Should you run a thermostat in Spec Miata?

Well... it depends.

This is a question that arises often.  I've read all the threads on various forums and opinions on both sides of the question.  Some say get rid of it that it is a failure point.  Some say that the cooling system needs the slight bit of restriction of the thermostat to prevent against boiling the water in the head.  I did some research into this topic and figured I'd share.

Some background on the Miata thermostat
The Miata uses a generic, common sized thermostat with a 52mm / 2 1/16" diameter.  NAPA was the only parts store that would give me a hard time when I ask for a generic 2 1/16" thermostat in 180* or 160*.  Every other part store would only look up the Miata and sell me whatever the stupid system said was the one.  Just walk into NAPA and ask for a generic thermostat in 2 1/16" and 180* temp with the part/reference number of 142 and they should be willing to help you.

Let's get to it
Let me start by sharing some facts from a well known Spec Miata builder and engineer Dan Tiley of Ti Speed Engineering.  He was also a Development Engineer and NASCAR.  Refer to this thread:
http://forum.specmiata.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=44;t=003785;p=0#000001

Dan's comments:
I absolutely disagree with the idea of targeting your run hot coolant temperature at 160, 170, or even 180. There are several reasons for this. Your Mazda engine has an iron block and aluminum pistons, which have very different coefficients of thermal expansion. The cylinder diameter will "grow" fractionally at a rate of approximately 7e-6 units per degree F. The pistons grow at nearly twice the rate at 13e-6 units per degree. What this means is that your the clearance between the piston and cylinder wall is larger at lower temperatures. My dyno tests have shown very repeatably with back to back runs that the car will make x HP cold, and will increase with each run and then starts to decrease again after 210, due to the ECU beginning to pull timing. To make the absolute most power, you want that piston to cylinder wall clearance to be as tight as possible. Of course, once the car starts heading for the 240-250 range, that clearance becomes 0 at which point the engine starts to try to make it's own clearance.

My point is that it's a delicate balance act. Peak power is achieved in the narrow window of tightest possible piston to cylinder wall clearance, and the point where the ECU pulls timing.

I can assure you that 100% of the ECM tuning was done with a 192 thermostat installed. Running at a lesser temperature means that you're operating in a region where your fuel and ignition maps are not optimized, thus robbing you of HP's. 

Target 195-205F for your running temperature. I've tapped into the stock Mazda CTS (Coolant Temp Sensor) and read this digitally live on my on-board display, and note the temp while making dyno runs.


Focus on the bold text where he says that the target temp should be 195-205* F.  I exchanged a few emails with Dan on the topic.  He's a smart dude.  He races in the South East US where it gets hot and humid in the summer.  At one point he used to run a thermostat.  Now that the front of the pack of the top prepped car drafts and bump drafts, he has found that he needed to remove the thermostat in order to run optimal temps.

So, like I said, it depends - on your water temps.  Install a coolant / water temp gauge on your car to ascertain what your operating temps are and determine what you should do.  I installed an Autometer Elite gauge with Peak and Hold functions measuring water temps from the back of the head - which is the hottest point in the Miata's cooling system.

If your temps are too low, run a thermostat so that you can get the operating temps up to the target 195-205* F.  If you see temps too high with a thermostat, test without the thermostat and see where your temps are.  I have done this testing here in northern California running at Thunderhill, Sonoma and Laguna Seca raceways.  I'll share my results.

OEM thermostat
The OEM thermostat opens at 192* F.  Lots of people on miata forums and some on spec Miata forums and race forums will go on and on about the OEM thermostat and how you must run an OEM thermostat or your car will spontaneously combust and aliens will come get you.  Yeah.  You can safely ignore them.  Dan Tiley confirmed as much in my email exchange with him.  I've had good luck with NAPA thermostats.  They seem well built.

In my car, running the OEM thermostat, a Koyo 52mm radiator, starting position around the middle / back half of the pack, minimal drafting, northern CA temps ranging from ~60-90* F in dry air, I would typically achieve operating around 210-215* F.  Sometimes as high as 220* depending on ambient temps and the length of the session.  30 minute sessions resulted in slightly higher temps (215+) toward the end of the session.  On hot days, I could feel the power decrease as temps rose and the session or 20 minute race.  The Miata ECU will pull timing as engine temps increase.  You can feel the power difference.

This is what the OEM thermostat looks like.  Note that I removed the 'jiggle pin' which would typically have occupied the space between that arm on the right and the small right protrusion on top.

NAPA 160* thermostat
I briefly experimented with the NAPA 160* thermostat.  This is sometimes referred to as the #42 NAPA thermostat since that is their part number for it.  I read a bunch of people on miata.net talking up the thermostat and l tried it.  It sucked on my car in northern California temps.  The engine would not get up to temp - which means excessive wear and low power.  The cooling temps would barely hit 180* F on a hot summer day.  Regardless of what 1950s hot rodders say, those temps aren't appropriate for the Miata.

