Course Dependent / SoPac Super Regional

  Once again this year El Toro hosted the Divisional, or Southern Pacific Super Regional, on the weekend of June 15-17.  Courses at ET typically use 2 runways and the crossover paths to make a large # symbol and ninety second courses or longer are common.  This usually creates several medium size 180* turnarounds and a bunch of 90* corners all connected with busy transitional legs with lots of room to occasionally need third gear.  Good grippy asphalt rubbers up nicely but also creates lots of sand off line.

  The printed course map looked great but when walking the course it was quicky apparent to me that I brought the wrong car.  Nearly every 'leg' was wide open with almost every transitional element offset the easy way, spaced far apart, non-existent (don't ask), or large enough radius not requiring a lift.  Horsepower course.

  This event would be the first event with the newly tuned piggyback and higher rev limit.  The power felt the same (it basically is) but the higher 7700 rpm rev limit worked flawlessly and kept me out of third gear, although I was still into the limiter several times on Saturday.  Sunday's course had me only on the limiter twice, but for a much longer duration, especially at the finish.  Not wanting to hurt the engine I am reserving 8K+ rpm limit for bigger events such as Solo Nationals.

 













  Above is the only course map that was provided and it is pretty accurate except for a missing a major element between stations five and six.  Area #2 was completely eliminated on Sunday.

    Day one:  The weather forecast was sunny and hot, well 80*F, so I brought the 70 run Hankook RS3 tires and scored another competent co-driver to help warm the tires. I left the water sprayer at home. STR runs last group and timing issues in the morning delay the event which means we don't go out till about 5pm or so. Visually the course is good, but being so long and with similar style corners it is easy to lose focus and after a long day in the sun I am exhausted.  Even with a tire warmer and sunny skies I still do not fully trust the first run on the Hankooks and it shows on the clock.  Run two was about perfect.  Run three was a half second slower and felt greasy which I attributed to me trying too hard. The car was a little pushy but nothing out of the ordinary. Setup was same as Qualcomm with the rear ride height at the low setting.  Clockwise direction course.  At the end of day one I was in seventh place about 1.6 seconds behind the leader.

  Day two:   The weather was several degrees warmer and the event was running smoothly, so we gridded up around 2pm during the heat of the day. The course was run backwards in the counter clockwise direction and both legs at station number two were elimated creating another fast rhythm section from station 3 directly to the finish. Car changes include rotating the tires and raising the rear ride height 1/8" to help aid rotation.  Tire pressures the same as day one at 28F, 25R.  First run I cone but the car is turning great and feels more lively.  Second run I make a huge mental mistake and briefly lose the course.  The greasy feeling I got on day one returns for our third runs and it seems the Hankooks were too hot (unpossible).  I manage a clean run but still about another 1.6 seconds behind the leader for the day barely keeping me in seventh position overall.

Final Results

   So why was the car turning-in and rotating so much better on day two?  Was the minor ride height change enough to make the difference?  Or was it the course flow?  Tire rotation?  Corner weights?  Alignment?  I seem to recall being faster on both left side pro courses (El Toro and Lincoln) and more confident on day one's SD Tour course.  Coincidence?  Psychological?

--------------------------------------------------------------------------------------
1/8" raise rear ( 1 5/8" from bottom of threaded collar to bottom of GC spring perch)

6 1/4" from lower shock eye to top of sping perch (bottom of spring)

6" springs and standard NB top mounts

Piggyback Tuning

   Having previously used Church Automotive Testing with good results in the past, I decided to have them tune my new Greddy EMU. Church uses a Dynapack dynamometer and the weather was 70F and sunny. I brought along a stock unmolested BP4W Federal ECU and the DPTune modified ECU (reflashed BP4W) for comparison.

   To my surprise, the DPTune ECU was right there with the best we could get from the Greddy EMU, only short about 1-2 horsepower and torque in a few spots.  Unfortunately I either lost the AFR file or Church did not give it to me.  The baseline runs for the BP4Y and BP4W show that the Federal ECU is the better of the two by a small margin, but both have poor AFR numbers.  Mazda engineered and tuned this engine well from the factory not leaving much to gain.  Although I am a little disappointed that we did not find more power, it is good to know the AFR is safe and the piggyback is reliable and easy to tune.
 

Thin blue line is maximum power from Greddy Emanage Ultimate and the thick red and green lines are both baseline runs from the BP4Y ecu.

Again, the thin blue line is Greddy EMU and the thick green line is the DPTune reflashed BP4W.


