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Friday, September 13, 2019

How strong is your wheel?


How strong is your wheel?
© copyright 949 Racing 2019

On test standards for the aftermarket automotive lightweight tuner "LHP" wheel  industry and choosing wheels

Stronger is heavier
Designing and engineering LHP wheels is about balancing strength versus weight.  Given the same spoke design, manufacturing process and size, the heavier wheel will generally be the stronger wheel  (stronger quantified as greater resistance to bending, longer fatigue life or both). Not too many HPDE drivers would want a wheel  10 lbs heavier than OEM no matter how strong it is though. This is the tradeoff.  More mass = more strength, everything else being equal.
For requirements street going vehicles that are not used in competition or any activity where the driver is required to wear a protective helmet, we believe the widely adopted test standards in the alloy wheel aftermarket industry adequately  represent the loads, stresses and fatigue life requirements for wheels. Where we feel those standards can be improved upon is precisely those conditions that they were not created for: competition or any high performance usage that requires the driver to wear a protective helmet or additional safety gear.
 In short,  we feel the aftermarket wheel industry is lagging behind the reality of how these alloy wheels are now being used. We feel it's time to change the paradigm.
How long should your LHP wheel last?
Every model of aftermarket wheel ever sold has had at least one crack or break.  The more popular the wheel, the more it is seen shared on social media and the more likely you are to see one or more cracked/broken wheels. The average HPDE driver is not aware that all pro race teams have stringent service life standards, more akin to highly stressed aircraft than road going cars. This means carefully recording hours of use and then scrapping them at a certain duration whether they show signs of failure or not. Most pro teams do not use wheels for more than one year. Note: This is a good reason not to buy used wheels from pro race teams.
For the amateur performance car enthusiast, the idea that any OEM component could "time out", crack or fail outright as a result of HPDE use often comes as a surprise. This reality does not make it any less true. Components most of us would expect to last a lifetime on a street car, might begin to show signs of excess fatigue within the first year of use on track. Ball joints, subframe mounts, hub flanges, hub bearings, control arms, engine mounts, miscellaneous brackets around the car and yes, those pretty new LHP wheels you saw on a pro race car last week.

