Targa Miata
MIATA BUILD
March 6, 2007 - There hasn't been much work on the Targa Miata for the past week because I was off in Texas.
Grassroots Motorsports magazine asked if I could attend a track session to provide a counterpoint to an Ariel Atom that they were testing. It's a long way to go for a track day but I was curious about what their drivers - BS Levy and Tim Webb - would have to say about my little homebuilt Lotus clone. We'll have to see exactly what the article says when it comes out in a few months, but both drivers were very impressed by the handling and setup of the car. It was fun and controllable. They were also impressed by its speed. It's good to have some independent judgment of the setup of the car, and it bodes well for the Targa car.
entry 86 - tags: other cars
March 11, 2007 - Driver development time!
Most of my track time is spent in the Seven, but it's time to start paying more attention to Miatas. So this weekend I was at the track with a big blue car instead of the usual little orange one. The Miata is supercharged (about 155 hp at the wheels, I'd estimate) and has an off-the-shelf suspension from Flyin' Miata that works very well - FM springs, Tokico Illumina shocks, FM rear shock mounts and FM sway bars. There's one of Flyin' Miata's "butterfly braces" underneath so it's a good solid chassis. I was also running a set of Toyo RA-1s that were nicely broken in and some autocross brakes. Overall, it's a pretty good test bed for the rally car as it's running the same ride height and spring rates we expect to use.
After all the time spent in the lightweight car, it's good to see how well a sorted Miata works. It's forgiving, it's controllable and it sticks like crazy. There's obviously more weight transfer going on (and this car is heavier than the Targa car will be) but it's easy to use this as part of your driving technique. The autocross brake pads weren't up to sustained hard braking, so this meant I had to carry in higher entry speeds and worked as an excellent training tool. We'll be running better brakes in the Targa.
I spent some time driving "off line" at the track, pretending I didn't know where I was going and trying to deal with very different situations than the usual ideal line. I also tried to avoid using all of the track to give myself some extra room like we'll have to do in Newfoundland. It's tricky to pretend you don't know a track that's quite familiar to you, but it's also quite eye-opening how a well-known corner changes when you enter it from a different angle! Not only did this help me improve my skills, it also illustrated quite dramatically how much of a difference it makes in speed around the track.
Luckily, there were very few cars on the track so nobody thought I was crazy.
A good day overall. Time to get back to work though!
entry 90 - tags: testing, other cars, skills
March 27, 2007 - More driver development.
I've been autocrossing my little Seven for the past few years. But it's time to start concentrating on Miatas again for a while, so I bolted some race tires and a race seat into my girlfriend's supercharged Miata and went hunting.
The event was a Corvette autocross, always a fun group to run with. My coworker Brandon - driving a turbocharged Miata with another 60-80 hp over mine - and I were the only two non-Corvettes at the race.
It took me a few runs to get used to the slower reflexes and lower grip levels of the Miata instead of the Seven, but it started to come back. Lower grip levels not just because of the different car, but also due to cold weather and a dusty parking lot - a good indication of what we can expect in Newfoundland.
It was a good battle between Brandon, myself and a supercharged 2006 Z-06 running on massive V710s. On my last run, I left the braking a millisecond too late on the last corner and understeered badly to the finish line. Brandon didn't make any mistakes and took the fastest time of the day, while the Z-06 ended up just ahead of me.
Lessons for the Targa? The adjustable brake proportioning will be quite useful and of course I'll have to leave some extra room to stop in adverse conditions. I don't have any trouble controlling the car in big slides (after the first run, I did most of my steering with the rear wheels) but sliding off the outside of a corner in the Targa with locked-up brakes is something to avoid.
entry 103 - tags: testing, other cars
April 24, 2007 - Time to take the engine from the Flyin' Miata shop to my garage, where the car is being built.
Putting this in the back of my old pickup increases the value of the truck by a factor of 5 at least.
