| MIATA BUILD |
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 | |  | May 12, 2007 - A little more ergonomic work.
I need to find a place to stash our intercom. The harness pads are a perfect place to run the wires.
Of course, I also spent some time in the driver's seat playing with the controls. The clutch pedal feels good with nice weighting, just like the twin to this unit that I've driven on the street. Given that it's a prototype unit that's no guarantee! My tall torso still puts my head awfully close to the roof of the car, but unless I build in some sort of Gurney GT-40-esque bump there's not much I can do about that. The Peltor helmets are pretty thick.
entry 171 - tags: ergonomics, intercom | | |  | May 12, 2007 - There's juice in the battery and the lights in the rear are working!
Okay, it's nothing like the sort of victory of finally firing up the engine, but it's still gratifying to have the car actually respond to a request. I'm hoping for first noise tomorrow, let's see if that happens!
entry 172 - tags: wiring | | | May 14, 2007 - More testing, and it's getting closer.
Brandon and I started firing up one system after another tonight, but when it came time to talk to the ECU we had difficulties. It was finally tracked down to a blown fuel injection fuse.
This particular fuse feeds a whole lot more than fuel injection. It's the one that supplies power to the main relay, and is the primary source of switched power in the car. So we started by disconnecting everything and powering up one system at a time to see if the fuse would go again. Nope. Everything came back online and we were able to communicate with the ECU - until Brandon unplugged the idle speed control solenoid and pop! the fuse went again. Playing with the intake tube seemed to cause a momentary problem once the fuse was replaced again.
We did a little more poking around and found a bare wire that had been grounding out at the block when the intake moved it slightly. Whoops! The wire was trimmed back and insulated and everything was good again. All sensors indicated reasonable numbers, so we decided to go for a start. We pulled the fuel injection fuse (the fourth one of the evening by this point) so we could crank the engine over to get the oil pressure up.
Except that the freshly charged battery didn't have the guts to turn over the 11.5:1 engine. Neither did any of the other freshly charged batteries scattered around the shop.
The moral? It's time to get rid of all those batteries I'm saving because they might still be good! They're not. It's time to go get a known good battery for this car and stop screwing around.
So that was it for the night. Tomorrow, I return with a fresh, powerful battery and we make this engine spin!
entry 173 - tags: wiring | | |  | May 15, 2007 - In order to exorcise my battery woes, I brought home a collection.
The largest is an original equipment Panasonic AGM, much sought-after by many Miata enthusiasts. The middle size is the standard Mazda "High Performance" replacement. The small one is the killer Odyssey PC680. Similar power to the others, but half the size and weight. The latter is what I use in the Seven and this particular new one was stolen from my boss' Westfield "to be installed" pile. I wouldn't mind running a PC680 if only due to the weight, but today it was the mid-size Mazda replacement that was put to work.
entry 174 - tags: wiring, interchange, weight loss | | |  | May 15, 2007 - It's alive!
The car runs!
The trouble light shown here is being used as an oil pressure light to back up the gauge. The fuel injector fuse is removed so I can crank the engine (that poor little battery) and get pressure up. The test light went out at 7 psi and the analog gauge woke up shortly after.
Once oil pressure had been established, I powered up the ECU and connected the laptop to make sure all the sensors were sensing appropriately. A turn of the key and a bit of cranking as the fuel system filled - and then boom! The engine came to life. There's an exhaust leak somewhere (maybe I forgot to install something), but the engine revs sweetly. I only ran it for a few seconds before shutting down. I have a few other things to attend to right now (such as my wedding on Sunday), but a major milestone has been reached. There was much rejoicing!
entry 175 - tags: wiring, tuning | | |  | May 15, 2007 - As part of a discussion on tools to carry on the Targa Newfoundland message board, it was recommended that we carry a spare tire.
I hadn't been planning on it because, well, that's an extra 30 lbs or so that I didn't want in the car. But it might be a very useful 30 lbs.
