Targa Miata
MIATA BUILD
August 6, 2008 - I love that blue.
The last time I installed the diff, I experimented with using Hylomar HPF instead of the usual RTV. Hylomar never really sets up, but stays tacky. This makes it really easy to separate later and to clean up. The old Land Rover guys use this a lot, and when I came across it in my toolbox I decided to give it a shot in something a little newer and hopefully more oil-tight. I'm pretty happy with the results, it's much cleaner to work with than RTV.
While writing this, I decided to check out the suggested uses of Hylomar from the manufacturer. And will you look at that, they recommend it for "differential covers". So there you go.
entry 508 - tags: differential
August 6, 2008 - I've been working behind the scenes on the website.
It's now easier for me to post updates - something that will be important on the road during the race! I am hoping to keep everyone up to date while the really exciting stuff is going on.
What's up with the picture? Well, I need to make sure the picture uploading is working. So that's what the car looked like a year ago. The Martini paint had been unwrapped just a couple of days earlier. It didn't even have a windshield or rear hardtop window yet.
entry 509
August 9, 2008 - A great shot from the last trackday at Pueblo.
The car's sitting nicely - this is a fairly fast corner with a quick dab of the brakes on entry, a bit of rotation and then back on the throttle. At least, that's how I do it. And I always exit this corner saying "next time, faster on entry..."
Back to the present day - the diff is in and working nicely. I'll know just how nicely after tomorrow. A surprise track day has come up at the Woody Creek track in Aspen, courtesy of the 25th anniversary gathering of the original quattro. This isn't a track we get a chance to drive very often. It's relatively short but is bumpy in spots and has a couple of challenging corners. I've only been on it once before. I'm going primarily because Janel has to work and because the weather forecast is poor. Hopefully it'll rain. It's not the usual wish for track work, but I don't have much experience in fast driving in the rain and I need the practice!
I have my new race tires all mounted and balanced. If it's rainy, I'll scrub them in and see how full-depth RA1s work in the wet stuff. Quite well by all accounts. If it's damp or dry, I'll use my well-seasoned test tires. I'm also going to drive the car out to see how the new padding works in the seat.
There's a Sport Quattro in attendance at the event. I can't wait to see one in person.
entry 510 - tags: testing, suspension, ergonomics
August 10, 2008 - In terms of rain, the trackday at Aspen was a failure.
For me, anyhow. One run group of Audis was lucky enough to get wet. I was the only one disappointed, however. Nobody else is any fun.
The day started with a really early morning (8 am driver's meeting and a 2.25 hour drive to the track). The good news? The new foam in the seats makes all the difference. No numb bum at all. That's a big win for the "backsaver" pad from Pegasus racing. Insert glowing testimonial here.
The bad news? The 8 am driver's meeting was at 9:50. My car was given a tech inspection four times. This kinda gives you an idea of the level of organization present. Still, we finally worked out way out to the track. I was staged right behind three Formula Fords that had me a little spooked - Aspen's track is a little on the small side, and I didn't want to accidentally squash one that had sneaked into my mirrors. That wasn't a concern. My biggest problem was trying to get one to give me a point-by. I had the same acceleration, better cornering and vastly better brakes than the driver in front of me, but he apparently didn't have mirrors. After seriously considering using the old "chrome horn" on an open-wheeled car, I ducked into the pits to get some clear track.
The car was okay, but it was hunting for grip. Both ends were skating. I checked the tire pressures and found I had them too high. The next session was better, but still too much hot pressure. Finally things settled down a bit. The car's quite safe right now, giving me lots of warning of what it's about to do. For a track car, I think there's still just a bit too much understeer. Of course, that means it will understeer, even mildly, on occasion. I can throttle steer the car fairly well. But given the unknown nature of most corners in the rally, that's a good setup. In my opinion, anyhow! I'll have the ability to tweak it at the rally if required.
And while it may not have been my preferred setup, a chicane at the fastest part of the track was handled very nicely, a high speed right-left jink that could have been a real problem if the car oversteered too much. Instead, it just screamed right through and surprised a few cars. I was also informed that my lap times were very good for running two-up with a chicane on the straight. Considering my lack of knowledge of this track, I'll take that as an endorsement.
