| MIATA BUILD |
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 | |  | May 10, 2009 - Another track day!
This time, the Targa car sat in the trailer and I drove Elvis, the LS1-powered bar (back in full health) instead. It took me some time to come to terms with the car. It simply seemed squirrely. Not so much under power - it behaved exactly as expected then - but during braking and cornering. It's the first time I've set up a car with this particular tire so that's part of it, and it has good brakes but without adjustment options.
But what I finally realized was going on was that I was expecting its cornering and braking ability to be in line with its acceleration ability. It thunders down the straight like the turbocharged Westfield beside it, but it still corners like a Miata and not a 1300 lb featherweight. So I had to bleed off more speed for the corners, and my Targa braking points didn't work because the car weighs 400 lbs more and was going considerably faster. So the problem wasn't the car's traction, it was simply that I was asking too much of it.
Of course, another problem was the red mist. My first session out, I'd blown away the fastest Miata to ever run the track. So I was hoping to beat the track record for Miatas by as much as possible. I did, by a considerable amount. And now that the mist has faded, I realize that I need to spend some time tuning this car on a big track, where I can get it settled on a long sweeper to set the basic handling balance and then tune the transitions from there. The car still handles well, I just want to bump it up to the top level. Not bad for a street car though.
I took Janel out for a few laps. She was impressed by the violence. It would be a very effective Targa car, but it would take a different driving style than the current setup. The fact that it was faster in street trim than the Targa car is in race trim is a good sign.
Janel also took her own car out for a couple of sessions. Now that she's experienced the Targa car at its best, she was quite adamant about the shortcomings of her previous ride. "I miss my tires! I want my brakes!", she informed me. Oh boy...
entry 678 - tags: other cars, v8 | | |  | May 14, 2009 - A peek at the Targa New Zealand.
I've been corresponding - on and off - with Euen Burke about his Targa NZ experiences. He drives a TG Sports, a MG-inspired kit car that uses Miata mechanicals. It's a pretty cool little device, giving the style of an older car with the Miata's reliability and handling. The picture shows one of his better parking jobs after a bit of a moment on a bridge. Sorry Euen, I had to use this shot because it's such a good parking job! He reports that it took six people to pull the car straight so they could continue, and they were not the first to hit the barriers!
Well, he recently sent me some video of one of his stages and it is in stark contrast to Newfoundland. First, look at the altitude gain! Also, note how smooth the road is. It's a completely different experience from what we dealt with. Here's what Euen had to say about the stage:
"It was a hillclimb stage on the last day, just north of Wellington. About 14 or 15km long. A piece of road that I have enjoyed for a long time as I used to live not far from it and used it frequently. We managed to catch a Reliant Scimitar about 4 minutes in (we started 30 seconds behind him). The Scimitar is powered by a 3.8 litre GM/Holden V6. Has the legs on the straights but cannot shake me on the tight stuff."
Video link
Thanks Euen!
entry 679 - tags: Targa NZ | | | May 19, 2009 - I had the car up on a lift today.
Mostly, I was checking out some details on the shocks as part of Flyin' Miata's development. But it gave me a chance to swap out the fuel filter and give the car a look-over. A vibration turned out to be the cat leaning against a heatshield. Some light rust has shown up on bare metal, probably as a result of that run over Donner Pass in the snow in March. Otherwise, everything looks pretty solid.
I've also made a change to the video section of the website. The videos are now ranked by rating instead of simply by when they were uploaded. If you think something deserves to be higher or lower, simply click on the + or - for that video. As Eric quickly discovered, there's no limit to the number of times you can do that, a feature I may come to regret.
The video page
entry 680 | | |  | June 9, 2009 - I decided it was time to install a quick-release steering wheel on the car.
I swear, every time I get out of it, I'm less graceful. Janel agrees (that we need a removable wheel, not that I'm not graceful - at least, not to my face) so I picked one up. Besides, they're cool.
