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Autocross- SCCA EV-X Class vs. SS

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@M3Pdude - Nice! I have a C8 deposit ready for an order, and I'm seriously considering the same switch as you.

You should really run in SSR at nationals. I don't know what is going on there, but that class seriously needs someone to show what a C8 can do with some hoosiers. The fastest SSR C8 on hoosiers ran a full second slower than the fastest C8 on 200TW and 5 seconds slower than the fastest SS cars!?

I'm really hoping someone can show that the C8 is a competitive SS car because it's frustrating if the only car you can win SS in is a $200k+ limited edition Porsche that has a 3 year allocation waiting list.
Do it!! This car is so fun!

I will be putting hoosiers on it at some point. Not sure if it fits in SSP or SSR, but either way I think it will be competitive on hoosiers. I have three events now on a fresh set of stones and it doesn't suck. I got my buddy in his GT3 on a short course and got top PAX. But then got beat up by him another GT3 this past weekend. All fun and friendly competition.


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But the fastest driver in a M3P was driving another class. Cameron was significantly quicker in the finale.
Hi Justin!

I'm not sure of your point. Cameron ran Solo in a BRZ so we have no idea how quick they are in a M3P in standard autocross.

They ran in Pro Solo in a M3P, but in S4 which is a PAX class due to low attendance. Pro Solo has a completely different PAX system, called PSI, which is probably a good idea given the launch a Pro Solo takes advantage of, as well as the shorter courses that Teslas tend to excel at:

Worth noting that Cameron didn't beat SS RAW in Pro Solo either, yet the EV-X Pro Solo PSI is significantly harder than SS. So I still think that the EV-X PSI is wrong just like EV-X PAX/RTP is wrong.

Either that or I guess we're back to everyone that drives a Tesla is a slow driver, and if they win a class now and then it just means other drivers were even slower ;)
 
Hi Justin!

I'm not sure of your point. Cameron ran Solo in a BRZ so we have no idea how quick they are in a M3P in standard autocross.

They ran in Pro Solo in a M3P, but in S4 which is a PAX class due to low attendance. Pro Solo has a completely different PAX system, called PSI, which is probably a good idea given the launch a Pro Solo takes advantage of, as well as the shorter courses that Teslas tend to excel at:

Worth noting that Cameron didn't beat SS RAW in Pro Solo either, yet the EV-X Pro Solo PSI is significantly harder than SS. So I still think that the EV-X PSI is wrong just like EV-X PAX/RTP is wrong.

Either that or I guess we're back to everyone that drives a Tesla is a slow driver, and if they win a class now and then it just means other drivers were even slower ;)
I am just saying you are pick and choosing the results. Cameron is obviously the quickest EVX driver, his result at the finale shows that. You choose to use the national results to make your point about the EVX pax when the fastest EVX driver isn’t there.

Also, it sounds like just because Cameron didn’t get top pax at the finale, you think that EVX should have a softer index than SS. So is pax only fair if a EVX car finish top PAX at a national event? The matter of fact is that EVX is a supplemental class, PAX should be harder for the class until there are enough competition's and development to show otherwise.

I honestly don’t care about PAX, but PSI is highly related to PAX and EVX runs in a national class with recognized classes.
 
I am just saying you are pick and choosing the results. Cameron is obviously the quickest EVX driver, his result at the finale shows that. You choose to use the national results to make your point about the EVX pax when the fastest EVX driver isn’t there.

Also, it sounds like just because Cameron didn’t get top pax at the finale, you think that EVX should have a softer index than SS. So is pax only fair if a EVX car finish top PAX at a national event? The matter of fact is that EVX is a supplemental class, PAX should be harder for the class until there are enough competition's and development to show otherwise.

I honestly don’t care about PAX, but PSI is highly related to PAX and EVX runs in a national class with recognized classes.
Cameron is quick. Let's imagine that he did not hit a cone on his best East course run and took 3rd in STX. Let's then imagine he ran the same PAX time in a Tesla. And then adjust to the .838 hypothetical PAX. He'd still be down in ~100th spot. I don't see how your theoretical point "the quickest Tesla driver did not run" changes the main thrust of GC's argument.

Additionally, Cameron's hypothetical winning time in a Tesla (114.44ish) would've still been 0.6% slower than the top SS time, right in line with GC's suggested SS/EVX PAX delta of 0.006.
 