 

Left side shows two baseline runs each from both the stock BP4W (thick green and red lines) and BP4Y (thin green and red lines) with EMU at the top (blue line). Right side shows Air/Fuel ratio.




 
Stock BP4W baseline runs versus EMU.








   The Greddy Ultimate can increase the factory rev limiter by fooling the stock ECU into allowing the fuel injectors to function past the factory rev limit.  Basically, it does this by holding the injector duty cycle a few hundred rpm prior to the factory fuel cut and using these values up to the new specified rev limit.  One additional duty cycle tuning column is supplied but that is all you get regardless of set rpm limit.  Ignition continues to fire as needed.  Once the values are saved, changing the rev limiter is as easy as keying in the new rev limit and saving the file to the EMU; no other changes needed.


Rev Limiter Set Table

Concrete

   So with the new piggyback installed I want to thrash the car to make sure all the connections are solid and there are no driveability issues before I schedule a dyno tuning appointment with Church. There is a local autox at Qualcomm on Sunday so I head down there with the car still bug splattered and stickered up from the Lincoln journey.

   Last weekend at Spring Nationals the Toyos felt great on Lincoln Air Park's concrete and the car's balance was near perfect.  I mentioned to my co-driver in Lincoln that I felt the tires were possibly heat cycled out because they were not putting power down as well as I expected and noticed a little push on corner exit. We both agreed to disagree, loosened up the car a tad and just drove with ultimately good results.

  











   What a difference a week makes.  Today I used the same Toyo tires at Qualcomm Stadium here in San Diego and the car was miserable.  The asphalt surface at the Q is low grip and the on-off camber changes are challenging, but I have never noticed such a dramatic swing in performance between two events.  I guess my Toyos were done after all.  

What is all this about and why am I rambling on?  I don't know.

   Due to the unique surface and low grip, new and/or full tread tires always seem to work best at the Q relative to other sites.  The site at El Toro has a high grip surface similar to LAP and I really need to focus more setup time at this venue in preparation for Nationals. 
 
   So now what?  Do I chance using the old Toyos again at the upcoming SCCA Southern Pacific Super Regional autox event at El Toro on June 15-17?  Or use the 225 Hankooks?  Bust out the new Toyos or save then for Nationals?

The piggyback survived just fine although the stock rev limiter at 7200 is annoying.

Piggyback Install

   Last month I purchased a used Greddy Emanage Ultimate and Boomslang harness and I finally had some time this week for the install.  Because the piggyback controller alters the OEM computer's code, I paired it with the original BP4Y California ECU instead of the modified DPTune ecu (BP4W).  The stock ecu is located under the driver side dash above the clutch pedal and there is just enough room to comfortably connect the plug and play harness and enough length to reach across to the passenger side dash.

   I found a nice area behind the glove box to mount the piggyback unit and fabricated up a small bracket to securely mount it to the firewall just past the air duct.  Loading the software and choosing the correct driver is all it took to get the EMU active and Vehicle Type and Throttle are the only two parameters that I needed to configure at this time.  I do have a CEL for knock sensor P0325 which is a known Greddy EMU issue for this application and apparently cannot be addressed via software or jumpers.  The CEL does not affect the car's performance and the forum at miataturbo.net says the solution is to simply cut the knock sensor harness wire, which turns out to be the blue/yellow stripe wire #2 in connector C.  Also some concerns in internet land about the cooling fan(s) not turning on, but my Torque App verified the fan kicks in at 204*F (96C).

   The ignition and injector tuning maps are currently all set at zero which means that there is no deviation from stock.  All other engine parameters are still controlled by the stock ECU so the car idles and drives as normal.

Jumpers are set to the following positions:

JP1     open
JP2     open
JP3     open
JP4     open
JP5     open
JP6     open
JP7     1-2
JP8     2-3
JP9     1-2
JP10    open
JP11    open
JP12    open
JP13    open
JP14    open
JP15    1-2
JP16    open
JP17    1-2
JP18    open
JP19    1-2
JP20    1-2

Lincoln Tour

   STR ran first run group Sunday morning on a reverse modified 2011 East course.  Windy and warm conditions.  Moderate speeds with a good mix of elements, but visually difficult to find a few key cones including the entrance to a couple sweepers. Same settings and ride height as used the previous day at the ProSolo. I picked up four tenths on my last run which placed me in fifth position after day one.  Toyos worked well.



   Following the theme from day one, Monday's course was also a reverse modified 2011 West course with the walloms removed along with some other changes. Overnite thunderstorms gave us a wet surface and bright morning sunshine resulted in drying conditions for the first run group.  Rear ride height lowered 1/8".  Course was basically dry during second runs with only minor slick spots at the entrance to the first two slaloms. I put down a fast second run but I was unable to pick up any more time on my third run when conditions were best.  Overall I picked up two positions to finish in third place.