The adapter from LTB Motorsports and nice and solid. It's a weld-on unit, as in my experience the bolt-on ones add quite a bit of extra space to the wheel location. The first step was to drill some holes in the adapter so I could weld it to the shaft.
entry 681 - tags: steering | | |  | June 9, 2009 - Because the stock shaft is tapered - that's how the stock wheel wedges on, really - I wanted a better support at the end.
I ground down a nut so that it was a nice tight fit inside the splined adapter, giving me more support.
entry 682 - tags: steering | | |  | June 9, 2009 - Before welding the splined tube on to the column, I made sure I didn't damage anything inside the car!
Not completely successfully, I needed an extra layer on top of the driver's seat, as it picked up a few dark freckles. Still, no holes.
Once the adapter was welded in to place, I had to make a few alterations to the combo switch to allow it to pass over the larger diameter steering column. This also meant I lost my self-cancelling turn indicators, and the way the adapter bolts to the wheel means I also lost my horn button. I have a few ideas on how to deal with the former, and the latter will not be a big problem to work around.
And now the steering wheel comes off! Race car cred. And easier exiting of the vehicle. Not completely necessary, but it'll make me giggle.
entry 683 - tags: steering | | | June 17, 2009 - I saw a copy of the Targa show that was aired on Speed today.
Before, I'd only seen it on the DVD the show producers sent me. Interesting, it's got different narration. Same script (with a few changes like saying our car was "chuckable" instead of "tossable") but a British accent. Interesting. I'm not sure which I like better. I certainly didn't expect a change.
Speaking of the actual race, the route for next year has been announced. Clarenville is no longer an overnight stop and they're going to run Brigus twice, amongst other changes. There's even an exhibition run in St. Johns. That would be fun.
Schedule.
One nice touch, the organizers have published a sample route book. I'm very glad to see this. We managed to borrow one to preview so we had an idea what to expect, but not everyone might have managed the same.
Prologue 2009 route book.
entry 684 - tags: race, tv | | |  | June 20, 2009 - About 9 months late, we finally have some transit headsets for the car.
They were right near the top of our "things we need for next time list" last September. I think those long days in the car would have been a bit shorter if we'd been able to chat on the transits instead of simply putting in earplugs.
Part of the problem was our super Peltor intercom. Fantastic piece of kit, but the pieces are ridiculously expensive. Around $230 each for transit headsets. In fact, it would be cheaper to buy a separate Terratrip intercom and headsets than it would to buy a pair of Peltor-compatible heatsets from rallylights.com.
But I managed to find the part number of the headsets, and discovered that they're also used in the military. Sure, they have a 30 foot non-coiled cord and some weird military plug on the end, but you can buy new surplus ones for $200 a pair shipped. Some hunting around also unearthed the Nexus plug used by Peltor, and Aircraft Spruce provided a pair of those.
So, all I needed to do was figure out the wiring for the plug. Peltor was not interested in helping at all so I was on my own. The microphones on the helmets actually have a small connector on them, so it was a fairly easy job to use that to figure out that the two pins on the end of the Nexus connector were for the microphone and the next two were for the speakers. Chop the cable down, do a bit of careful wirestripping and soldering and voila! They work!
After a test drive, Janel announced that we really really really should have had these on the race. They work beautifully.
Now, for anyone who wants to duplicate the job, here's the parts list.
Peltor MT7H79A headsets (sourced from eBay)
Nexus TP-120 plugs (part 11-00699 from Aircraft Spruce
wiring:
pin 1 (tip): black
pin 2: yellow
pin 3: red
pin 4: white
Pins 1 and 2 can be interchanged, there's no polarity that matters. Same with 3 and 4.
So there you go. That's how you make a set of Peltor transit headsets for half the price of new ones.
entry 685 - tags: intercom | | | July 27, 2009 - Not much going on of late.
Janel took the car to a track day a while back, after driving the car at Laguna she refuses to take anything lesser out. I can't really argue with that! The car did ping some while hoofing around, so I'll take it to the dyno to check a few things out. It's going to be at the Flyin' Miata Open House as a demo car so I should probably also wash it.
