August 14, 2011 - I have lots of important work to do on the car, but I'm back to painting wheels again. It would have been a lot easier if I'd just stuck with an off-the-shelf color, but the car looks much better with white. Besides, it's easier to inspect the wheels for damage this way!
So, after trying rattlecan paint from the auto parts store and powdercoating, I'm back to doing things right. That means real automotive paint and clearcoat. First, I had to clean the set of rattlebombed wheels of all the brake dust, rubber and debris from several track days. Simple Green, scotchbrite pads and a session in the bead blaster followed by a wipe-down with wax remover and they're ready to shoot.
I spent 45 minutes building this wheel rack out of a half-dozen 2x4s. It might seem like overkill, but it means I have the wheels at eye level so they'll be much easier to paint. Plus I can do both sides at the same time and, since they're supported by the barrel I don't have to worry about the paint on the rims getting damaged. Well worth the $12 investment in materials. I'll do this set of wheels first, then follow up with the second set later.
Tomorrow I'll be back to work on the car itself! entry 907 - tags: wheels, paint
August 14, 2011 - Emilio from 949Racing is very concerned about sub-standard wheels getting out. Because my powdercoated wheels were weakened, he asked me to render them unusable so there's no chance they'd end up on a car. I respect that. He suggested a 1/2" hole drilled in the barrel as well as a nice dent on the rim so nobody would be tempted to put them back in service, along with ensuring they went straight to the metal recycler. I had a different plan.
Just how strong are a set of good wheels? I've seen reviews of aftermarket wheels in a German magazine that included destructive testing, so I figured I'd take the opportunity for a bit of non-instrumented destructive testing myself. Besides, it's a lot more fun to use a sledgehammer than a drill. It's much harder to wreak this level of destruction on a set of 6ULs than you'd expect, even those with a heat treating problem. They're tough. We were all surprised at how hard we had to hit the lip in order to dent it, and knocking the center out requires quite a bit of determination. Emilio, it's fair to say these aren't going to get rescued.
For those who want more details on the actual problem: as part of the T6 heat-treating process, these wheels are aged at 350F for about 18 hours. Powdercoating takes the wheels up to 400F for 30 minutes, which can "over-age" the alloy and make it more brittle. I've heard - first-hand - of a German NC owner that had the stock wheels powdercoated and they cracked on him.
There actually is a 15x8 on the market that comes in white: the new Konig Wide Open. The weight is about the same as the 949Racing 6UL as well. I chose the 6UL over the Konig because of a proven track record - the 6UL is a well-known wheel that should take the abuse of the Targa, and Emilio stands behind his products. It's meant a lot of extra work on my part to make them white, but I think it's worth it. entry 908 - tags: wheels
August 15, 2011 - Now that's how you're supposed to finish wheels. Four coats of 1990-93 Miata white - which is actually almost pure white paint - finished with three coats of clearcoat. A nice smooth, hard finish that looks good and should shrug off brake dust. The special rack worked perfectly, making it easy for me to lay down a good coat without having to gyrate around. With the wheels at eye level, I could easily see how well the coverage was going down. Excellent. entry 909 - tags: wheels
August 17, 2011 - Time for some impact protection. The car has a few vulnerable areas such as the now-removed resonators. The metallic cats are also a potential problem spot, and they are required. I've actually grounded them out already doing some testing to discover exactly this sort of problem. So I welded a piece of 1x2" tube to the bottom of the frame rails and bolted a 1/2" piece of UHMW plastic to that. This means the slippery plastic will hit the ground just before the cats do, and avoid any damage. I also made a couple of extra skids just in case.
Yes, it will be a potential problem if the road is uneven. But that's something I'll have to keep in mind. Just like driving off-road, high spots should be run under the wheels instead of straddled.
After the picture was taken, it was all painted flat black. entry 910 - tags: skid plates
August 17, 2011 - I also want to protect the oil pan. It's welded aluminum instead of cast, so it's more likely to dent than to crack if I hit it. Still, there's no benefit to beating up the pan so I've put together this critter.
