Race recap! The weekend didn't go exactly according to plan, but it still went pretty dang well! The car didn't dish out a single issue, I set a new PB despite pulling off some of my aero bits to run TT5, and ol' girl was the fastest car on the TT grid that didn't have 8 cylinders!





Hang on, why's my name in TT3 class and not TT5? Well, my lack of attention to detail once again came back to bite me in the *** lol.

Saturday morning, I got on my first hot lap and slid into 1st place in TT5 class. F*cking sick, this was exactly what I was hoping for this weekend. I was ahead by a decent margin until Sergio Perez showed up in his full aero GR86 and posted up a lap just 0.4 seconds behind me. Holy hell, it was gonna be a tight one now! He ended up just behind me on grid in the final session and I was convinced he was going to see my line choices and use them to run me down. His car was running up on mine in the straights but I had him by a bit in the corners (for the time being at least). We went out and set two burner hot laps. He was hanging on to me but not quite running me down. Then, on our second flier, he dropped a tire into the dirt on the exit of turn 9, going at least 100mph, and called it quits. Whew! I did another couple hot laps and pulled in. We'd both beaten the lap record, and I managed to keep a half second lead on him, beating my PB by 0.2 seconds with a 1:29.62 according to the Aim. Hell yeah. What a sick way to end the day.



Unfortunately, I celebrated too early. The TT director audited both of our cars due to the lap record being broken I was DQ'd due to my fender cuts. D'oh! That's my fault entirely. Fender cuts aren't explicitly spoken about in the rules, but the TT5 ruleset implies that only factory aero is legal aside from airdams, hood vents, splitters, and wings. Again, I should've asked for a second opinion before I chopped up my fenders. Sergio took the W in TT5 along with the new lap record, and I got bumped into unlimited class for Saturday, still taking 3rd place out of 8. I almost wasn't even mad just because of how awesome our last session was.


Excellent midday nourishment.

Sunday, I had the option of racing TTU again or moving my car into TT4. There weren't any competitors in TT4 and my times were putting me in the mix with the TT3 gang, so I told the director I'd like to race TT3 for the day. The NC was only 120whp below it's class limit of 300whp I ended up getting right in the mix with the TT3 midpack. Session 1, I set a low-1:30, but went out with too little gas and fuel starved the car after 4 laps. Session 2, I set a solid 1:29.98 on the first flier, but a rollover incident shut down the rest of the session and I didn't get any more laps in. The following sessions got warmer and I couldn't get myself to run anything under a 1:30.4. That being said, the car and lap times for both sessions were very consistent, which was still worth being stoked on.


Little bit of data review between sessions.

At the end of Sunday, I placed 4th with that 1:29.98, with less than a tenth of a second separating 2nd and 4th place! Willow Springs is much more forgiving to drive in a light, low power car than a big V8. I have no doubt that I'd get smoked by these guys at any of our other tracks, but it was sick seeing the car punch way above its weight and hang with the big boys this weekend!

NASA has also been doing a new sub-category in TT for the last year. TTT takes the delta of a driver's fastest time for each session and adds them all up to determine who ran the most consistent fast laps of the weekend. I won that on Sunday and took 5th place on Saturday. Racers only qualify if they run all four sessions of a race day, so not all of the TT field is included. That being said, I'm still pretty amped on it.



It's been quite a few track weekends in a short time and I'm going to take a break until the next MTTC race at Las Vegas Motor Speedway in April. The car doesn't have any glaring issues to address but I have a grip of modifications I want to bolt up in the next few weeks. I'll finally be tossing in the 6 speed and SuperMiata clutch this weekend, then the ID1050s and E85 tune whenever I receive the file from Fab9. I'm also currently maxed out at 3.3* of camber in the front and obtained some poly FUCA offset bushings from a buddy to squeeze another 1/2* of camber at my current ride height.

The updates will continue as I tear into the car in the next few weeks!

 

Great results! It's always fun to punch above your weight...

Aside from the 1st place car, you were right in the mix for the podium. Pretty solid for being bumped up two classes.

 

Thanks Roda! Guess punching upward has always been the name of the game for Miatas haha.

And no joke, only half a sneeze away from that podium! Anything I can say now will just be excuses, but very glad to know the car's not far off. At the other tracks around, the same TT3 guys have me by another 2-3 seconds. With another 60 horsepower though...

 

Nice work out there. Bummer about the fender cuts but rules are rules I suppose.

That Aim data looks super cool. I love having data to look through. We have some stuff for autocross but I don't think it's nearly as professional as what you've got there. If there's a discrepancy in lap timing between the track and the Aim which one do you (personally) use/quote? I'd assume the track's time, but haven't ever come across that issue.