I have a few plans for the car. First, I want to play with the fuel pressure to see how the injectors react. Then I might try a set of very stiff springs for track use, as a lot of AFCO users are running much higher rates. Of course, they're not planning on taking on the roads of Newfoundland. But it behooves me to learn as much as I can, and if it's an excuse for more track time I won't complain.
entry 686 | | | August 5, 2009 - I pulled the suspension out today to install some upgraded bits and pieces.
Nothing major, just detail stuff. At the same time, I reinstalled the "rally springs", the 375/300 combo we ran in the Targa. I've got some different bumpstops installed and we're running a slightly higher ride height, so let's see how this works. I do enjoy the fluidity the car gains with this softer setup, but will I miss it on the track?
Well, I'll find out on Friday. The Flyin' Miata Open House (now called Summer Camp) is this weekend, and I'll be running yet another track day as part of it. The FM staff aren't allowed to run transponders to prevent us from all chasing the lap record (again), but I'll put the Traqmate data acquisition system in and see what interesting stuff pops loose.
entry 687 - tags: suspension, testing | | |  | August 6, 2009 - Ever wonder how the base times are calculated, and how the various classes are handicapped?
The organizers have released the factors for 2009. You can see the original here.
Basically, the Class 9 Modified Large cars (Evos, Challengers and the like) are assigned a time. Then that time is multiplied by the factor for each class. In other words, a Class 8 Modified Small (that's us) gets 3.25% more time to finish the class. That's pretty close to the big boys. If our car was a 1990, we would have had a 5.72% handicap instead - but then we would have had to use the weaker ring gear in the differential. The winning 2002 gets either 17.40% or 12.12% depending what class it's in. If I do put that V8 in the car, I'll have to complete the stages about 5% faster.
Details about the 2009 race are being released over at the Targa website. Looks like SRZs are out this year (yay!), maximum average speeds are back (a concern for the Open Class guys), race tires are allowed (this year) and a few other bits and pieces.
Do I wish I was going this year? Oh yes.
entry 688 - tags: regulations | | | August 6, 2009 - I've noticed recently that I'm getting some vibration through the chassis of the car.
I'm not sure if it appeared after my last header r&r, but I got under the car to check it out. It turns out the catalytic converter was pressed up against a bump in the transmission tunnel.
The bump is one that I hammered in place to give myself a bit more room for the driver's seat. Also, the car runs a cat from a 1999 car because the whole exhaust system is from that generation. No problem, there's a heatshield on the outside of the cat so I figured I could bend that out of the way.
I pulled the cat off, reshaped the heatshield and went to put it back on when a chunk fell out. That's not right! The cat was breaking up internally. Since this particular cat came from discarded exhaust with "bad kitty!" written on it, this isn't exactly heartbreaking. I grabbed a long prybar and encouraged the core of the cat to break up completely. The hollow cat went back on the car. And of course, I was able to place it so there was loads of room between that bump and the cat.
I've had a bit of pinging at full throttle and high rpm recently. Could a failed cat have raised the backpressure in the exhaust system? Quite possibly. We'll find out tomorrow when I return to the track.
The car doesn't sound as good now, having picked up a nasty rasp at about 2600 rpm. The long-term solution will involve a resonator in place of the cat, but I didn't have time to do that today.
entry 689 - tags: exhaust | | | August 9, 2009 - I didn't spend a whole lot of time on the track last weekend.
I was spending more time than usual organizing for some reason. I did take the Targa car out a few times, and also went out to play in Elvis the V8 Miata.
Tom Heath from Grassroots Motorsports was there, and he took the Targa car out for his first session. He really enjoyed it. And it is a fun car, I'm not going to argue. It was set up with a bit of oversteer and the softer springs (as used in the race) and I think it was faster with the stiffer setup, but it was still very entertaining and Tom seemed to enjoy himself quite a bit.