NAPA 180* thermostat
I next tried the NAPA 180* thermostat.  This works well for me.  Coolant temps typically stay at 200* with this the 180* thermostat.  They'll basically range from 195-205*.  I once observed cooling temps of 208* once when running in ~100* F ambient temps in the middle of August in Willows, CA at Thunderhill Raceway.  Never higher than that.  Power stayed consistent from the first lap to the last lap.  Like Goldilocks and the 3 Bears, the 180* thermostat was just right!

Here is a pic of the NAPA 180* thermostat - part reference number 142.

*Note: Do not use the crappy, paper thin generic gasket pictured above.  It won't seal.  Don't ask me how I know.... :(  Use an OEM or Fel-Pro gasket.  NAPA should have Fel-Pro.

The NAPA 180* looks exactly the same as the 160*.  If you have one installed in your car and are curious about what the temp rating might be, try looking underneath it like so.  This is the 160*.

Comparing the 3 thermostats, it seems like the engine would typically run about 20* F hotter than the thermostat opening point when driving at race pace in mostly clean air - meaning I wasn't drafting lap after lap like some of the guys at the front do.

Now, all this will vary depending on your ambient temps, humidity and how much drafting / clean air you have in your races.  The point is that although some people say that thermostats should be removed, other say thermostats should be kept, others say only run the OEM thermostat; the final answer as it relates to your car, in your region, in your race conditions is going to vary.  So test and figure out what works for you.

If you do wind up doing some testing and can confirm what works in your region, please come back here and share your experience so others can be well informed.

What tools do you need for Spec Miata?

If you are the DIY type like most of us budget racers are, you will want to wrench on your Miata and do your own basic maintenance and race preparation.  To do this requires tools.  However, it does not require a lot of tools as the Miata is put together very simply using a common size of fasteners (bolts, nuts etc).  If you just bought a Spec Miata or are preparing to build your own Spec Miata, the list of tools below will be sufficient to perform just about any job.

• Lug wrench or, if budget allows, a battery powered impact gun for the lug nuts
• Jack - I like the Sear's aluminum racing jacks.  Mine has been very reliable and solid to use and has a low front so it fits under the side rails.  Look for sales.  Harbor Freight has some small aluminum jacks that will work also 
• 4 jack stands - I personally like the aluminum jack stands from Harbor Freight because they are really light and are cheap.  2 ton jack stands are sufficient for a Miata but 3 ton also works.  
• 1/2" drive torque wrench - I have found that the 1/2" drive torque wrench is more useful than a 3/8" drive since it is capable of torquing fasteners to 150 ft-lbs.  I like the Sears Craftsman torque wrench for the combination of price and accuracy.
• 1/2" and 3/8" drive ratchets - again, I prefer Sears Craftsman for price and reliability and their warranty.
• 1/2" drive breaker bar (immensely useful!)
• 3" extension for 3/8" and 1/2" drive
• 6" extension in 3/8" drive
• Must have Sockets - You will use these sizes regularly.  Some more than others.
• 19 mm for the oil drain
• deep 17 mm 1/2" drive socket for the lug nuts 
• regular depth 17 mm socket in 3/8" and 1/2 drive
• 14 mm socket in 3/8" and 1/2" drive
• 12 mm socket in 3/8" drive 
• 10 mm socket in 3/8" drive
• 23 and 24 mm for the transmission and differential oil drain and fill plugs (or get crescent wrenches)
• 21 mm for the long bolt attaching the rear lower control arm to the spindle / upright
• 5/8" spark plug socket (use in conjunction with the 6" long 3/8" drive extension)
• 29 mm 1/2" drive socket for the front hubs.  This will work on the rears unless you are running a Torsen rear from a 99 car then you need a 32 mm socket for those.
• Crescent wrenches in 8 (brake caliper bleed), 10, 12, 14, 17, 23, 24 mm.  19 mm can be helpful also but not often used.
• 2 screwdrivers
• metric Allen wrench set - These are useful good for rear brake caliper adjuster (4 mm is needed to change rear brake pads) and also useful for other bits and bobs around a race car.  I have found 3, 4, 5, 6, 7, and 8 mm to be useful.
• Set of Pliers - I use channel lock pliers for pressing the front caliper pistons back into the caliper.  The other types of pliers are useful for hose clamps, air intake clamps, clipping wires and zip ties etc.  
• A Big Frickin' Hammer is always(!) useful
• Oddly enough, I have found a pry-bar to be very useful as well.  I use an old crowbar.
• Brake bleeder bottle or one of those fancy one-man bleeders 

Nice to have tools and socket sizes.  These are useful occasionally:

• deep 14 mm in 3/8"
• deep 10 mm in 3/8"
• 13 mm is useful in case someone changed an OEM 12 mm bolt or nut to an aftermarket bolt or nut.  The aftermarket ones typically have 13mm heads for the same thread pitch as OEM bolts.
• Ratcheting right angle Screw driver thingy from Sears has gotten me out of many tight binds...
• Punch and Chisel kit is also indispensable for pounding out the long bolt in the lower control arm when you bend one.  