Most drivers, us included, expect to get a minimum of one year out of an HPDE wheel,  and hope to get more like 6-10 years.  But things happen on track that can cause a wheel to fail during the second decade, the second year,  the second session or even second lap.  That's one of the many reasons we all wear helmets on track. There is a fundamental risk in driving 80mph next to other adrenaline junkies jockeying for the same piece of track in production cars not specifically engineered for that purpose.
Brief history of autocross, HPDE and wheel to wheel racing in the US.
We want to discuss this as it is vital to understand the relationship with the usage factors of HPDE and racing vs the standards LHP wheels are built to. The saying goes that the first wheel to wheel race happened when the second automobile was built.  Racing goes back that far, 1895. Autocross was a postwar phenomenon, growing rapidly in the mid 1960's. Most enthusiasts don't know that autocross is the #1, four wheel motorsports activity in the US, ranked by participation. Trackdays, or HPDE (High Performance Driving Event) came on the scene only in the late 90's. Up until then, HPDE events were rare, once a year events for marque-based clubs, generally only in major urban areas. In the late 1990's a few enterprising marque clubs began allowing non marque cars, perhaps Hondas in to a Alfa club track day for example. Other groups began promoting HPDE events that did not have any other marque requirements other than a drivers license and basic tech.  It's not uncommon now for virtually every state in the US to have at least one HPDE event per weekend, weather permitting. Some southern states may have 2-3 events on a given weekend. The participation rate is growing closer to that of autocross every year.  Auto manufacturers, tire companies and the aftermarket have adapted by producing ever faster cars and equipment designed to perform and withstand the rigors of track use. The wheel industry went the other way, using test standards created before HPDE events existed and making  ever lighter wheels to satisfy consumer demand for racing inspired designs. Breaking an alloy wheel in an autocross was and still is, exceedingly rare. Cracking or breaking an LHP wheel on track became more common as the number of drivers on tracks around the country grew. The awareness of LHP wheel  fatigue life has grown with the social media boom. A perfect storm of goal misalignment but a great opportunity to make consumers aware of the relationship between usage, fatigue life, test standards and expectations.
Wheel standards: SAE, DOT, JWL, TUV, VIA and other acronyms
The US government does not require aftermarket alloy wheels sold in the country to meet any performance standard.  It only requires wheel to have DOT (Department Of Transportation)  marking for dimensions, load capacity (not test load rating), date and country of manufacture, etc.  The applicable performance standard in the US was and is, SAE J2530 (Society of Automotive Engineers). Early versions of this SAE standard were rudimentary.  To this day, few, if any LHP wheel manufacturers use the SAE standard. In the late 80's Japanese made, performance oriented and race inspired wheels entered the US and worldwide markets in great numbers. With them came the JWL (Japan Wheel) test standard. This has now become the defacto standard that the entire tuner wheel segment uses, even for brands sold in other countries. An LHP wheel made in Vietnam, by an Italian company and sold in France will most likely have a JWL/VIA stamp and no others.
 The JWL standard was created in 1981. It has been revised and  updated a few times since then, mostly to add wider and larger diameter wheels to its test criteria charts. VIA is an independent council  in Japan that actually performs the lab tests of sample wheels submitted by the manufacturers.  Privately owned but VIA registered labs in other countries also perform VIA certification. This was a huge leap forward over basic pre-1981 industry standards  by adding a radial load test, cornering fatigue test (most relevant to sport cars) and impact test.  The JWL impact test actually strikes the aluminum flange, not the mounted tire. The pass/fail for passenger cars is whether the tire holds air. As such, the impact test is more an evaluation of the flange shape and basic material strength than the spoke or overall wheel capacity. Around 2012, SAE adopted a slightly modified version of the JWL standards and test methodology. The outlier in all this is TUV (Technical Inspection Association) Germany. TUV has far higher dynamic radial, dynamic cornering and impact test requirements than even JWL. Assuming the same strength to weight ratio, a TUV will usually have 15-25% greater mass (heavier) than a JWL certified wheel.
Is JWL/VIA good enough?
Generally speaking,  the accepted industry standard in the US is JWL/VIA even for wheels manufactured  outside of Japan. Some consumers will know to look for that VIA stamp next to the valve.