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This wouldn't all happen to be about the fact that if we made EV-X PAX 0.827 like the data says, then top EV-X would have PAX'd 2nd in STU just ahead of the #188 car instead of 6th behind the #88 car, would it? ;)

I am just saying you are pick and choosing the results. Cameron is obviously the quickest EVX driver, his result at the finale shows that. You choose to use the national results to make your point about the EVX pax when the fastest EVX driver isn’t there.
I'm not picking and choosing. I'm using the exact process Rick uses to set PAX. PAX is calculated by looking at actual results at actual events, and comparing how the classes did. Rick has a reasonable way of excluding events where no top-tier driver showed up, but that logic wouldn't apply to EV-X at nationals even if you dropped the 1st or even 2nd place drivers. Rick's method is not to manually identify the fastest driver in each class and then only use their times when they happen to run and then ignore all other events, or to theorize what that driver would have run if they had.

Well, except for the fact that was exactly what Rick was doing to EV-X a year ago, using the exact same biases you have about "supplemental classes". He found some great driver in a Model 3 in a tight 27 second course in AZ, decided that all of EV-X PAX should be based on that, and off to the moon we were with EV-X PAX, climbing WAY above SS. I showed him how unfair this was, and to his credit he agreed and adjusted the 2023 PAX to something much more supported by data. And now that 2023 is basically over, we have even more events with EV-X participation, and that data shows the 2023 PAX is still too high, at least relative to SS and AS.

As someone that does Solo and Pro Solo a lot, you know Pro Solo is very different, and that's why they have different PAX/PSI systems and numbers. Using Cameron's numbers when he got 7 runs on the course and set his best time on the last run doesn't align with 3 runs in normal Solo. This is especially true when 0.3 seconds in Pro Solo can easily be your reaction time. We also know the Teslas do better when acceleration is involved and Pro Solo has that in both the launch and the shorter course.

Cameron clearly has skills and might have won the normal Solo, but we'll never know. But you can also look at the SS Pro Solo and see that Greer won Pro Solo but came in 4th in Solo. So is Greer or Yom the better driver at Solo? You going to claim Greer is better because of his results at Pro Solo despite getting beaten at the actual Solo? What about Damhoff and Likert swapping places between Solo and ProSolo in AS by a huge margin? What about Vajdak, Herrick, Green and Waldbaum all moving around in SSC?

It's far from "obvious" who the quickest driver is when you try to bench race apples and oranges. We had a good set of drivers in the Solo event, and PAX says that's what we look at, not trying to theorize what Pro Solo driver would have done in Solo. Are you claiming that if Goode had just run EV-X in Solo it's unquestionable he would have run 1.3 seconds/1.2% faster than the top EV-X driver and beat the top SS time, and that if we had put Mudge in the EV-X car it would have gone even faster? Just imagine how fast it could have gone with the top PAX driver (Larry MacLeod in KM) in an EV-X!

Also, it sounds like just because Cameron didn’t get top pax at the finale, you think that EVX should have a softer index than SS. So is pax only fair if a EVX car finish top PAX at a national event? The matter of fact is that EVX is a supplemental class, PAX should be harder for the class until there are enough competition's and development to show otherwise.
Given I'm only discussing Solo PAX, I am making no arguments about Cameron's results in Pro Solo.
However, the fact remains that in Solo, no EV-X has EVER beat an SS car, and is generally closer to AS times than SS times. And per Rick's method, this means the EV-X PAX should be closer to AS than SS, not the same as SS or even harder.

It's unfortunate to see another Autocrosser doing the "EV is a supplemental class, screw them!" attitude. PAX is math. It should not have a bias. The SCCA has already buried the Stock Model 3 in SS where it is irrelevant so it doesn't upset anyone in any stock class. PAX is all we have to compare. EV's are the future of mass passenger vehicles in the USA, and giving them a hard PAX just because you don't like them isn't doing the sport any long term favors. We happily adjust PAX in SS when the GT3/GT4's show up and become the dominant car (0.817 in 2018 to 0.833 now), even though those are low volume, $200K+ cars that can't show up at most local events because few can afford them. Why can't we be equally fair to the EV-X class, based on actual affordable cars? Why isn't a 2018 Model 3 performance the same kind of neat, affordable, daily drivable performance car a 2006 STi is? Don't these cars form the actual foundation of the SCCA solo program? (the 2006 STi cost more than a 2023 M3P FYI)

I honestly don’t care about PAX, but PSI is highly related to PAX and EVX runs in a national class with recognized classes.
Well, I do care about PAX, because in a lot of regions only a few Teslas show up, and thus the only way to understand the class of the driver is via PAX. And all I want is PAX to be fair and set the exact same way PAX is set for every other class. Sure, I would prefer that we had so many Teslas showing up that they could just compete amongst themselves, but even SFR has to run a lot of PAX classes to give people some competition.
 