The chassis is almost ready for the engine. I need to plug a few extraneous holes (such as the heater and AC pass-throughs) and then it's time to drop the engine in.
entry 147 - tags: engine, other cars
May 6, 2007 - I couldn't resist.
I had a spare power plant frame, so I blasted it clean with the pressure washer and gave it a coat of nice red paint. For those who follow my various builds, it's the same paint I used on the interior of Basil. But there's a functional reason to change to the other PPF as well. Note the little "tooth" at one end of the painted PPF. That's to protect the bolt heads at the differential. Not a bad thing to have on a car that could easily bottom out! So there is a method to my madness, although the red PPF does make me giggle every time I see it under the car.
entry 161 - tags: drivetrain, other cars
July 1, 2007 - I spent the weekend working on another Miata.
Janel's little supercharged Miata is now turbocharged. The operation was a great success.
But that doesn't mean the Targa Miata was completely neglected. The new tires (Toyo RA-1 in a 205/50-15 size) came in so I had them mounted up. The wheels are some white SSR Competitions. Hang on, they never came in white! Ah, but they did in Japan. These date back from a previous race effort that was sponsored by SSR Japan. They're a custom 15x7 with a +20 offset, and are perfect for this application. The fact that they have a little tricolor stripe that happens to match the Martini colors is simply icing on the cake!
entry 228 - tags: tires, other cars, Martini
July 1, 2007 - I calibrated the wideband oxygen sensor today.
This has been holding me up because it needed to be wired in. Finally I just decided to get on with it, and it was a pretty straightforward procedure. So that's it for setting up the drivetrain. Now it's time to actually drive the car. I'll probably take it out of the garage for an extended drive on Wednesday, which is a holiday for some reason. It's also the third anniversary of the first drive of the Seven for a nice piece of symmetry. The Targa car is more complete than the Seven was at that point, though.
I hope.
entry 230 - tags: tuning, other cars
July 26, 2007 - Battery comparison time.
I've become fed up with trying to keep used batteries alive, so I sprung for a new one. See if you can guess which one it is!
The big one is a stock Miata Panasonic battery, only available in a new Miata - and no longer available at all, I guess. The blue stickers are on the Mazda replacement one, and the little red thing is an Odyssey PC680. It's about half the weight of the others, has more cranking power and it's a tough little AGM. I've been using one of these in the Seven for a couple of years and I love it.
entry 246 - tags: weight loss, other cars
August 19, 2007 - It wouldn't be a track day for me without an oversteer shot!
I was able to throw the car around a bit. By this point, I'd figured out that my banging noise was probably the exhaust hitting the differential. I knew that clearance was tight there, I'll have to get back underneath and take a peek.
The 1:07.977 was my fastest time of the day, and it was a pretty good one. By comparison, a turbo Miata with 225/45-15 Toyos (well scrubbed in) and the JIC shocks turned a 1:07.119. Another turbo Miata was close behind with a 1:07.337, both driven by coworkers of mine. And the Targa Miata was third, ahead of another 45or so Miatas. It was an excellent first day out. The fastest car on the track (1:03.733) was my little Seven, to my satisfaction.
So, what did I learn about the car? I'd like to try a nicely sized front sway bar to cut down the roll, and maybe a bit more front camber. That will make the car easier to throw around, something I'll need to be able to do on the Targa surfaces. Unlike the track, I'll be reacting a bit more instead of anticipating.
The braking is very light, almost to the point of being overassisted. It's the first time I've tried these brakes with the larger booster and master from the late Miatas, and that could be the reason. It could also be the street-only pads I was running (you could smell them at the end of the day) and the fact that I was jumping out of the Seven which has a very firm unassisted pedal. After the first lap, it wasn't really a problem so it may have been acclimatisation. Still, I'll get some proper pads in there and see.
