[IMSA GTU vintage racer build]

New addition to the shop! Almost destroyed my first tire, but didn't scratch the rim!

[Data Acquisition, fact or fiction, requirement for any car, or advanced.]

Post #3 – Lots and lots of data on the cheap

Now I am breaking into something new, a device that automatically and electronically records data for you.  Something that takes samples at least 5 times a second of additional parameters you cannot see easily with the human eye.  75 years of electronics development has given us tons of options to look at our race cars in different ways that were only a dream in the 1950’s.  And stuff has gotten so cheap, most everyone uses something more than a tire pressure gauge and pyrometer these days to analyze performance. 

 

First up let’s talk cameras, both still and motion.  Cary has posted on this subject many times in this forum and I think it deserves its own section here.  I am going to consider this really the first step into electronic data analysis.  There is just so much knowledge that can be gained with so little money.  From Cary:

 

“It also important to get pictures from the event where you can see your car loaded up in a corner as well as those that are faster than you or in the same class.  There's a lot that can be learned from these photos.  And ideally have someone take video of the same cars and if possible use a tripod so you can tell what are and are not trying to see if the car is hopping or the camera operator (phone owner) had too many lattes.  These days almost everyone has a camera and most of these also capture video and those get shared on social media, which makes it easy to collect this info.  “

 

I will also add, you don’t need any fancy equipment here.  Obviously phones can do this well,  everyone has one, they process the video immediately, and have big screens to review, but they do tend to be expensive and can be tricky to mount. Go-Pros are nice since they are hi-def, image stabilized, auto correct sound levels, etc.  If making high quality social media posts and movies, these are the best, but for extracting basic info they are kind of overkill and they are also expensive.  There are many Go-Pro clones out there and mini video cameras that are super cheap. Especially on the used market.  And 720p resolution is fine for most analysis. Over the years I have collected a small box full of video cameras that I use in various applications. Many are in the $25-30 range and I don’t care if they get destroyed in action. Some have small display screens so you can review the video immediately.

 

These are some examples of analyzing video:

 

1.     Facing the front you can analyze your racing line and track conditions. By freezing the frames you can look at distances to objects and the sound can indicate shift points and lifting points.

2.     Facing the dash you can record all the gauge readouts.  Minimum speed, maximum speed, RPM, shift points, etc.

3.     Facing the driver you can analyze how the 4 inputs are used.  Gas, brake, steering, and shifting.  Also eye placement.

4.     Under the hood you can look for leaks, smoke, strange sounds, vibrations.

5.     Aimed at suspension you can look at displacement, roll angles, shock travel, binding, vibration. Some distance markings or a ruler in the background for reference helps. I drop these videos into PowerPoint and create reference lines on top of video to scale.

6.     Aimed out back you can get a different perspective on the racing line and understand what happened when other drivers pass or attempted to pass. Also look for smoke!

 

And the list can go on.  Sometimes you can angle a camera to pick up multiple views. Or you can use a software like RaceRender to synchronize multiple videos together. About the only difficult thing is the more cameras you use, the more you need to plan ahead for.

 

1.     Making sure all cameras are fully charged and have memory capacity

2.     Making sure they are aimed in desired location

3.     Turning them all on at the proper time.  For a big race I have my crew person do a walk around before I go to grid.

4.     Turning them all off and extracting memory cards after the run.

5.     Downloading and then finding time to review the data.

 

Once you start collecting electronic data you will find it is easy to collect way more than you need.  Same with cameras.  They are so cheap and easy, I always run at least 1.  For big races I will run 2 or 3.  If only using cameras, it is best to think about what you want to gain from reviewing.  Have a plan before you go out.  Once you start reviewing it is easy to get hypnotized by the fun you were having. 

 

Enough for now.  Data systems next.  Tons of good stuff already posted by you guys so I don't need to write much.

Clark

[IMSA GTU vintage racer build]

I could not really find a way to check runout. I will assemble them to the hubs very carefully and hope for the best. I think that .005" play would allow quite a bit of runout without issue. 

 

I was traveling for 8 days but now back on point with the car. Starting from the front I am now working my way back assembling and fabricating to get it ready to get off jackstands and become a roller. My engine is getting close to finish also so I spent a few hours cleaning the oil pan, valve cover, and front cover to deliver next week.

