| MIATA BUILD |
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 | |  | June 8, 2008 - I spent some time patching up holes.
I think the exhaust fumes were affecting us pretty badly in the car on the way home. Cracking the windows open actually caused a problem, as it would pull air into the car from all the holes in the transmission tunnel. Very hot air. I usually drive the car fully closed up or with the windows fully open, so I'd never noticed this before. It's easy enough to fix. Small holes got rivets, big holes got rubber plugs.
While doing the diff swap, I also crawled underneath and took a good look for holes. I found quite a few, actually. The car had an Autopower roll bar in its previous life so there were 8 or more holes left over from that. There were also a number of unused bolt holes that I covered with waterproof foil tape. It should make a big difference.
entry 470 | | | June 10, 2008 - Testing results.
The influx of hot air seems to have succumbed to my patching and the car no longer smells like exhaust fumes. So that's good.
The car is much happier with the 4.10 rear end. I've always liked this gearing combination. The stiffer mounts in the differential have cut down on shifter movement and the car shifts very nicely now. So that's an improvement. There should theoretically be an increase in NVH from the new mounts but it's rather hard to tell in this car!
I took the car out to the track again for a few laps, just to see if the rear end was hooking up any differently. And the answer is nope. Maybe a little bit better, but I can still spin up that right inside wheel if I am being aggressive. It takes a turn that's tighter than any that would be used on the street - aka, that would be found in the Targa - but I'm starting to obsess about this a little bit again. On the theory that the car is rolling too much and the rear sway bar just can't deal with this much articulation, I stiffened up the low-speed compression. While the car get a bit happier in transitions (I need to spend more time with this adjustment, as I should be able to really make it pivot nicely) it didn't make a significant difference.
I do really have to thank the guys at the Grand Junction Motor Speedway for working with me and letting me drop in once in a while. When I left today, they were surprised that I'd only taken a half dozen laps!
I'm probably going to swap all the control arms out. The bushings seem to need lubrication again. That's odd, because I've run these sorts of bushings for years in the past without any noise. But that dirt road really seems to have done a number on them and they sound terrible. So the arms have to come out at least partially, so why not experiment? I will check to make sure it's not dry sway bar bushings, which I don't think were very well lubricated on installation. Remember, I installed them at the track and didn't spend a lot of time greasing. Hmm.
edit - I did check, and it is the ungreased front sway bar bushings. Duh. The control arms are fine.
One reason to swap out the arms is because I've managed to accumulate a set of 1999-05 control arms. The rears have only 1700 miles on them so they have nice fresh bushings, while the fronts are higher mileage. The later arms are more heavily reinforced for more strength.
Third, I'm also hoping it'll let me get a little more camber up front, which will allow me to run a smaller (or no) rear bar, which will help with the rear traction.
First, I'll check the cornerweights to see if the right rear is out of whack. The traction problem is not as bad with a passenger, and of course I'll have a passenger during the race! I can tell when I'm going to have problems with the traction, as it's all due to the weight on the right rear wheel. Actually, it's the weight on the right rear and the antics I get up to in order to provoke it.
entry 471 - tags: testing, drivetrain, ergonomics | | | June 10, 2008 - Hot.
It's a toasty day outside today (about 83F/28C) and the temperature inside the car was getting pretty warm on track. As I mentioned earlier, it's a hot little track to run. But even driving home it was warm. According to my pyrometer, the driver's footwell was 145F (68C). Obviously the ambient temperature will be lower during the Targa, but I am going to be generating lots of heat and I'm a bit concerned about some of the parts on the transmission tunnel. The intercom is right on top of it and is warm to the touch, while the brake proportioning valve is also getting the worst of it. So I think I'm going to find myself some adhesive heatshielding and see if I can cut down on the tunnel temperature from underneath.
entry 472 - tags: ergonomics | | |  | June 10, 2008 - I don't know why I didn't do this earlier.
On 1994-05 Miatas, there's a plate that covers a big open area above the radiator. The Targa car didn't have one - and even the stock ones wouldn't be ideal, as they leave room for a hood latch.
So I made my own out of aluminum. It's nothing special, but it will perhaps convince some wayward air to take the productive route through the radiator instead of being lazy and simply going around.
entry 473 - tags: cooling | | |  | June 10, 2008 - With a nice long list of things to do on the whiteboard in the garage, I decided to do something else.
I've had a box full of cams sitting in the garage for a couple of months now. It's time to give them a shot.
The golden ones are just gorgeous in person. They're stage 1 cams from Integral Camshafts. The others are stage 2 from the same company, but ground on a set of stock cams - a set of 1999-05 ones, interestingly. They're both designed for hydraulic lifters which is good, because that's what I have. One big advantage to the hydraulics is that I can simply bung these in without having to mess around with shims.