The shocks are the big question. They do an excellent job of damping surface imperfections. But can I run the car high enough to get the ground clearance I need for the Targa? I'll have to drop the rear down a bit and see how it works. There's another set of shocks sitting at work that have 5" of travel and I want to try them next.
entry 297 - tags: testing, other cars, brakes, suspension
August 19, 2007 - All the kids were available for rides at the Open House.
Orange is my Seven, yellow is the FM Westfield I helped to build and set up, white you know and blue is my wife Janel's little turbo Miata. The Targa car was pretty popular, both amongst people who had never heard of it and a bunch of regular readers who were exited to see it in the metal. Turns out I'm not the only person who thinks the stripes look good. It's obvious from the pictures at the track that the black FLYIN' MIATA on the nose and tail really stands out as well.
One thing I discovered on the test drives - I was leading my coworker Brandon in his turbo Miata that makes approximately 230 hp at the wheels and weighs around 2350 lb or so. When I put the throttle down, he could keep up. But he didn't seem to be gaining ground. Wow, maybe the engine is working better than I thought. It sure feels great, and it has just the flexible nature I'll need.
entry 298 - tags: other cars, Martini
September 6, 2007 - Lots of time spent working on cars, but not much on the Targa car.
I've been waist-deep in changing the engine on my old Toyota pickup. It makes me appreciate the amount of room and relative simplicity of the Miata engine bay, that's for sure.
I have been driving my "baseline" Miata around to help recalibrate my butt for the suspension tuning. The baseline setup is a set of Flyin' Miata springs with Tokico Illumina shocks and Flyin' Miata upper shock mounts. Despite using 17" wheels, the ride/handling compromise is an excellent one. The spring rates (318 F/233 R) are what I'd like to use for the Targa. The current suspension setup I'm working on uses 450/300 so my goal is to get the same compliance despite the higher spring rate. I think I'm on the right track. There's a short window for some track testing tomorrow and I'll see how the new long travel setup compares to the previous short travel Ohlins. The big question - should I install swaybars for the trackday?
entry 308 - tags: suspension, other cars
October 14, 2007 - Autocross baptism.
I've heard the Targa described as a combination of an autocross and Solo I racing. So I'm using both types of venue to test. This autocross was put on by the local Corvette club. They allow a small number of "metal" cars to participate by invitation, and I'm usually welcome. So I brought out both the Miata and the Seven.
So how did the car do? Quite well, really. I learned that it's quite easy to drive on the autocross course, with great braking ability and a nimble feel - just what you'd hope for out of a light Miata. The car's easy to drive although I'd like a little more feedback on a locked wheel.
What I didn't expect was the inability to put down any power. Again. It's not a wheel lifting this time, but it sure does act like it. I'm wondering if the Torsen LSD is actually a Torsen. Maybe I got my hands on an open diff instead. I never actually checked inside the casing. I have a good differential in the Seven that would work well in this application, but I hate to take it out.
On my third run, I almost entered a trance and just drove around the course. No real effort was involved, the car just did what it was supposed to. The end result? A time that was 0.3 seconds slower than a rotary-powered Fiat X1-9 autocross special and a C5 Z06 Corvette - good enough for fourth fastest of the day out of a field of about 24 cars. First place was, of course, the Seven.
So, in all a very good day. The car performed well despite a real weak point and showed no evil handling characteristics. That's about all I could ask at this point!
Video now available!
entry 324 - tags: testing, other cars, drivetrain
November 4, 2007 - An unfortunate finish to the day.
Bill took the Targa car out to see how it was working, and I borrowed his Westfield. The little car was working beautifully and I was quicker in it than I had been in the Miata. With 700 lbs less weight and only a bit less power, that's not a big surprise. Bill wasn't lagging too much, though, and some slower traffic bunched us up. Shortly after getting free, we entered turn 5, the best turn on the track. It's like a baby version of Eau Rouge, as one driver pointed out - an uphill corner with a nice compression at the bottom and a blind exit. Very entertaining and nicely quick. I came out of the series of bends and noticed Bill was gone from my mirrors - and there was a big cloud of dust on the inside of 5 with a Miata shape inside. The car had stopped just short of a flag station and tire wall.
