The Miata experience: his and hers.

I'm glad you trimmed the trunk floor, from a pure aesthetics it's about a hundred times better. 

In reply to Professor_Brap (Forum Supporter) :

Yeah, there's a big ol' chunk hanging down on the driver's side if you don't cut it off.

Swapped the street pads back in today, since our next track event is a month away, and I have a couple cars&coffee type things to hit in the meantime.

Took some outdoor pics today.  The stock front end looks less unbalanced than I thought it would with the rear mods. 

Hope to get started on the airdam/splitter this weekend...

This morning I took the NA on a quick canyon run on the way to our local C&C as a shakedown for all the recent work on the back of the car.  A little more NVH from the new exhaust mounting, but no more clanging and banging from it moving around like it used to.  I did install an aluminum heat shield between the muffler and trunk floor, with an air gap on both sides, and that seems to be pretty effective at keeping the trunk cool.  We'll see how it fares on the track.

The next project is the front bumper/airdam/splitter, which will be following the basic Supermiata forumula.

I started today by pulling the bumper cover, and then removing the factory bumper stuff...

Next up was cutting out the center support structure (I'll be building a new one out of tube).

Before remounting the bumper cover for cutting, I made up the base plates for the new tubular support bar.

Then the bumper cover went back on for trimming to the proper height.

Last for today was bolting on the splitter support brackets.  I got these a while back off a group buy on MT.net... they were made by Trackspeed Engineering, which is now essentially out of business.  At the time there wasn't anything else on the market, but now there are several alternatives.

That's it for today.

First up for today was the front support bar.  Quick and easy compared to the rear.

One of the fender supports I pulled out had a nice little bouquet of track rubber... 

Next was the splitter itself, cut from 1/2" birch plywood.  I was a little too conservative with the first prototype, but was able to make adjustments using it as a pattern.  I had picked up 2 4x8 sheets, expecting to have enough for four splitters:  prototype, pattern, one to use and a spare.  This was based on info from other threads that a 4x8 sheet could provide 2 splitters... it won't.  Not if the splitter goes all the way back to the crossmember.  So I have a prototype and a useable splitter.  Tomorrow, I'll pick up another sheet so I can make a permanent pattern to store and make backups.

Sorry about not having in-progress pics.  It was hot (over 90*) today, and I was just trying to grind it out...

This version is specc'd with a 2" stickout from the airdam.  I also set up a pattern for a 5" stickout for when I step up to a real wing.

The mounting bolts go into tee nuts in the splitter, so there is nearly zero protrusion on the bottom.

Tomorrow I plan to start on the airdam mounting, and weather treating the splitter.

Chugging along...

Found out you can get two splitters out of a 4x8 sheet... guess I didn't have enough coffee the other morning.  Although this only works up to ~3-4" of stickout.  At 5" two wouldn't fit.  So, now I have an in-service splitter, a spare, and a pattern to go in storage.  The original prototype got tossed.

So, with a couple more splitters cut, I started treating one with spar urethane for water resistance.  While that one was drying, I used the other to start mocking up the airdam.  The airdam is roll plastic from Speedway, available in a variety of colors.  It was rather unruly when I unrolled it... sitting in the sun for a while with some weight helped to flatten in out.  Next I trimmed it to the proper height, and set it on the splitter.

I found center and installed a rivnut on the bumper cover to hold the airdam while I was figuring things out.  First was to determine vertical around the bumper curve and layout the lower retention.  Since this is a true Home Depot Racing project, the lower retention is a plastic garden border.

After a little more trimming, I was able to install the rest of the rivnuts for the top of the airdam, and get the rear edges cut.

The airdam will flare out slightly to shroud the front tires, so I need to build a standoff piece for each side.  I also need to cut out the opening for the airflow to the radiator and locate the rivnuts for the bottom edge of the airdam.

Meanwhile, the urethane coating on the spare was drying.  After all the airdam work, I coated the splitter I'd been working on and it's drying now.  Finishing touches later in the week...

More airdam work today...

First up was cutting out the grille opening.  It's probably bigger than I really need for a naturally aspirated stock engine, but here in the desert Southwest, more air than I need is definitely better than less air than I need.

Corners cut with holesaw...

Opening cut

1/2" rabbit fence cut to keep track debris out of the ducting.

Grille installed.  Note that there's no ducting for the radiator in place yet.

Next up was a pair of standoffs to 'flare' the airdam out to shroud the front tires.

When you put wide tires on a Miata, a LOT of the front of the tire is exposed to the airstream, and it results in pretty significant drag.  Here's an old pic to show what I'm talking about:

One of the purposes of the airdam is to shroud the front tires and get that air moving down the side of the car.  To do this, it has to flare out from the fenders, and this is usually done at the panel line between the fender and bumper cover.  I built a pair of standoffs that will attach to the bumper cover, and the airdam will bolt to the standoff via rivnuts.

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Once I was happy with everything, I hit them with a coat of paint.

I still have a bit more fabrication to do (tow points and ducting), but hopefully I can get everything bolted together for a test drive tomorrow morning.

