| MIATA BUILD |
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 | |  | April 5, 2010 - Now, I have to get cold filtered air into that plenum.
I have a conical filter that fits into the inlet, but I need to do some dyno testing to see how well that works. The ideal plumbing here would be to put the conical filter in, then run straight to a hole in the hood. But not today.
So instead, I used some flexible 4" hose and ran it down to the filter. It's a tight fit and I'm not excited about the tight radius bends from an airflow standpoint. But it's critical I get this car as quiet as possible.
entry 745 - tags: intake, plenum, IRTB | | |  | April 5, 2010 - The filter is a monster.
I needed one with a 4" inlet to match the inlet on the plenum, so I grabbed the same filter we use for our V8 Miatas. It's Honda sized! A 90 degree piece of silicone and a slightly-fudged adapter into a piece of 4" tube, and we're hooked up to the hose.
entry 746 - tags: plenum, IRTB, intake | | |  | April 5, 2010 - The filter is pretty exposed to road muck and goo thrown by the tire in this location.
And the weather forecast for the trackday on Saturday was looking sketchy. So I took this plastic cover from a 2005 Mazdaspeed and did a very quick and dirty installation. Very quick and dirty - note the use of tape! That's what happens when the track day is Saturday morning and you're still working on the car on Friday night. As it was, the day was dry so it wasn't a concern.
The first day at Laguna Seca has a 92 dB limit. I'm hoping to get past that. The next two days are 103 dB, so I might just pull the plenum off and stick the sock filters back on for maximum roar! Because I'm a child.
entry 747 - tags: intake, filter, IRTB | | |  | April 14, 2010 - Welcome to California!
Three days of track time with two drivers, mixing it up with faster cars. It's a good thing this little car is tough.
The first day was sunny and beautiful. The track day was run by the Checkered Flag Racing Association, which is basically a grown-up version of the Red Rock Racers I run in Grand Junction. Sessions were 30 minutes long and full of some very serious machinery. Even the novice group had a Porsche GT3, a fast little Caterham and a couple of Nissan GT-Rs. The Nissans were being driven extremely quickly, and were really in the wrong group. Overall, a very experienced bunch that were good to share the track with.
The goal for the Friday session was for it all to be about Janel. She's spent so long hanging around as I run around at the track it only seemed fair for her to have her own track day. So our friend Rick Weldon offered to give her personal instruction, and I was pit crew.
We started off doing a sound check. The limit was 92 dB, and we went by the meter at 93.3 dB. After a certain amount of chaos on the part of the organizers who all told us different things, we found that by holding 4th gear through turn 5 we tripped the meter at 88 dB. So there's that solved then.
Rick was running behind, so I went out with Janel for the first three sessions. We had a good time and everything seemed to be working fairly well other than a car that was very grouchy when cold. The biggest problem was dealing with the traffic.
Rick showed up just as we left for the third session, so he only got to ride with Janel for a couple of sessions. She was all warmed up and ready to go, though. He's a fantastic instructor and not only helped her with her lines, but also with how to deal with traffic. She's a great learner, and if you tell her to go full throttle through a certain corner without lifting, she'll do it!
I was running a stopwatch, and we saw her times drop by about 12 seconds per lap - partly due to the way that she dealt with faster cars passing her. The big grin is from her last session, when she spent two or three laps holding off a 911 GT3 (really!) before the monster power on the straight finally proved to be too much for the little Miata. She was putting down consistent 2:00 laps with only a few tenths of a second of variation, plus one solid 1:59.28. You can see her session on the video page. After seeing the times, Rick commented that she'd be a great endurance driver. On the way to dinner a couple of nights later, she asked me how you get involved in endurance racing...
Does she look happy to you?
entry 748 - tags: janel, laguna seca, track | | |  | April 14, 2010 - After Janel had so much fun on Friday, it was time to meet the hundreds of Miatas that had come for Miatas at MRLS.
