July 21, 2014 - More track time at the Grand Junction Motor Speedway. But first, some news from the last event. My maximum speed (into the wind) on the back straight at High Plains was either 215 or 217 km/h that day - I forget. At the previous event which was run with the old L33 engine, my top speed was 197. That's an 18-20 km/h (11-12 mph) speed difference. Huge! This new engine is a hero.
You can see the car's on new wheels. Those are Advanti Storm S1s in a 15x9 size. They're part of a new breed of light and strong flow formed wheels. Despite being the biggest wheels I've ever had on the car, they may also be the lightest at 12.1 lbs. Excellent.
I've also swapped back to the fixed wing so I can concentrate on other things. It's still working well at higher speeds, but I didn't think it would help as much on the slow little Grand Junction track. I also want to experiment with some aero balance, so it's being used as a control for now.
Inside the car, I added some reflective gold heat shielding inside the transmission tunnel to mellow out the interior.
And of course, after all that work, the fuel pump failed as I was driving the car home the day before the track event. A late night run to the Flyin' Miata shop and a pump swap, and it was in full health again. It's about the best place it could have failed.
After all the planned and unplanned prep work, how was the track? Pretty fun. We built a black V8 track car at FM that has a lot of parts in common with mine. I accidentally ran a 1:00.2 in it while heat-cycling some Hoosiers, so it's quick. The new owner was at the track, and we spent some time playing tag. Here's the noisy result. While he has an advantage with those big fat Hoosiers, I know the track far better and you can hear me backing off the throttle early on a number of spots as I try to judge his braking points and adjust to his speed. Those Hoosiers are great around the tightest corners, but he was leaving a lot of time on the table on the long sweeper. Fair enough, it takes some time to get comfortable there.
I spent a bit of time haring around as well. The brakes felt good, although I was being careful to avoid lockups. The track's developed some new bumps in a couple of critical braking zones, although it's also quite possible that I'm going faster in said zones. The car was understeering in the long sweeper, which seems to be the fastest setup based on my times. Despite scorching summer temperatures nearing 100F, I put down repeated laps in the 1:01 range with a best of 1:01.692. I was hoping there was more in it, but I think the driver is too slow and it was hot!
Fun setup note: my tires were showing signs of a good setup. 100% consistent pressures at the end of a session across all four wheels, and the temps were dead even across the front tires. The rears were a bit hotter as I went inwards, which looks like camber. Not dramatically, though, and I'm going to keep playing with aero for balance.
Overall, the car's good. It's ready for the big FM Summer Camp in a couple of weeks. Which will again be very hot. entry 1125 - tags: testing, video, wheels, aero, setup
August 3, 2014 - FM Summer camp track time! This is a tough event for the Targa Miata. Two days of double sessions, giving rides to FM customers in brutal heat. I figure I did over 100 hard laps of the track in two days. Everything worked well. Despite the heat and the short, tight track, the car ran at normal temperatures. I wasn't taking it terribly easy on the brakes, and they also dealt well with the heat.
The blue car in this awesome picture by Travis Ingram is Elvis, another V8 car. It's got AFCO suspension with a bit less spring rate and the same basic tire setup that I do - and it provided a very dramatic visual example of how effective the aero is on the long sweeper as I came rampaging up on his rear bumper with a very high closing speed. Quite exciting for the passenger in Elvis as he saw me bearing down, too. There was also a great example of the wing's wake when a drone above the track got thrown around by the rooster tail from the car - I'll try to get the video of that.
I found the car to be pushing a bit on the tight track with the setup that had been working so well at High Plains a few weeks ago. There was no time for tuning, so I just drove around it after softening the front sway bar. I've found the car is fastest with a little bit of aero-induced understeer on the fast sweeper, but it was a bit more than I prefer. Next time, I'll try playing with tire pressures although they were right at my target. Even after about 150 laps of this track and the recent High Plains track day, the tires are looking good. The Toyo RR is my new favorite track day tire.