Lincoln Tour Results

Lincoln ProSolo

   The two day drive from San Diego to Lincoln was long and unusually hot and I chose to take the simple route through Las Vegas and Denver via highways 15, 70, 76, and 80.  As always the scenery in Utah and Colorado is beautiful.  Total round trip miles was 3255 and I averaged about 33 miles per gallon.  I managed to take a few pics with my cell phone.
 

   As usual, day one competition on Friday was all about getting familiar with the surface and adjusting launch rpm for best 60 foot and reaction time.  I was unable to get some practice launches, so testing the new clutch would happen during competition.  Eventually, 4000 rpm clutch dumps proved to offer the best 60 ft. times in the high 2.2 second range.  Leaving on the third yellow, my reaction times sucked as usual mostly between 600 - 700.

 







   The courses were very demanding with back to back decreasing radius sweepers heading into the finish.   With the extra grip from the concrete and nature of the courses, I raised the rear ride height 1/4" to help get some more rotation.  As the surface rubbered in and got faster it all came down to Saturday morning (day two) where yesterday's OPR slowed me down on the first left side run and a very brief rain spat took the edge off my first right side run.  My final two runs were quickest, about four tenths per side from the top spot.  I did not make the challenge.

ProSolo Results

   I have been using the rear ride height adjustment (rake) with good success to get the car set up for different conditions or surfaces.  Although quick and easy, the positive rake adjustment can cause too much lift-off oversteer and the car can be too twitchy transitionally.  For my next suspension tuning experiment I plan to stiffen the rear springs by 30-50 lbs. and keep the rear ride height low, or reverse rake.  This should give me the best of both worlds; good rotation without sacrificing as much transitional stability.  Or that is the idea anyway.  The Racing Beat 1.125" front sway bar is already adjusted full stiff and I don't want to try the monster 1.250" bar yet.
 

D'Leon's Mexican Food is located on West "O" street only a few miles from the event site in Lincoln. Great food and open 24 hours too.



IAT 132* at idle on 75F day.  115* at 75 mph cruise after 2 minutes.  105* at 75 mph cruise after 5 minutes.

Tire pressures:  27F, 25R

Clutch and Header

   I was a little nervous having the clutch and other maintenance work done the day before I leave for Lincoln, but my trusty mechanic Rocky specializes in Miatas and all the parts installed were OEM.  Probably the original with 120k miles, the clutch disk was worn unevenly and the flywheel was heat damaged.  The install went smoothly and there were no surprises. Synthetic GL-5 was replaced in both the transmission and differential and the fuel filter was also changed. 

 

  
  The new Racing Beat header fit perfectly and the EGR tube was a breeze to install.  The RB 4-1 design is supposed to generate more power than the OBX 4-2-1. 

Theoretical Weight

  So I rolled my Miata across the scales at the San Diego Tour and the display showed 2168 pounds with 1/4 tank of fuel, helmet, camera, and soft top boot.  This is with the 15x8 6UL / full tread RS3 combination and the quiet Enthuza NB Speeder muffler. Includes NB2 center console. Washer bottle empty and coolant overflow reservoir at 1/3 full.

Helmet 3.5
Camera 1.0
Soft top boot 1.5
Gas (2 gallons) 12.0

  My Odyssey PC545 works great for a daily driver but at over 11 lbs I can save a lot of weight by going with a modern 2 lb. lithium battery.  My complete exhaust is heavy too and it would be easy to save 10 lbs or more with a custom 97+db setup and Maxim header.  Note the wheel / tire weights below also;  I can save 18 lbs if I stay with the 195 Toyos / 7.5" 6UL.  Subtract another 5+ lbs for Bogart, Volk, or SSR wheels.  

   2085# seems like a reasonable weight without going crazy, and in my estimation 2020#  (after some thinking and rough calculating, and with the recent rules change regarding motor mounts, 2020# is probably not realistic. 2055# is closer, maybe.)  would require maximizing the rules with aluminum shock assemblies, custom brakes and rotors, delrin bushings, replacement control arms, billet motor mounts, and so on. How much time and money do I want to spend?  How bad do I want to win?


