Recently ran a 69 second lap as my fastest, how much would I realistically expect to shave off on a course of similar length with something like kumhos or even re71s.

Edit: thanks all, sounds like around 3 seconds which would have had me pretty squarely in the competition. Looks like my wallet will be getting a bit lighter soon.

So this coming weekend will be the first time I've done this with TW200 tires, specifically RE71RZ's. So far this year I have 6 weekends and about 90 runs on 5-year old Michelin Pilot Sport 4s's (which were finally at end-of-life), and I've been coming along nicely and improving things, and I feel like this is a reasonable "next step" ...

That said, I have read MANY times that tires like this are "a game changer" and "will take A LOT of time and practice to get used to" to take full advantage. Great!

So then, could any more experienced drivers try to explain how I should be doing things differently? What old behaviors should I try to not repeat? What new behaviors should I my trying to do? Any other advice or tips? Thanks!

Hey all. do you get tired of staring at a raw time knowing one run was faster but not really knowing why... ? Are you carrying more speed out of the corners, breaking too hard or too early?

I've been building a small app called ExitSpeed that logs the speed you carry through and out of each corner, so you can line up two runs and see where you actually gained or gave it away.

It's early and I'd rather build something people want rather than guess in a vacuum, so a few honest questions for regulars:

- Do you already track this with something (RaceChrono, TrackAddict, an AiM, a Solo box)? What's missing for you?

- Is per-corner speed the useful number, or do you care more about something else?

- What would it take for you to trust phone-GPS numbers enough to actually change something in your driving?

Happy to let anyone who's curious try it as I'm in beta mode and need testers ! ( DM me if you want it, only on Android)

Have a nice end of weekend

If you're in an autocross class that could change gearing (be it final drive, gearset, tires, any combo or all of the above) what top speed in 2nd gear should you aim for?

In this scenario, it's build it and leave it type of deal for the hobbyist. Not a multi million dollar firm where there's a specific gearset and final drive for every venue.

What's the ideal 2nd gear ratio where in 99% of courses you won't have to upshift to 3rd if it's too short of a second, or where you won't be tempted to go to 1 if you're bogging too much in the slower sections.

Hey everyone,

First, I'd like to note that my last post was definitely generated with the help of AI. I'm not a marketer, I'm a software engineer, so I thought I needed some help. Clearly, I was wrong, so this one is just me rambling on and using a bit of Grammarly (yes, it suggested I capitalize this word, for example) to help catch spelling and comma issues. I hope that's all right.

A while back, I posted here about the timing software I built during the off-season. That post got a bunch of helpful feedback, plus some skepticism, which honestly makes sense. Timing software doesn’t matter if it craps out on event day, no matter how nice the UI looks.

The main thing I’d like to share today is that it’s actually been used at real events. liveTiming.club has handled timing for three SCCA events, got used last week at a DriveAutoXtreme event, and will be running Summit Racing Autocross Week too.

The DriveAutoXtreme event was kind of the real test, though. It ran without any timing issues, drivers actually liked the mobile and live stuff, and the best part is someone with zero timing experience ran the whole thing, and it just worked. Which is very exciting to me, as that was basically the goal: timing software that doesn’t require a single timing person with 10 years of experience to run the event safely.

Since the last post, my partner and I have added a bunch of stuff beyond just basic timing:

• Event schedules, including multi-day schedules
• Run groups and work groups
• Worker assignments
• Custom leaderboards and scoring
• Participant-input scoring for special formats (like dial-in)
• Better multi-day live timing pages
• A bunch of timing sync, queue, restart, and serial-detection fixes

Custom scoring is probably the biggest new thing. A lot of clubs run formats that don’t fit into the usual “best raw time” or “best PAX time” buckets, so I want liveTiming.club to handle those without making people mess with spreadsheets after the event. In addition, all of this is done live; participants no longer have to wait until after the event for the results.
 
Timing, live results, schedules, run and work groups, custom scoring, and the driver stuff should all feel like one system, not a pile of duct-taped workarounds.

If you’re a timing chief, club admin, or just a driver who cares about a better experience at your events, I’d genuinely appreciate you taking a look and poking holes in it.

Hey everyone, I'm new to autocross (only one event so far) and I was looking for advice on tires. I used to live in a climate that occasionally got snow so I have both all season and summer tires, 540 and 320 treadwear respectively, and on my first event had the all seasons on. Do you think it would be more beneficial to continue learning on the 540s or should I swap to the 320s?

Thanks to everyone that tried and experimented with conecanvas.com in my earlier post. The feedback was great and I've implemented some of the changes already, check it out.

Here's a quick rundown of the updates....

This release makes the simulation more honest. Speed, time, and radius readouts are now computed from a realistic driven line instead of the hand-drawn path. It also adds a set of course-design aids (guide circles, sticky notes, turn-radius detection, and lot/view rotation), gives the course library a major usability pass, and fixes the cone numbering bug.

Realistic driving-line analysis

• Physics now runs on a derived driven line, not the drawn path. The drawn path is treated as a sketch: it gets resampled and smoothed within a ±4.5 ft corridor (pinned through gates), so hand-drawn wiggle no longer reads as tiny-radius corners or inflated course length. Real corners survive, noise doesn't.
• Speed profiles start from a standing start, and slalom spans use a sinusoid-line radius model, so the estimated run time is an honest one. Course length and time in the Stats panel are now simulated from the driven line and the speed profile for your selected reference class (Stock, Street, or Mod).
• Turn-radius circles (Experimental). The app auto-detects each near-constant turn of the driven line (at least 10° of sweep, radius under 200 ft, slaloms excluded) and overlays a dashed fitted circle with an R label. Lives in the new Experimental panel in the Review tab while it bakes.