 

Here are a couple pics of the radiator and oil cooler brackets.

[IMSA GTU vintage racer build]

It's a t-nut mounted with a Wilwood adapter plate. They came with screws drilled for safety wire so I assume I will lock them. At that specific interface, it's just screw torqued into t-nut. Hardend steel to hardend steel. But maybe a lot of high frequency vibration also.

Your number is exactly the play I have on the rotor. I really just need to verify runout on the hub/hat/plate assembly. I will assume rotor to be true. Just freaked out a little when I bolted it all up and put a runout gauge on it. It rattles with your hand.

[240z SCCA vintage race car, restoration]

Oh it will be a powerful engine no doubt. And should be around 300+ no problem. Just something about tertiary harmonic vibration on the V07 crank that likes to eat bearings. Even with a good damper. If you can sent it to 8k regularly, let me know and I will copy your recipe! 

[IMSA GTU vintage racer build]

In addition I finally got my rotors in. It only took 7 MONTHS!  Dropped them on the radial mounts just to take a look. Still missing the ARP wheel studs to finish out the spacers.

 

Does anyone have experience with floating rotors? They really do float. Both axially and radially. I can see why the bolts require lockwire. So how do I check runout with these? Seems like I need to somehow lock down the float first?

[IMSA GTU vintage racer build]

Didn't work very long tonight, but made enough progress to take a picture. CAD design at its best. And fun too!

I decided to integrate the radiator shroud into the G-nose for 1 big FG assembled design. It should not need to be removed very often.

[240z SCCA vintage race car, restoration]

I'm no expert at all on this. But I can say what works and add remarks from other engine builders. I don't think knife edging is worth it. I've heard a bull nose rounding is preferred for reduced wet sump drag but have no data to back it up. My builder is doing nothing to my V07 crank. And yes they usually require a little straighten.

 

I also do not have the secret sauce to spin a V07 build beyond 7200 RPM. Lighter weight pistons and rods? I don't know. I don't think super precise balancing is enough. I destroyed one years ago over reving.  You can review the TonyD posts, and I have no reason to doubt him. But he doesn't post the recipe either for others to follow. Nor should he.

So with that said, the devil is always in the details for a good build. Tolerances, gaps, and clearances must be perfect. And most good builders have their own recipe they don't tell you. My personal experience, and I have built many myself, is pay attention to the details or trust a race engine builder who does. Either way, I do not intend to spin mine very high.

As far as bearings, Nismo still sells the "choose your clearance" mix of sizes. I just found that ACR has similar and that is what I ordered for my current build. Maybe I will need to mix a few, maybe not. But with either you have the possibility to control oil cushion to the tenths.

[Data Acquisition, fact or fiction, requirement for any car, or advanced.]

I will dig a little deeper into data collection systems in future posts.  After I thought about it, it just seemed like a disservice to jump into higher level stuff without first covering the basics. There is a huge amount of insight than can be gained through a little discipline and basic tools.  It is best to exploit these to the fullest before moving up the ladder to more advanced systems.

 

Post #2 – The most basic data you should work with

As a continuation of my first post on discipline and making a habit of recording data, I would like to go a little more in depth on what data is important. By far the most important component of a competition car is the tire.  It just so happens that it is also the most complicated thing on a car.  A tire is composed of fused polymers and chemical additives that once cured exhibit certain characteristics that directly affect the grip and performance of a car.  And to make things even more difficult, tire manufacturers cannot predict what the final performance characteristics will be.  It is not uncommon for a new race tire compound to be slower than the compound before, deteriorate quicker, require a different set up, etc.  And tire manufacturers do occasionally change compounds.  If you are at the sharp end of the stick, you will sometimes see manufacturers release new compounds just before the SCCA Runoffs each year.  Sometimes everyone switches over, sometimes not.  You don’t have to look any farther than today’s modern F1 racing to see how a team’s tire strategy can make or break a weekend.  Just a few degrees of ambient temperature change or track moisture can make a tire compound undriveable, and they must race with at least 2 compound changes during a 2 hour race. And by now it should be obvious if you change tire brands you will definitely have something different to deal with when hitting the track.

 

So let me make a couple clear statements which will drive our future priorities on data collection.