Even though the JWL standard is thorough for passenger car wheels on public roads, it is inadequate for competition use. To the best of our knowledge, 949 Racing was the first wheel manufacturer of any size to release a lightweight tuner wheel  with 10% greater test load on all three dynamic tests comprised of Radial Fatigue, Cornering Fatigue and Impact test.  We call this proprietary standard that surpasses industry standards HP10/10.  HP for High Performance, indicative of the intended usage profile, "10" for 10% greater Impact and Radial test loads and "10" again for Cornering Fatigue test load. We combine impact and radial load values as our experience has shown that the more critical dynamic test for race track use is cornering fatigue.  To our knowledge, four other wheel companies have adopted similar internal standards to surpass the JWL standard.  Two companies were seemingly directly inspired by our new standard, replicating it verbatim a few years after we first shipped HP10/10 wheels in 2015. Two other companies increased load cycles for their proprietary standards before 2010. It is good to see our industry showing an awareness and action in response to the higher stresses LHP wheels  are now seeing  in comparison to nearly 30 years ago when JWL standards were created.
 It is our belief that a 10% greater test load has a greater bearing on increasing  fatigue life than 10% greater test cycles. In laypersons terms, increasing test cycles means you hit it just as hard, but hit it a few more times. Take a wheel with a FoS of 2, double the number of test cycles. Most likely it will still survive the test. Take that same wheel and double the load at the standard number of test cycles. In theory, and in practice, it will fail much sooner. What is "FoS?, read on.
 Factor of Safety
"FoS" in engineering vernacular. A degreed engineer might cringe but in laypersons terms, this is "how much stronger the part is than it needs to be". FoS is roughly equivalent to yield strength.  Example, an FoS of 2 means stresses are allowed to reach 50% of the components yield strength. It's far more complicated than that but key to understand are the inputs: The part (wheel), the load and the duty cycle.  How hard you hit it and how many times you hit it in other words.  Structures undergoing high loads but not under significant restrictions to save weight,  can have FoS of 5 to 20. Yes, that's 20x stronger than it needs to be. Most bridges you drive on have a minimum FoS of 7 but could be as high as 20. These are structures and components  intended to last virtually forever, or least decades. Aircraft parts on the other hand, are subject to the most severe weight restrictions. Thus it is common for aircraft parts to be engineered with FoS as low as 1.5. Yikes! How do planes keep from falling apart? The aircraft industry and owners keep very careful track of the number of hours on every single component in the aircraft. If the engineer estimates it will last 100 hours and has a FoS of 1.5, that bit will be swapped out long before it reaches 100 hrs duty cycle. It is near impossible to get FoS data from auto manufacturers for OEM wheels but  its assumed to be 2 to 3. How do we know that? We can extrapolate that from currently available data.
JWL vs track day (bro)
Let's start with an 18x8 +40 5x1143 pcd wheel, low pressure cast, flow formed weighing 19 lbs. Max load rating of JWL standard for this diameter/PCD of 620kg. The dynamic Cornering Fatigue test mounts a tire, inflates to max psi, tilts 30° and rolls on a drum to simulate the road. The test load of 620kg is applied vertically, in the same radial plane as the drum. 620kg is 1364 lbs. If we are simulating the average car that a 5x114.3 pcd 18x8 would be on, we can use 3800lb as a reference. The engineers reading this have already done the rough calc in their head. Yes, that's barely 1g simulated. Why so little? Because the standards were created when even the highest performance street cars struggled to turn at .85g on street legal tires. That was 30 years ago.  Some LHP wheel buyers  30 years ago might have been autocrossers but HPDE events weren't even a "thing" yet. Now your parents Camry generates .85g on its all season tires.  Your high performance prepped street car generates 1.4g on street legal tires without breaking a sweat. Mount slicks, add a little downforce with bolt on aerodynamics and a street going production car can see 1.6G sustained cornering force. Perhaps you do a half dozen track days in your 300whp sports coupe every year, averaging maybe 85mph laps.  That load and duty cycle is worlds past what JWL standards were intended to simulate. The world has changed, wheel industry standards have not kept up.
A cheap gravity cast, T-4 solution treated OEM 18x8 JWL approved wheel might weigh 27 lbs. The fancy low pressure cast, flow formed  T-6 heat treated aftermarket 18x8 with the same JWL approval might weigh only 19 lbs,  about 33% less. Not accounting for the slightly greater strength to weight ratio of pressure vs gravity cast material, the FoS of that far lighter wheel is likely to be lower than the heavier one.  But we all want the lightest wheels right?
