build diary

February 28, 2006:
Almost.

I got a late start on the Seven last night due to some entertainment with the brand new 2006 MX5 that just arrived at Flyin' Miata.
I can report that a 225/50-16 tire will fit without difficulty. Anyhow, once that was over and the Seven moved in I started cutting up the exhaust. About halfway through I realised that it really wasn't too bright to maroon myself at work if something went wrong but I just kept plugging away. It's the third time I've built the exhaust for this thing, you think I'd be good at it by now. The typical number of little bumbling mistakes and it was ready for paint.

While the paint dried (I couldn't bring myself to watch), I installed the grille. Three well-placed studs on the backside, three slightly oversize holes and wow! It looks so much more finished. Eric is sitting back and saying "I told you so", but it's true. A huge thanks to Chris for donating this to me.

Paint's (almost) dry so I bolted the exhaust on. It looks appropriately sized to the car and will hopefully sound good. I don't know yet because the car decided to simulaneously foul all four plugs and wear out the battery. A jumper box solved the latter but the plug cleaner had vanished into thin air. So had the charger. So the Seven was abandoned in the shop. I'll find out tomorrow if my muffler experimentation is finally complete.
entry 1127

Studs to hold the grille on the nose.
They're not quite as splayed as the wide-angle lens makes them appear.
entry 1128
The grille on the car.
It looks quite different from this morning.
entry 1129
No grille, old exhaust.
entry 1130
12 hours later.
New grille, new exhaust.
entry 1131

March 1, 2006:
Some clean plugs, a full battery and the car fired up immediately.
I've only had the chance to drive the car for a short period but it sounds pretty good. The painful blare at full volume has gone away with the Magnaflow muffler. The car's still loud, but it's good loud and doesn't have any rasp or nasty noises that I've heard so far. Earplugs should not be necessary. We'll see how it behaves as it ages a little.
entry 1132

March 2, 2006:
I couldn't help myself last night.
The garage door was open and beckoning me. Well, I had to see how the new exhaust sounded, didn't I?

And it sounds good. My initial impressions are still true - it's a nice sound right up to redline. It's not a quiet sound but it's acceptable for street use. Quieter than a Harley, that's for sure. When I dropped by to visit some friends who were working on stuffing a twin-turbo rotary into an unsuspecting Miata, they thought a Hayabusa or some other sport bike had pulled up outside. A big part of this was how fast the engine revved when I blipped the throttle as I manouvered around.

Of course, part of the fun of testing at night is the fireballs. On closed throttle deceleration, I'm still running pretty rich. That means that coming into corners the car is blowing flame and making the classic little sports car burbles and pops. Then BLAM! and a fireball. I giggle a lot when this happens.
entry 1133

March 3, 2006:
I'll be off in Moab this weekend on various bicycles, but given the weather report I'll be missing the Seven.
There's a local track day too. I seem to have rekindled my fire for the car. Or the backfires lit something.

This popped up on a Caterham list. Now, I'm pretty proud of my little Caterham model (see here if you don't know of it) but these are astounding.
1:18 scale
1:12 scale page 1 (like my own)
1:12 scale page 2
entry 1134

March 12, 2006:
The battery has been moved.
It was a tougher job than I'd anticipated - it appears I built the car around the main power cables! The old battery won't even come out of the car without removing either the rear panel or the fuel tank! Good thing I have plans to make a new tank then.

It was a struggle to get to the various ties holding the main power leads in the transmission tunnel. Last time I was in there, there was no driveshaft or rear end and I was making very sure everything was clear of the driveshaft. There were an amazing number of zipties in the way! I did eventually triumph and freed the cables from their prison. The battery is now situated in the passenger's footwell. I considered mounting in the engine bay but this worked out better for the new kill switch I also installed. I have always been able to disable the ignition by taking the ECU keypad out of the car, but the starter motor was always energised. The new kill switch not only is a good idea for track use but also lets me remove the "key" from the car for a bit more security. It also lets me cut the battery while working on the car, something I've always appreciated on my old Land Rover. I can also easily access a hot terminal in the engine bay for jumping or charging - a nice touch. It has a removeable insulator on it so nothing exciting happens.

While removing things from the car, I also pulled the intake manifold off. This gives me a little more room for working on the wiring but more importantly lets me fix a little slop in the mechanism.
entry 1135

March 13, 2006:
One option for a battery location.
entry 1136
The final location before the tiedowns were added.
The bundle of green wire is for an ECU-triggered shift light or some other RPM-related function. I'm not using it at the moment.
entry 1137
It really doesn't take long to disassemble the car this far although it sure looks like major work.
entry 1138
Stolen from Caterham, here's my kill switch location.
In person you don't see any white around the switch - the flash really emphasised that.
entry 1139
A little touch to make the car look a little more finished.
I stretched a mountain bike inner tube over the bare metal steering column. This picture is not flattering of the result - it's a cleaner look in person.
entry 1140
A cheap way to clamp off fuel lines.
That's a 99 cent tool!
entry 1141

March 15, 2006:
Lots of destruction last night.
I reinstalled the throttle bodies a couple of days ago after fixing a small amount of play in the synchronising mechanism. It wasn't causing a huge problem but it did mean that I couldn't run an idle switch for the ECU. See, the ECU gets upset if the engine speed hits 2000 rpm and the throttle body is still at idle. I had just enough slop to make this happen when leaving from rest, leading to a bad driveability problem. So I'd been driving around without an idle switch which was fine other than cold start up. After installing the fixed throttle bodies, I adjusted the butterflies by eye and fired up the car. It idled happily even though it was stone cold. Very nice.

I drove the car out the garage, turned it around and then went right back in. Why? Time to work on the gas tank! First the fenders came off (didn't I just put one of those on?), then the rear panel was removed. Now the fun part - the fuel tank. I'd forgotten how much fun that was, having to remove every single fitting on the tank by putting my arm inside. At least it's the last time for this tank! The car now looks truly sad but I'm on a mission to build this tank as quickly as possible.

The new design will sit at the rear of the car behind the differential instead of on top. This is a more traditional Se7en tank. It'll be wider and thus more susceptible to fuel slosh, but I'll address that with internal baffles. The best thing is that the center of gravity in the rear will drop down significantly, cutting down on roll. This is my primary reason for the work. I'll also have a trunk of sorts! Initial calculations tell me that by simply filling the area below where the old tank sat, I'll have a 6-7 gallon capacity. Not bad at all! Tonight I'll make a cardboard version.
entry 1142

Fixing the throttle bodies for better synchronisation.
There was a bit of slop in the mechanism that joined the two halves.
entry 1143
I had a request for a better shot of the exhaust.
I haven't had the car outside in the light for a while so this is the best I can do at the moment...
entry 1144
The rear bodywork is off, now it's time to get that old fuel tank out of there.
entry 1145
The rear end naked and ready for a new tank.
I'm going to put the tank in the deep area at the back and use the small hole in the center (you can see the grey sway bar in it) as a sump. It should work out pretty nicely.
entry 1146
A new project, as if I needed one.
This is going to become a fairly potent naturally aspirated Miata rally car. More details to come!
entry 1147
Maybe I should put one of these cars together so I can drive it!
entry 1148
<< | show individual entries | >>