Destination SSM One Miata's Journey through Hell

4Apr/14Off

Update

Posted by David de Regt

I took much of last year off, made some poor suspension choices, and didn't pay much attention to the car.  I got my butt kicked in most events I went to, and wasn't very happy with the car or my driving.  In the end, though, it gave me what I needed -- most of a year off.  I flew around the country and codrove with the Woottons a few times, autocrossed a bunch of random cars, and had some fun anyway.  I also noticed that, despite lots of attention to the car everywhere I posted it for sale, no one even sniffed around at a real offer, so I know that, someday when I do actually sell, parting it out is the way to go.

1530326_619095470648_962636239_n[1]For this year, I'm going to make a little more of an effort again.  We moved into a new house last year and didn't have a good way to deal with the towing situation, so this year my dad sold his giant trailer and I bought a tiny little trailer, perfect for a Miata.  Most importantly of all, I can back the trailer, with the car on it, into my garage, and leave it there, ready for an event at any time, with the truck parked in front of it.  I'm hoping that I'll find a lot more motivation to autocross when it means spending 5 minutes in the morning and 10 in the evening loading/unloading instead of 2+ hours on each side getting the truck/trailer to/from my parents'.

I decided to attack some of my root annoyances with the car as well this year.  At the end of last season, I realized that my traction control system was a little flaky.  While it often helped, it often cut in when it had no reason to.  I spent some time debugging it at the first event this year and learned that it is, in fact, cutting fuel even with the system completely disabled -- when I bypass the unit and plug the injectors directly into the ECU, it runs perfectly.  I've been working with RaceLogic the past couple weeks trying to narrow down what the problem actually is.  So far, we think it's the adjuster unit, but it will require further diagnosis.  Until I get that sorted out, the unit is staying fully disconnected, forcing me to learn how to modulate a gas pedal -- something I'm not very good at, apparently.

intake[1]Another big annoyance was the general tune of the car.  In addition to feeling like I didn't have enough power, there was always a bunch of hiccups in the tune (above and beyond the RaceLogic-induced ones).  Throttle pump (tip-in) was always sketchy, leading to unpredictable power levels on corner exit.  At 2012 nationals we noticed that underhood temps were crazy, and put a hole in the hood for the intake.  Since then, I'd switched back to a more traditional intake, but pulling air from the driver's side headlight area.  I also upgraded to Flyin Miata's big flex fuel kit, which is a pretty awesome setup, and upgraded to ID1000 injectors in preparation for E85.

miatadyno_20140302[1]Last spring, I changed from an AEM to a Hydra Nemesis for an ECU, and immediately was able to improve the drivability of the car quite a bit.  However, it was still far off what I wanted/needed it to be for consistent driving.  I gave the car to Kris Osheim of KO Racing early this year and he spent a few weeks road tuning it to help with drivability and low end torque.  The car is an entirely different beast now -- mashing the gas at 2000 RPMs produces an instant wall of torque, and different rates of tip-in actually produce linearly proportional amounts of power.  Using the flex fuel setup, I can now put anything from full pump gas to full E85 or any mix in between, and the car fires right up and makes a safe amount of power for whatever ethanol mix I'm running.  The car now makes 359rwhp/279rwtq (Dynojet corrected) on E85 and 316/256 on 92.  The old power numbers were falsely inflated by the previous dyno I was using -- he applied a fixed 20% correction factor, so this is actually quite a huge bump in power over the old setup.

Suspension-wise, I knew I needed to change things.  In 2012 I was running 700/450 springs, and based on the math said we should be running 800s in the front, so for the 2013 season I tried just bumping to 800s.  Of course, the car went from fairly well balanced to ultra-pushy.  I spent the limited season trying to dial it out with shock adjustments, but for 2014 I went up to 550 rear springs and added a small rear swaybar.  Two events into the season, the balance of the car is proving to be a huge improvement over last year, which makes it a lot more fun to drive.

The brakes had always been a big complaint of mine with the car -- they were a little unpredictable and, especially on concrete, you were essentially unable to bring the car into ABS.  For 2013, I upgraded the fronts to Flyin Miata's little big brake kit with the 11" rotors, and went to a 1" 929 master cylinder with a dual diaphragm brake booster, which were a huge improvement.  I'll likely upgrade the rears to their rear little big brake kit this season as well, but I haven't pulled the trigger on that yet.  I've also changed out the rear wheel bearings and front hubs for this season, as they were starting to get some play in them noticeable as pad-knockback after hard cornering.