15x8 / RS3  35.5
15x7.5 / R1R  31.0
Passenger seat  31.0
NB1 console 3.29
NB2 console  3.33
Odyssey PC545  11.5
Maximworks header  11.0
Racing Beat header  15.5
Enthuza XR   12.0
Enthuza NB Speeder 12.5
Roadstersport muffler 17.0
Boomslang and EMUltimate  2.5
Crank pulley 3.85
Complete side power mirror assembly  2.00
OEM fuel filter .50


Rear lower OEM chassis brace
Swaybar reinforcement blocks
Alt & WP pulleys
Intake assembly
Power windows
Power locks
Clearwater speakers
Hardtop latches
Cat / midpipe
Control arms
Motor mounts
Suspension bushings
Differential bushings
Brakes
Lug nuts
Convertible top
Emblems
Shifter
Differential
Filters and Hoses
Frankenstein bolts

Lincoln 'Spring Nationals' Pre-Show

   Recently I've had a few inquiries about my build and the parts I have chosen for my STR Miata.  Aside from being thrifty and on a moderate budget, my idea is to keep it simple, easy to drive, and reliable.  Almost everything added to the car is a readily available off the shelf part, with only minor fabrication needed to fit the driver's seat and to mount the battery.  The only custom parts are the upper shock mounts from PES which have been carefully designed to allow a great balance of bump/rebound shock travel at various ride heights without bottoming out or binding.  Autox is all about minimizing mistakes, both in driving and build execution, and special attention to a few key parts is what can make the car more forgiving and ultimately faster.

http://lateapexphoto.com/

   So a few weeks after the El Toro Pro I find myself unemployed and decide to take a little break and prepare to head off to Lincoln, NE for the "Spring Nationals" which is a four day SCCA event scheduled for the Memorial Day weekend of May 25-28.  Friday and Saturday consist of a Pro Solo with Sunday and Monday being a regular Tour.  I have an appointment to replace the clutch on Monday, May 21st at Rocky's Miatomotive with a planned departure for Lincoln at 6am Tuesday morning. 

   My biggest decision regarding this trip is what tire to use. Actually, tire choice has been my biggest issue during this whole build (aside from the poor ECU service from DPTune). Both the Toyo and Hankook leave me frustrated because neither one is a great tire and both work best at completely opposite temperatures and feel and drive differently.  For this event I will bring my used 75+ run 195 Toyos on 15x7.5" 6UL wheels.

   Although the Miata is one of the few cars in class that can fit the 195 Toyo, I believe the Dunlop SS Z1 is a superior tire and easier to drive in a wider variety of conditions.  Available in a decent 205/50-15 size, actual same day comparison testing is needed to determine if the Dunlop is quicker than its competition.  The 225/45-15 Toyo R1R is also a good tire and I successfully used this tire on a 7.5" wheel on my 1995 STS Miata.  A wider 9" wheel would compliment the 225 Toyo and this could be the combination to have.  In the meantime, I will primarily use the 195 Toyo on a 7.5" wheel because it is relatively cheap, pays contingency, works well in the wet, and is fast on the first lap.

  So while I was typing this post UPS delivers two boxes; one from Mazda containing a 2001 Miata EGR tube and the other from Racing Beat containing a 2001 Miata 4-1 header.  The NB2 (2001-2005 Miata) parts were ordered because the 99-2000 RB headers are not in stock at this time.  The only difference between the two is the connection of the EGR tube to the header; one has male threads, the other is female.

   Due to the poor fitment of my eBay OBX header the original egr tube was bent and modified to fit so a new replacement tube would be needed anyway.  Plus, the new egr tube is compatible with the  2001+ OEM tubular header which makes an easy stealthy swap for SMOG inspection.

 









   I bought the Racing Beat header in anticipation of the upcoming clutch replacement knowing that the header needs to be removed completely to best complete the job.  Since I had to fight the OBX header install, I decided to hit the easy button and get a header that I know will fit the first time without frustration, and of course the RB header has been well developed and proven to make power.

Power

  In my quest for more power and frustration from dealing with Dynotronics Tuning, I purchased a used Greddy Emanage Ultimate and Boomslang harness.  The special plug and play harness meets the rules requirement of no splicing and offers a clean and simple install of the piggyback controller.  Unlike the reflash from DPTune, the Emanage Ultimate gives the user full control over most of the engine management and I will primarily focus on fuel and timing to maximize horsepower and torque.  The rpm limiter can also be changed.  As with my STS car, tuning will be done by Shawn at Church Automotive Testing.

  The install will have to wait until the clutch is replaced, which unfortunately just started slipping as the SCCA Tour and Pro came to SoCal.  A new pressure plate, clutch disc, and flywheel was delivered today thanks to Mazdaspeed Motorsports.  The plan is to have the clutch replaced and engine tuned before the next big regional event scheduled for June 15-17 at El Toro.