New canvas tools

• Guide circles (K). Nationals-map-style template circles for measuring radii and arcs. This is a pure measurement aid that never places cones. Selecting one opens a floating, draggable panel with a radius input, sweep-angle presets, and an arc-length readout, and the canvas labels show R and the sweep arc.
• Sticky notes. Drop free-text notes anywhere on the canvas to annotate a spot. Drag to move, resize from the corner, and they pan, zoom, and rotate with the map.

Lot & layout

• Rotation controls in the Lot panel: rotate the view, rotate the event layout (staging, grid, and ProSolo structures) in 90° steps, or rotate the course geometry itself.
• New event-zone kinds: spectator and timing areas.

Library overhaul

• Saved courses now show PNG thumbnails (rendered from course data, so they stay small).
• Rename courses, search by title, and sort by Recent or A to Z.
• A save-state line tells you whether the editor has unsaved changes versus the library copy, and a "Save as new copy" button forks the current course.

Cone numbering fixes

• Fixed: repeated 101 through 107 blocks. The old renumbering treated every stamped element (slalom, chicane) as its own phantom section, so each stamp restarted at 101. Renumbering now attributes stamped and hand-placed cones to real sections by section-flag position along the course. Place a flag for each section and cones number correctly as 101…, 201…, 301….
• Stale numbers are cleared. Re-running "Renumber cones" on a course numbered by the old algorithm no longer leaves the broken numbers on screen. Any cone that can't be attributed to a section has its old number removed instead of silently keeping it, and the toast reports how many were skipped.
• Courses with no sections at all get a plain 1 to N sequence in driving order rather than nothing.

Hi folks, I'm regularly 5-6 seconds slower than a comparable miata. I have a ND Miata, stock tires, capable of handling 1G. Please help me improve 3 things to get faster the next time. (Edit: I want to get faster with my existing setup)

My hypothesis:

1] Car is capable of 1G, but I'm mostly at 0.7 - 0.8G in corners. This means I can enter corners faster (brake later, less etc).

2] I'm not on gas at the Apex

3] Some of my lines are not correct, eg: not backing cones in slalom hurting my speed.

Here is my video: https://youtube.com/shorts/ugMDDqCq_5o

More details about the car:

Tecna GT coilovers, set dampers to middle.

Precision alignment 1.8 Front, 1.5 Rear camber

https://reddit.com/link/1ukc524/video/vp3hw1in2kah1/player

I'm still learning how to use the RE-71RZ's. Sticky tires are a game changer for autocross but the learning curve is steep.
As usual for these courses my car is stuck between first and second gear. Decide when to downshift or not requires a little trial and error. With only five runs, I need to accelerate how fast I learn the course.

Hi all - My question concerns some abnormal tire wear I noticed after autocrossing my 2006 Miata this weekend.

First, some background. (Sorry for the long post, but I want you to have all the information so you can provide good answers.) I’m relatively new to A/X, and I got the car during the winter. It’s mechanically in excellent shape. It's all stock. This is my first season autocrossing it. I’ve done one school and three events so far this year. I use the car almost exclusively for A/X; I have another vehicle as a daily driver. So, the tires have about 500 miles on them, including drives to and from events.

The tires are Continental Extreme Contact Sport 02, in 205/45-17, bought new. Treadwear Rating is 320. The car was aligned to factory specs. On the street, it tracks and drives fine. No wandering, no vibration, etc.

Now, the issue. During an A/X this weekend, I drove the car a little harder than in the past, because I’m trying to learn its limits and, of course, improve my times. We got seven runs. On the last two runs, I could feel the tires (probably the fronts) making a chattering sound and feel during some of the turns.

I asked one of the experienced drivers about this, and he said it sounded like I was experiencing oversteer. That is, I was taking the turns too fast, so that the car wanted to keep going straight, and that’s what caused the chattering. The solution, he said, is to either take the turns slower if I was going to continue taking that same line through the curves, or to change the line I was taking through the turns.

When I got home, I actually looked at the tires while I was checking some other things. That’s when I noticed that on both front tires, the outer tread (second from the outside tread), had a dip in it, as shown in the attached photos. That is, instead of a smooth arc from one side of the cross-section of the tire to the other, there is a noticeable dip that seems to indicate that I actually wore a significant amount of tread off. (I discovered it when I was rolling my hand over the tires.) So that part of the tire may not even be contacting the road.

It’s possible that this has been going on for awhile, and that I never noticed it before. But I am somewhat doubtful. (I’m pretty observant.) Then again, it also sounds odd that a few runs in A/X would have done this.

My three questions for you:

1. What are your thoughts on the cause of this? (I assume that it’s not normal.)

2. Are the tires still usable for A/X?

3. How do I prevent them from getting worse?

I know this is difficult to diagnose based on a couple photos, but I thought I would give it a shot.

https://preview.redd.it/260lr99qliah1.jpg?width=2000&format=pjpg&auto=webp&s=54f8eb3a183df88c9fec5afc2a513dbb1fe58b79

https://preview.redd.it/bq80la9qliah1.jpg?width=2000&format=pjpg&auto=webp&s=c688aa38e2781ae2a7839ba547a22a5db3921edd

Thanks in advance.

Hey everyone,

I’m looking for feedback/reviews on an EBC brake setup for my 2011 Corvette Grand Sport.

My intended setup is:

Front: EBC Stage 27 Kit (EBC SG2F Rotor-piece floating slotted rotors and EBC Bluestuff NDX pads)
Rear: EBC Stage 6 Kit (EBC GD slotted and dimpled one-piece rotors together with EBC Bluestuff NDX pads)
The car is used for street driving, autocross, and occasional track days. I’m not building a full-time track car, but I do drive it hard at events, so I’m mainly looking for feedback on this setup or if someone else have done it and have a feedback?