing

Corner by corner, let's look at what the data tells us...

Step 3a: Compare Final Drives-- Corner by Corner Analysis

In this next sub-step, we will go through each of the corners we deemed most important and select the final drive ratio that benefits us most.

Turns 1 and 2:

Below is a graph of RPM vs speed for a transmission with a 4.2 final drive and a 4.7 final drive.  We can see that when proceeding through Turns 1 and 2 in a 4.7:1 final drive transmission, we have two options for gear choice:

We can stay in fourth gear through turn 1 and keep our feet to the floor as we progress through turn 2, minimizing brake input.  Or, we can keep the car in 3rd, turn into corner #1, and shift into 4th out of turn 2.  Either way, we need to row through the gears to optimize mid-corner to corner exit speed with the 4.7:1 final drive.

Graph of RPM vs. speed for a transmission with a 4.2:1 final and a 4.7:1 final

Yet if you look at the green line in the above graph, you'll see that through turn 1, you can maintain 3rd gear, through turn 2 you can maintain 3rd gear, and once through turn 2, onto the back straight, you can shift into 4th all while staying in the powerband.

This implies that a 4.2:1 final drive is most advantageous for turns 1 and 2.

Turn 5:

The next corner we'll analyze is the slow left-hander out of the high-speed, sweeping right-hander at NJMP Thundebrolt-- also known as Turn 5.

Photo of Condor Speed Shop's Bimmer through what looks like Turn 5

The graph shown below is similar to those above, but the x-axis line in this graph is for Turn 5.

Turn 5 min speed, stock Integra powerband RPM range, and RPM vs speed plots on one graph

Driving a 4.2:1 transmission, we have two options for gear choice-- 2nd or 3rd.  In either gear, we're significantly far from the powerband while close to the minimum speed for this corner.  4.2:1 is far from optimal for this corner.

However, a 4.7:1 final drive puts us at the intersection of the powerband for our motor and the minimum speed for Turn 5 when in 3rd gear.

From this, we can conclude a 4.7:1 final drive is better for Turn 5.

Turn 7:

The second-to-last corner we'll analyze is Turn 7 at NJMP Thunderbolt.  This corner is a lot of fun because it requires a lot of braking, but if you choose the proper line and throttle/brake inputs through here, passing can be completed against a fierce competitor.

Looking at the graph below, it appears that a 4.2:1 final drive would be the best from the middle to the end of turn 7 as it requires less shifting and starts at the bottom of the powerband.

Keep in mind, however, that exiting turn 7 is not a straight, but a decreasing radius right-hander that requires grip.  Not all speed through this section is due to final drive selection.  It could be due to other factors not covered in the scope of this article, such as driving style or differential setup.

With situations like this, it's best to rely on your experience driving the track.  Feel the corner and use your intuition to gauge what would be most advantageous in the big picture.  I may think this is an important corner for final drive selection, but maybe it's not!  Remember what I said in the beginning disclaimer-- this is an art.

Take a look at the graph and map below:

Graph of turn 7's min speed on an RPM vs speed graph for a stock Integra with different final drives

Diagram of T7 at Thunderbolt

The Exit of the Octopus

 If we zoom out on Turn 7 and The Octopus together we can better put things into perspective.

The "back half" of NJMP Thunderbolt

From the exit of The Octopus, it's easy to see that the 4.7 final drive is better positioned to exit the corner than the 4.2 final drive is.  The 4.7 AND the 4.2 final drive are both in 3rd gear which means they still have a 4th gear to shift through before they reach the abysmal, long fifth gear in these cars.

Engine speed vs car speed chart for the exit of The Octopus

However, a car must be tuned within the context of the track and therefore it is an art as mentioned above.  Keep in mind that after the exit of The Octopus, racers in a low-powered car will never lift until they get all the way back to Turn 1 at NJMP Thunderbolt.

This reinforces the point that tuning a car cannot focus on only one aspect-- road racing or for the drag strip...