Finished up the airdam today.  Also made a new tow point for the soft tow loop that will protrude through the airdam, though I apparently forgot to take pics of that.  Also installed the inlets for the brake cooling ducts.

Splitter height ended up ~3.25" inches.   Should be fine for the track as long as I don't go kerb hunting.

I did order a set of RaceRamps today, since trailer loading will be an issue...  even though I set the whole thing up to be removed in ~10 minutes, I'd rather not have to if I can avoid it.

Next up is installing the brake ducting hoses, and building the ducting for the radiator.

That looks great!

Thanks!

Worked on ducting today.  Used 5mm corrugated plastic and some light aluminum angle to build the ducting 'box'.  This should be plenty for the current car configuration.  It was kind of a PITA to get it all mocked up before cutting the material... the posterboard I was using for patterning was a little too flimsy.

Inital 'box' fitting...

I added brackets to the bumper cover support bar to support the 'box'.

'Box' installed

I used pipe insulation foam to seal the gaps front and rear.  Splitter and airdam back on...

Also installed the brake cooling hoses... zip ties are temporary.  Working on a better support setup for the hoses.

So, except for the attachment for the brake cooling hoses, I think I'm finally done with the current 'aero' project.  I'll take it for a test drive up to highway speeds to see if there are any issues tomorrow.

That's pretty serious. I love it. 

Test drive today at higher speeds revealed no problems with anything, so I think we're all done.   For now... 

Stopped by the local hot rod gathering this morning... which one of  these is not like the others... LOL

Also put the final touch on the brake ducting.  I didn't like the bare zipties on the ducting hose, so I got some longer ties and ran them through some clear vinyl tubing to help protect the hose.

While it was up in the air, I switched back to track pads, and touched every bolt that had been part of the aero/exhaust project.  Also re-did my pre-event inspection.

It's ready to go back in the trailer for our next event in early November.  Raceramps should arrive Monday, so I can actually put it back in the trailer without removing the splitter...

That's a near idea to protect the hose... Car looking great!

That's a really nice how to for front aero! Thanks for the photos and ideas!

The Raceramps arrived yesterday... still a tight fit!

Combined with my trailer's door ramp, they don't really work that well on uneven ground... that being the paved street in front of my house.  After some fiddling, I was able to get the NA loaded and back to storage.  No way I could have loaded it without the ramps, at least not with the splitter attached.

While I was waiting around for FedEx to drop off the ramps, I snapped a pic of Marine One departing the area after the President's rally here in Prescott yesterday.  Sorry for the crappy pic, but it was at pretty extreme range for my little 250mm lens.

Today I washed, clay-barred, polished and waxed the dually.  7.5 hours... I feel like my arms are going to fall off... 

But, it needed it badly, and I had been procrastinating for a long time.  Looks better than new.

One of the major issues is it's too long to fit in the garage, so I had to do the front half, then turn it around and do the back half so I could keep what I was working on in the shade.

I also pulled the soft tonneau cover off, washed it and treated it with 303 Aerospace protectant.  This stuff works pretty dang well.  The tonneau is on it's second truck, and is over six years old.  That's pretty good considering how brutal the AZ sun is at this altitude.

Been a while since I had any Camaro content in here... We're now at 21k miles on the ZL1.

Today I did an oil/filter change and pre-event inspection on the ZL1.  Spaced out and only ordered 6qts of oil (it takes 10)... fortunately, I had enough leftovers from previous purchases of 12 packs to finish the job.  Also ran the front tires to the local Discount and had them flipped on the wheels.  The aggressive alignment I run was starting to show increased wear on the inside, though wear across the tread was consistent.  Rear tires were showing more wear in the center, so I dropped them back a couple of pounds.

With the Camaro ready to go, the tow rig needed a little attention.  It was due for a drain/fill on the transmission, so I rolled it into the garage... tight fit!  At least it didn't need to be jacked up...

Old v. new fluid...

Looks like the fluid is still in pretty good shape.  Which is good, because the service schedule calls for a drain/fill at 30k and drain/filter/fill at 60k.  Drain/fill only gets around 1/2 the total trans fluid out of the system.  I'll see what things look like at 60k, but I certainly don't want to have to pay the dealer to do a full fluid transfusion.

Today I picked up some secondhand NIB parts for a future engine build for the NA...  Boundary Oil pump, ARP main and head studs and a set of Maxpeedingrods connecting rods.

I'm not yet convinced I'll actually use the chinese rods, but the price was right.  Looking around the 'net, there's a lot of folks who say "NO WAY... because CHINA!!!!", but there's not a lot of actual first hand reviews.  Not even a lot of failure stories.  Found one failure on a VW forum (at 500whp!)  where it actually appears the rod bolt, and not the rod, failed.  Found a couple other reports of out of round, out of spec, etc.  I did find one report of a set of these working fine in a Miata BP at 300whp.  Found no reported failures in a BP engine.

I'll do a close inspection, then see if they measure up before using them... 

Just returned from a weekend at INDE Motorsports Ranch in Willcox, AZ with the Porsche Club.  Lots of pics, video and data to go through.  Pretty wiped out, but here's a couple of teasers...