How do they work? Well, the car fires up and runs fine. It has a very lumpy idle. I'll check the timing tomorrow night and then take the car on a run on Thursday. No track time, just a burn down the highway to see if it wants more fuel or less. That's a really crude way to tell if it's making more power - a thirsty engine is a powerful engine.
entry 474 - tags: engine | | | June 12, 2008 - I put the car on the cornerweight scales last night.
No surprise, the right rear was the lightest corner of the car. That's how Miatas are. But it wasn't extreme, and the cross weights were actually pretty good.
I drove the car to work - the long, long way - this morning to see how it likes the new cams. It feels pretty good, although I just cannot make it idle at all. Of course, when I got to work, I found out that I had the closed loop autotuning turned off, so the car didn't do any fuel tuning. Whoops. I'm going to double-check the cam timing to make sure it's at least close, then probably change idle modes in the Hydra to the "big cam" setup that uses the TPS instead of MAP.
entry 475 - tags: suspension, tuning | | |  | June 16, 2008 - I swapped out all the control arms for new ones this weekend, as planned.
I'll get it aligned on Wednesday, then we'll see what effect this has on the car. It does appear that I have more negative camber up front, which is good. Not very much of it, but more.
While I was under there, I welded this little ramp on the lower rear control arms. The adjuster for the shock protrudes through the arm just slightly. It's not something I'd be worried about in any other car, but just in case I drop a wheel off the edge of the road this should provide a bit of protection for the adjuster. It ended up being taller than it needed, but that's better than too short!
entry 476 - tags: suspension | | |  | June 17, 2008 - After our sore butts following the 12-hour MG rally, I ordered some new padding for the bottom of the seats.
The blue pad is a "backsaver" pad from Pegasus Racing. It's another type of memory foam, but very different to play with. It's firmer than the original cheap bedtopper I was using before, and almost feels like a gel pad when you try to push it sideways. Weird stuff.
entry 477 - tags: ergonomics | | | June 17, 2008 - I had the car aligned today.
I had a 9 am appointment and the car went on to the (empty) rack at 10. Sigh. Still, by 11:30 it was all lined up and looks to be a decent job. The right front wheel wouldn't give any more than 1.4 degrees of negative camber, which is a bit of a shame. I was hoping for about 0.5 degrees more. It could very well be my ride height, of course. According to the Spec Miata Constructor's Manual, I should be able to do a bit better. But I know from hanging out with certain Spec racers that it's not unusual for the upper control arm to be accidentally and carefully bent a bit, giving more camber. Good book, by the way.
So, how does it work? I took the car out for a run on my local Targa Simulation Road (assuming the Targa has pinon tree, red rocks and 95F temperatures) and it feels pretty good. The front end sticks beautifully and it puts power down well. Of course, I'll have to take it to the track to see if the low speed, tight radius wheelspin is gone but fast road work is not a concern. I still want to spend a little more time fine-tuning the shocks but I feel the car would be quite competitive at the Targa as it sits.
The new padding for the seats seems to work quite nicely. It wasn't a 2+ hour test, but so far it's an improvement.
I also spent a bit of time tuning the engine with the new cams. They don't like to idle much, but I'm starting to get that under control. The car feels pretty strong and it's adding a whole pile of fuel at 4500 rpm or so - right where the previous cams had a big dip in power, and right where I need a big slug of torque. So far they're promising.
entry 478 - tags: suspension, testing, ergonomics, tuning | | |  | June 17, 2008 - I've been trying to figure out how to mount a rear tow hook to the car.
I cleverly took the frame extensions that hold the tie-down hooks off over a year ago, and this made things a little more difficult for me. I can't just bolt on a normal tow loop.
The MX-5 Cup racers use a loop made out of webbing, so I figured I'd give that a try. It took some searching, but I finally found one at I/O Port. It's light and with a bit of creativity I can mount it to the chassis nicely.
entry 479 - tags: safety | | |  | June 17, 2008 - To mount the tow strap, I welded a triangular plate to the frame arm.
There's a Grade 8 bolt passed through the plate and welded in as well. A 2.5" hole in the bumper cover and voila! a tow strap. I think it should work pretty nicely, actually, and it added less weight to the car than a bolt-on tow loop.
Okay, there's one more item off the checklist...
entry 480 - tags: safety | | |  | June 19, 2008 - I got myself a new set of safety triangles.
The last set I picked up were unbelievably heavy - and they proved to be remarkably pervasive when I was looking for others. In Europe, there are many options for safety triangles. In the US, there appears to be one model that rules the marketplace. After a lot of hunting, I found a website with exactly what I wanted, and placed an order.