Photo by Viken Photography

Step 4: Repeat 3A

Using different ratios, now it's time to experiment with which one works best for your driving style for a given track.  Additionally, remember to consider corner speeds for other tracks you regularly drive.  Lime Rock Park and Watkins Glen may deserve two totally different final drives for example.

Step 5: Test

Lastly, get your car on the track and see if it works.  Compare data using your on-track lap timer.  This is an essential tool.

Conclusion

As stated above, a final drive can have a large influence in corner exit speed for a track car.  While it also factors into the top speed of a track car, there are other factors to consider such as gear ratios for each individual gear and overall horsepower/torque for the car.  Additionally, there are factors that will make the car corner faster, thus potentially affecting final drive choice.

Photo by Viken Photography

I'm glad you guys had a chance to stop by.  Please recommend my blog and share my posts if they help you at all.  See you guys next time!

#ChelseaTheCivic, Part 3: Aftermarket Headers and Hondas

Last season, I was in a rush to get my car together.  I skimmed over a lot of details while doing so in an effort to pass competition school with the National Auto Sport Association (NASA) and to race with my friends in the Honda Challenge H4 Series which we were reviving in the Northeast.

In the process, I ordered a DC Sports header with a 2.25" collector for an exhaust system that had a diameter of 2.5".  I was struggling to make it to my first event of the season at Lime Rock Park to test the car.  And on my final weekend before trailering up to Connecticut, I was faced with the dilemma of making this header work with my exhaust system.

With no flux wire or gas, and minimal welding experience, I welded the monstrosity you'll see above.  This monstrosity is a 2.5" PLM (Private Label Manufacturing) test pipe.  I thought I had a 2.5" collector on my header, but this is when I first discovered that I was mistaken.  As a result, the collector on my test pipe did not fit and I was forced to improvise.  So, I cut the flange off of my 25-year-old catalytic converter, cut the flange off of my brand new, shiny test pipe, and welded it onto the test pipe.

As you may be able to see, this last-minute concoction left a leading edge entering into the test pipe, providing for turbulence and most likely a loss of power.  On the dyno at Lime Rock Park after a race, my car had less horsepower than the three other H4 cars dyno'd-- most likely due to this and my janky intake, which I will not discuss in this post.  Additionally the welds were not very good as you can see below...however, the test pipe held up for a full season of racing.

When the off-season came, I knew I had to put this on my list of improvements for the 2019 racing season.  So, I started by purchasing a $211 PLM header off eBay.  

If you'd like to see more photos like this, you can follow me on Instagram:

This header is a replica of an SMSP Tri-Y Header.  It has a 2.5" collector and is a 4-2-1 which leads to less turbulence and higher flow than the 4-1 DC-Sports header I was previously using.  It's also fully stainless steel, very light, and tig-welded together.

The reason I was able to get this header for so cheap is because it is an open-box sale.  PLM and 1320 Performance are two brands which both sell a lot of headers for Honda.  And they have sales like this going on a lot of the time.  

Think of it.  

Your Facebook friend car meet fanatic wants to make 5 extra horsepower on the butt dyno.  He or she goes on eBay and buys a brand new, shiny, tig-welded header that has no damage at all and intends to put it in a car that is likely daily driven, and if not, is street-driven in his or her leisure.

This header is shipped through FedEx, UPS, USPS, or another service that throws the box around, sets it on fire, or dips it in a bath of acid (they damage it).  It gets to the customer, and they no longer want it.

As a racer, you can take advantage of this scenario by buying the scratched or minorly dented header second-hand, and you have a new, but unboxed item delivered to your door for a fraction of the cost.

Next, I purchased a new PLM test pipe.  This extendable test pipe was ~40-50 dollars and its length can be adjusted to fit your new header to your existing exhaust.

I mounted the header, mocked up the test pipe and got to work cutting and welding.  Having a vise is great for almost anything in the garage.  I even use it to hold pipes or other objects that need welding as I don't have a welding table, I have a wooden table.  The picture below shows one section of my three-piece test pipe in a vise with a white mark around it where it is to be cut.