Made of 3/16" (I think) aluminum, it was an opportunity to practice my aluminum welding. I don't do this very often, but it usually comes back pretty quickly. entry 911 - tags: skid plates
August 17, 2011 - The oil pan skid plate in place. It's quite easy to install, just hook the curved section over the front of the subframe and bolt it to the car using the two rear mounting points. Everything is protected but it's quickly removed for service. There are a couple of things I could do to make it stronger and I may do that if I get the chance, but at the moment it should protect things in case I make a mistake and bottom out the pan. You can see the side skids are just about level with the back of the plate. entry 912 - tags: skid plates
August 18, 2011 - Brandon surveys his new race car. In case you missed the announcement on the FM site, Bill broke his shoulder over the weekend and is unable to race. Brandon, trying to act sympathetic but secretly giggling like a little girl, has stepped into his place. Now he's working to get the 2006 ready for the race. The plan to run a set of Corbeau FX1 Pro seats has been set aside - Bill doesn't find the stock NC seats comfortable, but they fit Brandon just fine. He's also working on smaller things such as wiring in the Terratrip rally computer and generally sorting out where everything will go. Reading the rulebook over and over is a big part of preparation for the event, to make sure there are no surprises at scrutineering. entry 913 - tags: nancy, brandon, accident
August 18, 2011 - Not all the work on the Targa car is big cool projects like skid plates. It's also getting some maintenance. For one, I'm changing out the front hubs to make sure they're at full strength. The current hubs had a total of about 10,000 miles on them but a large proportion of that was with hot race rubber bolted on. And, just like the original build, I had to grind off 75% of the teeth on the ABS trigger wheel in order to drop the number of pulses per mile to a reasonable number. The ABS sensor is used to trigger my Coralba rally computer, and it can only deal with 16,000 pulses per mile or so. With the modified ABS wheels, I get about 9,900.
And then I found a problem. The replacement hubs have an ABS ring that's about 2 mm smaller in diameter than the stock part. This meant the air gap to the non-adjustable pickup was too big, and it wasn't triggering the rally computer. That's not good. Luckily, the rings are just pressed on so I pulled off the old stock one and put it on the new hub. If only I'd noticed that before I spent all that time grinding! entry 914 - tags: hubs, wiring, computer
August 19, 2011 - Lots of little jobs on the car today. Mostly exciting things like wiring in a permanent power supply for the intercom and installing a wideband air/fuel gauge in the car. Plus some nut-and-bolt checks and other glamorous jobs like an oil change. But I did take a few minutes to put this little guy together. entry 915 - tags: maintenance
August 19, 2011 - Here's what that little doodad does. It's a brace for the brake master cylinder, tied into the shock tower brace. This should give a nice solid pedal - not something that's ever concerned me with this car, but it can't hurt. The brace is ridiculously simple, just a steel tube with a nut welded to the end. A threaded...I'm not sure what to call this thing, it's basically a bolt with a knurled knob at the end...presses up against the end of the master.
Did I have better things to do? Maybe. entry 916 - tags: brakes
August 20, 2011 - Race rubber! The painted 6UL wheels are an awesome, blinding white. Whiter than the powdercoat was, which is kinda nice. They've now been mounted with the actual tires that will be used in the race, a set of six Toyo R1Rs in 225/45-15.
A rehash of the tire rules that led to this choice: I am allowed a maximum of six tires for the race, and they have to have a minimum of 140 treadwear. This means I can't run a tire such as the Toyo RA1 that did so well for me last time. So the Toyo R1R is it. entry 917 - tags: tires, wheels
August 20, 2011 - Off the lift and on the road. It's time to get the engine tuned properly and make sure the suspension setup is good. Basically, everything needs to get the final shakedown.
The alignment will be sorted out in a few days. One nice feature of the V8Roadsters control arms is that I can play with camber to my heart's content without messing up the rear toe or the front caster. I'm still fine-tuning the damping settings for the 550/400 spring rates, but that should go fairly quickly.
The big thing is the engine. I've decided to take a different tack with how to set it up, and things are progressing fairly quickly. I'm just setting up air/fuel ratios without using a MAF at the moment, and it's possible I might just run that way during the race. We'll see how well the MAF dials in. Once it's all set up, the long-term fuel trim will make sure it stays that way.
As part of the fuel tuning, I'm working through the entire repertoire of the engine: low rpm, high rpm, low load, high load, etc. And at higher rpm, when I nail the throttle this car just boogies. It's still a bit rich down low so that will get stronger as I keep working. entry 918 - tags: tuning, alignment, suspension, testing
August 22, 2011 - A bit of extra airflow management thanks to Mark Rivera at Paco Motorsports. The NACA duct and the turn signal intake helped, but the air pressure underhood is just too high for them to really make a big difference. So these louvered panels will pull hot high pressure air out and make room for the cold stuff. As an added bonus, they'll keep the hood from lifting above 100 mph.