Well, it was another great weekend with the Porsche Club.  First, I've gotta give them credit for putting on a very well run event, and second most of the attendees are very friendly, and more polite on track than the typical HPDE event.  At least in my group, after the first couple of sessions, everyone was really good about gridding up in order of their pace, and with a long track, I rarely had to slow up for anyone, and I think I only pointed two cars by the whole weekend... in the NA!  My wife had a few issues with a driver in an R8 the first day, but it all worked out.

As a result, I could concentrate on driving, which was a good thing.  The track had been resurfaced since last year, and the surface was very smooth, which was great.  It was also a little green, and uniformly black, which wasn't so good.   Not quite the maximum grip we had the previous year, and it was very difficult to pick out visual references on the track surface.  And as much as I love this track, there are a variety of configurations and we ran different configurations Saturday and Sunday.  Fortunately, our Sunday configuration this year was the same as Saturday last year, so I was able to directly compare lap times from those days.

I did go faster in both cars.  Still haven't had time to take a deep dive into the data, but improved from 2:12.3 last year to 2:07.8 this year in the NA, so I am happy with that.  I also improved in the ZL1, but the lap times I was able to directly compare were from a single session with a flat tire last year...  I'm definitely learning the ZL1 better as I get more track time, and overall was much faster than last year.

Some more pics:

Overall the conditions were good, but we had strong winds both days, with a headwind on the front straight up to 20mph + gusts to 30+.  Late Saturday, we had some light rain, which came during one of my sessions in the ZL1.

I've got some video from the ZL1, and I'll try to post some thoughts on the NA data when I have a chance to digest it a bit.  Since it's back to work today, it'll take a few days...

ZL1 video is uploaded.  First clip is Saturday running Configuration 1, second is Sunday running Configuration 5.

I was definitely having some consistency issues with the ZL1, especially through the turn at the end of the main straight, and the complex past the tower and start/finish.  I really need more track time here to dial it in.  The ZL1 is so different from the Miata through these sections it's really screwing me up.

Overall, the ZL1 did well on the R888Rs (which are on their 7th event day) but it was really pushing in the slower corners.  I really had to lower my corner entry speed compared to the Miata and be patient and make it up on the exit.  And the exits were glorious... 

For the first time, I found a bit of fault with the A10 transmission... there were a couple of places were it would downshift when I would have let the higher gear carry through.  This thing has 500+lb/ft of torque from 2000 rpm... it doesn't need to be in the upper RPM range to pull off a corner.  It's still really darn good, though.  The stock brakes (still on the original pads) held up great, but don't have the greatest feel... something to look into.

For some reason, the recorder didn't pick up the track map or lap timing on Saturday.  Best lap Saturday (config 1)  1:53.9, Sunday (config 5) 2:04.9

It's still really a street car, so I shouldn't be surprised it wants a gentler hand than the Miata.  But what a street car!  I still laugh out loud every time I drive it... 

It's been a long week at work, and some numbnuts cut the fiber optic cable so all of Northern AZ was without internet almost all day yesterday...

The NA made a big improvement in lap times from last year, as noted above... 4.5 seconds.  Hard not to be happy with that!  The two major variables were the change from 5sp to 6sp transmission, and the new aero.  The track was also completely repaved.  And last year was our first time on this track, so this year I didn't have to learn which way the track goes, and could concentrate on going faster.  We did have 20-30mph (steady!) headwinds on the main straight both days.

So, here's the speeds around the track... 2019 inside (in red), and 2020 outside (in black).

Interestingly, the track felt like it was lacking grip but it clearly wasn't.  Speeds were up almost everywhere... mid-corner, and at every braking point.   Only the front straight was down, and it was way down.  I believe a big factor was the transmission swap.  Last year with the 5 speed, I was coming onto the straight in 3rd gear.  With the 6 speed, I was in 4th gear.  Even with the higher corner speed, the difference on track is about a 200-300 rpm drop with the 6sp, and pulling against a longer gear.  Combined with the headwind, it felt like I was down about 25hp.  The end result was a 3mph drop at the end of the straight and a full second longer covering the straight than last year.  Everywhere else on this configuration, the 6 speed was perfect.

The car felt really planted with the new aero after a minor adjustment to the spoiler after the first session.  I'm looking forward to getting it on a track I spend more time with to help quantify the improvement more clearly.  A couple of interesting notes:

I came in from the first session, and was surprised by the amount of brake dust on the front wheels, especially because I was taking it easy.  Then I realized I had finally hooked up the brake cooling ducts, so it was a clear indication that they were getting far more airflow than previously.  The brakes are so understressed at this power level, I didn't experience a difference on track, but it's nice to know things are working as intended.

For several years, I've run without the factory undertray on the front, which can cause cooling issues with Miatas.  I've never had an issue, but always planned to fix it.  The new front aero solved that issue, with ducting from the air dam straight to the radiator.  The car ran cooler than it ever has, with coolant temps never rising above the mid 180*F range all weekend.