The plan was for me to drive the car in the fastest A group and take people for rides, and Janel would drive in the C group. However, when I first jumped in the car, I discovered that it was very unhappy under part throttle. It was too late for me to do any more tuning on the car, but spending a single session with a laptop jammed under a seat would have made a big difference. Still, it was easy enough to drive around. I also discovered that while my spare rubber was up to pressure, I had the tires on the car about 7 psi low. Whoops. So the car should have been faster on Friday for Janel if I'd been able to take a quick test drive. Sorry!
For the rest of the weekend, the car pounded around and around the track. The other cars from Flyin' Miata were under orders not to run at 10/10ths to ensure they'd last, but that didn't apply to the Targa car. So I ran it pretty hard, and I know Janel did as well. This is one solid little critter, and so much fun.
The new suspension wasn't a big hit with Janel, and it certainly did allow a lot of lean. Still, it put down the power well and seemed friendly enough. I wanted just a bit less understeer but didn't want to mess with it after Janel had spent so long honing things with Rick.
I spent a lot of my time staying out of trouble with the A group, populated with winged beasts and drivers that were considerably faster than me.
Janel had a different problem. She was much faster than everyone in her group, and so she spent most of the time waiting for the slower driver to point her by. It was frustrating. She really should have been in the B group.
Sunday started off cold and looking like rain, and it started to sprinkle fairly early. Janel came into the Corkscrew with the back end of the car quite loose and almost looped it, and I found the grip level changing on every corner. So we parked the car, and shortly afterwards the skies opened. The track was closed early due to the deep water, and we packed up to go home.
A pretty good weekend.
entry 749 - tags: laguna seca, track | | |  | April 14, 2010 - New videos have been uploaded!
There's a video of Janel's fastest session on Friday as well as a couple with me driving in the middle of a fairly entertaining group. Videos
On Saturday, the event organizers gathered a few of us together for a video shoot. There was a hand-held camera in one of the cars, and the rest of us were basically tasked with putting on a good show. Two Spec Miata drivers and a couple of modified super Miatas - and my little rally toy. I was probably the least experienced track driver of the bunch, so I had to pedal pretty hard just to keep up! The extra horsepower of the Targa car let me reel in the Spec Miatas most of the time, but not always.
Still, it was like a little race. One of us would take the lead, then allow someone else to pass. Meanwhile, the camera car was zooming back and forth. I certainly wasn't the fastest driver or car in the group, but I consoled myself with the thought that if there was a speedbump in the middle of the front straight, I was the only person who could take it at full speed!
The Targa Miata is one solid little car. This picture was taken after Janel ran for a full day on Friday, and then she and I both drove the car on Saturday. On Saturday, the car was on the track for 20 minutes, then parked for 20 minutes before it went out again. And that's the state of one of the tires. A tire that we used in the Targa. A week long race, followed by a bunch of local track days, followed by two days at Laguna Seca last year, then repeat the local track days and two more days at Laguna. And it's only about half worn! Amazing.
entry 750 - tags: play, laguna seca, video | | |  | April 25, 2010 - Some pictures from the Laguna event.
More are coming. This is the first session on Saturday (it must be, I'm not wearing my driving suit) and that's John Anker coming down the Corkscrew behind me. He was never behind me for long!
Photo by Mark Booth.
entry 751 - tags: laguna seca | | |  | April 25, 2010 - Mark got a this great shot of Janel at speed.
I'm not sure where it was taken - it's a right hand turn, so I'm thinking it's either turn 4 or 10, and something it telling me it's 4 - but I really like it.
Photo by Mark Booth.
entry 752 - tags: laguna seca | | |  | April 25, 2010 - A shot of our video session from outside turn 2.
I'd just steamed by the whole group on the straight (with their acquiescence, as there's no way I could power by a couple of those cars), and was taking a wide line into 2 to let that Spec Miata run inside me for a cool pass. The camera is in the red car about halfway back. This was fun stuff. The photo was taken right at 2:00 in this video.