 A VIA certified wheel rated at say, 620kg (1,364 lbs) could have a FoS in a street environment of say 2. Or roughly twice as strong as it needs to be. The greater the safety factor at 620kg rating, the more load and duration it will survive.  We understand that track driving and autocross put far more load into an alloy wheel than street driving does.  We do have significant and useful data on how many hours from which load cycles can be extrapolated.  On a typical 2.5 mile road course, the baseline JWL dynamic test cycle equates to a minimum 55-75 hours use, depending on the diameter of wheel/tire combination. How many and how long the curves are on a given track affect this estimation. This assumes that at no time the wheel was subject to any load beyond the baseline. Spin off course, hit a kerb, drop a wheel off the edge of the pavement or simply turn harder than our ~1g baseline and that duty cycle value plummets. That is how a wheel that one might expect to last "forever", doesn't.
  JWL standards require cast wheels to be tested at 2x the number of load cycles as forged wheels. Wheel manufacturers design a wheel in CAD (Computer Aided Design), simulate loads and perform virtual testing in FEA (Finite Element Analysis). Then they make samples and perform physical tests. FEA is good enough now that an engineer can virtually guarantee a new design will pass JWL/VIA on the first try. What they cannot tell you is precisely how many cycles beyond the test standard it will run before it ultimately fails. Only a predicted range. Most non-engineers would be surprised to learn that Fatigue Analysis  science is as much parsing metadata on actual test results and those statistics as it is actual metallurgy. A fatigue life estimate is just that, an estimate. That is the nature of materials fatigue science, more statistics and probabilities than absolutes.
 This leaves the automotive aftermarket in a quandary on how to design and engineer a wheel that will meet the modern high performance enthusiast customer expectations without being unfashionably heavy.  Should the industry standard VIA certification be used or something new? Should manufacturers simply build stronger and heavier wheels? Our review of these standards comes to a few conclusions. Not all will agree with us but most will agree that any standard that is specifically tailored for street cars in 1981 may not be ideal for your trailered race car thirty years later in 2011, particularly when you spent weeks searching for the absolute lightest wheel available in your size.  It's not too difficult to make a wheel that is pretty much indestructible but no one wants a 35lb "race" wheel.
Manufacturing techniques
Cast or forged? It may come as a surprise to some consumers, but the stiffness and weight of forged and cast alloy material is basically the same. The difference is forged materials have higher yield and tensile strength. This means forged material will flex further before it stays bent and bend further before it cracks. This allows designers to use a little bit less material in a forged wheel  to match the fatigue life of a cast wheel. Or use the same amount of forged material to achieve greater fatigue life than a cast wheel.  There is no magic that allows a forged wheel to be significantly lighter and have greater fatigue life than the best cast wheels. Weight or fatigue life, pick one.
Flow Forming
Flow forming, also marketed as flow forging, roll forming, rotary forging, MAT  is a process where only  the barrel portion is hot forged.  This process results in a barrel material almost identical in tensile and yield strength to a pure forged wheel.
Die vs billet forging
Die forging is the process where the final spoke shape is created by a die under tremendous pressure and heat. By forging the spoke shape with a die, the crystalline structure or "grain" of the material is aligned with the shape of the part. Die forging is also known as near net forging. Meaning that die pretty much makes the final wheel.  The little remaining machine work is just to cut the lug holes and back pad.  A billet forged wheel starts with a featureless forged puck, with no wheel design, spokes or ports. This puck can either be forged into a puck shape by a die, or cut into a puck shape from a larger block of forged material.  In either case, the grain structure in this billet blank is aligned in one direction like the longitudinal grain in a pine 2x4. It is tricky to explain how this grain structure impacts design and fatigue life without a bunch of charts, images and technical explanations. One can imagine the die forged as a tree trunk with a branch, grain unidirectionally aligned to its specific shape. It is difficult to break that branch off where it meets the root because of that grain structure blending  deeply into the trunk.  The billet forged wheel  is more like a trunk and branch shape cut from a larger piece of wood without the grain matching the structure.  Anyone reading this with a knowledge of woodcraft understand this second "tree" will be much easier to break the branch off of than the real tree with structurally aligned grain. That perhaps oversimplifies but the analogy is relevant.  So everything else being equal, a billet forged wheel requires more material to match the fatigue life of a die forged wheel.  In the US, there are precious few die forged LHP wheels on the market. A far greater number of forged LHP wheels are of the billet forged variety.