Back in the pits, we saw the typical damage for an off-track excursion around here - one tire pulled off the wheel and another with grass jammed in the bead. There were some scuff marks and scratches on the nose as well.
We pulled the wheels off and headed for the local Discount Tire. I was still wearing my driving suit, and when I got out of the truck a little kid asked "are you a racing car driver?". Not really, but I'm trying!
The staff at Discount were really helpful, getting right to work despite the fact that it was the middle of a busy Saturday. They pulled off the tires, vacuumed them out (to our great amusement) and reseated them in about 4 minutes. Then we were called in to have a look at the balancing machine. One wheel was wobbling badly. There are custom-made SSRs and can't be replaced, nuts. It's a good thing that I have access to a total of 8-12 of them.
Oh well, we figured we'd see how it felt. After all this, the tire shop didn't even charge us! Note to self, always wear Nomex to a tire store. Thank you Discount.
Back at the track, the tires went on and I headed to the track for some gentle exploratory laps. Heading down pit lane, I noticed that my steering wheel was off center. That was it, I headed for the trailer. Between a potentially shaky wheel with some damage and unknown suspension problems, it was not time to go push hard.
Nothing was obviously bent under the car although it appears one of the caster adjustment cams might have slipped. I didn't get the chance to mark the suspension settings before loading on to the trailer, unfortunately, and this simple change may account for the steering wheel offset. I'll check that out shortly. The paint damage is all on the lower half of the front bumper and should be easy to fix.
A sad finish to the day, but nothing that can't be repaired fairly easily and nobody was hurt. We never did figure out exactly what happened to cause the off, from looking at tire marks I think the car simply ran out of grip, possibly brought on by a slight crest in the track there. This is why we test on the track instead of the road, though!
entry 336 - tags: testing, other cars, tires, crash
December 4, 2007 - The car is all healthy.
I finally got around to taking it for a short test drive after catching up on some of the rest of my life. Using the scientific method of the steering wheel location when driving in a straight line, it appears that I have a healthy car. When it came off the track, the problems meant that the steering wheel was badly off center. Now it's almost right, which means I just need to align the car and I should be good. The car sure is dusty, and the temporary suspension that's installed sure isn't any good!
So, it's time to get down to work. I have a good list of jobs to do on the car, all in nice bite-size chunks. None of this "weld in roll cage, build an engine and paint a complex paint scheme" that I had before. I have some time between now and the new year so it's an excellent chance to get a lot of the required detail work done.
I also took the opportunity to take both my Mini and the Seven out for a spin yesterday. In all three cases, the last time the car was driven was either on the track or the autocross course. I think that's a promising sign.
entry 343 - tags: crash, suspension, other cars
December 19, 2007 - The last time I built a header was for my little Seven.
I used pool hose to work out the basic routing, then improved on that with some welding rod. It worked out well, but that car did have a lot of space available to work with. You can read the whole saga starting here, you'll have to skip over a few days worth of installing side panels and the like as I procrastinated.
This time, I have the advantage of a very cool tool. This "header Lego" from icengineworks is exactly what it sounds like - 1" pieces of tube that snap together into whatever shape I need. I have 2", 3" and 4" radius bends as well as short bits, and they're all beautifully marked up to make fabrication of the final product easy. Well, easier. This is going to be quite interesting to play with. I'm going to have some fun. Although I do think the pool hose might have to make a comeback to get me started on layout. Where did it go?
entry 351 - tags: header, other cars
January 8, 2008 - So, I didn't have any work I could do on the Targa car last weekend.
So I worked on something else. We seriously considered this little guy as a potential Targa car. It certainly would have been fun.
entry 365 - tags: other cars
March 10, 2008 - A very serious sticker.