I think that about covers the basic hand tools that use on a regular basis.  I carry them in a small plastic tool box from Sears.

Let me know if you have any questions.  Happy wrenching!

Time to rebuild a Spec Miata motor!

I've been racing on a low mileage (91k miles), unopened, street motor for the last 3 years.  It dyno'ed 107 RWHP 2 years ago.  Being down on HP in a Spec class means you are at a disadvantage.  My plan had been to practice and get experience on this street motor and then upgrade to a better motor down the line when my skills improved.

At one point, a friend and fellow competitor did a practice session on my car with fresh tires and was able to do a 2:13 at Thunderhill.  He typically lays down 2:08 - 2:10 and better lap times in a 99 with a "pro-built" motor.  That was my target time.  If I could improve up to that time, then my skills would have improved sufficiently to make full use of a pro motor.

I have finally improved enough where I can hit a 2:13 but I still wasn't as consistent as I'd like so I've been holding off.  Until the events of Laguna Seca a couple of weeks ago.....

At Laguna, I made contact with a tire wall when I made a mistake at Turn 4.  When I changed the oil after the event, I found a few metal chunks stuck to my magnetic oil drain plug.  My theory is that the impact shifted something inside the motor.  On a thread on MazdaRacers.com, knowledgeable people speculated that it could be casting flash while other suspected pieces of a thrust bearing.  Either way, having metal bits coming our of your oil is never a good sign...  See pic:

In your typical Spec Miata field, the engine situation typically breaks down as follows:

1. Cheap bastards like me with untouched street or junk yard motors.
2. Decent, unopened street motor bottom ends with a "pro-built" head that has been rebuilt and machined for higher compression with blueprinting at the valve throats and whatnot as the rules allow.  This typically yields 110-116+ RWHP.  Pro built heads are typically $1k - 1,500k.
3. A rebuilt "regional", "pro-built" motor that is a budget rebuild of the bottom end and head and maybe some head work.  This typically seems to yield around 113-118 RWHP.  Rebello offers a package for $2,500 which a few friends run.
4. A full "nationals" "pro-built" motor that gets all kinds of attention, special sauce and special grease.  Pixie dust as well.  This typically seems to yield around 120+ RWHP.  Haag, Rebello, (local shops) and Race Engineering, East Street are the big names here with prices upwards of $5k.

I could have gone to any number of good engine builders but I decided to try and rebuild the original motor that was in the car.  I'm a low budget, weekend racer.  I don't want to piss away a ton of money on a recreational activity.  I'd rather have it in the bank.  Plus I've always wanted to rebuild a motor.  Now I have an excuse!  I know the history of the 180k miles of the original motor that was in the car so I know it was taken care of.  The poor, neglected motor has been whispering at me from the corner of the garage where it lay for the past 3 years asking to make it run again.

So hear goes nothing.  Over the next few weeks and 2 months, I'm going to chronicle my rebuild, take lots of pics and write a few blog posts about my adventure.  Follow along.  Hope you enjoy it.

I'll leave off with a pic of the poor engine on it's dolly.

Suggestions and advice are greatly appreciated so post up or email me.

Tips on installing a new Alternator on the Miata

Creating this short article to try and help out others who may be confused trying to setup the tensioner bolts. I've seen a few people in the pits struggling with them and a few people DNF when they installed them incorrectly.

When I was unloading the Miata after the last race, I noticed that the headlights seemed dim.  So I located my voltage tester and started the car to check the voltage.  Sure enough, voltage was around 12 volts measured at the battery terminals with the car running.  Should be about 14 volts when running.  So I went over the local O'Rielly's Auto Parts and got a new alternator.  Shiny. :)

Here is a pic of the tensioner bolts:

Here is a pic of the tensioner bolts positioned on the alternator off the car:

Here is a pic of the tensioner bolts positioned on the alternator bracket on the car:

Here I have positioned the alternator on the tensioner bracket and fed the bolt through the alternator.  Don't tighten the bolt that goes through the alternator too much yet as you still need to tension the belt properly.

In order to properly tension the belt, don't try to wedge a screw driver or something to put tension on the belt.  Instead, tighten the long bolt against the bracket using a 12mm ratcheting socket.  Don't overtighten.  The only purpose of the long bolt is to put tension on the belt.  Once you have the belt tight, tighten the short bolt that goes through the tensioner block and attaches the alternator to the tensioner bracket.  Don't overtighten this bolt either as it threads into the soft aluminum of the alternator.  Hopefully the following pic does a good job of explaining this visually:

Hope that helps.  Check to ensure that it remains tight next time you run or drive the car just in case....

Also make sure you install the air tube/intake correctly so it doesn't rub up against the alternator belt.

2013 Racing Season Has Started!

The 2013 racing season has officially begun!