Only to discover that their website wasn't really up. They emailed me to let me know that the store would be open in a few months. Then called me a few hours later saying they could actually ship the stuff in a week, then I got a tracking number about a day later. Talk about lowering expectations!
They showed up today, and they're significantly lighter than the previous ones. The new ones (set up on the left) even have more reflective area than the old ones, and the set of three weighs less than a single one of the old. So that's all good then.
I've been looking for places to stash them in the car. I have some ideas. Right now, one is attached under the dash with Velcro for rapid deployment.
entry 481 - tags: safety | | |  | June 22, 2008 - One of the rules - a fairly common one for racing - says that the fuel tank needs to be isolated from the cockpit by a sheet metal barrier.
The tank's under that bulge in the middle, and it is isolated. But I've had people point to that bulge in the past and state it is a safety hazard. In order to avoid any potential unpleasantness at scrutineering , I decided to close this area up a bit.
In this picture, you can see the fuel tank cover (not the tank itself) and half of the factory shielding behind the driver's seat. I had to cut it in half in order to be able to install and remove it without pulling the fixed seats! You can also see how much of the rear deck I chopped out during the install of the roll bar.
entry 482 - tags: safety | | |  | June 22, 2008 - Showing off my mad fabrication skills, I made a plate to cover the removed steel from the rear deck.
I used a cardboard template (underneath the box'o'rivets), cut out the plate and riveted it into place. To add a little bit of provenance, I made the plate out of an old piece of the Seven.
entry 483 - tags: safety | | |  | June 22, 2008 - While I was working on the rear shelf, I decided to move the Camelbaks back there.
They're more accessible now and I have a little more hose available. Velcro straps are riveted or bolted to the rear deck, and those slip through loops in the Camelbak "Unbottles". It holds the Unbottles in place quite nicely and they're fairly easily accessible. They'll boil in the hot sun around here, but that's unlikely to be a major problem in Newfoundland.
entry 484 - tags: ergonomics | | |  | June 22, 2008 - And voila, the finished rear deck.
The black piece is the stock sheetmetal, painted because it was really nasty looking. As usual for the Targa Miata, it was rescued from a salvage car. The Unbottles are strapped down and all the openings are closed up in the deck.
Sorted.
entry 485 - tags: safety, ergonomics | | |  | June 22, 2008 - I needed a place to stash the safety triangles where they're both out of the way and easily accessible.
I was thinking of putting them on the rear shelf, but finally decided to put them under Janel's legs. The velcro is riveted to the floor and they're nice and secure, but immediately accessible.
Those who have been paying attention will remember that I mounted the fire extinguisher in this same place. It's now been moved over in front of my seat. Why? Because the driver's side is a bit narrower than the passenger's side, and there wasn't enough room for the triangles on my side.
entry 486 - tags: safety, ergonomics | | | July 1, 2008 - I haven't had the chance to do much work on the car for the past week due to Real Life getting in the way.
But the good news is that it's actually getting pretty close to being ready. My to-do list on the whiteboard is getting shorter and more trivial. There are still some logistical questions to be answered such as getting the car to Newfoundland (time to do a little work on the trailer) and how we do everything when we're there, but it's coming along.
The most productive thing I did last week was go to an interview with USCIS, previously known as the INS. It turns out that Janel and I are as married as we think we are, and I was approved for a green card. This is what prevented me from taking part in the Targa last year, of course. So it's a big relief. That delay did work in my favor, allowing me to build a better car and change codrivers. It's hard to believe that a year ago, the car was barely self-propelled!
entry 487 - tags: logistics | | | July 7, 2008 - Our NASA rally licenses are here!
Yes, the same licenses we took the class for back in February. I didn't send in the paperwork for a while, but it took about two months for the licenses to arrive. After all that, they're only good until the end of 2008. Oh well, now we have the qualifications required!
entry 488 - tags: skills | | |  | July 8, 2008 - Targa Miata clothes have arrived!
If you want to get a high-quality t-shirt or sweatshirt and show that you're a fan of the coolest rally Miata around, now's your chance. I had to wait until I saw the quality of the sample shirt, but it's good stuff. It's not only a heavy, high-quality shirt but the printing is perfect. Can't say the same about the out-of-focus picture, of course...
The store is at targamiata.spreadshirt.com and about 10% of the proceeds will go towards the race effort. Yes, I know, they're not the cheapest shirts in town. But they're high quality and this way we don't have to do a big print run and hope we got the quantities and sizes right! You can choose whatever size and style you want.
Currently, all of the clothes are navy blue with the Martini stripes, but white is coming at Janel's request. I'm going to order some team sweatshirts to keep us feeling warm and looking cool during the race.
entry 489 - tags: announcements, Martini | | |
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THE DIARY