1.       At amateur levels of competition, the DRIVER has the most influence on competitive lap/sector times. Sometimes up to 70-80%. There is no better way to knock whole seconds out of your lap/sector times than becoming a better driver.    

2.       Following driver ability, most races are won and lost based on the ability to extract the most out of a tire, as opposed to horsepower.

So, getting back to basic data, our top priorities are making sure the tires are happy and somehow measuring the driver.  Luckily the first step does not require a large expenditure or knowledge.  You are probably already measuring the driver.  If involved in competition, you are already comparing yourself to others.   As mentioned in my first post, keep a record of where you are at.  Here are some examples:

 

1.       Lap times at a circuit and why they were slower or faster than previous run or visit to track.  Weather, perceived surface grip, struggles on track are good details here.

2.       Your ranking against your peers. Getting better or worse?

3.       Get some segment times, have someone with stopwatch measure your time within two key points and other cars at the event.

4.       Target another driver who often attends your events

5.       Try something different on track and see if the lap times changed for better.

 

Pretty basic stuff but can reveal some trends.  Recording this kind of info does 2 things. Forces you into setting goals, and hopefully understanding why sometimes you are faster or slower than other times.

 

Next up it tires.  As mentioned, a difficult subject even at the most basic level.  So let me make another all-encompassing statement here:

 

Every tire has a happy spot related to temperature, pressure, and camber where it makes the most grip.

 

Again, not a lot of special tools or fancy systems required at the basic level.  And depending on how restrictive your class is, this may be as far as you will ever need to go

. 

The first thing I will talk about is pressure.  As mentioned, there is an optimum pressure you want to hit.  What is that pressure?  Without getting into too many details, you will need to find this out for yourself and that can only come with testing.  A tire works best when hot, so that is where you when you want to measure the pressure.  Tire manufacturers often provide a window but this can be misleading without knowledge of the weight characteristics of your vehicle.  And manufacturer provided info will lean on the side of safety, so usually a little higher pressure than required.  So to start out take recommendations wherever you can.  Online forums, friends, competitors, and the manufacturer info. Then test for yourself.  Don’t make small changes at first, for a radial try what you think is a good number then at least 5 psi above and 5 psi below.  If you can’t feel anything, try 8psi delta. Record how it feels and which was fastest. Most likely you will find your happy middle number will need to creep up or down. Then over time you can fine tune with lower increments until you are satisfied.  And if running a spec class, it is possible that tire pressure is the only thing you have to change handling characteristics.

 

But “hot” pressure can depend on a few factors.  Air expands as it heats up, so where you set your cold pressure will be less than the pressure you read as you come off course.  With the exception of tire warmers, most everyone will need to predict a cold pressure to start with and measure the pressure as soon as you come off course.  So here are the things to consider:

 

1.       Tire air moisture content.  The wetter the air, the more expansion.  If you use the same air source over and over, this should be consistent.  If you would like to limit the amount of expansion, use a compressed air dryer or bottled gas.  Air is mostly nitrogen, so switching to pure nitrogen is no better than just using dry air.  You can build your own compressed air dryer on the cheap using silica gel desiccant.  We have also used scuba air.

2.       Ambient temperature has to be adjusted for. Setting your cold pressures on a 40 degree day will be lower than on a 80 degree day.  If you normally allow for 5psi of pressure rise, you may need to allow for a 10psi rise. Be careful here, the fastest way to heat a tire is pushing high slip angles, but if it is really cold you may need to bring up the temp slowly before attacking a corner.

3.       Use a reliable pressure gauge that is calibrated.  0.1-0.2 psi resolution. Don’t be afraid to check it against other gauges over time. Never use a friends gauge to set your pressures unless you can verify it reads the same.  Repeating the same pressures you like every time is important.

4.       Your goal should be predicting the hot pressure +/- 1 psi or better.

5.       And as a side note, swaying back and forth to warm the tires before a race has limited impact.  You can also use the brakes to create slip angles and put heat in the tires with the added benefit of getting some residual heat through the rotors and wheels. Often this is more beneficial.

