| MIATA BUILD |
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 | |  | 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 | | | September 14, 2010 - More video!
Again at High Plains Raceway, but this time there are other cars to play with. I'm still learning the track and not running as fast as the other video at the same track, but it's fun to see where the Targa car gains on the high power turbo car.
Video
entry 765 - tags: video, HPR, GTR, turbo | | | September 23, 2010 - I spent last weekend at Hallett, near Tulsa Oklahoma.
I was there with one of the Flyin' Miata shop cars at a Miata event. So no Targa car and not even any AFCO suspension. It's a pity, because that track is relatively rough and would have been a fun test. Still, it was a good weekend. The car I was driving was a 2006 model which made for a very interesting comparison to the 1999 we had also brought along. The newer car has a very stiff structure and generated surprising levels of grip while coping with the rough surface. In fact, the more hard-core 1999 wasn't dramatically faster.
The 2010 edition of the Targa finished while I was there. I might not have run in the race this year, but I did spend three days on tracks I'd never seen before and racked up nearly 3000 miles of driving going to and from various tracks! So it was about as good a substitute as I could have arranged.
The 2010 event was quite eventful. Lots of lead changes in Modern with a number of cars encountering problems. As with last year, I kept up a running commentary on the race on the Grassroots Motorsports forum. Yup, living vicariously.
entry 766 - tags: hallett, 2010 | | | October 5, 2010 - Over the past couple of years, I've had a number of questions about the Backsaver foam that we used in the Corbeau seats.
It made all the difference in the world to comfort, but it's not cheap stuff. Well, a recent phone call from a customer made me dig up some of my old information, and I'm pretty sure it's actually Confor CF45 foam, 1" thick with an extra piece of fabric on one side and a rubber pad on the other. Armed with this knowledge, you can find less expensive sources elsewhere as long as you're willing to forgo the rubber and fabric. It's hard to believe, but aviation stores such as this one are actually a less expensive source.
If you're looking for a way to make a set of race seats more comfortable, this is a great place to start.
entry 767 - tags: ergonomics, comfort, seats | | | October 11, 2010 - The local Corvette club had an autocross yesterday.
I haven't run through the cones for a while, but it was just a few minutes from my house so I figured I'd go out and have some fun. Brandon brought out his bike-engined Seven so I had someone to play with.
The car is set up exactly the same way it was at High Plains Raceway. Heck, it hadn't even been out of the trailer yet. I did put a bit more pressure in the tires, as the cooler weather had dropped them down a few pounds. I also wanted higher pressure for the short autocross runs instead of 20-30 minute track sessions.
The car felt pretty good. The first run was a scrabble for traction, but this particular lot is always slippery at first due to a lot of dust. I softened up the shocks a bit (two clicks in front, one in the rear) to help it grip the rough surface and because it felt a bit too stiff to me anyhow, and that helped. The car would grip well at the front up to a certain point, but I still spent a fair bit of time trying to manage my front grip. A large part of that could have been my driving, as I suspect I was sawing away at the wheel too quickly and breaking traction. It's an easy bad habit to get into.
More interesting was the fact that I seemed to have too much front brake bias. Now, the lot was fairly slippery so that means less weight transfer and thus less (relative) front traction - but even with the rear brakes turned up all the way I couldn't get the back to rotate properly. I found the same thing the last time I was at our local track. I did recently replace the front pads, and I suspect the front brakes are simply working too well. I'll try swapping in some new rear pads and see if that solves things.
While I wasn't completely happy with my driving, the results were pretty good. Brandon walked away with the event because nothing can touch a Seven in the autocross, and we left before the final runs of the fastest drivers. But at that point, I was around 2.5 seconds ahead of the next car, giving me a solid second place. Can't complain there!
entry 768 - tags: autox, brakes | | |  | November 14, 2010 - The new Miata book is here!
I got the call from my editor suggesting this title when I was driving through Nova Scotia on the way home from the Targa, and it's finally a reality. "How to build a High Performance Mazda Miata" is a technical book that explains the theory behind how cars work, what that means for the car and how to make it work to your advantage. Turbocharger and supercharger theory and design, the role of weight transfer in handling, even safety and aerodynamics.
Naturally, the Targa Miata makes quite a few appearances including an inset photo on the cover. It's used as an example several times of how to make design and setup choices to achieve a certain goal.
I'm proud of this one.
entry 769 - tags: book | | | January 10, 2011 - We are going back to Newfoundland!
Our entry is in for 2011. But we need your help. We need to raise at least $10,000 to bring our two-car team back, and we're asking Targa fans to help by donating. Details
If you're a fan of the car and the team, please consider giving us a hand to make it back and compete at the top level.
The top level? Yes indeed. With the loss of the handicapping system, the only hope cars like ours have is for a class win - and there are so many of those that it's unlikely there would be more than one or two cars in each class. This basically renders the classes irrelevant. So we're throwing out the carefully designed rule book and going into Open class. This means we're up against the fastest of the fast. Heady company indeed.
However, there is The Lesson Of The Blue Mini. Doug Mepham ran close to us in outright speed in 2008 - we were always staged at the start line together. In 2010, he finished 6th overall by simply staying out of trouble. Granted, Doug does have as much Targa experience as anyone, but if a team with similar speed to ours can finish so well, what could we do with a faster car?
So the Targa Miata is going to get that V8 I've been dreaming about for two years. Yes, the beautiful little 2.0 is coming out. I'm going to miss it (and it's for sale!). Going into its place is an LS1 V8: all-aluminum, 5.7 litres and something like 350 hp. The exact specification hasn't been decided yet, but it should be dramatically healthier than the previous. The weight will go up slightly, but probably only around 150 lbs. So, the plan is for the same handling but the ability to vaporize the boring straight bits. This year, I'll have to lift to avoid hitting 200 kmh even in the town stages!