  After cutting, I then mocked the test pipe up between the header and the exhaust one more time and welded the pipe in the appropriate spot.  This time I used flux core wire, to preclude accelerated rusting as seen on my older test pipe.  A better weld with less slag and less porosity would likely be achieved with gas, but this blog is about doing racing on a budget, so forget about it.

Mounted up, this is what the test pipe looked like.  It fits well, not pulling the exhaust too far forward or pushing it too back.

I also noticed that the SMSP tri-y header was touching the oil pan after I installed it.  Even in a 25-40 minute race, conductive heat transfer from a header to an oil pan could be bad.  You see, exhaust gases leaving an internal combustion engine's cylinder are typically around 1,000 degrees F (based on passing knowledge).  I knew I had to increase the clearance between the header and the oil pan.

Oil pans are cheap and made of soft, malleable, durable steel.  Headers are expensive and made of more expensive stainless steel.  When push comes to shove, one must give-- and in this scenario, I made the pan give with a hammer-- I mean I massaged it gently and carefully as I am a skilled fabricator:

In the above picture, the horizontal lines at the bottom of the pan mark where the header and oil pan were originally touching.  The dots at the top of the oil pan tell me in which order I need to torque the oil pan bolts.  5 bolts tells me that a given bolt is the fifth bolt in the sequence, 17 dots tells me it's the seventeenth bolt.  There are over 17 bolts on a B Series oil pan.

The hardest work was complete, but the last thing to do was to install the O2 sensor.  The problem with this is that on a 1992-1995 Honda Civic with a B Series Engine from an Integra or something similar is that the O2 sensor wire for the B Series Engine is too short for the Honda Civic engine wiring harness.  As a result, you have to lengthen it.  I began by cutting my brand new Denso sensor in half.

Next, I grabbed some wire, measured from the sensor to the connector in the engine bay, and cut the appropriate amount to connect the O2 sensor on the Integra engine to the Honda Civic harness.

Here's a tip: when you take apart any electronics for anything, save the wires.  Good wire is hard to come by at local hardware stores and if you can find it, you have to pay for it.  I save wire from cars that I part out, or machines that break around the house.  I then take these wires and use them in automotive projects.  I haven't spent money on wire in three years.

Then I grabbed my soldering gun and got to work.  I cut all wires needing connection, stripped all said wires of their insulation, soldered all wires together, and added heat shrink around the soldered connections to prevent damage via water intrusion or other external factors.

Here is the heat shrink I applied.  You can get it from a local hardware store, a local auto parts store, or online:

Lastly, I taped the wires together and wrapped the lower part of the wires that sit next to the header with insulation.  I was careful to wrap the soldered joints with tape so that they would not flex.  I was also careful to ensure an equal spacing of tape about the length of this loom of wire.

The finished product is shown below:

Lastly, I installed the O2 sensor...

...And I fired up the car.  The car was difficult to start at first, but ended up idling and running with no check engine light at temperature for several minutes.  The car was sitting for months not having turned over and it didn't even need a jump start.  I love this Honda.

I have some actions going forward to make the car faster, but for now I am focusing on getting it on track next month (April of 2019) at Lime Rock Park for testing with NASA NE.

I appreciate you all reading and wish you the best.  Peace!

#TrashTeg, The Chronicles; Part 2-- Safety Gear

#TrashTeg, The Chronicles; Part 2-- Safety Gear

When EJ2 Track Rat last left off regarding the story of #TrashTeg, we touched on how we got this free car from Delaware to Philadelphia and we touched on how we made it run with a distributor cap, spark plug wires, spark plugs, and some water in the radiator.

In this next part, we'll talk about how we stripped the car down and installed some safety gear.

Figure 1: Alex at New Jersey Motorsports Park Shaking Down the Teg After we Built it

Since my Civic was being converted into a race car, I no longer needed the roll bar that I installed for high performance driving education (HPDE) and street driving.  I was installing a cage, and the car was no longer going to be street-driven as this is required in wheel-to-wheel racing.  However Alex was building a track car and it's never a bad thing to have additional safety.