Sunday was event #7 on the year. These 660's are well beyond their service life so I lent a seat to a buddy again who has been autocrossing FWD cars for 20+ years. Was interesting seeing him adapt to the car but couldn't keep it off of the cones, mainly from sliding the rear into them lol. He scratch timed quicker than I ran clean.

My best run

Me vs Dave comparison on our best runs (his best scratch). Interesting that he peaked 7mph more than I did in the front section but I reeled him back in at every major turn. He hit the first cone in the slalom before finish in this run.

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@M3Pdude
You should really run in SSR at nationals. I don't know what is going on there, but that class seriously needs someone to show what a C8 can do with some hoosiers. The fastest SSR C8 on hoosiers ran a full second slower than the fastest C8 on 200TW and 5 seconds slower than the fastest SS cars!?
National killed SSR by asking if it should be earlier in the year. All but 1 of the regulars left the class through out the year. Overall PAX shows a lot about drivers ability. 2023 was probably the last year for SSR.

And if you are even more curious about driver ability/PAX you can scrutinize this guys ranking system: RANK: v23.08.21
 
And if you are even more curious about driver ability/PAX you can scrutinize this guys ranking system
That's just re-mixing the biases in PAX, and the prep level of cars in low participation / pay to play classes. It feeds back on the very issues in PAX.

Any ranking system that proposes that the best drivers happen to be in AM and EM, both hyper modified cars which always dominate PAX when they show up, isn't working very well. This is just showing that EM PAX is really low, which is a natural outcome of the way PAX is calculated across the thousands of events per year across the USA which rarely have EM cars show up.

At nationals this year, the top PAX times looked like this:
KM, FM, DSP, STR, STR, STR, SMF, DSP, XP, CAMS, CAMC, XP, DM, EP, DP, KM, STS, STR, STS, CAMT, FSP, SSP, STR, SS...

You can see the issue here- there are 5 STR drivers before the first SS driver. Do you really think that 3 of the top 5 AutoX drivers just happened to pick SSR cars, and that there are 24 people in modified cars that are better drivers before we hit the first street car? And that if we put any of those DSP drivers in an SS car, it would have run over a second faster when the 1-2-3 gap in SS wasn't even a second? Oh, and that the 1st and 3rd fastest drivers at nationals just happened to be in the same Kart, but this was driver skill, not the vehicle? It's sure weird how often two drivers in very modified vehicles tend to perform very similar.

It's just the reality of how any real PAX system will work, and why all I focus on is EV-X vs SS and AS PAX, because those are the most common and related cars to ours. Trying to use PAX to actually compare a GS car driver to a KM kart driver is pretty pointless. But I agree it's a fun spreadsheet to mess with.

However, I do agree with Bryan at the top. That guy is not human. Watching him gap the rest of STX by 2.2 seconds at Crows was amazing. Yet supposedly he was only the 4th best driver by PAX at that event....
 
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That's just re-mixing the biases in PAX, and the prep level of cars in low participation / pay to play classes. It feeds back on the very issues in PAX.

Any ranking system that proposes that the best drivers happen to be in AM and EM, both hyper modified cars which always dominate PAX when they show up, isn't working very well. This is just showing that EM PAX is really low, which is a natural outcome of the way PAX is calculated across the thousands of events per year across the USA which rarely have EM cars show up.

At nationals this year, the top PAX times looked like this:
KM, FM, DSP, STR, STR, STR, SMF, DSP, XP, CAMS, CAMC, XP, DM, EP, DP, KM, STS, STR, STS, CAMT, FSP, SSP, STR, SS...

You can see the issue here- there are 5 STR drivers before the first SS driver. Do you really think that 3 of the top 5 AutoX drivers just happened to pick SSR cars, and that there are 24 people in modified cars that are better drivers before we hit the first street car? And that if we put any of those DSP drivers in an SS car, it would have run over a second faster when the 1-2-3 gap in SS wasn't even a second? Oh, and that the 1st and 3rd fastest drivers at nationals just happened to be in the same Kart, but this was driver skill, not the vehicle? It's sure weird how often two drivers in very modified vehicles tend to perform very similar.