I'm planning on attempting to get the car out to several big events this year -- Crow's Landing, Packwood, Spring Nationals (Lincoln), and Nationals.  There's still a bunch to get working on the car for real -- Eric Anderson's car proves how effective the RaceLogic can be if I can work the demons out of my system, dialing in the new suspension setup, and learning how to drive a car that can break the tires loose at will in a straight line in 2nd gear on Asphalt.

12Sep/120

Wanna buy a fast car?

Posted by David de Regt

With several things going on in my life right now (not having much fun autocrossing the past few years, switching jobs, tired of being broke) I think the best move right now for me is to get rid of the car and get my life in order for a few years before trying autocross again.  I was hoping that the SSM experiment would bring the fun back into autocross for me, and while it did somewhat, it still isn't enough for me to justify how much money and time I'm spending on all these out of town events.  Maybe when I have enough money in the bank to not be scared anymore, and I've stopped doing so much side work that eats all my time and stress, I'll come back, but I think my best move right now is just to get my life in order.

As such, I'm putting the project up for sale as a whole right now to see if anyone bites, and if no one does, I'll start parting the car out.  I have something over 45k into the project, not including tires, repair parts, a ton of misc hardware, and probably a thousand hours of labor.  The car can win nationals right now as it sits with the right driver, and with a few simple mods can go even faster than that.  If you're interested in individual parts, feel free to shoot me an email as well -- if there's enough interest in the parts I may just go that route even sooner.  The detailed parts list is available both all over the Wiki, and also in the Expense Log.

Quick important bits list:

  • 1991 Chassis, 316k original miles
  • Dyno: 330rwhp, 258rwtq @ 19 psi peak, on 92 octane pump gas
  • Car weighs 2030 lbs dry, well short of its min weight of 2057 lbs
  • Built 1.87L 99 Miata Motor -- should be good to 9k RPMs, but I've been keeping it at 8k for longevity
  • 5-speed transmission case rebuilt with a Quaife custom gearset and all new Mazda parts.  Car does 49mph in 1st gear and 75mph in 2nd gear (GPS verified), and is built to survive twice the torque the car is making right now
  • RB Header with custom 3" stainless exhaust, runs at 92-94 dB at most sites, with a clamp on extra muffler and turndown for San Diego
  • Custom BEGi intake manifold with a Lysholm (Whipple) 1.6L twin screw supercharger with custom half-width intercooler setup for short charge pipes (incredibly quick throttle response)
  • Coolant reroute with custom half-width radiator -- in 100 degree heat at nationals the engine never got above 192 degrees during/after a run
  • Carbon Fiber hood (5 lbs), front fenders (1 lb each), and seats (6 lbs each!)
  • Custom splitter (now shorter than it used to be), removable for getting on and off a trailer
  • Ciro Designs/APR latest-generation rear twin-element wing
  • AEM PnP EMS, fully tuned for safe power and drivability, with Zt-3 wideband
  • RaceLogic adjustable traction control (includes launch control)
  • AIM Evo4 data acquisition system + MyChron3 dash, integrates with the AEM EMS to display and log all engine parameters, combined with internal GPS, accelerometer, and oil pressure
  • Flyin Miata little big brake kit (powerlite calipers with custom adapters) up front, SS lines on stock calipers in the rear, with Carbotech AX6 pads all around
  • 2004 Miata next-generation ABS unit retrofitted
  • FatCat Motorsports double-adjustable custom shortened-shaft coilovers, racing beat front bar, no rear bar
  • Rear upper control arms by EPMiata, all other control arms currently stock with Delrin inserts on all connecting joints to reduce play, with long wheel studs, and V8roadster ball joints
  • Deutchwerks 300LPH fuel pump (quiet) with 720cc Injector Dynamics injectors on a dual feed fuel rail -- upgrade to 1000cc injectors and jump to E85 for a nice power bump
  • Custom modified wiring harnesses to cleanly build in all modifications (speed density sensors, 2004 ABS unit, coil-on-plug, etc.)
  • Custom headlights to save 19 lbs off the front end (and still shine better than the stockers)
  • Full access to pick my brain for a long time
  • Comes with 15x9 6ULs with nearly new (1 pouring-wet event) H20s, and two sets of 15x10 6ULs with nearly new (one 20-run set, one 12-run set) Goodyears

I'm asking $35,000 for the car.  If you're interested in either the car or a set of parts, shoot me an email (akilla at akilla.net) or call me (206-276-0433).  Car is currently in Redmond, WA.  Happy to ship at buyer's expense.