Photo by Mark Booth
entry 753 - tags: laguna seca | | |  | April 25, 2010 - Laguna Seca is a pretty track.
Quite a change from the dusty desert. Here's Janel about to dive over the edge into the Corkscrew. Photo by Got Blue Milk.
entry 754 - tags: laguna seca | | |  | May 1, 2010 - More magazine coverage!
The June 2010 issue of Grassroots Motorsports has a good article on our Targa adventure. Not just the story of the race, but also some sidebars on how to survive your first performance rally, details on the car and what it's like to run an event like this with your spouse. Thanks to Grassroots for the attention!
If you'd like a free copy, they're happy to send you one. It's a good magazine, even the issues that don't have a mention of the Targa Miata in them.
Get a free copy
entry 755 - tags: magazine, grassroots, publicity | | | May 13, 2010 - The 2010 Targa factors have been released!
This has been a long wait, and I think it's because the organizers have been making sure their fairly major change is correct. Basically, the event is now split into two.
The classic cars (1981 and older) continue as-is. The Level 3 preparation level is expected to be dramatically faster than Level 1 or Level 2, and I think that's to be expected. Level 3 is aimed at the cars that are taking full advantage of four or more decades of hard-won competition knowledge, and are basically new cars in a vintage shell.
The big change is in Modern: there are no more factors. In other words, Modern is a full-on race. I expect the base times to be fairly aggressive, which means that many penalties will be taken. The fastest car will win. Awards will be given for the five classes, based on age range. There's no mention of any distinction between preparation levels, so basically everyone will build for Level 3 preparation. The Targa Miata is a Level 2 car other than the fact that it runs a 1999 cylinder head. If I installed a 1994-97 head, it would be fully legal in Level 2.
But since there's no handicapping, why not run in Open? Instead of competing for class honors with big-engined Level 3 cars of similar age (1991-97 in my case, which means a whole lot of rally-bred Subarus and Mitsubishis), run for the overall win with the big boys and throw away most of the rulebook.
That's what I would do if I were building from scratch. I'd stuff in that big V8 and proceed to scare myself silly. I might not be competitive at the top level due to my driving ability, but the car would be a real beast to drive and a massive rush.
The smaller cars won't be in the hunt for an overall win and probably not even for a class win. Minis, Civics and Miatas will now be racing for fun. But you know what? These cars wouldn't be racing for an overall win in any other race event either.
The biggest problem I see with the Modern setup has to do with the trophy times. Any novice team sets themselves the target of winning a Targa plate. The trophy times are set based off the target time for the stage - I think it's about 40% slower or so. It's an excellent goal. But without different factors for the different classes, that 40% of the target time is far more difficult to hit with the slower cars. Faster cars will have an easier time. The Targa plate (in my mind) is meant to be a test of consistency and reliability. This change will put a much greater emphasis on speed with the slower cars.
Of course, it's easy to poke holes and not offer a solution. The only alternative that comes to mind is to scale the trophy times off the fastest car in a particular class. For example, the trophy times for Early Modern for each stage will be set at 40% of the fastest Early Modern car to finish the stage. It means they'd have to be calculated after the stage is finished, but that's not a big problem with automated timing.
I'm hoping this change will attract more monster cars to the event, now that they no longer have to worry about explaining how they lost to an old BMW.
Targa factor announcement
2010 factors
entry 756 - tags: factors, 2010 | | |  | May 16, 2010 - Road trip!
The big Miatas in Moab event took place this weekend, and I headed down to say hi. It's only about 75 minutes from my house to the lodge where the event was based on Saturday. The crowd at this event is almost the exact opposite of the folks that were at Laguna Seca a month ago, and the race-scarred Targa car did stand out. Most of the attendees didn't have roll bars, and nobody else had brake dust on their wheels, well-scuffed race tires and a cage! Still, there were a lot of fans of the car and it did get a lot of attention and I spent a fair bit of time talking for various Miata enthusiasts from all over the US. I also took a couple of people out for test rides in the newest V8 car - yowza, that's a fast, fast car. As you can see in the picture, the Targa car got the prime spot for the big group photo.