We're also going as part of a team, under the Flyin' Miata banner. Flyin' Miata (or FM) was a major sponsor of ours in 2008, but this year we're actually driving for them. The team will have two cars, the Targa Miata in Open Class and another Miata running in Grand Touring. That one will (likely) be another V8 car, but in full luxe street trim and with Bill Cardell driving. Bill's the owner of Flyin' Miata, and I think he's tired of hearing me talk about the Targa! His codriver has not yet been announced, but we're speaking to several high-profile journalists about it.
So that's it. We're going back - if we can raise enough money. Our entries are in, help us get to the start line!
Buckle up, there's some serious construction ahead.
entry 770 - tags: annoucements | | | January 12, 2011 - Planning, planning, planning.
First, we have a new sponsor. MNMazda.com - a Mazda enthusiast forum based in Minnesota, as you might have guessed - has stepped up and sponsored the Flyin' Miata team. This is great news for two reasons. First, it's a step towards the start line of the race. Second, it's completely enthusiast-driven. As with the Underground Miata Network in 2008, this means a lot more to me than a donation from a company. Thank you very much!
The fundraising is going well. As expected, the first couple of days were the busiest, but we're a good way along. At the moment, we're nearly halfway to our minimum of $10,000. This is all from individuals! I'm still chasing bigger fish, but it's a very heartening response. We're not there yet, so if you enjoy watching the Targa Miata in action, please help.
More on the proposed car specification shortly.
entry 771 - tags: sponsorship | | |  | January 13, 2011 - Plans for the car are coming together.
There's been a change in the engine specification. There's a proposed Spec V8 series in the making, called V8R Spec. V8Roadsters and V8R Spec has offered to not only provide the hardware for the V8 conversion, but also a built-up L33 engine. In exchange, we'll send off the old LS1 from Elvis that has a few of the parts needed, such as the improved LS6 heads and intake. The support from V8 Roadsters and V8R Spec is fantastic. That's Elvis' old engine in the picture, looking rather forlorn after being booted out for a 480 hp LS3. In case you don't know Elvis, that's Flyin' Miata's first V8 car, the blue car I've been playing with at various autocrosses and at Laguna Seca over the past couple of years. It'll be the sister car on the 2011 Targa team, running in Touring.
So what is this L33? It's a runt in the LS engine family. The big boys run as big as 7.0 litres, but the L33 is only 5.3. It's also known as the Vortec 5300 and is found in trucks. Specifically, the 2005–2007 Chevrolet Silverado 1500 4WD and GMC Sierra 1500 4WD extended cab trucks. What makes it interesting? Well, it's the only one of the truck engines with an aluminum block, making it lighter than most. It's actually a fairly popular one to use for various swaps, as they're generally less sought-after than the bigger variants but still able to make good power.
It will be modified, however. The LS6 intake and heads make a big difference, as does the V8R Spec camshaft. Basically, the engine will be set up for a nice power increase but without sacrificing behavior. Expected power levels are 410 hp and 350 ft-lbs. Steve at V8Roadsters thinks it's the best of the various LS engines. So we'll have approximately double the power and torque of our 2008 car with a weight penalty of around 200 lbs. Seems like a good trade.
entry 772 - tags: engine, ls1, l33 | | |  | January 13, 2011 - There is a sad side to the big plans.
That sweet little 2.0 is going to have to come out. It's been a rock-solid engine, giving very little trouble despite what we've asked of it. Ever since Janel discovered how much fun the Targa Miata is to drive, the car's had to do double duty at trackdays. It just goes and goes and goes. I'm going to be truly sorry to see the engine go, but it's for sale to support the transformation. The header is also going to be available along with the rest of the exhaust.
It's a bit like selling a child, but I'm hoping it'll go to a good home where it can roam free and play on fun roads or tracks. Contact me if you're interested in any of the driveline, engine computer or exhaust.
entry 773 - tags: for sale, engine, header | | | January 13, 2011 - We've made some big promises.
The goal this year is to compete for the top prize. We'll have the car for it, and if we can stay out of trouble I think we'll do well. However, our goals are still basically the same as 2008, in the same order:
- stay out of the Atlantic
- finish the race
- get a Targa plate
- go as quick as we can
We're not just out for the experience this year, but to show off the performance and reliability of FM's little super Miatas. We can't do that if we break or crash, so that's off the menu then. I'm not going to discount the competition - we're up against some very, very quick drivers with much more experience at the event. Could we prevail against Steve Millen and his GTR if he came back, or unseat Matt Oldford who won last year? Not without quite a bit of difficulty and no small helping of luck.
The weak point is going to be the crew - again. We've got some Targa experience now, but we're also going to be piloting a much faster car. Am I bit nervous about this? Of course, I'd be foolish if I wasn't. We'll prepare ourselves as best we can and I'll build the best car I can, but it's going to be a challenge.
entry 774 - tags: goals | | |  | January 20, 2011 - The first of the V8 conversion parts is here.
This is the mounting system for the rear differential. Two tabs need to be welded to the rear subframe to locate the nose of the diff and that grey cross-bar bolts into the factory mounting spots. The big aluminum disc is an adapter that goes on the pinion flange of the differential.
entry 775 - tags: parts, differential | | |  | January 24, 2011 - Here's our differential.
It looks used because it is - it's the one originally used in Elvis. That car has a new rear end in it and this one landed in a box awaiting the Targa Miata. It's a Getrag rear originally used in the Cadillac CTS-V and has a 3.42 ratio and a Positraction clutch-type limited slip. It's a very effective package.
entry 776 - tags: differential | | |
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THE DIARY