 

Next to consider is overall tire temperature.  A tire pyrometer works best but a cheap IR gun also works in a pinch. Believe it or not, this is the simplest thing but many have problems here.  Most pure race tires operate in a range from 170 to 210 degrees F.  I don’t know what the current crop of 100 and 200 TR tires operate at.  So if you are running an R compound or slick, and you measure 130, you are not in the range of most grip. There can be many reasons for this, the least of which is not driving hard enough.  Too stiff a spring rate and excess shock valving can also show up here.  Along with a damp cold track.  If you can’t get enough heat in your tires most other testing is useless.  Remember to take good notes.  Tires that are too hot can also cause handing problems and deteriorate quickly.

 

Next up is temperature across the tread.  This is where you can really pick up some grip if driving a stock based car.  Street vehicles have only a small amount of positive camber allowed within their nominal alignment settings.  When a car corners aggressively, the body lean overcomes this angle and most of the weight transfer ends up on the outside edge of the tire.  The tire contact patch area becomes very small.  Continue and you can cord the outside edge very quickly when track driving.  I am not going to go dive very deep here, most race rules allow for some kind of camber adjustment to compensate for this.  Even restrictive spec class rules allow you to loosen every thing up and maximize the bolt hole runouts.  Better than nothing.  Anyway the idea is to have the tire tread as flat as it can be during maximum cornering.  This usually requires some positive caster, especially on strut based suspensions.  One of the best ways to measure this is by taking tire temperatures when exiting the track.  You are looking for even temperatures across the tread measured on outside, middle, and inside.  It is generally accepted 10-20 degree more on the outside measurement compared to the other 2 is about right to maximize the contact patch.   Some considerations for temp measurement:

 

1.       Take temperatures as soon as you can when safely exiting the track from a hot lap all the way up to the last turn.  The tires will cool down very quickly on a cool down lap or a long straight before the pits.  Best is to test on a skid pad.

2.       Take temps the same way every time and measure pressures following.  A recording tire pyrometer works wonders here.

3.       Record everything.  Adjust camber accordingly.  Don’t forget to set toe also following a front camber adjustment.

4.       LOOK AT THE TIRES!  I mean really look close at how they are wearing.  Make notes, take pictures. Look for evidence of over driving, bad camber, flat spots, wear rings, excess or inadequate pressure.

 

Other data to think about includes various temps and gauge readouts.  Ever look at an oil pressure gauge and wonder if it 5psi lower than it should be?  It’s a good idea to make a note of what your various gauges read nominally.  Maybe even put a little piece of tape on the glass as an indicator.  Just knowing there is oil pressure is not enough.  Better to know immediately if there is a couple psi drop or a few degrees increase in temp.   IR guns are good for this also.  Cylinder head temps, transmission temps, differential temps are all good things to record and refer back to if needed.

 

Enough for now.

[240z SCCA vintage race car, restoration]

Umm the red eye.  Believe it or not, depending on which road you take, I am on the way to Daytona.  My shop is maybe 3 miles off the 417 Toll Road in Oviedo. My weekend is fairly open except for plans Saturday night.   When are you driving back?

[IMSA GTU vintage racer build]

Finally, finally, finally, got the front panels locked in with gaps I think are "acceptable". This was pure hell tack welding in the 1/4 turn fasteners where they exactly need to be, then cutting them and rewelding 3 or 4 times, in between fitting the panels 5 or 6 times for each weld. 5 panels fixed, 2 fenders, g-nose, hood, and cowl panel in relation to 2 doors and window frame. Think 3 dimensional chess with 3 players and 3 boards. No way to predict what will happen when you move something 1/8 inch. Maybe 20 hours of this AFTER I thought I already had the fenders in correct place. And this is by no means close enough for a show car. Panel gaps and heights of panels are still all over the place. I'm only shooting for a good aero properties and looking good from 25ft away. But reshaping the FG panels is off limits for this build. I do not have enough time and will not make me any faster. But I still think I may try to alter the hood shape to match the g-nose.

 

I will claim another milestone complete. Next is integrating the customer radiator shroud into the g-nose.

[240z SCCA vintage race car, restoration]

What is your schedule for the Daytona race? I was planning to go for the day Friday but too many other things to do. Would like to meet you. My shop is about 50min away from track.

[Data Acquisition, fact or fiction, requirement for any car, or advanced.]

This is what I plan to cover in more detail.