 

Yeah, at the end of the day it's my responsibility to know the ruleset, so can't really be mad there haha. Won't make that mistake again, though.

Dude the Aim is a game changer. Might be harder to use for autocross since you're running a different course every time, but running through the data between sessions (and comparing it to previous weekends' data if you're at the track) is super valuable. I'm definitely not using it to maximum potential, but it's pretty easy to take a look at your three fastest laps and see what line/braking zone/etc was fastest for a session. Plus the predictive lap timer gives you feedback on your line choice/driving in real time.

Funny you'd ask that. I've never run into a conundrum with the discrepancy in lap timing until this weekend. Normally, I'd just take the fastest time from the two and say that was my PB. This weekend, though, the transponder read faster (1:29.569) for my fastest lap. I ended up going with the Aim data's time though, since my buddies and I are all pitting our Aim data against each other. Felt like cheating to tell them I ran a 1:29.57 and then send over an Aim file of a 1:29.62 lap lol.

But it's also .05 of a second and I'm still a couple years off from my F1 career debut, so who cares right?

 

Sometimes the location of the transponder timing point (start finish for lap timing) for a given track organization is in a slightly different location than the AiM track map. With the fluctuations in speed on a given lap at a given point on the track, this can tip a few hundreths/thousandths of a second back and forth between a lap timed by AiM vs. the transponder. Also, being GPS based, there can be some discrepancy in the AiM data compared to the transponder. In my experience, it's usually just a very slight difference and doesn't matter much when looking at data. Transponder rules for official timing, though.

 

Yeah, the transponder works off a physical timing loop (wires embedded in the pavement), whereas the AIM is just looking at an imaginary point defined by lat/long and there's no requirement that they be the same. You can actually move the S/F location in the AIM analysis software if you want, and it will recalculate all of the lap data based off of it.

One thing to be careful of when comparing data between different days (or even morning vs afternoon!) is that conditions matter a lot. Most California tracks get 1-2 seconds slower in the afternoon when it warms up, and the amount and type of rubber laid down by whoever was there last week also makes a big difference. Assuming you're comparing dry-vs-dry, the shapes of the curves usually don't change by much and the locations of the important parts of the corners (brakes on/off, turn in, min speed location, etc) will be pretty close, but you can easily be 2-3 mph slower entering the corner due to higher temps meaning less power, and actual min speed (in mph) can move change a bunch with grip level.

--Ian

 

Huh! Never knew that, but probably should have. I totally assumed the transponders just worked off of GPS as well. Good to know. I'm gonna go off of the faster transponder PB time for this weekend then, lol.

I'm up to speed on the temperature variables. Didn't want to clutter my previous response but I have been adding notes to each of my Aim sessions with ambient temps. My NC seems to get a decent bit slower as temps increase compared to my turbo NA, and I remember @Fireindc said the same of his buddy's NC as well. Weird. But yeah, definitely a big factor that I'm aware of.

Regarding rubber laid down on the track, how/when does the base rubber layer change or reset? It rained in the high desert all last week until the night before the event. Obviously there's variables with the rain, but would three days of cold/moderate rain "wash" the rubber layer off the hot line?

 

Interesting info. For autocross the people who are running data are using 10hz GPS modules that connect to tablets/phones via bluetooth. I would assume the AIM is probably a similar refresh rate.

Z, for autocross most people walk the track in the morning with their tablets, or at least set the start and finish points in the app. The accuracy is pretty good and the data is useful enough to be able to tell where you're losing or gaining time compared to others.

 

My experience with desert tracks is the more they get used, the better the traction. Dry and windy will deposit a lot of dust/sand on the surface that will need to be cleaned off, rain before an event is usually a good thing, but it will take a bit of running for the track to start to 'rubber in'. As Codrus noted, the earlier the lap, the better. Once things start warming up, lap times will get longer.

 

Both ambient and track surface temperatures are relevant -- ambient affects power levels, track surface temp will affect the grip. F1 teams have people go out and measure the track surface temp every 5 minutes or so, but that's probably overkill. . Basically, would be worth adding sunny/cloudy/mixed to your notes.

The type of rubber on the track depends on what kind of tires were being run by the previous people who were there. If it was Lucky Dog then you've got lots of Hankook RS4, SCCA will leave behind a lot of racing slick rubber, etc. How much this affects the tires can vary a lot, but in general a tire is going to be happier the more rubber that's similar to its own compound has been laid down. There's not really any way to measure it, about all you can do is jot it down in the notes and use it as an excuse for when your times are slow.