Casting, heat treating
Most consumers by now understand the basic difference between gravity or "tilt" casting and pressure casting.  Gravity casting basically pours molten aluminum into a mold with the face of the wheel at the bottom. Pressure casting injects the molten aluminum under pressure which results in fewer voids, tiny air pockets in the material once its cooled. It also compacts the grain somewhat, similar to what forging accomplishes, albeit to a much lesser degree than forging.
Some cast wheels are heat treated to T-4 condition. Most LHP wheels available now are T-6 heat treated. Heat treating increases tensile and yield strength. Effectively making aluminum more "springy", allowing it to flex more before it stays bent or cracks. Un-heat treated aluminum is far more brittle than any alloy in T-6 condition.
Stiffness vs weight
This is a conversation that very few amateur racers have but large budget pro race teams have carefully mapped out in simulations and data collection. Wheel stiffness plays a huge role in the suspension tuning process and significantly impacts the way a high performance cars feels. Most consumers assume that rigid feeling wheel they pulled out of the box is not flexing at all during high cornering loads. In fact however, all wheels have considerable flex during high load conditions. In cornering, this constant rotating bending moment actually reduces camber, the lower part of the wheel being pulled out of alignment with the hub as it rolls. This is not marketing speak, it is the very basis of the JWL cornering load test and key to a better understanding of the subject.
You might ask, but will a stiffer wheel make me faster?  The answer is an unequivocal yes. Just as wheel width has been repeatedly demonstrated to have a greater influence on lowering lap times than wheel weight, stiffness is more critical than a few ounces of weight in lowering lap times.  If you are mulling this over and realizing a much stiffer wheel might allow you to run less camber on your performance car to achieve the same optimized contact patch loading.. you are getting the picture.
So racers want and need stiffer wheels right? But exactly how much weight penalty are racers willing to accept for improved wheel stiffness?  Without a clear understanding of how much stiffer a wheel might be than a different design, most consumers are in the dark here.  A few simple tools to ascertain the relative stiffness of two different LHP wheel designs of the same size:  Look at JWL load ratings and total weight of the wheel. While spoke design and layout have a significant effect on relative stiffness, most LHP wheels are pretty well optimized. More often than not, the slightly heavier option will be stiffer and result in better performance.
What is the best test standard?
This is the million dollar question. While 10% more test load may not seem like much, it significantly increases the FoS. We recognize that everything else being equal and expressed as percentage, test load matters more than test cycles in the context of the usage environment, namely race tracks, apex kerbs and the occasional off track excursion. We also recognize the dynamic cornering fatigue test is the most relevant of the three dynamic tests of JWL, TUV and SAE. So our focus going forward is increasing test load to between 10% and 20% greater than the JWL standard just for cornering load. This may still not result in an indestructible wheel, and it certainly won't reduce weight but it more acutely addresses the actual usage environment a wheel sees on that noisy, low car with big sticky tires. We are labeling our newest wheels with "VIA HP10/10", "VIA HP10/20" and so on. So you know what you are getting and how to compare our wheels to other options on the market. Our 15x10, 15x11, 15x12 4x100 pcd wheels first shipped in 2015 are HP10/10 but not labeled as such. Our little company has occasionally generated friction with some members of the public by refusing to spoon feed answers. This generally occurs when we believe someone is simply asking the wrong question to effectively solve their problem. 10 years ago, last year and last week questions have been asked of us. There is an old saying, often attributed to the wrong person "Give a man a fish, feed him for a day. Teach a man to fish, feed him for a lifetime". We would much rather share the information with enthusiasts to help them decide for themselves than simply "do what everyone else does" when we feel the status quo is not in anyone's best interest.
© copyright 949 Racing 2019