There are some larger ones available on the market, but I wanted a small set for a few reasons: they fit better around the underhood bracing and they'll fit with the Martini livery! Yes, perhaps that last reason is a bit shallow. But I don't care. The panels were punched out by Mark to my dimensions - thanks Mark! entry 919 - tags: aerodynamics
August 22, 2011 - In case you missed the announcement on the front page of the Flyin' Miata site and on various forums - there's a documentary underway about our Targa run. If you have come across this elsewhere, I apologize for posting it twice. But I'm excited! Adam Costa is a Miata fan who has decided to follow us during the race and tell the story of the team. Based on the preview he just released, it's going to be one heck of a show. I've known about this for a while, but it looks better than I could have imagined. Don't worry, the final result won't just be me - I was just the only one that was available for lots of interview time when Adam was in town!
Adam's trying to raise some funds so he can bring along another cameraman during the race, and thus he's pre-selling DVDs and posters. You can sign up on his Kickstarter page. entry 920 - tags: movie
August 23, 2011 - Going over the whole car has revealed a few potential weak spots. Such as this cap for the heater bypass, for example. It's only a few months old - I installed it when I put the engine in - but I suspect it had been on the shelf for quite some time. Check out that cracking. It might have made it through the race, but there's no guarantee. So I replaced it with a brand new one out of a fresh package, seen on the right here.
Interestingly, the slightly larger cap that is installed right beside it was put on at the same time. And it was fine. entry 921 - tags: maintenance
August 23, 2011 - Time to install those new louver panels. The first step was to figure out where they should go. Ideally, they'll go at the point of lowest pressure so they do the best job of pulling hot air out of the engine bay. On this 1994, that's roughly where the hood starts to flatten out when viewed from the side. But there are other factors, such as the underhood bracing. It's hard on airflow, and if you cut too much of it your hood gets all floppy.
Plus there are aesthetic considerations. In my case, that means "no vents in the Martini logo". entry 922 - tags: aerodynamics
August 23, 2011 - Here's the location of the vents viewed from underneath. You can see how they're tucked into the bracing. I also used the rivets to firmly attach the bracing to the bottom of the hood, to retain as much strength as possible. One of the cross bars had to be cut, but it's riveted to the hood on each side (one of those rivets hasn't been installed yet, but you can see the hole) and the louvers actually add strength in this direction. entry 923 - tags: aerodynamics
August 23, 2011 - The view from on top. For those who are curious, the outermost forward rivet is 210mm from the headlight cutout and 100mm from the side of the hood. It's a bit further forward than is ideal, but any further back and I'd be into the big brace. I could have also placed them in a more central location on the other side of that big brace, which would have let me move them further back. But then they'd be into the Martini logo! Oh, what we do to look good. I think they're still going to be quite effective, and it's possible the more central location would have been too far back.
You'll also notice a couple of rivets below the Martini logo. There's also a black on right by the R. Those attach the big brace to the bottom of the hood, replacing some factory adhesive that had failed. The amount of extra rigidity this adds to the hood is significant. You may also notice an extra oddly-spaced rivet on each of the louver panels, that is anchoring the stump of the brace I had to cut.
In the first "install" picture, you can see a matte finish I got from bead-blasting the raw aluminum. Now they've been sprayed with white paint to match the hood, and they actually blend in very well. I considered making them black or leaving them matte, but I'm happy with this. entry 924 - tags: aerodynamics
August 23, 2011 - In case you didn't know, the Targa Miata's sister car is being navigated by Zach Bowman from Autoblog. He'll hopefully be posting during the race, giving his viewpoint on the experience. He's just posted an update about his change of driver's thanks to Bill's damaged shoulder - and about how he narrowly escaped a similar fate. Autoblog at Targa Newfoundland entry 925 - tags: media
August 24, 2011 - The tune for the engine computer is coming together pretty quickly. Changing tacks and concentrating on the MAP-based tables did the trick. It's close enough now that the computer's effective short- and long-term trims will keep everything in line, although I'll do a little extra tweaking once I get down to sea level. I'm also going to keep working on it before I leave to fine-tune as much as possible.
I did discover a vibration from the rear at high speeds. I'll see what I can find. It's not massive, but it's enough to make me look for it.
With exterior temperatures being a solid 100F outside, this was some pretty hot work. It's hard to say exactly how much the intake temperatures have dropped thanks to the louvers, but they're far better than they were when I started. I did confirm that the hood doesn't bulge or flutter at high speed the way it used to, even in 4-cylinder configuration before I had to start altering the underhood bracing. So that's good, and hopefully an indication of the lower underhood pressures.
The screenshot is from the video camera I'll use during the race. I fitted a 0.5x wide angle lens to the camera to get a wider view and I'm pretty happy with the result. Between having the camera wired to car power and the ability to use removable 32GB cards that store over 4 hours of HD video, I should be able to get coverage of every stage without having to worry about space or power. entry 926 - tags: testing, video, aerodynamics,
THE DIARY