It's just the reality of how any real PAX system will work, and why all I focus on is EV-X vs SS and AS PAX, because those are the most common and related cars to ours. Trying to use PAX to actually compare a GS car driver to a KM kart driver is pretty pointless. But I agree it's a fun spreadsheet to mess with.

However, I do agree with Bryan at the top. That guy is not human. Watching him gap the rest of STX by 2.2 seconds at Crows was amazing. Yet supposedly he was only the 4th best driver by PAX at that event....
Wasn't directed at you as you well know PAX is a perfectly imperfect system by definition haha.

Just wanted to help show some justification for SSR results and other "anomalies" pointed out. While the RANK system has the same pitfalls as PAX, it does have some value especially when arguing about who is a fast driver.
 
Both front outside brake bleeding nipples seem to be seeping or leaking, is this normal? Noticed after two quick back to back ax/track sprint runs with hard braking and very high heat. No long term noticeable effects, fluid level ok, later runs did not produce additional leaks. Should I look into replacing these bleed nipples or just re-torque when I flush the fluid?
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Can we talk about spring rates optimized for AutoX?
Generic guidelines are to aim for 2.0-2.2 Hz for an Autocross car. But calculating this and damper tuning requires a lot of knowledge of the suspension geometry of the car as well as other data.

Does anyone have good measurements of the car or data to share here?

I'll start with what I know:
Weight on Front tires: 1025 lbs (465 kg) (from my own corner weights on a 2018 M3P, no driver)
Weight on Rear Tires: 1010 lbs (458 kg)

Here's what I know less:
Front Motion Ratio: 0.67
Rear Motion Ratio spring: 0.56
Rear Motion Ratio shock: 0.94

I did the motion ratios by measuring the inner pivot to the outer ball joint, and then the inner ball to the spring centerline. But these are pretty low motion ratios.

What is interesting to me is that if I use my KW V3 stock spring rates of 8.2F/9.2R (kg/mm), I get:
1.4Hz Front
1.25Hz Rear (but a progressive spring)

Offhand I have heard people mention 10k or 13k front and 12k or 16k rear as optimal for AutoX. These give 1.5-1.7Hz Front and 1.5-1.65 rear. But this is still lower than 2Hz by a lot. You'd need 19F/26R to hit 2.1Hz.

This site lists many supposed spring rates for Model 3 suspensions: Guide: Tesla Model 3 Coilovers

Interesting to me that almost every one listed is well over 10k front, yet my KW V3's clearly have 80-70-250* printed on them, which should be 80N/mm, which is only 8.16 kg/mm. Maybe the KW V3's are just really soft springs and a bad choice for AutoX?
But then Redwood in their most aggressive kit only uses 11k/12k, so it's not like Redwood/Ohlins thinks we should be running super stiff springs either. (Ohlins R&T Coilovers with Swift Springs!)

Anyone now if my motion ratios are right, or have other input on picking better spring rates? Why am I ending up with such low frequencies? Is there a reason the M3 chassis doesn't want such high frequencies?
 
Those are pretty close to the motion ratios I've been able to find as well. I'm working on my tesla uprights now and will take apart the car to measure directly soon.

Your numbers above, you have to subtract unsprung weight from corner weight. NF only cares about the sprung mass.

So assume 125lbs unsprung weight, the above example would raise from from 1.4 to ~1.5hz. Which for 8k, is about right. Thats super soft.

If I was pushing the Tesla like the Evo, I would be looking at something more like 22-24k front, 32-36k rear. Which would still be softer than the Evo.

For a casual dual purpose car, 12k/20k would be a good place to start.

No one running standard OTS spring rates on their coilovers is in the realm of full prep EVX.
 
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A little fast into that first corner young buck!
I think a common misconception here is if someone is new to posting here that they are new to SCCA or autox in general. In my case neither is true and I've worked with Rick on the PAX numbers over the years as well as talked to Jason about his venture into it when he got interested.

I'm not following the logic that the EV-X nats winner should be top X spot in PAX.

And at whoever asked, no not planning to do any tours, the value just isn't there anymore to travel so far for events since Mineral Wells, PPIR, etc tours/pros all went away. A slight chance of doing Vegas if that happens again but likely Nats in a minimum prep effort which my car is.