Wednesday, December 28, 2016

Club Racing needs a paradigm shift

Auto racing in general, began with two manufacturers pitting disparate designs against each other. As it became commercialized and "the show" was more important than validating a product, BOP adjustments became the norm. Amateurs dream about pro racing but never consider that it is fundamentally, a cost ineffective method of providing close competition. Club racers come and go as budgets briefly bloom then evaporate like the tire smoke they generate. We have to rethink the paradigm by building a series that borrows little from pro racing. The biggest and most painful step is removing the car from the equation. This means one platform, no nooks and crannies in the rules that reward spending wars. Carefully choosing a spec tire that is competitive right down to the cord. Points tables that reward consistency over a few wins. Those are the building blocks. The mortar, as it were, is the mission statement of supporting and coaching both new and experienced drivers from within the series. It should be about the drivers experience, not the fans, promoters or manufacturers. SRF is the largest club racing series in the US and follows this formula. Supermiata was created in the same vein. One single specification for all cars, easily met and monitored performance caps. Native coaching from the "leaders" or most experienced drivers in the series. Inverted grids, short races.Sponsored BBQ for drivers and crew with high quality catered food and beverages Saturday night. Racing now becomes less about the anxiety of the car's competitiveness and more about the excitement of expanding your knowledge under the wing of the pros and national champions running at the front. We're doing things a new way and if the growing field sizes and general buzz are any indication, it is what the drivers have always wanted. Looking forward to 2017 with two new classes and expansion to the east coast with WRL. See you in grid!

Tuesday, December 6, 2016

I am branded

Yes I am an asshole. That is because I stubbornly refuse to spoon feed those individuals that ask a question based on several layers of misconceptions and are insulted when I don't stop to either give them the answer they want to hear or take the time to explain why their question doesn't make any sense. For this, I am thus labeled.

   I have a choice to spend a not inconsiderable amount of time walking the customer through all the reasons they are asking the wrong question. To be blunt, we are not here for that. We make parts. They are good parts, priced fairly, shipped quickly and perform as advertised.  Got a simple question about one of our products? We'll handle it. Got a giant, open ended question based on years of misinformation and conjecture that we know won't actually help you to attempt to answer? We'll redirect you to our website, or a forum somewhere so you can do some additional research. We do this because it is not any company's obligation or responsibility to be your" best friend that knows a lot about cars".  It is a pragmatic choice, though not always a popular one.

  Got a  tech question entirely unrelated to anything we sell? We'll redirect. We will do this even if we know the answer. Why? Same reason as above.

  We could, simply answer every question ever posed to us  to the best of our knowledge, in perpetuity. In fact, I did this for the first few years of my current business.  After a few years, I realized I was the only one in our little niche industry doing so. I also realized it was costing me almost a day a week. That's expensive and something we could not afford. Some of those customers would eventually buy something, most would not. So I gradually learned to filter questions pertaining to our products from the general  "I'm clueless, impatient and it's your fault if I can't find an answer" inquiries. Thus the reaction from some individuals.

  Communicate with any large company with such a impossible or convoluted question. You will usually get a patronizing, canned answer that does nothing to help you. Now try to get the owner of the company on the line for a "straight" answer. What?  You mean that's not possible? If you could, there is pretty good chance they would also not have a satisfactory answer anyway.  

 I choose to educate, to be distinguished from spoon feeding by rote. An example might be a customer asking what our wheel offset is (published on our website) so they can make sure our 17" wheel fits the back of their Honda Civic. Giving them the simple two digit answer will not help them. It will instead, help them dig a deeper hole of mis-application. I know that. The fellow on the other end of the phone does not. When I suggest that the wheel we offer will not fit his car and that they do some additional research on Honda forums to see what other Civic owners are installing, I am met with righteous indignation. Sometimes quite colorful indignation. 10 minutes later I am branded on facebook and two forums. Why didn't I just take the fellows money? I know, I'm an idiot for trying to raise their awareness instead of taking their cash.

  We get contacted for info because we are experts, professionals in our field. This is what we do for a living and we are very good at it, just like your lawyer, doctor, psychiatrist or real estate agent.  Contrary to those professions however, we do not bear a recognized certification that makes it socially or commercially acceptable to charge for that professional advice. So like your friend that is a florist, we are expected to dispense free expert advice upon demand, in perpetuity.  For this, I am branded.