So, despite the lack of rain, a good day. I had fun playing with some purpose-built race cars (who were a little surprised to see how fast this particular Miata could squirt out of corners) and Brandon had an excellent time bonding with his new Locost. Smiles all around.
entry 511 - tags: suspension, ergonomics, testing
August 18, 2008 - The Flyin' Miata Open House track day was last weekend.
It's always been my plan to have the car finished by this point. Last year, the Open House marked the first track outing of the car. Since then, of course, I've done a whole lot of work!
I'm a little conflicted. The car didn't feel that great to drive, with a soft turn-in and a steady-state cornering balance that was slightly biased towards understeer. Just like last weekend, naturally. This time I had a passenger every time I went out and the car was happier putting down power.
However, the car was fast. Really fast. The fastest Miata out there despite a big power gap.
I was a full 3.230 seconds faster than last year. Granted, everyone was going 1 or 2 seconds faster this year, either due to track conditions or improved cars. But still - over 3 seconds. Some of that is engine, some of it is driver, and the majority of it is setup. I also picked up 0.2 seconds over my time on the same track in April, and the track was fast that day.
I'm going to check the toe on the car and then call it finished. There's another track day next weekend, but I'm going to resist the urge to keep tweaking. It's time to concentrate on final preparation for the race. After all, I have to hit the road in less than three weeks!
One of the other drivers there did note that the fastest Spec Miatas aren't as fun to drive as the slower ones due to their setup. I suspect that I have the same problem. Don't get me wrong, the car is still a lot of fun. The first corner on the track shows off the light weight of the car as the nose dives for the apex, and it's still quite faithful. I've probably given the impression that the car understeers badly, when really it is fairly neutral. Never does the front end wash out on me, and I can always get the back end to step out if I try. A couple of times on the day, I got the rear end out a little too far! So it's a good balance, especially as I'm not a hero rally driver.
entry 512 - tags: testing
August 19, 2008 - Okay, we know the car's set up.
So it's time to start working on the other aspects of preparing for the race. The countdown is on.
First, it's time to fit a spare tire in the trunk. I couldn't do this before I had a full-depth tire on hand. It'll change the handling slightly but not enough to worry me. A bigger worry was making it fit! A little bit of clearancing on the rear of the trunk (ie, I sawed a slot in it and hit it with a hammer) lets me slide the wheel right into place. A stud was attached to the bottom of the trunk so a wingnut can hold the wheel in place.
entry 513
August 19, 2008 - Continuing with tire preparation - I put some tape over the wheelweights.
This will theoretically prevent them from coming off. I don't know if that's a legitimate thought or not, but it's a trick I've learned from other racers. It can't hurt!
entry 514
August 19, 2008 - We're only allowed six tires for the race.
Theoretically we can carry a space-saver spare as well, but we can't run closed stages with one. Since our wheel/tire combo isn't much heavier than a space saver, there's no point.
Anyhow, thanks to this tire restriction, we'll need to be able to track which tires have been used. I marked the sidewalls with 1, 2 or 3 as well as L or R depending on the direction of the tread.
It's worth noting that the rotation direction really only matters with full tread depth in wet conditions. When the tire's worn or it's dry outside, the direction doesn't matter to the RA1 anymore.
entry 515
August 21, 2008 - I had a bit of a close call yesterday.
I was mountain biking (it's world-class stuff around here) and, while dropping off a ledge, I went over the handlebars. It was a pretty good crash, really, and I landed hard on both hands before doing a shoulder roll. Other than some deep bruises on my palms and a bit of scraped up skin on a shoulder, I'm fine. I was hurt enough that we had to back-track out of the trail instead of continuing though. I'm sore now but I should be healed in a few days.
But all I could think about was the potential consequences. If I'd damaged myself, I might not be able to run the Targa. Ask Sebastien Loeb about that!
So, it's easier rides only for the next few weeks.
entry 516
August 24, 2008 - Another track day.