 

#1 tire pressure, temp overall, temp across. IR temps of various components. And gauge read outs. Continuation of my last post and JHM post. Video.  No data ack system required.

 

#2 Data you need vs. Data you want. Autox, hill climb, rally stages, hot lapping, racing, sim racing, testing. Intro to electronic data ack. How much should you spend?

 

#3 Basic systems. Basic info. What to look for. Car vs driver. Comparisons with self and others. Trends. Consistency. Money trace (speed vs. Distance) G circle. Keeping it simple so everyone can use and understand basic info from any system. 

 

#4 Advanced, math channels explanation, braking, kpi's for track, car, and driver.

Shock tuning, combined with other chassis analysis. Not too deep here, but awareness of possibilities.

 

My posts will be very generic. No references to manufacturers or systems to get the data.  I will rely on the community to fill in the blanks for the best or optimum or cheapest way to get there. I am no expert on everything out there. I have played with AIM, MOTEC, and Race Technology analysis software which are all similar. And I have been studying basic analysis recomendations for the last year which kind of gave me a appreciation for the basics, and triggered me to start this thread. With the exception of post #4, most all data is available from phones, AIM solo, Garmin, or similar inexpensive systems. 

 

You guys fill in the rest, which you already are!

[Data Acquisition, fact or fiction, requirement for any car, or advanced.]

On 10/30/2022 at 10:38 PM, NewZed said:

 

-  advice from an amateur woodworker (the guy that wrote the article above).  Don't know how deep it is.  I just know that things keep changing.

 

My wife says that all the time! 

.

.

.

(I could not resist)

 

Clark

[Data Acquisition, fact or fiction, requirement for any car, or advanced.]

Thanks all for adding to discussion! Very good comments on phone based systems of which I have not played with for 7-8 years. I have been putting off my 2nd installment in this series, but now motivated to type it up. It will be the next step beyond my 1st post.

 

In the meantime, I have an older Race Technology DL1 currently for sale on Ebay at $100 if anyone is interested in moving up to something VERY powerful. I tested it and it works great. Contact me and I will be happy to answer questions about it. For a Hybrid buyer, I will even put some analysis setups in with it.

 

Eventually I intend to make a number of posts with very good primer on progression into data systems.. what you need at what level you are. Just need to get all this work travel behind me.

[240z SCCA vintage race car, restoration]

Never had a problem with grooves, but I still prefer disks with spring combined with HD pressure plate and lightweight Flywheel for street apps and racing "on the cheap". Feels so much better and can handle anything a NA L6 puts out.

[240z SCCA vintage race car, restoration]

I have found the toughest thing on a 5.5 and smaller button clutch is pulling it on a trailer. Many winch just for that reason. I also found the 7.25" dual clutch set up to be much more forgiving. Virtually same durability and heat resistant as a stock based setup. Can work for street or track.

[IMSA GTU vintage racer build]

Still slow progress. Hurt my back and lost the weekend. Getting really close to having the gnose and fenders fixed. At least I finally have the steering column in. And then found 2 interference points. At least I feel like the week was progress. Slowly chugging along.

[IMSA GTU vintage racer build]

Well, long pause on posts. Spent a week in Germany for work and a week in North Morocco for pleasure. Once again, way behind on progress to where I want to be. So I got the 3d printer back on track on my return. I did some prototypes and then printed a complex duct that routes air from the fiberglass radiator air box (I intend to make next) that directs air from the g-nose inlet to the radiator. The 3d printed part directs high pressure air on passenger side to the brake rotor and oil cooler. I will design another for the drivers side the goes to cold air box and brake rotor. 

[AME complete chassis '77 280Z]

On 9/11/2022 at 12:19 AM, lifeprojectZ said:

 

Ouch, I hope not!   I want to get thoughts, opinions and questions through sharing my progress, as I know that will make me consider my steps more carefully and ultimately make the project better.   I can think through many things on my own, but the experience of those here who have already modified their Z's and raced them is invaluable to me.  I've done a lot of reading and research over the years including on this site, but have put off the doing until now....   Thanks for your comments.   More to come...

Didn’t mean it that way. Just that every problem you run into I think will be ‘unique’ for this forum, perhaps for any forum. I am up to the challenge if I see something familiar.