Saturday, February 11, 2012

SuperMiata aero

Some pics from Streets of Willow today. Testing the SuperMiata Cup Car spec aero wing and air dam.Balance is good, height is just right. Doesn't look to shabby either. 



OGK 2.0 engine

This is the engine we built for the OGK last year. Finally got it into a car. Making 182whp on CA91 with a rough tune. Still a few more things to adjust and test. Should make close to 200whp when we're done. Then we'll add a C30-94 Rotrex and aim for 400whp. Should be fun.




Wednesday, February 1, 2012

Daily driver gets a new heart


The 95R package we picked up for $750 two years ago finally got it's makeover. The goal was a clean looking daily driver that should pass emissions testing in every state. Current weight is about 2150lbs with a splash of fuel. 147whp on CA91.

Suspension
We fitted Xida-S with 700/400 rates. RB 1.125" #54105 front sway bar. Rear is the OEM 12mm with urethane bushings for street, 14mm bar for track use. Prothane control arm and diff bushings, SuperMiata end links. Diff is the stock 4.1 type 1 Torsen.

Brakes are OEM Sport Brakes with our two piece rotors and XP10's up front, XP8's in back, stainless lines all around with Motul RBF600.

The car has an NB front subframe, spindles and depowered steering rack.

Engine
We blueprinted an NB2 motor with Supertech 11.0:1 83.5mm pistons that were shaved down to create 10.5:1 compression. Supertech valve springs, SCAT forged rods and ACL race bearings. The rest is 100% OEM parts. Head and bottom end is otherwise stock. 5W30 Amsoil. Magnaflow Metal core cat. Exhaust we built is a bit too loud so we're putting a Racing Beat midpipe and Powerflow muffler on it. ECU is a special Adaptronic 440 ECU configured just for this type of conversion. Thread on the ECU here http://forum.miata.net/vb/showthread.php?t=403239

  As an experiment, we initially built the car with an EUDM header and heatshield to retain a full OEM appearance and functionality. We also kept the OEM NA8 airbox and NB2 MAF. With all that OEM hardware and a cat, we squeaked out 126whp on CA91.

  Next we experimented with a few different intakes and settled on a K&N 60-6900 CARB legal kit. With that kit installed we made 147whp after wrapping the crossover pipe in thermal sheet and adding a Racing beat header. With the header, our CARB emissions compliance went out the window.

For now the car has no oil cooler but we'll add a very small Setrab with -10 push on hoses and Mocal thermostatic sandwich plate. Koyo 37mm radiator and Koyo cap with M-Tuned reroute.


Drivetrain
6 speed trans running Amsoil MTG. Clutch is a clutchnet stage 2 for 1.6 (200mm), organic sprung hub. Lightweight 8.8 lb Cr-Mo flywheel. 15x9 6UL's on 225/454 RS3's running about 26psi. I painted the wheels Ford tungsten gray code T8.

Miscellaneous bits
Harnesses are G-Force 5 pt camlocks. Seats are OMP Grip with custom made fixed brackets. Bar is a Hard Dog HC DD. Wheel is a Momo 350mm mod 78, NRG 2.5 QR and Momo hub.

We added V8 Roadsters subframe braces for added torsional rigidity. We'll some E-Code 55/65 halogen lights so we can actually see where we are going once the sun goes down.

John did a partial wire tuck under the hood. The relay box and ECU are behind the pax airbag cover.

Driving it
  It's a blast! Amazing throttle response and torque way down low. The gearing and light flywheel let it zip through the gears like a kart. One can short shift at like 2500rpm and still keep way ahead of traffic from a light. In 6th gear at 45mph, it still has enough torque to squirt into spaces in traffic. The ride with the 700/400 Xida-S is very firm but not harsh at all. Feels a bit lumpy at very low speeds but smooths out and begins to glide once you start hammering it. Brakes feel amazing. Super sensitive, tons of power. The XP's dust quite a bit but that's typical of the XP's.