The 2012 season sucked for me.  I started a new job and didn't have the time to race.  I managed to get out and do 3 races.  However, my performance was rather poor compared to my friends from the 2011 SCCA Licensing School.  They were able to attend regularly (monthly) and their times and performance improved regularly.  My performance did not improve during the few races I did.  Seat time - Practice Practice Practice is what you need to improve and get ahead.

I did manage to get out to the San Francisco Region SCCA season opener last weekend at Thunderhill.  I did absolutely nothing to the car to prep.  I didn't even change the oil.  I just showed up, set tire pressures and ran.  I was expecting to have terrible lap times but was very surprised by my performance in qualifying.  I ran a personal best and consistent 2:14 lap times.  The best I did prior was 2:15s so I was stoked.  After this performance I was really looking forward to Sunday's races. :)  Here is a link to video from my qualifying:



I raced both Spec Miata and in ITA.  ITA races in Group 5 which is a mixed marque group of classes including some very fast cars from ITS and ITE and others.  Unfortunately, my Sunday races sucked.  I couldn't string together a consistent, mistake free set of laps nor could I match my times from Sat.  Oh well, I kept it clean and drove the car home in one piece.  Here is video from the race:



My video camera battery went dead so you won't see the closing laps of the race where I spun in Turn 3 and had to go both feet in.  :(

Next race Laguna Seca.  Going to change the oil this time.

I Fabricated a Water Temp Gauge Bracket for the Miata

It is currently September and starting to cool off here in Northern California.  However, in July and August the San Francisco Region SCCA had 2 races scheduled at Thunderhill Raceway.  Those are the hottest months of the year in lovely Willows, CA with temps in the 90s.  I did happen to make the race in July (and did terribly because it was only the second race I've been to all year - more on that in another blog post) and it was HOT.  Miatas aren't particularly difficult to run in hot weather if you have a good radiator but a couple of guys overheated and seized motors.  I decided to install a water temp gauge.  Along with the gauge, I needed a way to mount it.  I decided to fabricate my own bracket.

Why fabricate my own water temp gauge bracket?  Why not just buy one somewhere?

Two reasons:

1. I couldn't find a bracket that would place the gauge front and center right in front of my field of vision.  Lots of people mount the gauges in the vent holes in the center console but that is out of my direct line of sight.  I don't want to have to remember to look to the right or left to see the gauge.  I'd rather it be directly in front of me.
2. Because I can. :-)

Miatas are dead-nuts reliable cars.  They don't really suffer too much in hot weather compared to other cars.  However, during the race in July I noticed after the race that the Miata's coolant temp gauge had moved a little bit from it's normal position in the center of the range.  Sadly, I couldn't recall when I had last looked at the stock water temp gauge.  Hence my desire to have the gauge front and center.  I also got a cool top of the line Autometer gauge with a warning light that will be impossible for me to miss but more on that in another blog post.

Anyway, here are a couple of pics of version 4 of the bracket.  Yeah, I made 4 prototypes before finally settling on this location. I thought it would be easier and quicker.  I lost count of how many hours it took me to finally get the gauge so that it didn't block redline on the tach and had minimal blockage of the speedometer.  Quite a bit of trial and error.

Check it out.  Look cool?  I'm wondering if I should make a few more and sell them...

Sorry about the wash-out from the flash and lighting.  I'll get some better pics in the sunlight next race.  Here is a closer view from the side:

Cheers!

How to override the Miata's clutch switch (aka starter interlock switch)

What is a clutch switch aka starter interlock switch you ask?  It is the switch that is attached to the top of the clutch pedal that tells the ECU whether the clutch is depressed.  The stock setup requires that the driver hold the clutch down to start the car - probably for insurance liability reasons.  Don't really need this on a race car.

Why override this?  Sometimes, you want to start the car to check something and it gets annoying crawling in through the roll cage to do so.  For that reason, I had been meaning to override the clutch switch / starter interlock for a long time now.  It also gave me something to do as I had some time to kill. :-)  People smarter than me say that depressing the clutch pedal to start causes wear on the thrust bearings.  I personally don't know if that is true but there you go...  

How do you do this?  It takes about 10 minutes.  It took me about 30 minutes googling around trying to figure out how and 10 minutes to do it once I figured it out.  The easiest way to explain it is probably to post these two pics.  If you have any questions, get in touch.

and

Good luck.

Transmission Oil Change & intervals

Let's talk about transmission oil on a Spec Miata race car.  I finally changed the oil in the transmission the other day in preparation for the 2012 racing season and wanted to share some thoughts and experiences.

Let's start with some background....  The transmission (and engine) in my car (1990) is from a 1991 Miata and only has 91k miles.  I saw the odometer of the car it came from so I know it is legit.  It shifts incredibly well and doesn't make any odd noises.  I installed the engine and trans late in 2010 for my rookie season in 2011.

The first decision I had to make was which oil use.