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12Sep/120

Nationals

Posted by David de Regt

Nationals was an ... interesting experience this year.  I originally didn't want to go, due to being broke, not terribly into the sport right now, and knowing the car wasn't ready, but was convinced by my dad and some friends to make the trip.  So, out we went.

At the Pro Finale, the car wasn't handling terribly well, and was bogging miserably coming out of slow corners again.  We tweaked some suspension settings and that improved the handling situation a little bit, but we couldn't figure out what was up with the bogging.  So, I finished out the pro in 4th place, 1.2 out from the win overall.  There were a bunch of slow digs that the car couldn't get out of its own way for, so that time was easily there, especially if I could have landed a left side run (I was only 0.3 behind the winner on the right, 0.9 on the left.)  I was generally happy with the car's performance at this point.  It was obviously capable of running the times, especially if I could fix the slow corner problem.

So, we spent Monday driving around the streets of Lincoln with a laptop, working on trying to smooth out the AFRs on tip-in.  I fixed a bunch of stuff, which made the car feel like it drove much better, and so my dad (who didn't run the Pro) took practice runs on Tuesday, and ... after a couple runs got the same misfiring under tip-in as before.  This time, I pulled data from the AIM system and saw that with each run, our intake temps were jumping by ~20 degrees, culminating in 180 degrees during our practice last (and very misfirey) run.

That seemed likely to be the problem, so we drove all over Lincoln, bought a hole saw and some tubing parts, and cut a hole in the hood right over the supercharger, put a 90 degree bend on the inlet, and popped the filter through the hood.  We bought some more practice runs for Wednesday morning, spent more time on the street and really got the tip-in working pretty solidly, and then had no problems with heat or misfiring Wednesday.  The filter through the hood isn't the most attractive part of the car, but it's certainly doing the job.

Thursday came and the car was awesome -- handling's still a little quirky, but better than the Pro, but after the runs, I was in 2nd, only 0.4 off Carter, with 3rd several tenths more behind me.  Joy quickly turned to disgust, however.  We were immediately protested by Jake Namer for an illegal splitter, which was later upheld, and gave us a 1 second penalty on all of our runs.  We then lazily shaved off enough of the splitter to be a couple inches under the limit.  I was disgusted enough by the whole process that I just went back to the hotel and caught up on work all night instead of walking the other course, so for Friday runs I didn't really know my way around, and coned all 3 runs.   It was a long drive home, but at least by 2pm Friday we were on the road instead of having to go to the banquet, and, as such, got home at midnight Saturday night, so I got a full Sunday to unpack and unwind.

For reference, the splitter in question is pictured at the right.  The green photoshopped area is the legal area of an SSM splitter (which we are almost a square foot below.)  The little green penned area on the chopped off part (3/8" deep by a few inches wide) is the illegal area of the splitter, as determined by the protest committee.  When Bill and I built the splitter, we measured it in my garage to be 5" from the bumper (a full inch under the max rule), but somehow since April, our mounting mechanism has bent out to bring it over 6", and hence illegal.  Turns out that using sliding forks to locate the splitter isn't a great idea for autocross, since there's the maximum forward distance rule.  We were hoping it would help absorb cone hits, but that turns out to be less important than staying legal.  Oh well.  That's autocross.  Live and learn.

On the bright side, the car is very competitive, even in its primordial form right now.  0.4 off Carter is better than I ever would have hoped, and the data showed that there was a lot more time on top of that run.  So, it's proof that the SSM Miata concept is viable, which was the goal of this year.

 

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12Aug/120

Month of Slow Progress

Posted by David de Regt

I haven't posted much in the last month because, well, not a lot has happened.  I've been mostly just driving the car at events and playing with setup ideas while planning the next phase of the build.  I've now ordered a full set of custom control arms and spindle modifications with a 1" drop from Jon Brakke.  They won't be finished until after nationals, unfortunately, but that's what I get for not ordering anything until this late.  He's seen the pictures of the failed EPMiata arms and couldn't believe how underbuilt they were, so it'll be interesting to see how much stronger his will (hopefully) be.

Due to my dad running over the old hardtop at Lincoln this spring, I've also ordered a new CF hardtop from Axis Power Racing before realizing that they possibly weren't legal (it's a bit of a grey area, apparently.)  There's a proposal out to make them explicitly legal, which will hopefully pass, or else I'll have to use the top on a time attack car or something...  I also finally picked up the FM Little Big Brake Kit which required minor clearancing of the calipers to fit on the 9" rotor with the 15x10 6ULs, but is giving quite a bit better braking between them and the SS lines I finally added to the rear.  The V8Roadster Bump Steer Kit finally arrived as well, but I haven't had a chance to put them on the car yet.  Hopefully in the next week or so.