One excuse for this little excursion was to test the dual-spring suspension a bit more. It had acquitted itself fairly well at Laguna, although with a lot of roll. On the highway, it felt a bit odd. The change in spring rates definitely make it difficult to get the damping right - it's either heavily over-damped on small movements or under-damped on big ones. I have it set up for the former.
I did find out where it works best, though. There's one way to get to Moab from Grand Junction that runs across a few miles of abandoned road near a ghost town. It's paved, but fairly rough. And at "targa speeds", the suspension ate it up. I can see this setup working well on Leading Tickles, for example. The car just went supple and absorbed almost everything.
It's not perfect. A really big hit would bottom out the rear hard. Granted, I'm running a track ride height and not a Targa height, so there's at least an inch of travel missing there - but I think the problem is that the secondary spring rate is too close to the primary. The effect is that the secondary spring never really closes up, so the rear spring rate is too low for too long. I'm planning to pick up some new secondaries that are around 150 lbs as opposed to my current 300, and I think that will address all of my concerns with this setup.
It never stops. I'm always trying to make this car better!
entry 757 - tags: Moab, suspension | | |  | July 16, 2010 - I've been working on other cars, and the Targa Miata has been sitting.
"Sure boss, I guess I'll drive the supercharged 2006 at the track day to see how it does" - that was actually a really good track day, as it poured rain. The combination of a powerful car on wide street tires and heavy rain made me work on some skills that could prove very useful at Targa.
But the car hasn't been forgotten. I've removed the 300 lb secondary springs to cut down on that initial body roll and sharpen up the car's reflexes. The radiator was removed as part of some cooling system testing and has ended up in Janel's street Miata. The differential is coming out so we can test a different unit. All of this should be on the track in a bit over a week.
But when I was working on the car, I discovered a problem. I know the Performance Friction PFC97 pads are hard on rotors, and I've been watching the slots on the rotor as a guide of wear. But when the wheels were off for something else, I took a closer look and was shocked. The rotor in the picture used to have slots! The outer face still has lots of meat and isn't showing dramatic wear, but the inner face is completely worn away. Both front wheels were like this. Yikes. I also discovered a cracked rear rotor.
So, what happened? Good question. The brackets on my brakes are from a source that often needs a bit of shimming to get them aligned well enough to clear the rotors, and even then my calipers are off-center on the rotor. I wouldn't think a 4-piston caliper would matter, but the brackets are being replaced with new ones that are perfectly designed and machined to keep the caliper centered. New rotor rings are on the way. Flyin' Miata is also testing a different brake kit that will be on the car for the next couple of track days, so there's no big hurry.
I have new rotor rings on the way to replace these.
entry 758 - tags: brakes, suspension, cooling | | | August 9, 2010 - Now THAT was fun!
Last weekend was the Flyin' Miata Summer Camp, previously known as the Open House. Some may remember that the car made its track debut at the Open House in 2007 - it's hard to believe it's been three years. That time, the car managed a best of 1:07.977. These days, I'm consistently in the 1:04.xxx range on the same set of tires I used in the race.
The original plan wasn't for me to drive the Targa car. After some memorable battles for the lap record in 2008, a decision was made that the staff should spend more time taking customers for rides. I was scheduled to drive the supercharged 2006, which is a pretty fun car. I did get the Targa car all reassembled and bedded the new brake pads in, just in case. I actually ended up using it as transport to get to the track that morning.
It became apparent fairly early on that something wasn't right with the 2006. It had some wiring problems recently due to a poorly installed O2 sensor hardness and we're still chasing down gremlins. The car was way down on power so we decided to park it. I jumped in the Targa car and took people for rides in that instead.