I did a bit of data acquisition with a Traqmate during my few laps. I was having trouble with my line on the fastest part of the track, and this is pretty clear from the data. At least, I think it is. I'm not accelerating as hard as I should down the straight, and I'm not at my maximum cornering speed until right near the end. There, it peaks at over a g and then is followed by about .75g braking while still cornering at 0.5g.
I also compared it to a log from our previous datalogging session, a lap that was 1.2 seconds faster. I have a lot more analysis to do, but this is going to make for some really interesting reading.
Not a terribly coherent report, I know. It's been a long weekend. The Targa car acquitted itself well, and after talking to a number of people about the race and watching the videos, I have the itch to go back again very badly.
entry 690 - tags: datalog | | |  | August 18, 2009 - I am such a child.
These are roof vents. It's hot here in the summer, and it would be great to force more air through the car. But really, I just want roof vents because roof vents are cool.
You can get these from Primitive Motorsports for $89 each. Or you can get them from these guys (click on the Vents and Fans category, then choose Side Vents) for $22.25. So I bought two, just in case it makes more sense to have one per person.
They're pretty large in person, and I think headroom may be a problem if they're put to each side. So one per person it is. They can be opened in either direction to act as a scoop or an exhaust vent.
Do I have the nerve to install one? Will I want to add a Primitive scoop on top? Only time will tell.
Janel was not as excited as I was when these arrived.
entry 691 - tags: roof vents | | |  | August 28, 2009 - Don't tell Janel.
I bought a Primitive roof scoop. As mentioned previously, I'm a child. I want my race car to have a roof vent!
In person, it's pretty easy to tell that this thing was sized for larger cars. It looks about half the size of the hardtop! If I could install it temporarily to get an idea of how it looks and works, I would. But installation requires permanent defacement of the hardtop, and Miata hardtops aren't cheap. Even ones that have had the glass smashed out of the back.
Do I dare? And no, I didn't have it sitting in the center of the roof when I took the picture.
entry 692 - tags: roof vents | | |  | August 28, 2009 - Another view of the roof scoop from the back.
Not subtle. The small hole in the back is intended to cut down on wind noise, apparently.
entry 693 - tags: roof vents | | |  | August 28, 2009 - One more view from the front.
I'm going to have to spend some time walking around looking at this. Other than the fact that it gets pretty hot here in the summer (it's 92F/33C here right now at 6 pm), I don't need one. It's purely for the little kid in me.
How much does the little kid want a roof scoop?
entry 694 - tags: roof vents | | | September 3, 2009 - I've decided not to go with the vent.
Partially due to aesthetic reasons, but mostly because it doesn't work with the car. The car's been built with a very specific purpose in mind, and the roof vent is simply goofing around. I want it to retain that purposefulness, so if I do anything for in-cockpit ventilation I'll just add a NACA duct to the door window.
entry 695 - tags: roof vents | | | September 3, 2009 - A very interesting car was at Flyin' Miata yesterday.
It's a national-level autocross car, and it had some fascinating tweaks in it. I was given a guided tour by the owner before the car went on the dyno. His weight-savings techniques extended as far as grinding off unused bosses on the intake manifold.
The car also spent some time on the FM dyno. This car already has a lot of dyno time on it, testing every change made from intake pipe length to various intake manifolds. It did extremely well. It's time for me to dig into the engine on the Targa car and see what I can do for the output.
Or at least, it will be as soon as I'm done with the current book. Six more week and I'm free!
entry 696 - tags: engine | | | September 8, 2009 - Targa 2009 starts this weekend.
I wish I was going to be there and I've been daydreaming about it more and more in the last few weeks, but so it goes. As we said right from the start, we always knew this was liable to be a one-time race for us. The cost of taking part is just so high - and not just in terms of money. Someday we'll be back. In the meantime, I'll be trying to live vicariously as much as possible.
Matthew Oldford, who ran a turbo Integra in the Open Class last year, posted a new video that shows the event pretty well from inside and outside the car. Just what I needed, something else to get me all wound up even further about the race. Watch for us at a couple of spots!
entry 697 - tags: video, 2009 | | |
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