Figure 2: The Roll Bar Previously in my Civic

The National Auto Sport Association's Northeast Region typically informs new drivers that the most important mods one can make to their car are in the form of safety upgrades.  A useful acronym to keep in mind when doing safety upgrades was originally coined by our HPDE 1 Instructor, Enrique, and goes as follows:

S-H-H 

AKA 

"SHH! STOP BUYING CAR PARTS AND GET ON TRACK!"

Figure 3: Rally Armor Mud Flaps Look Great but Don't Make You Safer

AKA (for real this time)

SEAT.  HARNESS.  HANS.

Figure 4: A Driver Strapped Into a Seat with a Harness, a Hans, and (in This Case) a Roll Cage

Hans is a popular model of "head and neck restraint" which is used in combination with your harnesses and your helmet to prevent whiplash from occurring in a high-velocity frontal accident.

Figure 5: How a Hans Device Works

A roll bar is used to prevent rollover damage to the driver's person, but it is also used as a mounting point for the harness.  Other options out there include harness bars, but these are not recommended as they have been known to buckle inward in the event of a forward collision.

Figure 6: Bent Harness Bar in 8th Gen Civic on Frontal Collision

The safety components mentioned above are meant to work as a system and using harnesses with your stock seat, or a regular Hans with your 3-point factory belt are not recommended.  I've done tech with NASA since 2016 and we always prefer a stock car to roll through over a car with improperly installed harnesses, roll bars without padding, and/or 3-point seat belts over fixed-back, bucket seats.

The simplest rule?

Before heading to a track day, always review the rule book and reach out to the officials for help when you are in doubt.  Ask for help and ye shall receive it!

Figure 7: A Car with 4-Point Harnesses Not Intended for Use with Stock Seats

Once we got the roll bar removed from my Civic, we had to begin prepping the interior of Alex's Integra, the #TrashTeg.  To start, we stripped all of the interior out of the car.  The major interior items that needed to be removed were:

The carpet

The seats

The center console

The seat belts

And the headliner

Figure 8: Interior of the Trash Teg

Next we removed the sound deadening from the car.  Sound deadening is found in most passenger cars in various areas around the chassis-- most notably the floor and transmission tunnel.  It is used to dampen vibrations and suppress road noise transmitted from the tires to the driver, but we don't care about noise and comfort in racing!  We care about going FAST.

Figure 9: Ricky Bobby

Sound deadening removal can be long and tedious or quick and easy depending on the fanciness of your car.  For example, my Civic's sound deadening came up on its own with some snow, a hammer, and a chisel (we did it outside).

However some cars have thicker, better quality sound deadening that requires more convincing to come off.  A common technique is dry ice.  For our project, we used about $20 of dry ice from a beer distributor.  However, a low buck method to remove sound deadening for people who have a winter season is to leave the race car out in freezing, cold weather overnight and knock the sound deadening loose in the morning.

Figure 10: Sound Deadening Removal with Dry Ice, a Mallet, and (Maybe) a Chisel

Given that this car was sitting in such rough conditions for such a long time (outside, not moving, when it did move it was driven and worked on by a sub-par mechanic), the sound deadening wasn't too hard to remove.  Alex and I got it all up within about 1.5 hours.

Figure 11: Our Tools we Used for Removal of Sound Deadening

Figure 12: The Trunk Area without Sound Deadening

While it was great for sound deadening removal, the neglect this car was put through was not good for much else.  When we pulled the carpet, we discovered that a significant amount of rust had eaten through one of the areas of the floor where the roll bar was supposed to mount to.

Figure 13: Passenger Side Rear Passenger Footwell with Rust

Alex and I took an old welder that had stopped working in his garage, we cut it up for scrap metal, pulled the wires for electronics spares, and salvaged whatever else we could before leaving it out on the Northwest Philly streets for scrappers.  With that same metal, we welded up a patch in the floor and removed as much of the rust we could.  Given that we had just started at welding, we didn't consider our work too shabby (though it could use improvement).