Halfway through my first session, I just started laughing and yelled out "it's great to be home!" This is such a good car. Without the secondary springs I'd been running before, the 600/450 lb setup made the car super-responsive. The balance was a bit understeery (I hadn't had time to set up the sway bars) but the car still worked well and could be easily balanced.
By the second session, I was taking the "AFCO line" through the chicane, actually leaping the inside wheels across the gap inside the corners and probing the limits of the braking zone. In the FM cars, we had to be a bit conservative to make sure the tires and brakes were good and we gave the customers a good ride. But the Targa Miata is like an anvil, and I could push it to the limit without having to worry about anything. It's made to be run hard.
We didn't have transponders on the cars, but it would not surprise me if I'd been in the 1:03 range. The car felt that good, and a number of my passengers commented that I gave them the ride of the weekend.
Oh man, was that ever a good time. What a great little car.
entry 759 - tags: track | | | August 24, 2010 - I spent part of the day replacing the differential.
I'm going to try out a new unit that's a clutch-type instead of the Guru helical I have now. The car's tendency to spin an inside wheel on right turns should be abolished!
Or should I say, the car's old tendency. At the Open House, I didn't have any trouble with that. I always had a passenger which does alleviate the problem - but likely more important, I was running a different spring setup with a lower ride height than usual. I also didn't have the rear sway connected, but I know I've run without it before. Interesting. It could have simply been the passenger and the fact that I've been driving other cars and taking lines that alleviate wheelspin. Anyhow, it'll be interesting to see how this new diff turns out.
I've also pulled one of the front shocks off. Due to an assembly error on my part, it was leaking pretty badly at the track day and acting very poorly on right turns - maybe that was the secret! The good thing is that if an AFCO leaks, you can just refill it with the correct oil and it's as good as new. I have the oil, so I'll top it up and test the result on the track by Sept 4th at the latest.
entry 760 - tags: suspension, differential | | | September 5, 2010 - Track day test!
The good news? The new diff works beautifully. I could get on the power much earlier and get a solid drive off turns - left and right. It's a clutch-type diff. I had an idea this might be effective as the V8 cars from Flyin' Miata have shown an uncanny ability to hook up out of corners. On the first session, I managed a 1:03.796. That's nearly a full second off my personal best in the car. Now that is some serious progress!
It wasn't without a cost, however. I found the handling of the car was difficult. In particular, I had trouble with corner entry understeer. It didn't seem to be there for that first session, but almost seemed to get worse as the day went on. I tried to drive around it and I tried to tune around it with shock settings and a stiffer rear sway. Interestingly, the sway bar change didn't seem to have any effect. I also found I couldn't get enough rear bias into the brakes - even with the rears turned up all the way, I'd still lock up the fronts too easily.
I suspect what might have happened is that the old tires have finally given up. This is the same rubber I ran in the Targa almost exactly two years ago. They've seen 5 days at Laguna Seca with two drivers, probably a dozen track days on this track, some road use and of course the Targa itself. When the Seven is too low on traction, it gets a similar behavior. Oddly, the car doesn't feel slippery, it's just not hooking up the front under braking or turn-in. Am I going in the wrong direction? Hard to say. I might just have been trying too hard.
I have another track day on a big track next weekend, and I flat-spotted at least one of the fronts badly enough that it's done now. I have two more mounted tires and two unmounted ones in the garage. Both pairs from the Targa (or possibly pre-Targa testing) of course, but they haven't seen as many heat cycles. So I'll swap the flat spotted front tires out for the "new" unmounted ones and put the other pair on the rear, then take the existing rears with me as spares. I'm also going to double-check that front shock to make sure it's working as well as bleed the brake system again, and if things aren't any better then I might throw in some extra front camber if possible.
I ended the day a bit bummed out that I couldn't go faster, but I'm feeling a bit better now that I look at the times again. Another Miata at the event - a turbo car running some Nitto 225/45-15 tires on 15x9 rubber!- was putting down times right around the same as I, and his times fell off over the day like mine did.