Deciding on a Transmission Oil

NEO Synthetic 75/90 gear/transmission oil

As part of maintenance and in preparation for the 2011 racing season, I drained what looked like the original transmission oil and filled it with NEO 75/90 synthetic gear/transmission oil.  I had decided to try NEO for 2 reasons:
1. Based on feedback from various 3rd generation RX7 owners that I know
2. Because the transmission on my street/track 3rd generation RX7 had run Redline MTL its entire, long, hard life on race tracks across the US and the bearings were absolutely trashed when I had the trans rebuilt.  MTL is pretty thin and slippery which makes for great shifting but some people have mentioned bearing wear on transmissions that have used MTL regularly.  Granted, this is anecdotal but good enough for me for now...

I ran the NEO synthetic 75/90 on the street and track here in Northern California and it worked reasonably well.  The transmission shifted OK using NEO.  The one issue that I did have was on the 2-3 shift.  It was a challenge to get that shift done smoothly during a race.  I noticed this at Thunderhill in turn 5 and in Turn 11 and also at Laguna Seca in turn 2 and turn 11.  My motor mounts (Mazda Competition) and diff bushings are in good shape so I couldn't blame driveline slop for this issue.

Time for a switch but which oil to use???

Swepco

I know a few local Spec Miata racers that use Swepco gear oil in their transmissions and differentials.  I have been thinking of trying this oil but it isn't available locally so it is takes more effort to get my hands on it. I didn't do enough planning in advance to order some and wound up not using it but I suspect I will try it.

Redline gear/transmission oil

I decided to switch back to Redline transmission oils.  Redline actually makes two oils for manual transmissions - MTL and MT90.  If you read your owners manual for recommended oil viscosity, you will notice that it says to use 75/90 in colder climates and 80/90 for warmer/hotter climates.  At least, I think that is what I remember reading...  I had tried Redline MT90 in my RX7 and liked it so I thought I'd try it in the Spec Miata.

Redline MTL is a 75/80 weight gear/transmission oil.
Redline MT90 is a 75/90 weight gear/transmission oil.

When I drained the NEO from the transmission, the oil only had about 4 events including SCCA Driver Licensing School and some street usage.  It looked like it was in reasonably good shape and there wasn't a lot of metal "fuzz" or flakes on the magnet in the transmission drain plug.  Too much metal shavings on the drain plug magnet means too much wear on the gears and bearings.  I filled the trans with the Redline MT90 and also topped off the shifter turret - don't forget to do that!

Results

Switching to the Redline MT90 had the desired result improving the transmission's shifting overall.  The transmission shifted smoother than the NEO and the fast 2-3 upshift was noticeably smoother in race usage at both Thunderhill and Laguna Seca.  I wound up keeping it in there for the rest of the 2011 season and the test days that I did at year end.

Maintenance - Transmission Oil Change Intervals - Spec Miata

What do racers do in the off season when waiting for the race season to start?  Maintenance for one.  I had about 8 race weekends on the transmission oil at this point so I knew I had to change it for the 2012 season.    I briefly thought of trying Swepco but I forgot to order it and wound up going to Rotorsport since they are local to pick up some more Redline MT90 since they stock Redline, Motul, Royal Purple and a bunch of other race lubricants.

I drained the transmission oil and was surprised by the amount of "fuzz" from metal shavings on the drain plug magnet.  I should have taken a pic but I usually make a mess when changing the transmission oil...  There was too much metal shavings on the magnet than I was comfortable with.  I am going to decrease the transmission oil change interval on my Spec Miata to 4 or 5 weekends.  Hopefully there will be less metal on the drain plug next time around.  If there isn't, then I will probably switch again.  I wound up taking a sample of the oil and will be sending it to Blackstone Labs for analysis so that I have actual data on the performance of the Redline MT90 in Spec Miata race usage.  Real data is better than anecdotal "evidence".

If anyone has input on transmission oil and oil change intervals, please comment.

Making weight on the Spec Miata - East Street Racing Ballast System

For 2012, SCCA and NASA both increased the weight for the 1990 - 1993 Spec Miata to 2,300 lbs including driver.  The car weighed 2,275 lbs last year with my ~185lbs and I barely made weight with some fuel.   My car is a 1990 model.  The VIN confirms that it is an early build car and was actually built in 1989.  This car started life as a base model, no options car - so one of the lightest Miatas.

With the new rules, I needed to add weight to the car.  I've seen a lot of other cars running the kind of weights you normally see around the gym mounted to the floor boards with long bolts.  Ever see the floor boards of the Miata?  They are paper thin and move if you breath on it let along mount weight to it.  With all the Miatas in the world, somebody had to have made something better than gym weights, right?