In the last few events, I'd been noticing that the traction control seemed to be getting increasingly invasive, so last weekend at a practice, I tried turning the TC system completely off, and was still getting massive misfiring coming out of corners (getting on the gas early.)  I tried replacing my 3 remaining Chinese Toyota knock-off coil packs with genuine Toyota ones, and, shockingly, my misfire problem disappeared, which was a welcome development.  At this point, it suddenly seems like I can put a lot more power down than I thought I was able to, so it will soon be time to up the power by quite a bit.  I keep finding myself floored and waiting coming out of slow corners.  Even with ~220 ft/lbs at the wheels that low in the powerband, I'm getting killed out of those corners by Bob Bundy, who has more like 350 ft/lbs down there, so I think some power bumps are in order for next season.

The only major issue the car's had for a while now was last weekend, when an apparently undertorqued crank pulley bolt came loose and bent/embedded itself into the crankshaft, while simultaneously allowing the supercharger to shear off the woodruff key and spread the keyway wide open on both the crank and the pulley boss.  Oops.  So much for that crank.  I picked up a new crank from Coop's Miata, got bearings overnighted from Flyin Miata, rebuilt the motor Thursday and Friday, threw it back in the car, and towed up to Canada for the VCMC Super Challenge this weekend.

The event went pretty well.  The course was an uninspired set of 7 very tight corners, each connected by either essentially a straightaway or a 180 degree sweeper, which isn't the greatest set of elements for the car -- all the grip in the world isn't terribly useful when you still are floored for 2-4 seconds out of every slow corner.  The event format was really neat, though.  At the end of the event, they take the top 30 drivers on PAX, add 10 randomly drawn drivers, and everyone takes a single run.  The bottom 20 PAXed times are eliminated, they change the course, and repeat.  Halve two more times, then the last group of 5 run for the final finishing order.  It's an interesting variation on the ProSolo challenge idea and really forces you to be both consistent and fast.  I managed to finish 4th overall, which was several spots higher than I was expecting.  Our current tires are up to ~50+ runs and the course was not well suited to the car in it current state, so doing this well was an unexpected surprise.  I also tried some Hail Mary setup changes between Saturday and Sunday which helped a fair bit (the car was very loose Saturday.)

Looking ahead to Solo Nationals, I've organized a local test and tune for Friday, where I'll finally have my first chance all year to really mess around extensively with shock and pressure tuning.  Unfortunately, with how absurdly busy I've been the last few weeks, the 2-driver reg deadline for the Pro Finale came and went without us noticing, so we're now on the waitlist.  If we don't get in, we might not even bother making the journey.  The idea of spending 8 days and a few thousand dollars of gas, hotels, food, and general costs for 5 minutes of  racing time on an unfinished car isn't the most appealing thing in the world right now.  As annoying as it would be to work toward this all year and then not go, it may be the right decision to make when the time comes.  In the meantime, we'll stare at the waitlist and hope.

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8Jul/120

Packwood ProSolo

Posted by David de Regt

The ProSolo was an interesting weekend.  The course was the most annoyingly not-fun collection of ridiculously tight offsets and stupidly slow corners that I've ever driven.  I feel like, in 8 years of autocrossing, I have to have driven a less fun course than that, but none come to mind.  On the upsides, I managed to squeak out a win (barely -- 0.009 seconds) and it highlighted a lot of things to focus on for the next phase of development for the car.  Also, we had zero reliability issues with the car again, so I'm just waiting for something expensive to explode at this point...

One of the big obvious weaknesses this weekend was power application.  I think that part of the problem with my current build is the forward weight bias (we're at about 56% front right now), which isn't leaving any weight on the rears to put power down.  I've been working on a design to try out that will let me drop down to a 1.6 motor, non-intercooled, which would drop a ton of weight off the front end, and potentially give me room to ballast up the rear.  In the interim, I need to explore a fuel cell so we can run less fuel without starving, allowing me to ballast up the rear a bit.  I'm starting to wonder in general about just running more fuel after seeing Sam Strano, a man who is already heavily ballasted, running a full tank of fuel in his SS C6 Corvette, because the extra power application he gets out of the weight over the rear is worth the weight gain from the gas.