--Ian

 

Current AIM devices are a minimum of 25 Hz, I believe.

--Ian

 

LOL - True!

 

This might be the most pertinent information in the whole thread. Thank you.

Currently going down a rabbit hole regarding track temps and their relation to tire temps, etc. Thanks for kickstarting that train of thought for me. Sounds like I gotta gather some more tire temp data and figure out what these RC1's like (or just look it up I guess). I was running around too much this weekend to do much testing and tuning aside from adjusting my hot tire pressures. All I know currently is that these tires seem to hook up best at 33psi hot, but it'd be good to know the optimal track temperature for these things as well.

 

The one time I raced Willow Springs with Lucky Dog, the morning times were better than the afternoon because of the wind on the main straight. I lost at least 5 mph on the main straight in the afternoon. That was with a turbobrick though, not a Miata.

 

Yeah, wind speed (and direction!) can make a big difference too, especially if you've got aero on the car.

The best time for testing is, unsurprisingly, a test day. Buttonwillow has a decent number of them, and if you go to one that isn't right before a super popular event you can run all day with no sessions and limited other traffic for $350. They also have "semi-private" days that are about twice that much, but happen essentially every Mon-Thursday and often have fewer than 10 cars there total.

--Ian

 

Noted! Yeah, I've never done an actual test and tune at BW or any of our other tracks, but have done similar with some of the low car count/open track day organizers. Back in January, I did a day at Willow Springs with Speed District that included five run sessions followed by 3 hours of open track at the end of the day. So nice going out for three hot laps at a time, making adjustments, and still feeling like you got your money's worth at the end of the day. Great point, I should probably sign up for another event like such now that the car's running different tires and stiffer sway bars.

So I was going to wait until next weekend to install the Whiteline poly offset FUCA bushings I've been sitting on, but I haven't messed with the car in a few weeks and decided I'd knock 'em out sooner. I didn't enjoy installing all the poly bushings on my NA, and wasn't looking forward to doing these, but the car was maxed out at 3.3* camber up front. Based on what I've heard from others and what I believe based off the pyrometer readings, I needed to up my camber numbers a bit.

The NC control arm bushings suck a little bit more to remove versus the NA/NB units. Instead of the OD being rubber, they use metal sleeves. I melted out the inner rubber part with a blowtorch, then ran a hacksaw blade through the ID of the control arm, made a few cuts in the outer metal bushing, and tapped it out using a hammer and punch. It took way longer than it sounds, but it worked.


My hands aren't greasy, your hands are greasy.

I kinda assumed that because the extra camber was being generated by the upper control arm placement only, front toe wouldn't be heavily affected. I was wrong. After putting the front of the car back on the ground and rolling it out, it was pretty obvious that the front end was toed out. My roommate and I spent fifteen minutes with a couple flashlights, eyeballing and adjusting the toe so I could drive the car 10 miles to work today without murdering the tires. I ended up toeing in each tie rod one full rotation. By an act of god, I put the car on the alignment rack this morning and found that we somehow f*cking nailed it.


Steering wheel was only a couple degrees off center as well.

Another small positive, Whiteline advertises these bushings as adding a half degree of camber, but they added 1.1* on my setup. I don't foresee ever going over 4*, so it's good to know the car likely won't end up maxed out on front camber again.

Was in a bit of a time crunch this morning, so I only did the front alignment for the time being. Next week, I'm going to bump the rear up to 3.0* camber and fix the left rear toe. Here's what I ended up with in the front for now, though.



I ended up having to order a shifter bushing and reverse lockout plate for the 6 speed. Both parts were shipped earlier this week but got delayed. Assuming they show up tonight, I'll do the transmission swap this weekend. Fingers crossed!

 

FWIW, toe plates are pretty cheap (you can get a no-name set for less than $50 on Amazon). It's worth having a set "in the trailer" (or where ever you keep your track tools if it's an open trailer) as a good way of doing a quick check after an off-track excursion or a big curb hit.

--Ian

 

Nice numbers man! Good work on the eyeball alignment as well. I grabbed my tires out of the basement yesterday and there was a ton of wear on the outsides, so I might be joining you in the camber game pretty soon.

I missed the bit about the transmission swap. What are you going to now?

 

100% agreed for how often Zak does the Trak Attak, and it's way better than running through the paddock trying to find anyone with a set.

If your camber bolt slips, just use your previous toe settings as a barometer for where your camber is at. If the toe matches before and after, the camber will be pretty darn close.