Figure 14: Shabby but Functional Welds on Alex's Floor Pan

After getting the roll bar installed, Alex then needed a pair of seats-- one for the driver and one for the instructor.  For HPDE I always recommend having a second seat.  You're not worried about the extra weight an instructor will gain you because you're not trying to win, but you'll also likely learn more from the right-seat advice.

Figure 15: Even Seasoned Racers Benefit from Good Instruction

Originally, Alex was contemplating spending major coin on these racing seats, but I told him that for HPDE we could use some cheap fixed back seats and be compliant with the rules.  Additionally, if he ever decided to go racing, when the cage got installed in the car, we could brace the back of the seats to the roll cage harness bar and still be legal!

Figure 16: Back Brace Used to Reinforce Back of Fiberglass Seat to Roll Cage Harness Bar

After some discussion, Alex and I set out to find some cheap seats on Craigslist, quickly coming up with an ad for some old Corbeaus that used to be in a Mustang.  The seller listed the seats for $200 but Alex ended up scooping them for a smoking deal of about $140.

Figure 17: These Seats were Intact and Ready to be Used

For brackets, we utilized the high quality, OEM seat rails, and $35 worth of steel bar stock with some spare hardware for the materials.  We cut the steel bar stock into four separate 18-inch-long pieces and mounted one at the fore-end and one at the aft-end of the OEM seat rails, securing them with spare hardware.  We then bolted the seats to the bars with the same said hardware.

Figure 18: Two Pieces of Bar Stock for Each Seat

Figure 19: Spare Hardware Used to Mount Seat to Bracket and Bracket to Sliders

Figure 20: Side View of Seat Mounted in Car

After we installed the seats, we had two last items to install-- the harnesses!  One of the harnesses, like many of the parts in Honda Challenge, was handed down to me from one friend, Anthony.

Since I didn't plan on having a passenger seat while racing initially, I gave Alex this spare harness so he could build his #TrashTeg.  Alex then bought a second harness of his own and some hardware to keep the driver and passenger safe.

Figure 21: G-Force Racing Harnesses and Associated Hardware for Install

With all of our gear laid out, we went to work getting alex seated in his ideal position for driving.

Figure 22: That Awkward Moment when You're Too Fast for Anything in Life

Once you have the seating position, the install for the harnesses is pretty much done by the book.  When I install harnesses on vehicles I'm working on, I typically use the Schroth Racing installation guide which can easily be found on their website.  A quick link to the PDF can be found here as well.

Figure 23: Drawing from the Schroth Racing Website's Guide Showing Proper Vs. Improper Harness Mounting Angles

As shown above, there is a given range of angles the installer must adhere to to make the system safe for the driver.  This is why it is imperative for the driver to be in their desired position when installing their harnesses.  It allows them to have control over where the lap belt mounting points need to go and if a cage is being welded in the car, the cage builder has a reference for a good harness bar height.

Lastly, in the picture below, note the metal collars that are on the harness bar.  These collars are on the roll bar to prevent the harnesses from sliding to the left or the right in the event of a frontal collision.  A simple and cheap, alternative solution to using these collars is roll bar padding foam or even generous amounts of duct or electrical tape.

Figure 24: Picture with Collars Circled for Reference

The final product was not beautiful, but it was safe and functional-- a good race car's desired state.  Check out some pictures of the final product below:

Figure 25 and 26: Passenger Seat with Old Harness from My Civic

Figure 27: Driver Seat with New Harness

Figure 28: Stock Steering Wheel with Air Bag Removed for Track-Only Safety (Remember, All Safety Components Act as a System)

Figure 29: View from Rear of Car Showing Newly Installed Safety Gear

In the next installation of #TrashTeg, you can expect to see regular maintenance activities that are good to attend to before hitting the track as well as some other minor changes.

Thank you for reading and keep coming back.

.