The first step, of course, is to see if we actually can carry a spare. Uhoh.
entry 176 - tags: tires | | |  | May 15, 2007 - The tire in the previous picture was a 225/45-15, the tire size I'm favoring for the race.
This is a 205/55-14, identical in size to my second-choice 205/50-15. In a number of competitions, I've walked away swearing I'd never want for rubber. But the smaller size is 3 lbs lighter (rotating unsprung mass, the worst place for it) and, as you can see, it fits in the trunk. The larger rubber will fit in the trunk if I make some small alterations to the sheetmetal though.
Some advise against running too much tire in the Targa for more resistance to hydroplaning and more grip on gravel, but even a 225 is a smaller tire than a lot of cars will run. I want the sheer mechanical grip of the larger tire. According to Toyo's measurements, the 205 has a tread width of 8.4" when mounted on a 6.5" wheel. The 225 has a width of 9" on a 7.5" wheel. We'll have 7" wheels, but how much of that extra width comes from the extra wheel width? So many questions.
entry 177 - tags: tires | | | May 16, 2007 - More tire thoughts.
I spent some time on the phone with Joe Woodward, a fellow racer who just finished the One Lap. His day job sees him at the Tire Rack and he used to run Spec Miata, so he's very well suited to answer questions.
He noted that in direct comparisons between the 225/45-15 and 205/50-15 RA-1s, the smaller tires were actually faster on a Spec Miata. This could have been due to lower rolling resistance, as Specs are relatively low-powered cars. But he reports that the car is easier to rotate with the smaller rubber. This could also be a power-related artifact of course. Still, between the lighter weight and these reports, perhaps I should rethink my 225 obsession.
Other tire suggestions were the Yokohama A048 and the Michelin Pilot Cup. They're both considerably more expensive than the RA-1, but it's worth investigating.
entry 178 - tags: tires | | | May 23, 2007 - Okay, the wedding is out of the way.
Some good discussion on the Targa forum has reinforced my decision to run the Toyo RA-1 or possibly the upcoming R888. We'll see about the latter, availability may be a problem as it's a brand new tire for North America.
Over the course of the wedding weekend (essentially a 4-day BBQ with a short ceremony stuck in the middle), Eric got a chance to see the Targa Miata for the first time. Good news, he fits in the co-driver's seat and I was able to sort out the location for the footrest.
Time to get back to work.
entry 179 - tags: tires, ergonomics | | |  | May 24, 2007 - Chop chop!
A bit of work with the angle grinder and some tin snips took a bunch of weight out of the trunklid. This steel panel is about as heavy as the aluminum hood! The hinges and latch are removed, and I'll pin it on. The bracing removed from the bottom of the trunklid is probably about the same weight as the spoiler I'm going to glue to the top, but I can't resist it.
Last time I did this to a trunklid I went a little further, but I'd prefer to keep the Targa Miata's trunklid weatherproof so I used the gasket mounting surface as my cut line.
entry 180 - tags: weight loss | | |  | May 24, 2007 - The rear bumper support is bolted on the car, and the bumper is ready to be attached.
The two black pieces on the floor were redundant, so all that's left to add here is the actual skin. It should be light, and an initial fit indicates that it doesn't move around much.
I'm working on the body panels so I can give them a squirt of paint soon and make the car appear to be streetable. That will make it a lot easier to break in the engine!
entry 181 - tags: weight loss | | | May 26, 2007 - I got an email from Ander Tenno about tire selection.
He's tried both the R888 and the RA-1 on his car in the past, and here's what he has to say:
The short summary is this: the RA-1 gives up very little grip in optimal circumstances (~20-25 C sunny weather with heat in the tires) to the R888 while being significantly better in the wet and when the tires are cold. If the RA-1 was still available in Europe, I’d be still using those.
It certainly sounds as if the RA-1 would be the better choice for the Targa! Thanks so much for the feedback, Ander!
entry 182 - tags: tires | | |  | May 28, 2007 - One last step before preparing the panels for paint - locating the pins to hold the trunklid in place.