An unrelated huge problem this weekend was that my front splitter wasn't playing nice with the Pro light sensors. I could get the car to "stage" in a couple different places, and it was very hard to tell which one of the two places I was staged in.  As a result, when runs really mattered, I had to run extremely conservative lights (7xx-8xx) just to make sure I wouldn't redlight.  If I'd hit the deep stage hot spot, then I'd still redlight even waiting that long (see my first run of the challenge, for example -- 498 redlight, and I didn't even start to release the clutch until right before the GREEN light came on, so I must have been deep staged millimeters from the next sensor...)  I've emailed Howard Duncan to ask how high the lights are, so I can make some "endplates" for my splitter to make sure that I hit the sensors in a reliable place at the next event.  This problem made every run an unpredictable nightmare.

I also need to just learn how to launch.  I cut everything from a 1.935 to mid 2.2s 60-ft times all weekend, mostly doing around 2.10ish, which is pretty terrible.  On low grip asphalt, even after the course rubbers in, the car has enough torque to break the rears loose at basically any point in first gear, so it's extremely hard to find the balance between a little bit of wheelspin and way too much wheelspin.  I'll hopefully learn eventually, but until then I'll be running almost STS 60 foots while I burn up expensive rubber.

2Jul/120

Packwood National Tour

Posted by David de Regt

The whole month of June has been filled with rainy weekends that we didn't even bother bringing the car out to autocross in.  One of the downsides to running a high power car is that, in the wet, you just get hosed on PAX.  So, as little fun as I have autocrossing in the rain in general, it's also uncompetitive, so the idea of towing for 3 hours each way to get creamed in the rain is unappealing.  Seattle might not have been the greatest place to build this car...

Fortunately, it gave me some time to mess around a bit with the car.  I bought a 12+1 tooth crank trigger wheel from Trackspeed Engineering, and after ~20 hours of trying to make it run reliably, I gave up and switched back to the stock wheel.  I don't know if there's noise on the crank hall sensor from something or if the AEM just doesn't like getting that many tooth updates, but it's off the car until I have time to spend more time debugging.  I replaced both the cam and crank angle sensors with brand new ones from Mazda (they had absolutely no effect on the 12+1 wheel, incidentally,) and replaced the main relay (the relay that broke in Lincoln) while I was in there, which, interestingly, had been superceded by a much different part.  We also learned that we're not allowed to run shoulder harnesses in a non-rollbar-convertible, so we pulled the 4/5 point belts and put in simple lap belts, which removed a bunch of weight from the car and made it a lot easier to get in and out as well.

After having no problem with power application in Lincoln (and even limited problems with power in Packwood,) I upsized the crank pulley (that the SC feeds off) from 120mm to 125mm, and spent a bunch more time on the dyno.  We're up to 330rwhp and 258rwtq and spent a lot more time on the low RPM portion of the map.  The car is now faster and has much smoother power ramp-up, so it's more drivable too, and is better at putting its power down than it used to be.  I think this will be the end of my attempted power mods before 2012 Solo Nationals.  It's time to work on the suspension setup and on my driving.

The 2012 Packwood National Tour arrived in a real hurry.  I spent 2 weeks messing with the trigger wheel to no avail, and had to rapidly switch back to the stock wheel on the Monday night before the NT.  Wednesday the car went in to get a new muffler, since we were consistently blowing 102dB at Lincoln (over the limit.)  Thursday I spent 3 hours on the Dyno at Pina Motorsports, and then 6am Friday morning we pulled out from Redmond to head down to Packwood.

The practice course was the dirtiest (gravel/etc.) course I've ever driven on, but we did some rough shock tuning and the car was working really well.  Ironically, both of our paddock-mates' cars broke, so we spent some time helping fix them.  The rest of the weekend, the car performed perfectly (despite us driving it inadequately,) and I managed to put a 1.776 second victory on the class, running fairly consistent times.  At the end of the weekend, we rolled the car onto the trailer and drove home, ready for the Pro in a few short days.

We learned that the car's fuel starving at around a third of a tank, which will require some investigation after the ProSolo.  I am also sure at this point that the car will be faster with more confidence-inspiring brakes, so that will be another focus for after the ProSolo.  The traction control also needs some further tweaking, and the wing really needs some string+video attention and a Gurney Flap.  Time, time time...

Here's some videos of my fastest runs for the weekend (expand for 720p.)  As you can tell, I'm still driving the car incredibly abruptly.  It's still more than a bit of a shock, coming out of stock class.  At this point, I have at least as much speed to be gained in learning to drive than will be found with further car setup...