Was the diff a success? Well, if I can sort out the handling, yes. Right now, the car wouldn't be happy on the Targa because it's too easy to wash out the front end, but if I can get that sorted then it's a real winner in terms of fast corner exit speeds.
entry 761 - tags: testing, differential | | | September 5, 2010 - Whoops.
I figured out what was wrong with the car yesterday. Yesterday morning I'd set the tire pressures and found them a bit low. At one point during the day, I tried pulling a bit of pressure out just to see how it worked. It seemed to get a bit better but I was still chasing the handling.
Just to confirm, I went back to my notes to see what the hot pressures should be - and I'd mistakenly set the cold pressures about right for the hot pressures! Even better, it was cool that morning and the day got pretty darn hot - up to the mid-90s. So that explains what was going on. On the first, relatively cool session I was probably pretty much dead on until the tires started to take temperature. And my second lap was the fastest. On later ones, as the track got hotter and I started taking more aggressive warmup laps to get heat in the tires, they were getting badly over-inflated.
I've dropped the pressures down to my usual track starting point now. We'll see how well it does at the track this weekend. I suspect much better! Boy, is my face red.
entry 762 - tags: tires, handling | | | September 11, 2010 - Track day at High Plains Raceway!
To celebrate scrutineering and odometer check day for Targa Newfoundland 2010, we headed to a new track near Denver to try it out. HPR is a 2+ mile track with a surprising amount of elevation, and I'd heard quite a few good things about it. Not a quick drive from Grand Junction, but not far off Pueblo where I did a lot of the original development of the car.
The day was put on by the Z Car Club of Colorado, and I think they only do a couple of days a year. There was a very complex and ambitious schedule that was broken by the time the driver's meeting started 40 minutes late, but that happens. They were quite safety conscious, so no complaints there.
It took a bit of time to become familiar with the track - there are two sections that look fairly similar, and a number of blind spots. But after a couple of sessions, I was up to speed pretty well. The sessions got longer and longer as the day went on, and my last time out was a full 30 minutes. I was only going to do a portion of it, but I got chasing other cars. You know how it is. The best was a new 370Z which was a bit of a chase - great fun.
Janel also spent some time in the driver's seat, of course. She started off a bit tentative, but got faster and faster as the day went on. On her last session, she pointed by a couple of cars and then proceeded to reel them right back in again. It really got her competitive juices going and all three drivers had a fantastic time.
The car felt good, but not perfect. The right front shock felt low on fluid again, so I'd get some shaking through the wheel on hard right turns when it was unloaded. It didn't affect grip at all and it worked fine when the wheel was heavily loaded on lefts, so I just dealt with it. Otherwise, the car rotated nicely with a good high speed balance, and the new diff worked well to pull the car out of corners very strongly. The tires were working well, even though I have a pair on the front that I used to set the car up for the Targa more than two years ago! They're pretty well worn as you might imagine. A few other drivers commented on how quick the car was for a naturally aspirated Miata! Part of that was the car's ability to hold speed through the corners, it really reeled in other cars on the fast corners. Both Janel and I found it comfortable to really smear around the track at high speed, forgiving but agile. Like a Miata is supposed to be.
The car spent between three and four hours on track today, and was as reliable as an anvil. We just kept pounding around and around and around the track, with Janel and I doing back-to-back sessions so the car would usually run for a full hour at a time without a real break. A really fun day.
Video will come later, as will some reports on Targa 2010.
entry 763 - tags: track, testing, HPR | | |  | September 13, 2010 - New video!
I've put up a clear lap of the High Plains Raceway. I have a few more with me chasing down various cars, and I may put them up later. Janel's the one who got in the best scraps anyhow!
Video
There were some truly delicious cars at the track day. The green 260Z in the foreground looked great. The 635CSi hiding behind it is one of my favorite car designs, but I have yet to convince Janel of its inherent goodness.
entry 764 - tags: video, high plains raceway | | |
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THE DIARY