I saw some spy shots of the Porsche Panamerica taken in South Africa. They had this sticker. I had to have one, so a friend duplicated it for me.
The track day wasn't all work on the race car. I got to drive the FM Westfield, now with 100% more turbocharger. Holy cow, it was a great ride. The chassis of the Westfield was easily able to deal with the horsepower, and it became a massively fast machine. It had a better power/weight ratio than the Atom I drove almost a year ago, while also having a much better gearshift and more exploitable handling. It's a beast.
Another car that I got to drive was a V8 powered MGB GT. It made a wonderful noise. It wasn't fast - there's still a lot of work to do on the car - but the combination of the shape in BRG and the rumble was compelling. There's an advantage to hanging out in the pits wearing a driver's suit and playing with an obvious race car - people ask you to drive their cars and want to know what you think!
entry 433 - tags: other cars
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
April 14, 2009 - The garage is a little full right now, and the Miata is pretty much the biggest car here!
In the foreground is an Austin-Healey Sprite that's here for a bit of work, mostly because I'm the only person dumb enough to take it on. In the back is the MG getting an LS1 engine. The Mini is trapped by dead cars, and the Seven is also visiting temporarily from its usual living space.
entry 669 - tags: other cars
April 27, 2009 - Almost all the kids were out of the garage yesterday as I shuffled cars around.
The Targa car is now strapped down in the trailer, ready for the trip to Georgia for The Mitty. I'm not looking forward to the drive, but it'll be the last one for a while.
I also ran the race car for a while to bake in the new ceramic. It picked up a slight yellowish tinge but looks good. The car's all scrubbed and shiny clean now too. Watch this, it'll rain all weekend in Atlanta...
entry 673 - tags: other cars
May 10, 2009 - Another track day!
This time, the Targa car sat in the trailer and I drove Elvis, the LS1-powered bar (back in full health) instead. It took me some time to come to terms with the car. It simply seemed squirrely. Not so much under power - it behaved exactly as expected then - but during braking and cornering. It's the first time I've set up a car with this particular tire so that's part of it, and it has good brakes but without adjustment options.
But what I finally realized was going on was that I was expecting its cornering and braking ability to be in line with its acceleration ability. It thunders down the straight like the turbocharged Westfield beside it, but it still corners like a Miata and not a 1300 lb featherweight. So I had to bleed off more speed for the corners, and my Targa braking points didn't work because the car weighs 400 lbs more and was going considerably faster. So the problem wasn't the car's traction, it was simply that I was asking too much of it.
Of course, another problem was the red mist. My first session out, I'd blown away the fastest Miata to ever run the track. So I was hoping to beat the track record for Miatas by as much as possible. I did, by a considerable amount. And now that the mist has faded, I realize that I need to spend some time tuning this car on a big track, where I can get it settled on a long sweeper to set the basic handling balance and then tune the transitions from there. The car still handles well, I just want to bump it up to the top level. Not bad for a street car though.
I took Janel out for a few laps. She was impressed by the violence. It would be a very effective Targa car, but it would take a different driving style than the current setup. The fact that it was faster in street trim than the Targa car is in race trim is a good sign.
Janel also took her own car out for a couple of sessions. Now that she's experienced the Targa car at its best, she was quite adamant about the shortcomings of her previous ride. "I miss my tires! I want my brakes!", she informed me. Oh boy...
entry 678 - tags: other cars, v8
January 17, 2013 - A couple of unlikely cousins.
These two cars have a lot more in common than you think. They're both running similar engines (5.3 for the race car, 5.7 for the MG), T56 6-speed transmissions, AFCO suspension, FM radiators and fans, FM fuel plumbing, etc. The MG actually runs Miata brakes, steering and a number of other bits as well. Heck, they even weigh the same. Most importantly, they both perform well beyond their original manufacturer's intentions and put a big stupid grin on the driver's face.
entry 1070 - tags: other cars