We took it to round 1 of the 2012 Miata Challenge at buttonwillow Sunday Jan 29th. Clocked a 2:02.813 which is almost 2s faster than the Spec Miata lap record, and we did it on "street" tires.Very happy to have a concept, piece it all together tune it and have it turn out even better than I envisioned. These cars just so much fun to play with.

Friday, January 27, 2012

2011 Thunderhill 25 hours - Winnage


  It's taken me a while, perhaps too long, to sort of assimilate the win and what it means to me. In a word; huge. Certainly my greatest motorsports accomplishment. I say "my" with the significant qualifier that we had a 20 person team that made it possible. It's traditional for a team owner to offer some thanks to the team, "job well done" and all that, after a big win. In this case, it's simple, the team held us together when the shit hit the fan. The team fixed stuff that they hadn't trained for. The team went far above and beyond to ensure we had the best chance of winning. We would not have won if our team had not been the walking talking action heroes they are. There are forum posts sprinkled around the web by team members recalling their stories so I won't even try to tell them all here. Here are at least a few brief insights into the level of commitment and admirable skill displayed by everyone:

Good to the last drop
 The two fuelers, Manny Rodriguez and Murat Guruz were scheduled to switch off roughly 6hr shifts fueling. Early in the race they figured out that they could knock 12~15s off our pit stops by doubling up and fueling together. So, entirely of their own accord, decided to stay up the entire 25 hours in order to increase our chances of winning. Those guys moved 3000 lbs of fuel into the spec 5gal jugs. Filled both cars all week and made about 28 flawless fuel stops during the race for both cars. Not a drop spilled. To see the guys at 3am in full fire retardant fueling gear, helmet on, visor down, sleeping under a blanket in the pit right next to the wall.. inspiring. None of us wanted to let them down.

Hell Hour
  Between about 12:30-1:30am, we had a successive rash of failures and mechanicals on both cars. For an hour our crew was literally sprinting from the pit back across the wall to the paddock spot to perform emergency repairs. Shouted commands, tools clanging, guys diving under cars, frantic calls for spare parts. That some of the mechanics were asleep when the cars came it added to the confusion. Just before the chaos, we at about the halfway point in the race with a unassailable 10 & 12 lap lead over P3. Killin' it pretty much.

  We had a wheel fall off of Enzo after the improperly installed wheel studs sheared off. This after an unscheduled stop for front pads. A few laps after that, Crusher had a big brake fade sending William off the top of T9 onto the hillside. As it turns out, there is an access road there. Good thing because by the time he got the car slowed down, he was about 200' from the track edge. The in car video shows him about 100' up on the hillside above the track. He crept along about 1/4 mile down to T11 to rejoin. A lap later the brakes failed completely, just before the pits. He managed not to stuff it into anything and limp into the pits brakeless. Crew jumping on the hood to stop it.

When the dust settled around 1:30, the two cars were back on track, running fast but about 11 laps down on P1. Crusher spent more time in the pits so Enzo inherited P2.

Recovery
   Just after the frantic repairs and getting the cars back out, our team collectively had a short phase of well, dejection. It was easy to get discouraged. A big lead evaporated, confidence in our entire effort seriously shaken. Me and a few key members made an effort to rally the guys back on point. The reality was that we easily had enough time to regain the lead considering our pace and track position before the mechanicals. The somber air was short lived. Everyonne quickly realized we were very much still in the race for the win. From there on out we all had this unspoken feeling that we were just plain going to win it. As if the mechanicals were some sort of test we had passed. Are we worthy? Damn straight we are.

In the end, we finished 1-3 in class and 8th overall. What's blew us away was that we beat every other class except ES. Huge.