Yes, August has been a busy month! This time, the Targa car stayed in the garage. There was no need to beat on it any more, and I was busy defending my shiny new lap record in the Seven. So I took the old race rubber off the Targa car and stuck them on Janel's little Miata so she could have some fun. She did pretty well, taking a second off her previous best time.
I took her car out for a few laps to show her how much she could trust the race tires, and it was an interesting drive. Her car is fitted with a small, responsive turbocharger (an FM Voodoo II with the smallest turbo) and has a number of chassis braces installed as well as a Flyin' Miata Stage 2.5 suspension. Peak power isn't much different than the Targa car although it's a more civilized drive due to the full interior and a bit of extra sound deadening. But other than the lack of a full cage, it would be a good specification for the Targa for much less work and cost than our purpose-built racer. It uses off-the-shelf components and the whole car would cost less to duplicate than building a Spec Miata. It would have to run in the Unlimited class thanks to the turbo, however.
On the track, the car felt softer. The suspension dealt well with the berms, although I wasn't taking anywhere near as many liberties with them! The car had good power that was easy to control, friendly handling and nice brakes. But everything was just turned down and softened a bit. The brakes were nowhere near as aggressive, the power response wasn't as hyperactive and the car just didn't have the sharp reflexes of the full-on race car. I didn't have a transponder on the car so I didn't get times, but I'd guess it would be at least a couple of seconds a lap slower. That will translate to a lot of time over the course of a Targa stage. This isn't a big shock and I was quite happy with how friendly the blue car was to drive. It's under full braking in the picture, in case you're wondering. That's Janel setting a personal best.
One piece of good news: while the bruising to my hands did make things a little less comfortable and meant I didn't have much grip strength in my right, it didn't seem to slow me down. By the time the Targa rolls around, I'll be just fine.
entry 517 - tags: skills, suspension, other cars
August 26, 2008 - With the car finished, other aspects of preparation are moving into high gear.
I'm busy gathering up documentation and tools, and starting to wonder about things like having cellphones that don't cost $1/minute in Canada. The truck should be serviced before it goes into harness. I need a haircut. Janel and I will be taking our First Aid certification in a couple of days. Do I have everything? Have we thought of everything?
All through the build of the car, I've had the luxury of time. Lots of time. And now I'm aware that there's only a little bit of time left and little room for error if I forget something.
And I lied about the car being ready. It's on the dyno today, making sure the engine is happy. Then it's time for a bit of heat insulation and an oil change, and I need to scrub in the race tires. But it's close.
So close.
entry 518 - tags: preparation
August 27, 2008 - I spent some time under the car last night.
An oil change, a quick nut-and-bolt check and a general under-car inspection. Remember that red PPF?
I also decided to add a bit of heatshielding. You can see the factory heat shield that I've added above the catalytic converter in this picture. It weighs next to nothing so I'm not sure why I never put this in before. Probably because it's the sort of sharp, oddly shaped piece of metal that always gets first squashed flat by accident and then eventually thrown away.
There's also some Reflectix insulation inside the transmission tunnel. It's not very visible here, but it's near the white header. I attached it with waterproof foil tape which has been very effective in other applications, but which seems to disapprove of the particular texture of the bottom of the car. So while I'm happy with the effect of this shield, a quick peek under the car when I arrived home showed that the bottom tape had separated. Shame. The material itself is pretty neat, just a double layer of bubble wrap with a Mylar coating on each side. It weighs next to nothing (a 24"x25' roll is about 3 lbs) and can withstand 180F in direct contact. That's borderline for this use but the air space will help a lot. A good thing about it for under-car use is that it's also completely unaffected by water. I'll probably end up removing it if I can't manage to adhere it. Still, given the lower temperatures in Newfoundland, the heat shouldn't be too big a problem.
entry 519 - tags: ergonomics
August 27, 2008 - Dyno run!
The car spent some time on the dyno yesterday, making sure that it was safe and ready to go. Jeremy at Flyin' Miata managed to pick up a bit of top-end power but more importantly he was able to confirm that everything was in good shape and ready to go.