I'll do the hood once there are fenders in the car to help me align it. Unfortunately, the location of the pins precludes the use of the cool factory R package spoiler I'd been planning to run. Oh well, that's 3 lbs less weight in the tail.
entry 183 - tags: weight loss | | |  | May 28, 2007 - I'm committed to hood pins for the hood now.
This is the hood latch loop. It was a little disappointing, I was hoping for more weight. Given that the entire hood weighs about the same as the tiny trunk lid, I guess that it's not surprising the latch mechanism would be super-light.
entry 184 - tags: weight loss | | |  | May 28, 2007 - Bath time!
The body panels came outside for a date with the pressure washer. There are a lot of parts left to install to put the body together! They'll all go on quickly enough - that rear bumper will take about 3 minutes - but it's a bit daunting to see them all arrayed in the driveway like this.
The pressure washer (I love this thing) did a good job of removing all the various grime, oil and gunk from the used parts. Some are very used.
For those who are curious, we have Montego Blue Mica, Brilliant Black, Crystal White and Classic Red represented here. There's also a Silverstone Metallic trunklid in the garage but it's not going to be used.
entry 185 - tags: paint | | |  | May 28, 2007 - The worst part of the cleaning - the gunk on the inside of the doors.
Miata owners know what I'm talking about here. It turns out that WD-40 does a real number on this stuff, diluting it slightly and defeating its tenacity. This is the result of a bit of WD-40 and rag work. The pressure washer took care of much of the rest, and the pre-paint clean should finish the job.
Those with sharp eyes will note that the doors that were gutted before were black and this one is not. It was pointed out to me that the particular Spec Miata cage we're using does not have a substitute for the factory door bars. Since I'd cut the door bars out of the other, I'd left Eric and myself without much in the way of side impact protection. That's not a smart thing to do, so a new set of doors was substituted and left whole.
entry 186 - tags: paint, safety | | |  | May 28, 2007 - I like this little thing.
It makes me giggle. When I asked other Targa competitors about tools to carry, most seem to keep a spare in the car along with a jack. Adding a 1/2" drive socket to the factory scissor jack was suggested so an electric impact could be used to lift the car. I went one better and welded on a nut with a 17mm head - the same size as our lug nuts. This way I don't need to swap the socket on the impact gun.
The jack works ridiculously fast. I'm going to make another one to keep around the shop, partly because I'm going to wear this one out zipping it up and down. It'll make tire changes in the shop a snap as well though.
Oh, and Eric - if you're looking for the jack for your Miata, that's it.
entry 187 | | | June 4, 2007 - My house is conspiring against me.
My "Targa time" has been eaten up by a recalcitrant irrigation system (if you think of electronic sprinkler valves as fuel injectors it's all quite obvious, although I do prefer that fuel injectors aren't buried in the dirt) and some interior plumbing problems. Regardless, I've managed to make some progress. The remaining body panels are now scuffed up and clean, so they just need a final wipe down and then it's time to paint. I'm hoping to have the primer on them tonight.
entry 188 - tags: paint | | |  | June 5, 2007 - Primer time!
I don't have enough stands for all the parts, so I'm having to do this in stages. However, most of the body panels have primer on at least one side now. I'll finish the rest tonight.
Thanks to better gun setup, I'm seeing a far superior finish than on the car body. The larger smooth surfaces of the body panels - as opposed to engine bay crevices and roll cage - make it a lot easier to practice, and I've learned just how critical gun distance is. I've also learned it's really hard to tell where you've applied white primer to white panels!
entry 189 - tags: paint | | |  | June 6, 2007 - Okay, that's it for primer.
Tomorrow I'll break out the top coat and then it will be time to start assembling great big chunks of car!
I'm really enjoying the painting. Once you get the paint gun in hand, progress is very visible and very rapid. I wouldn't want to do it for a living, but it makes a great contrast to wiring!
entry 190 - tags: paint | | |
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