29May/120

Spring Nationals

Posted by David de Regt

Because of the alignment and truck issues, we, of course, had another frantic last minute prep session.  We spent Monday afternoon pulling the front UCAs off to bend them more, reinstalling them, and getting the car to an alignment shop with zero notice in time for them to work on it.  While some of that was in process, we had to pull the alternator off the truck and get a rebuilt alternator and install it.  That evening we finally got to clean up some last minute stuff on the car and packed up the rig to head to Lincoln.

2 days of towing later, we arrived to glorious 90 degrees and humid Lincoln, NE.  We spent Thursday doing practice starts to figure out how to launch the thing (which neither of us ever got any good at – my best 60ft was 2.01s.)  Everything was going well, so we retired to beer.

Friday (ProSolo day 1) morning, I got 3 runs then the car sputtered and died sitting in line to take my 4th run and wouldn’t restart.  We pushed it off to the 2nd driver line and let it sit for a minute.  We checked everything – nothing obvious was wrong, but a minute later we tried firing the car back up, and it happily did.  My dad then got 2 runs in before it died in the same way for him and we retired to impound.

Very perplexed, we guessed it was a fueling issue, and I’d been worried about my fuel pump since the Packwood weekend of harness melting/shorting.  So, at lunch we changed the fuel pump to the new Deutchwerks pump.  I didn’t get a right side run (apparently I rolled out of my one right side run, grr), so my dad got to go first.  We sent him out without a hood for afternoon runs, on the off chance something was overheating, to get some more ventilation into the engine bay.  He got his 4 runs in, so we hoped it was fixed and put the hood on for my runs.  I got one run before it died again briefly after I departed for my second run.  We again retired to impound and had an evening to consider.

Fortunately, I had noticed, when it wigged out on me, that the tach was going nuts, implying that the ECU had lost cam/crank sync (or something far more heinous, possibly.)  I asked around the paddock and found two very nice competitors (Bill Schenker and Mike Heinitz) that had spare crank and cam angle sensors to loan me, and swapped them onto the car.

The next day, we decided the better part of valor was to run without the hood again (but we “replaced” the hood with a strip of tape, which is technically legal under SSM rules, stupid as that may be) and I went out for my runs.  The car had no issues, and I managed to save for 3rd place, and my dad also got his 4 runs in without issue.  When we tried to start the car up again after weighing it, it wouldn’t start, or even show any signs of ignition signal.  We towed it back to the paddock and poked around at it for a bit.

I found nothing wrong, but finally decided to try swapping the main relay out for a spare I had lying around, and the car sprung to life.  That relay had likely been damaged in the wiring debacle of the Packwood weekend, but it’s still a little distressing.  The car seemed fine after that, so we declared victory and went for celebratory BBQ and beer.

The NT went mostly without issue.  They yelled at us after the ProSolo, because apparently our exhaust was blowing 103dB consistently (limit of 100dB), so we had to attach a clamp on muffler for the tour.  I had a small power burble on day 1 in the middle of my third run, but it’s vaguely possible it was just fuel starvation.  We made it through -- I got 3rd again, 1.4 off the win.  The only day two issue was when, on the way out to grid for our day 2 heat, my dad drove the truck over the hardtop I've been using to keep the car dry/sealed overnight, which is now forcing me to come up with some new solution...

On the drive home, so far, I’ve ordered brand new replacement relays from Mazda and also new crank and cam angle sensors.  I noticed the cam sensor and the main relay had both been superceded, and reading up on miata.net, it looks like my issues are pretty known issues, so I’m vaguely hopeful that I’ve discovered the cause(s) of my more major problems.

We also had a chance to play with the Hoosiers vs. Goodyears at the Prosolo, and we both agreed that the Goodyears make the car much more drivable, so for the forseable future, it looks like it’s going to be a Goodyear car.  They seem to be able to put down power much better, and also they don’t overheat nearly as badly as the Hoosiers do, both of which are good things for an SSM car, especially at a hot site like Lincoln.

I hopefully will have time coming up to work on some of the other projects for the car: a front brakes solution, possibly moving to a permanent carbon hard top, venting the hood for real, tuning the rear wing, canards, etc.  The really short summary, though, is that the car, for its first showing, when it was working, proved that a Miata can get it done in SSM (if I stopped driving like such an idiot.)  So, despite all the other stresses of the weekend, it was a resounding success.  I also had some more time to mess with the data system that I'm developing, and worked some of the usability kinks out, which was helpful at the events and should be even more useful as the year goes on...