There was one small area of concern. At the end of the last session, I had an odd noise in the steering. A clunk at a specific point of steering angle. Fearing the worst, I got under the car - and found that a motor mount heat shield had moved out of place and was making contact with a bolt on the steering column. Well, that's an easy fix! Whew. entry 1126 - tags: testing, summer camp
August 13, 2014 - An interesting upgrade. I'm seeing a bit of oil in the intake from the PCV system, and came across this factory part for the Camaro ZL1. It's an oil separator, designed to pull oil out of the air being recirculated. Installation is easy, it just replaces the filler cap.
Well, it would be easy on a giant Camaro. It wasn't even close to fitting under the hood. After a bit of head scratching, I tried swapping the valve covers around and it tucks in nicely by the firewall. Let's hear it for symmetrical heads! We'll see how this works out. entry 1127 - tags: engine, ls3
August 13, 2014 - Adjustable rear control arm test. First note: white gets grubby handprints all over. This part is a new adjustable arm from Paco Motorsports that will be available from Flyin' Miata soon. It'll let me adjust camber in the rear without affecting toe, which is a nice ability to have. The fact that it uses stock size bushings is a bonus as well.
It's also designed for maximum suspension travel. To my surprise, I found that the previous aftermarket upper control arm wasn't quite so good in this regard and had been making contact with the body of the car at full compression. The body of the car lost, so there's some damage to the lip above the arm. No problem, although it would explain why the hit on full compression seemed a bit abrupt. entry 1128 - tags: suspension, testing, control arm
August 26, 2014 - Wet track day! This was supposed to be the big shakedown before the Laguna Seca event. The weather, unfortunately, had different plans. I took the car out on the sodden track on my treadless Toyos, but it was just a big slither-fest. So I took it home after one session. I still did okay, running about the same speed as a 4WD 911 on all-seasons and an Evo - but it wasn't telling me anything and wasn't really that much fun. entry 1129 - tags: testing, wet
September 13, 2014 - Miatas at Mazda Raceway! This is always a big event, but this year it was massive with the public reveal of the 2016 MX-5, a world record attempt, a showing of Racing The Rock under the stars and nearly 2000 cars. The paddock was mobbed and the track time was full.
It was also my first time to really let the new engine rip at sea level. I'm still in awe, it's a spectacular thing. Every time we got on the straight, I'd just power past every car in sight. Sure, it may not be as cool as catching a high power car in the corners and working out a clever way to get in front, but the big hammer is still pretty gratifying. Here's what it looked like from inside one of the other cars - I make an appearance at 2:00.
I was taking it a bit easy in the corners. Mostly because there's no prize for being the fastest at an event like this, and I did not want to crash. I was also backing off the throttle as I went over the crest halfway down the straight because the cars entering the next turn had no idea I was coming. With the closing speeds, I was essentially coming out of nowhere. This was a particular problem in the slower Group B, where I had one exciting moment as a Spec Miata moved over close to the wall as I came barreling up with about a 40 mph closing speed. I thought I was going to lose both door mirrors, one on him and one on the wall. The car was actually really well balanced, with a bit of inherent high speed understeer from the aero that could be counteracted with throttle.
The car, unfortunately, was not rock solid. When I had it down at Road Atlanta this spring for display purposes, it went into some sort of limp-home mode on me. I was never able to duplicate it and the car's been great ever since. Well, it started doing the same thing at Laguna Seca. I'd be powering along, and all of a sudden my drive-by-wire throttle would disable after a shift. It's not a fun experience, losing all power just when you're hitting the next gear. I found I could bring it back if I turned off the main battery switch, resetting the ECU. Of course, this wiped any error codes. Eventually, it failed on the way up the hill to the Corkscrew and I was able to coast back to the pits without resorting to the reset. It had to do with the electronic throttle.
Lots of theories bandied about and I tried to eliminate potential interference by wrapping the wiring harness, swapped out the pedal for another and generally got frustrated. It seemed to be heat related - and it alway happened on a shift. So eventually I just left it in fourth gear and avoided shifting all together. Still, I didn't trust the car so I parked it early. A bit of a letdown after the buildup to the event.