[280z FP Build]

4 hours ago, Dat73z said:

 

Aydin, fwiw on a street driven turbo Z and setrab cooler I was struggling to hit 180F oil temps boosting around for hours during this last heatwave of >100F days in CA. 

That's cool! Pun intended. Also depends on where you take the measurement at.  My last car I mounted in oil pan. That seemed to read hotter and had a quicker rise. I center drilled the stock drain plug for a sensor.

 

Another point, as far as I know, on a street L series you should not see anything above thermostat setting running a cooler, even with turbo. It really takes sustained driving wide open throttle for 10+ minutes to make it climb. And if not enough cooler, it keeps climbing. Even still, with 20 min on track, you can live with a 250-275 reading on synthetics. If doing track days, you can actually alternate in a " slow" lap and the Temps will drop quickly with a small cooler.

 

And Aydin, yes a thermostat oil bypass will automatically take car of this. I ran one on 1 of my cars successfully. Most racers skip it because it is just another part that could fail. But conversely, I have never heard of 1 failing. But you would still.want to idle for a few minutes to get oil warm. You just can not head out on track with cold engine and oil. I think that goes for any engine.

 

And again to direct back to Ben's thread. Yes a dry sump makes for a thin oil pan and more mounting options. Also guaranteed oil pressure. Possibly little extra HP from less windage over even a well designed windage tray. The ONLY risk is the belt. I saw one break in a long back straight pull at Mid-Ohio on a friend's car. And reflecting once again to previous post, he had a idiot light on the dash tied to oil pressure. On his video we watched a 5 second delay from when light came on and he shutting down car. There was zero damage.

 

 

 

 

[AME complete chassis '77 280Z]

Man, you are on your own for this build. But it sounds like you have the capabilities to work through it. The CSK screw solution is fine. You can probably find a good torque number for steel into aluminum on Google. Trust your instincts, they seem fine.

[280z FP Build]

The brass gear adds “extra insurance”. Hard to say where the break point is. 7500rpm on 90degree oil will probably destroy the brass. 7500 on 150+ degree oil, no problems with steel. All about the viscosity. Good amount of idle time along with a lower rev limit 1st lap usually get you there on a cool day. But on cold days around freezing temps you may need to block some or all air from the oil cooler. I would not run any oil cooler for AutoX.

Probably a good question for TonyD unless there is a previous post on it.

 

Again, just my experiences.

[Data Acquisition, fact or fiction, requirement for any car, or advanced.]

And more food for thought. When it comes to data, I have 3 contradictory quotes that all apply. They hang on my wall at work so I read every day. 

 

"You can't improve what you don't measure" - Drucker

 

"You can't fatten a calf by weighing it" - Anonymous 

 

"Not everything that can be counted counts, and not everything that counts can be counted" - Einstein

[Data Acquisition, fact or fiction, requirement for any car, or advanced.]

No, THAT IS AN EXCELLENT RESPONSE, and the perfect place to start the discussion. What is data anyway? Facts, figures, numbers, words, pictures, video? It's all of the above. Think of it as something to save that describes something that happened that you can refer to later. 

 

So let's start with the bare minimum. A system for collecting data is #1. Pad and pen, track maps, spreadsheets, etc. Whatever works for you and find a way to keep it organized. I still use a notebook with a pen to record everything I can think of of during a race weekend. Weather, Temps, problems I had, what bolts I had to tighten, things I need to pack next time or discard, parts that need to be replaced, parts I did replace, how the car felt, etc. After a few entries, some patterns appeared. I developed a pre race check list, and a maintenance check list from this along with many other insights. And my main focus is creating an action list to implement before the next event. What do I want to change and why.

 

If starting out, I suggest trying to record everything you can think of. How to drive the track, how you were feeling that day, what felt good about car and what did not. I used to scuba dive and did the same thing in my dive logs. Some of my entries are numbers, some look like I am writing a diary. And they reflect other sources that are disconnected, like a note that I took video or recorded something with another system and it was successful. Over time you get a better feeling for what you really need to write down. I review it after the event and address the action items. Then I review it again before next event.

 

I stipulate these are only my opinions, but I say you need to start with the above before you go to step #2, which looks exactly like the picture posted by jhm.