29May/120

Second Packwood weekend and Spring Nationals Leadups

Posted by David de Regt

It’s been an incredibly hectic two weeks.  I spent a couple days tearing into more of the electrics and found that the fuel pump wire down the driver’s side of the rear harness had rubbed through to the chassis, which is probably what started everything.  I ran a new thicker gauge wire and re-loomed/moved some of the harness, so it should hopefully never rub through again, and the thicker wire will be less prone to heating.  I also ordered a Deutchwerks 300LPH pump due to my decreased confidence in the Walbro, intending to use it as a spare if the Walbro died.  Finally, I moved the fusebox out from under the side of the engine bay into a spot near the intake with some airflow, in case it just needed some ventilation as well.

The subframe that we were told existed wasn’t actually the right subframe, which we didn’t discover until after close of business Thursday night.  We got to wake up early Friday morning and call every parts shop in the area to find a new subframe.  The only one we could get before Monday wouldn’t be pulled until 5pm that night, 2 hours from home.  So, we picked it up, got back home around 7:30pm, and spent the entire night swapping the subframe and front control arms.  Shaikh finished up the shocks Thursday night and overnighted them so those arrived Friday morning, and when we finished with the subframe, we got to also assemble/swap the new shocks (mounting canisters, etc.)  Around 11:30pm we finally finished with all the work, then spent until almost 2am doing a ride height set and string alignment.  We realized the alignment wasn’t going terribly well, and we couldn’t get enough camber out of the front anyway, so we called it good enough for a shakedown and went to bed.

We decided that waking up in 3 hours and driving to Packwood for the morning session was out of the question, so we went down for the afternoon, which was a nice dry day, and had no major issues at all with the car.  The car was pretty loose, but still drivable, and we settled into liking a RaceLogic setting of 20% slip and 5.0mph wheel differential.  Sunday morning we woke up to a wet ground and ongoing rain, and we ran a very wet morning session, where we got to throw on the Hoosier Wets (225/50/15 H2Os on 15x9 6ULs) and play with the RaceLogic to figure out a wet setup, which worked out quite well.  We tried 5%, which seemed pretty good, but 10% was really the sweet spot, if you had quick enough hands.  The car is remarkably drivable in the wet, which is good to know.  On a very representative course, I was only 0.4 behind the Hyman GT-R car in full wet trim, which is closer than I would have hoped to get.  We had no issues with the car in the wet either, called it a day, and drove home.

On the tow home, the alternator on the truck let go, though, adding some more insult to the existing injury.  Nothing is ever easy...

15May/120

Ups and Downs

Posted by David de Regt

It's been an interesting month.  Soon after the last post, I decided that nothing was coming in soon enough and that I should just bring the car in to get painted.  I had Showcase Auto do it, and it came out great (for a racecar -- painting carbon fiber body parts is never fantastic unless you put 20 pounds of paint and bondo on it, hence removing the point.)

I got the car back a week and a half ago, just in time to try to put all the new parts that arrived on it.  The Ciro Designs wing came in, and we fabbed up a splitter (currently in revision 1, there'll be canards and paint later).  The control arms and delrin finally came in, and we spent days assembling the car and finally, this past weekend, had a chance to bring the car down to Packwood for what was supposed to be a 2 day event, getting a ton of runs on the car in preparation for the Lincoln mini-nationals in 2 weekends.

Unfortunately, that was not to be the case.  We took a couple runs in the car, which were pretty good, but quickly started getting some nasty rubbing making the sharp turn to get to the start line from grid.  We ignored it, planning to look into it at lunch.  A couple runs later, we started getting something acting like the car being out of gas in the middle of my dad's run, and then shortly thereafter it gave out entirely and refused to run any more.  Some quick diagnosing led me to find that the ignition lead was shorted to an always-on battery line somewhere, and it wasn't obvious where.  In addition, when you shorted the fuel pump on with the diagnostic connector, the circuit main relay under the dash started buzzing heavily, and was rapidly heating up (to the point that the wire insulation was melting).  So, after spending a while with it, we decided to bail and head home to diagnose with more tools and time.