The chart is interesting. There's a big dip in the curve at around 4000 rpm. I don't feel it when driving, but the car would be faster without it of course! Jeremy spent some time trying to tune it out but didn't have much luck. If I was building the car now, I'd probably use a VVT head from a 2001-05 Miata instead of the 1999-00 one I used. They have much better torque curves down low. But if you don't learn something over the course of a project, you're not trying hard enough.
I waffled a little bit about whether I should put this chart online as it will invariably get held up on various forums for ridicule and taken out of context, but what the heck. Here goes.
This is Janel's little blue car vs the race car. She has a Flyin' Miata Voodoo II turbo installed on a stock 110,000 mile 1.6 engine. The turbocharger itself is the smaller 2554 unit, chosen for response instead of ultimate power. Since her power level is limited by the injectors in the car regardless of altitude, I used an uncorrected chart for her. Since I'll be able to make more power at sea level (close to 20% more), I used the SAE standard correction. This chart should be accurate for the relative behaviors of the two cars at sea level. The biggest change will be that the turbo will spool up a bit quicker.
What's interesting about the chart is how similar the power curves are, once you hit 3700 rpm. Two very different ways of making power but with surprisingly consistent results. Below 3700, the big displacement of the naturally aspirated car really helps. It's no wonder people comment on how quickly it squirts out of corners, with almost full torque available at 3200 rpm. That's more important than some sort of headline horsepower number. The dip that bothers me (intellectually, I've never noticed it driving) in the race car is there in the turbo car as well, but it's not as noticeable because it doesn't have the big torque swell earlier in the range.
I've always known that I chose a more difficult way of making power. If I was using that little turbo 1.6 in the Targa, I'd be running in the Unlimited class and would have to drive much faster to avoid penalties. But really, it was an excuse to build a cool engine. I love the response of a good naturally aspirated motor. I'll do more development on the engine when I return from the race, trying to open up the breathing on the intake side and maybe swapping a VVT head on. For the race, reliability and tractability are more important and I didn't want to have to babysit a fussy mill. Focusing on the handling and suspension of the car will pay greater dividends, so that's why I spent my time there.
I'm looking forward to feeling how the race engine feels at sea level with a 20% power boost. I think it's going to be a very good tool for the job at hand - dealing with unknown roads as expeditiously as possible.
Dyno chart
entry 520 - tags: engine, dyno
August 29, 2008 - Janel and I took a First Aid course yesterday.
Both of us have had fairly extensive training in the past - I used to be a swimming instructor, her job in the construction industry opens up the option for all sorts of gruesome problems - so it wasn't a difficult thing. Still, it's good to shake the dust off those skills again.
While going through the regulations one last time to avoid problems at scrutineering, I discovered that our first aid kit (supplied by the good folks at Rallylights.com) needed to be in the cockpit instead of in the trunk where I'd mounted it earlier. Finding room for the big white box was a bit tricky, so I stuffed everything in a small tool bag. This is strapped up under the dashboard where it can be in Janel's hands in seconds, but it's out of the way. It's also less than half the weight it used to be!
entry 521 - tags: skills, preparation, safety
August 29, 2008 - Something else that showed up in the rereading of the regulations was that the car should not have antifreeze in the cooling system.
This is fairly common with race cars because antifreeze is really slippery stuff. I should have thought of that. So the coolant was drained and refilled with straight water and Water Wetter. It's a water pump lubricant (as per the regulations) that also drops the surface tension of the water to avoid spot boiling. According to the bottle it has all sorts of magical properties, and it really does work according to some testing we've done at Flyin' Miata. It's also the coolest color.
entry 522 - tags: preparation, cooling
August 29, 2008 - Preparation goes beyond working on the car.
I need to pack enough tools to deal with any job I should be expected to do, from the nightly nut-and-bolt to a rebuild of one corner of the car. But I want it all to fit in my super-cool wheely toolbox with extendo-legs so it's easy to deal with. Thanks to the recent track visits, I have a basic tool load figured out - I started taking notes about what I commonly packed so it's easy to duplicate in 15 minutes before leaving.