Researching revealed a few options:

1. Get in touch with your local race fabrication shop or roll cage builder and see what ideas he as.  Chances are they probably have some ideas.  I thought about doing this but using the power of Google search stumbled upon another blog from a racer who took a different route...
2. Local racer Brian Ghidinelli dealt with the issue on his blog: Ghidinelli ballast blog post  He had a local metal retailer cut some metal plates to fit the floorboards of the Miata and bolted the plates in.  Good approach but I didn't quite like it since it still relied upon being bolted to the flimsy floor boards.
3. Rennenmetal makes some ballast plates that fit the curvature of the Miata's floorboards and includes mounting brackets.  Pretty nice but I still don't like the idea of bolting that much weight to the Miata's flimsy floor boards.  Check these links for Rennenmetal's parts:
Rennenmetal Miata Ballast Plates
Rennenmetal Miata Ballast Mounts

4.  East Street Racing Spec Miata Ballast System - I stumbled upon these on MazdaRacers.com.  East Street Racing developed a ballast system that bolts to the OEM passenger seat mounts.  This decreases the risk of the weight loosening or ripping out of the floor boards if something were to happen.  The stock passenger seat mounts were designed to hold a normal sized human being so they are probably good to about 200lbs or so.  While a little pricey, my safety is worth it.  

I highly recommend the East Street Racing Ballast System if you are looking to add ballast to your car. They came nicely wrapped, shipped quickly and install easily.  The bottom plate seems to be bent/formed so that one particular side fits better on the front than the rear seat mounts.  Test fit the bottom plate and you'll figure it out.  The bottom plate also has 4 nuts welded to the bottom to facilitate mounting the extra top plates.  Nicely thought out and very well fabricated system.

You'll need some bolts to mount the top weight plates.  They are 1/2" coarse thread.  A 1.5" length bolt will fit the bottom plate and 1 or 2 top plates.  I only have one plate mounted so far and it seems to have plenty of length to fit another plate.  I bought some Grade 8 bolts and washers from the local hardware store.

You can buy them here: East Street Racing Ballast System

The plates are not painted so I decided to paint them prior to installing so that they don't rust.  This led to me painting the passenger side floor boards and hitting them with a wire wheel to get some surface rust off the floor boards.  I basically got some brush on Rustoleum from the local hardware store and got to work.  I was too lazy to paint the whole interior so I stopped at the passenger floor.

Here are pics of the final product installed.

Enjoy.

Here is a view from the front seat mounts.

Flipping Tires - Things you should know

In the weeks after the race at Infineon, I spoke with other racers about my experience with my tires lack of grip.  Lots of speculation.  Most people thought it was b/c I had so many heat cycles on them.  It was an obvious conclusion - but it was not correct.  Testing the tread with a durometer showed that the tires were actually still nice and soft and not hardened from heat cycles.

I kept on exploring and finally figured it out.

At the last race, I had decided to "flip" the tires to even out wear patterns.  Flipping the tires refers to dismounting them and remounting them so that the inside tread is now on the outside.  This enables you to get a little more life out of the tire and saves money.

Turns out when you "flip" a tire, you need to put at least one session on them.  Otherwise the tires do not grip.  Major lesson learned....

In retrospect, I'm not sure if this actually saved me any money.  It cost me a few $ to flip the tires and the car didn't have any grip, ruining a race weekend.

When "Flipping Tires", plan on doing a session or two on them so that the tread grips again.

Racing at a new track - SCCA @ Infineon

So the next race was Infineon Raceway in Sonoma, CA.  I have only been to this track once before in my street car (RX7).  Infineon is known as a technical track.  It is more challenging and difficult to learn than Laguna Seca or Thunderhill.  There are many and frequent elevation changes.  Most corners are blind (meaning you can't see the apex or exit).  It doesn't even really have a straight.  This track keeps you busy working the car the whole time.

The scariest thing about this track is that it doesn't have any run-off.  If you go off, you are probably going to hit something.  I had just finished fixing my car and was not looking forward to breaking anything else...



How to prep for a new track
I wish I could give you pointers on how to do this but I don't know if I have much to go on.

In preparation for this race at a track that I wasn't familiar with, I watched many Spec Miata videos on YouTube and Vimeo to try and understand braking points, turn in points and see if I could learn this line.  Viewing the videos, made me feel comfortable.  However, once I got out on track, what I had seen in the videos just didn't translate well to what I did on track.

With the large elevation changes at this track and blind apexes, the videos just didn't seem to help me all that much.  I felt totally lost out there.  Next time, I'm going to try and do a test day before attempting to race a track that I've never been to before.



Let's talk tires for a bit.  

This race was at the mid-point of the season and I was still running the original 6/32 shaved Toyo RA1 tires that I had bought at the beginning of the season.  They were wearing surprisingly well.  The outside edges were showing a bit more wear than the inside of the tires.  Some people "flip" tires to get more life out of them.  This involves dismounting the tire and remounting with the inside "flipped" so that it now on the outside.  Being the frugal person that I am, I decided to do this.  I had AIM Tire flip the tires Sat morning of the race weekend.




Racing at a new track
So, new track, learning the lines, trying to re-build confidence after my last race where I damaged my car.  Lots of challenges.  I just could not get comfortable.  I tried following people during practice but my tires didn't seem to have any grip.  What could be wrong?  The tires felt awesome last race.  Could I have used them up suddenly due to all the heat cycles?  The tires still had about 2/32nds of tread.  Was it just the driver's self confidence?  Very un-nerving at a track as challenging as Infineon....  My qualifying times had me last.