Monday, my dad and I converged on the car and pulled the front wheel off, only to discover something really unfortunate.  The rubbing apparently was caused by the new front control arms pretzeling themselves under the stress of the Packwood bumps, or somethingorother.  I'm working with the EPMiata folks to try to figure out if we have a good answer, or if their arms are just not strong enough for SSM autocross duty.  However, that give us a bit of a major problem.  There's one more weekend of events (19/20th) and then we have to hit the road Tuesday to get to the Lincoln events in time, which means we only have one more shot to test this stuff out, and it needs to be ready for this weekend.

As a result, just to have a prayer of making it to Lincoln, I'm enacting a fallback plan of using stock front UCAs.  AWR is overnighting me some delrin bushings for them, which come in Wednesday, and I'm putting the V8Roadster ball joints into them.  We're going to bend them in a press a little bit to get the camber level we need, and run it as is for now to hopefully get some events under it before going with another custom solution of some sort.

I also pulled apart most of the electrics in the car today (pulled the dash, fuseboxes, and relay blocks) to try to figure out the problem.  The only issue I can find so far is that two of the wires in the main fusebox had melted together, which shorted the ignition (white/red) line to another fused always-on line (white/green).  I re-insulated them and separated them, and I will be moving the fusebox to somewhere with more airflow to keep it cool (the event this weekend was quite warm, and I think the splitter was keeping underhood temps higher than usual).  In addition, I should probably add some vents to the hood to let some of the air out, which will likely assist with front downforce as well.  I'm replacing the main circuit opening relay with another I had kicking around from a lower mileage car, and hoping for the best this weekend.

With any luck, I'll have better news to relay soon.  Tomorrow I get a different used front subframe to swap mine out with (we had to drill the front UCA sleeve out to 5/8" to use the EPMiata control arms) so I need to get another stock one to put the stock arms back onto, and the delrin bushings come in to reassemble everything.  The real DA shocks come in from Shaikh either late Thursday or early Friday, leaving me a few hours to get the car aligned for the weekend.  From there, hopefully our last minute changes here will keep it running long enough to abuse it all weekend, then head east to Lincoln a few days after that...

16Apr/120

Test Run – Phase 1 Complete

Posted by David de Regt

The past several weeks have been on and off busy and not.  Even though the car dynoed, there were a lot of loose ends to tie up.  I had the car aligned and ride heighted while I got some work done the next day, and we had an emergency all day session on Friday trying to finish the car in time for going out to a karting track (that allowed cars that day) -- seatbelt installs onto the firewall, custom bracket for passenger seat, fender and bumper cutting to fit the giant tires, front swaybar install, etc.  We decided not to bother going down to the kart track by the time we finally finished up all the last touches (weather/lack of daylight to make it worth it), but at least the car was drivable.

Instead, Brian and I spend Saturday doing a bunch of work.  We measured bump travel vs offset for the front and rear of the car, to plan the new uprights, and then took the car out for its first spin (turned out to be a gorgeous day, but with no autocross all weekend anywhere in the northwest).  The car worked great and we dialed in the Throttle Pump settings and had some fun.  The car was showing signs of being incredibly loose, but we didn't care too much at the time.

Over the next week, I continued tweaking things.  I built a temporary intake out of cheap parts, we added some lexan panels to the hood to block water getting all over the headlights, I added a cabin-switchable intercooler fan, etc.  There's so many little things to do building an SSM car.  The weekend had an event in Packwood, but it was going to definitely be rainy (100% chance of rain both days) so I ordered a set of 15x9 6ULs and some Hoosier Wets on Monday, which ended up having 3 come in Friday and one come in Tuesday (good job UPS), so I missed that weekend of events.

Fortunately, the following weekend had a gorgeous pair of events up in Vancouver.  My dad and I towed the car up and ran a PCA event Saturday and a VCMC event Sunday, where the car showed great promise.  It turned out to be at least as loose as we anticipated, but it was still keeping up with CSP cars on a non-power course (we checked the datalogs, and were both over 60% throttle for a collective less than 1 full second).  In any event, my dad signed on for codriving for the rest of the year, which should make for a smooth first year of towing to events.

The car's waiting for several things right now.  The shocks are taking a little longer than originally anticipated, the wing pushed out a couple weeks longer than they thought, and the EPMiata upper control arms are also being pushed out a couple weeks.  As a result, even though there was an event this past weekend, I didn't figure on there being much point in running it, as the car's current handling is largely a result of the temporary suspension setup on it.  So, instead, I brought it into the local body shop to start prepwork on painting it, and over the next week or two it'll get painted while I wait for the rest of the parts to come in.  I've abandoned my San Diego entry and I'm aiming at the Lincoln double now, which should actually be doable...

Filed under: Delays, Handling No Comments