My current thinking is that I was hitting an airflow limit on the car's programming. There's one particular table that has to do with the amount of airflow expected for a given throttle opening, and I may have been exceeding it. That would explain why it's never been a problem with high altitude use, and why it happened when I was shifting and getting a big gulp of air when the throttle smacked open again. I'm going to mess with the table and see if I can duplicate the problem at altitude, then we'll see what happens next time it goes down to sea level again. Unfortunately, that probably won't be for another year, and I really don't want any questions around the car at that time. Some troubleshooting lies ahead.
Photo by Ben Sale. It's definitely not the classic Corkscrew shot, I love the different take on it. entry 1130 - tags: MRLS, laguna
December 15, 2014 - It's time for some traction. Maxxis has just introduced a new size of their RC-1 track tire: a nice fat 245/45-15. It's been a long time coming. The tire is aimed at the track day crowd, promising a long life and good traction. I'll be mounting them on a set of Jongbloed 15x10 wheels.
I'll have to do some work to make them fit under the fenders, that's for sure. But I'm looking forward to the first track day in the spring! entry 1131 - tags: tires, maxxis
January 15, 2015 - The new track rubber is mounted and ready to try out. Those are 245/40-15 Maxxis RC-1 tires wrapped around a 15x10 Jongbloed wheel. It's a lot of rubber, and it's going to be a real challenge to get it to fit. I'm a bit worried about the fenders. entry 1132
January 21, 2015 - Test fit of the new Maxxis RC-1 tires! And it's a problem. In the front, I could probably get them to just barely clear with a hard pull of the fenders. Probably. entry 1133 - tags: wheels
January 21, 2015 - The tire fitment on the rear is a bigger problem. I don't think I can pull that fender enough to clear the tire. Almost all of the extra width of the big 245/40-15 ends up on the outside. So it's time to look at some real body modifications. entry 1134 - tags: tires, maxxis
July 1, 2015 - Track day! I was back at High Plains Raceway with the Z Car Club. Usually, this event attracts some pretty fast cars. But attendance was down and the top echelon didn't show up. There was one notable exception - a 60's 911 that had a bunch of modifications, including a MAST-built 7.0 l LS7 V8 stuck in the tail. We had some fun. I was quicker than he was on sweepers and I think I had the edge on him on high speed acceleration, but he had me under braking and on acceleration out of corners. It's hard to beat having all your weight on the rear wheels sometimes.
Otherwise, it was an exercise in passing and passing and passing. No worries, it's kind of fun to be Godzilla once in a while, and I had enough of a challenge dealing with my driving. The car was a rock star and didn't miss a beat all day.
The biggest problem was heat. It was a hot day - somewhere around 100F - and I was generating a lot of heat. Enough that I measured the temperature of the transmission tunnel at 196F and the heel of my shoe at 147. Yes, that was uncomfortable. After about 6 hard laps, I'd see the temp gauge start to move a bit on the dash, but that's still a very happy range for LS motors like mine. Even with 20 minutes on, 20 minutes off the track the car never flagged.
The brakes were much improved from a year ago. That's when I was boiling fluid and having to be very conservative. I've upgraded my brake ducting from 2" diameter to 3" and gone to 660F fluid. The brakes were still pretty hot and I wore out a set of front pads, but they never went away. I wasn't as aggressive as I could have been under braking at times - never my strongest point - but it wasn't due to a lack of braking power.
I love this engine. My maximum speed with the old one at this track was 197 kmh. Last time I was here, I had a headwind and peaked at 215 or 217. This time, I saw 222 kmh. That's a full 25 kmh faster than I ever managed with the old engine.
I had the prototype FOX suspension on the car. The Targa Miata was used as one of the development platforms, and this was the chance to get it out on the really fast stuff. After two sessions, I had it pretty dialed in and the car just felt fast and balanced. It's got great stability and fast turn-in, making the old rally-bred AFCO stuff feel surprisingly soft and wooly. I like it.
Video! Here's a clean lap, followed by the one lap I spent behind the 911. I had him on the straight, but decided to hang back and watch. Then he overheated.
This video is just a compilation of passes. NSX, Noble (or the new equivalent), new Corvette, WRX and a bunch of minnows.
THE DIARY