The race finally came and I approached feeling very uncomfortable.  The car didn't have any grip and I couldn't keep up.  Pretty soon, I was getting lapped.  Approaching the Esses, I noticed a string of front runners coming up fast.  There isn't enough room for a 5 car train to pass in the Esses.  What should I do?  If I held my line, I was afraid I'd get taken out so I slowed up and pulled off line so the train could get through. Then I drove into the hot pits and called it a day.  I'd rather have the car in one piece so I can figure out what was wrong and save it for the next race.

How to Diagnose a Bent Ball Joint

If you ever need to diagnose if you have a bent ball joint, here is a video tutorial. Hope it helps.

Assessing and Fixing the Damaged Front End

If you read my last post, you'll learn that I wrecked the front end of the car in a bad spin at the last SCCA race at Thunderhill in July 2011.

Damage Assessment

I got the car home and got the front up on jackstands and started to assess damage.  Here is what I found.

1. Upper control arm bent:

2. Lower Control Arm very slightly bent (forgot to get picture).  I probably could have re-used it but it would have affected how much camber could be adjusted.

3. Front Subframe bent badly.  Here are a few pics illustrating the damage:

- Subframe Lower Control Arm rear mounting tab bent:

- Subframe Lower Control Arm front mounting tab bent:

4. Front wheel bent:

I had already changed the front subframe once before while building the car b/c the driver side mounting tabs for the steering rack had been bent at one point in the car's life.  It isn't that difficult to do but is a bit time consuming and not fun.  I decided to tackle the repair myself so I started sourcing parts.  "Where to source these parts?" you might be thinking.  The answer is craigslist. :-)

Most of the used parts sourced for this car came from craigslist.  So I turned there again.  It seems like there is always somebody local parting out a Miata on Craigslist.  Since the parts are local, shipping costs are eliminated.  

I decided to upgrade the front subframe to the one from the 94-97 Miatas.  These cars came equipped with more bracing from the factory on the front and rear subframes.  You technically could add these braces to the original subframe of the 90-93 cars but that would require more work on my part.  When I started looking for parts, I discovered that a fellow racer had the parts I needed.  He cut me an awesome deal at $100 for the front subframe, spindle and lower control arm.  I didn't need the upper since I had a spare.  I sourced  a new wheel from our local race tire supplier and series sponsor - AIM Tire.

So I picked up the parts and started wrenching to get the car ready for the next race.  I replaced the subframe and control arms.  I didn't replace the spindle at this time because a I couldn't get the ball joint separated so I left it alone since I had replaced the ball joint when I built the car.

Here is a comparison of a bent subframe the straight, un-bent replacement.  The bent subframe is on top.  The replacement is on the bottom.  The control arm mounting tabs were bent a good 1/4".

If you never replaced a front subframe on a Miata, it isn't particularly difficult.  It took me the better part of a day to do it 4-6 hours.  If you want specifics, please contact me and I can prepare a write-up with pics.

Do you think I got it right?  Sadly, no....

Once the car was back together, I brought it over to TFB Performance to get the car corner balanced and aligned.  Here is where we discovered that I had not replaced ALL of the bent parts.  We couldn't get more than -1.5* of camber on the passenger front.  Turns out the spindle and the ball joint were also bent.  I never even knew those parts could bend....  Thankfully, TFB does a lot of Miatas and had the parts in stock.  He installed a new ball joint and a used spindle.  I spent about $700 in total on this repair.  Expensive mistake but it could have been worse.

If you are curious about how to diagnose a bent ball joint.  Here is a video I took repeating the diagnostic procedure that TFB had done in the shop.  Basically, put a socket on the ball joint, put pressure so that the ball joint is pushed downward or outward so that it is against the outer edge that it sits in, then turn the wrench as if you were tightening the nut.  Hopefully the video makes sense of this:

Frustrating repair but it got done.  When's the next race?

SCCA Spec Miata Race - July @ Thunderhill = Spin and wreck...

This was a frustrating race. Blogging about it made it more frustrating. Hence the radio silence on the blog.

I was having a great weekend. The car felt great. The tires were performing well and I was getting a lot out of them. Pressures were 38 PSI checked after hot practice and qualifying which is perfect. My lap times improved a lot. I was finally doing 2:16s at Thunderhill which ain't bad for a rookie. Then the race started....

Check out the race on YouTube here:

I was chasing fellow rookie Cliff in the white car with the burgundy stripe. I was pushing hard and making him work for his position. Problem was that the tires were starting to lose grip. My mind was telling me that I had to slow it up a bit and let the tires cool off a bit and come back to me. The "Red Mist" was telling me to push harder. Just one more turn. So I kept pushing. And then.... I had no grip at T5... Oops.

I crested the hill and the car was already sliding and eventually looped around. The passenger side front wheel hit the adjoining road surface sideways and damaged the front end of the car. I could have rolled it if the rear wheel had also made contact there but thankfully that didn't happen. I wound up sitting in that spot and waiting for the race to finish so I could get the car back into the pits.

