| MIATA BUILD |
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 | |  | May 6, 2007 - I dropped the radiator in to check some clearances.
It's from an automatic car so it has a dual core instead of the truly weedy single core used on the manual cars. It has steel tanks on it instead of the crack-prone plastic ones found on factory rads as well. It is better than an aluminum race radiator? Well, no. But I am trying to build this car out of available parts for a reasonable cost. It's easy to forget that with the recent engine build.
It's close to engine start time. I need to hook up the crank angle sensor and get a lower radiator hose on the car. And then it's a matter of taking a deep breath and putting some electricity through the car. I'm a little nervous about that actually - I don't have as high a level of familiarity with this particular ECU as I'd like, and there are a lot of changes to the wiring. Maybe I'll see if Jeremy from Flyin' Miata wants to drop by for an evening.
entry 165 - tags: interchange, wiring | | |  | May 8, 2007 - While rooting around the piles of parts in the salvage area of Flyin' Miata, I came across this fan and shroud setup.
They're two powerful Spal fans on a nicely fitted shroud to ensure maximum efficiency for the fans. The shroud was a prototype part from Flyin' Miata. This setup was actually originally installed on the red shell that has become the Targa Miata, so it seemed fitting to return it to its original home. Quite possibly overkill for the car, but it's not going to hurt anything and I didn't have fans yet anyhow.
entry 166 | | |  | May 8, 2007 - The red silicone hoses were also donated by the previous incarnation of the Targa Miata.
But the real work in this picture was on the power steering lines. The 2003 steering rack has a loop of hard line that's intended to help cool the fluid. The 1994 rack doesn't have this loop and ours was kinked from the accident, so it was removed. A bit of trimming to the hoses and careful routing around the coolant lines finished the job. I may still hook up a cooler of some sort.
So it's almost time for the big startup. I've wired up everything but the oxygen sensors and almost all the vacuum lines and fluid lines are complete. Now all I have to do is load the new program into the ECU and see if I can find a battery that's fully charged.
entry 167 - tags: interchange | | | May 11, 2007 - It's alive!
Well, only in an electrical sense. I ran current through the car last night and no smoke got out, so that's a bit of a success. My battery was pretty low on power so I put it on the charger. The low voltage was causing some odd behavior as various systems would wake up partway but not all the way - for example, the hazard lights kept trying to come on.
This morning, I checked again. Brake lights, good. Turn indicators, good. Functioning oil pressure gauge (tested by grounding out the signal wire), good. Headlights...well, I'll have to look at that one later. Power to the fuel pump and ECU, good. I didn't fire the car up because there's no oil in the engine, so those tests will come along in the next few days.
I'm a little nervous about it, to be honest. This car is such an odd collection of bits, and even the sensors on the engine are put together out of several model years and patched together with software. Will it work? Of course it will, eventually. But that doesn't prevent me from imagining terrible things.
entry 168 - tags: wiring | | |  | May 12, 2007 - As final prep before starting the car, I installed an air temperature sensor (seen carefully installed on the intake manifold here) and an intake of clever design.
Brandon filled the engine with oil. And then we discovered that my battery didn't actually have any juice in it other than enough to make some lights blink dimly. So that was enough for a while. I went out to buy a real battery charger and charge up my collection of Miata batteries.
entry 169 | | |  | May 12, 2007 - While waiting for the battery to charge, I busied myself with other things.
The tan and crusty dashboard had a date with the hose, then I sprayed it with flat black paint. It's only partially dry here, but even when dry it's hard to get a uniformly flat surface. There are pockets of gloss where there's a bit more paint buildup. I'll try a couple more coats and see if I can mist the paint on well enough.
entry 170 - tags: paint | | |  | 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 | | |
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THE DIARY