In this case, though, I'm also packing a smaller toolkit to go in the car. It'll include emergency tools, the sort of thing I need to perform roadside repairs until I can rendezvous with the mothership. Radiator stop-leak, a test light, duct tape (and the superior foil tape as well as electrical tape), the Holy Trinity of Miata wrenches (10, 14 and 17mm), zip ties, etc. The toolbag also includes the required tow strap. I'm apparently the first person to ask how long it should be!
So, almost ready then. I've been going through the tech inspection required before leaving, and just to be sure I changed the front brake lines which had a little damage to the cosmetic colored sheath. So I need to bleed the brakes and then cornerweight the car with the correct tool and people load in it. I'm trying to decide if I should scrub in all six race wheels or if I should just take them as virgins. Maybe I'll stop by the track on Wednesday and give them a few laps to get the initial scuffing done. But even if I do that, I'm almost ready to go. It's getting close!
entry 523 - tags: preparation
August 31, 2008 - Sharp-eyed readers will have noticed an addition to the menu on the left side of the page: RACE UPDATES.
Hopefully the purpose is clear! During the race, I'm planning to make regular updates on our progress. There are no guarantees that I'll find time or have the ability to do this, and it'll only happen in the evenings if I do. But I will do the best I can.
The weather in Colorado today is almost exactly the same as in St. John's - wet (I think we got half of our 6-9" of annual precipitation last night!), cool and kinda blah. I pointed this out to Janel and she said "Uh oh".
entry 524 - tags: announcements, preparation
August 31, 2008 - Remember how I said the weather today was like St John's?
Well, during one heavy burst of rain, I looked at Janel and said "I should take the car out and test it in this weather". She looked back and said "I'll come along". So we buckled in and backed the nice clean car out into the storm.
Unfortunately, traffic was heavy on my Targa Simulation Road and there is absolutely no place to pass on it. So we were stymied going both up and down and didn't get a chance to feel what the RA1s were like in standing water at full chat. But it wasn't without merit. First off, I learned the car is pretty resistant to hydroplaning. I wasn't able to travel too fast (curse the luck) but my best efforts were met with dogged traction. So that's good.
We also got a chance to test the defroster. Finally! It worked a treat on my side, but it blew off one of the ducts on Janel's side and was less than effective. I'd disturbed things when working on the dash light wiring a few weeks ago and never bothered to tape it all back up again properly. It's an easy fix, but an important one. Had it happened in Newfoundland, I would have have had everything needed to fix it in the car with me.
So that's a success then. I'll crawl under the car and see if my new, improved heatshield mounting held up as well - I have high hopes for it. All I did was scrape the undercoating off in that one area so there was smooth metal for the tape to grab, and I know from experience that this tape loves the smooth metal.
It's quite refreshing to be able to spend the day just poking around like this, two weeks before the start of the race. There's no big list of problems to solve or jobs to do. The car's basically ready to load into the trailer. This is very unlike normal racing practices but exactly the way I wanted it. Tomorrow, I think I'll do some painting inside the house.
I've just jinxed myself, I know it.
entry 525 - tags: preparation, testing
September 3, 2008 - Lots of detail work today.
I needed TOW stickers for both the front and the rear and I only had them on the rear. So I cut a couple out of reflective blue vinyl. Why not? They shine!
I also spent some time chasing insurance. The latest revision of the regulations require us to carry a million dollars in liability insurance. But normal auto coverage has a half-million limit. Of course, as soon as I mentioned racing to the insurance company, they got all nervous. The coverage is only for the transit sections but they were still spooked. A call to the Targa organizers and everything was sorted out quite easily. Whew.
entry 526 - tags: preparation
September 3, 2008 - I spent the day cleaning the car and doing final prep.
The last thing I did was bolt the camera mount in to place. It's about eye level so it should be pretty good for capturing the race nicely. I'm hoping to tape every competitive stage, although this particular camera can be quite ornery.
entry 527