Thankfully I was able to load the car onto the trailer so I could get it home and figure out what I was going to do and how I was going to get this fixed.

This sucked.

 Lessons learned = Beware the Red Mist. Believe what your tires are telling you. Loss of control can be expensive.

Preparation: Weight Loss

I had my car aligned and corner balanced back in January when I finished the build.  A bunch of local winning racers that I met at the track when doing my research and on the MazdaRacers.com forum had recommended that I go to TFB.  Tim F. Barber has won more races and has so many trophies that his shop is absolutely overflowing.  His shop is located at Infineon Raceway.  Tim did a great job on my car at the time.

However since that time, I have had about 5 off track excursions (remember the big spin I told you about at Thunderhill...?).   After the last Laguna race, I removed the wheels, rotated them and washed the car.  While the wheels were off, I noticed that the passenger side tires seemed a bit more worn on the outside than I expected.  I didn't think much of it at the time.  However, when I drove the car over to TC Design when I had Tony build my exhaust.  I noticed that the car didn't feel the same and the steering wheel was slightly turned to the left.

My car is still registered and insured by the way.

Something was obviously wrong and tires are expensive.  I am planning on taking the car into TFB so I can have it aligned and corner weighted again.  In preparation of taking the car to him, I want to do 2 things:
1. Remove some weight.
2. Install a Cool Suite system.

I had my car weighed at Laguna on the Tech Inspectors scales just to check what it weighed in at.  I had half a tank of gas when I weighed the car at TFB the first time.  The fuel gauge was on E so I probably only had 2 gallons of gas in the car.  I weighed in at 2302 with me in the car.  The rules state that minimum weight is 2275 for the 1.6 Miata.  Fuel weighs about 6lbs per gallon so I figured I could stand to loose a bit of weight from the car.

TC Design trimmed material from the doors when they did the cage.  They trimmed enough to fit the dual NASCAR bars on each side so I had a little bit to loose - or so I thought.

There was a recent discussion on Mazda Racers about removing material from the doors:
http://mazdaracers.com/index.php?showtopic=1040
In that discussion, everyone seemed to think that you needed a plasma cutter or air tools to trim the doors.  It sounded a bit over kill when I read that thread.  I had a look at my doors and the sheet metal is really thin and flimsy.  It seemed like it wouldn't be that hard to trim the doors with the tools that I had available.  Remember - I don't have air tools or a welder.  I work on my car in my garage with hand tools that I bought I Sears.

I had some time today and decided to try some weight loss techniques on my driver's door while I was doing laundry.

Have a look at this pic here.  Note that I already removed a rather heavy part in this pic as you can tell by the gray colored area at the top.  I also started cutting out a small triangle of sheet metal in front of the door handle.

If you look closely, you will notice a series of 1/2" sized holes along the top and bottom of that gray area.  That is where I used my power drill and a Uni-bit to drill out the spot welds and pull that part off.  Check out the pic below of the part removed and the tools I used:

Sorry, the Uni-bit is not pictured.  Do notice that long white piece of sheet metal.  Can you guess how much it weighs?
.
.
.
No?
.
.
That part along weights 2.5 lbs!  Frickin amazing how heavy that part is.  It is rather thick gauge metal and is butted up against some thinner gauge metal.  I was able to remove that using the power drill alone and a screw driver to do a little bit of prying in about 20 minutes.

As you can see in my pic with the tools, there is a bunch of scrap sheet metal, a Dremel and some sheet metal sheers.  I put them to use as well removing a bit more of the door metal as you can see in this pic:

Notice the line where I stopped cutting on the top end.  There is a reason behind that.  That top section is two layer metal spot welded together.  It is actually quite strong.  The sheet metal used for those two layers is nowhere near as thick as the part that I removed.  I left that dual layer area intact and just cut/trimmed the single layer of sheet metal around that section.  I don't need to loose a lot of weight so it really wasn't worth the effort to go crazy cutting stuff out.  Plus the laundry was done. :)

Oh, by the way, that pile of scrap metal didn't even register on the scales so not much to loose there...

I stopped there for today, cleaned up and got the shop vac out to vacuum out all of the metal shards that the drilling created.  If you decide to to this yourself, do wear proper safety equipment.  I wore glasses and gloves and put shoes on once the shards of hot metal started sprinkling down over my sandal wearing feet.  That stuff is HOT.  I also got hit in the face with a decent amount of metal scrap while drilling so do be careful.  Some metal in the eye will result in a trip to the emergency room or worse....  I will drill out that top section that weighs 2.5 lbs from the passenger side during the week as I have time.

Regarding the cool suit, I'm going to try and build my own next weekend.  They retail for about $300.  Judging by some threads floating around the net, I should be able to build my own for about $100.  I'll post up about that when/if I'm able to pull it off.  The temps at the next race at Thunderhill is expected to be in the 90s and 100s!  Gotta keep cool.