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Autocross- SCCA EV-X Class vs. SS
- Thread starter RacerChris
- Start date
Rodney!
Looking for a hot receptacle
My first place loser fist bump in the NJ Superchallenge...
Sorry guys, I f'd up and let down the Tesla community...
Sorry guys, I f'd up and let down the Tesla community...
Rodney!
Looking for a hot receptacle
Thanks. I won S4 by .024 over Josh Luster in Aaron Shoe's SM/XA Evo. In 3rd place was Jeremy in his stock M3P (save for a set of my SCCA street class legal 19's/re71rs). Jeremy was in the challenge and coned it away getting 6th iirc.
That was my first time in the challenge with the new format, and I liked the old way better, but i understand the new way shortens the timeframe.
Overall, great weekend, but I keep thinking about that dang redlight...
My experience is that with the TC and AWD in the M3P, it completely dominates in the wet. I've run FTD by seconds in the wet against competition that usually beats me in the dry. I've even had days where it either dries out or rains later so I get to see both times and I just don't drop off by as far as other cars when the traction starts decreasing. But this is also not in a completely normal AutoX environment admittedly.
My discussions with Rick Ruth as he's tried to PAX the M3P also indicates that he sees big improvements in where the car lands when it rains, and it's one of the reasons that the EV-X PAX is so hard for dry, national courses because when it rains at a local event, the M3P inevitably pops out on top and messes with the numbers.
David Marcus in '19 brought a M3P to nationals just "Because if it rains, the Tesla is the car to have.” And then after he won BS in the dry he argued for the car to go to SS because it "might" get a software update.
Not sure there has ever really been a great nationals event with good drivers in an EV-X prepped M3P against other good drivers to really see if it does hold up to the theory though.
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Yeah, sure I would take the TM3 over 2wd in the wet but the lack of LSD is pretty significant. I did a bunch of testing and I came to the conclusion you have to run more TC with wet because if you run it low the TC braking cuts it late but overly aggressively. But running it high it seemed to be a bit smoother how it came in and more useful.
BUT, at the end of the day, it just cant put the power down and has to reduce it with slip. A normal AWD car with 3 LSDs manages to find more grip at the expense of potentially blowing all 4 tires off. But driven well, An STI or Evo on same tire as TM3 "should" be superior.
I think there's more of an advantage of traditional AWD in the dry where LSDs aren't as critical and the complete lack of front/rear crosstalk does have turning benefits. Though still a rear LSD would be huge if we could then run maximal rear bias and have full front power come in as wheel straightens.
Of course this is all pontification without testing. But my experience seems to lead me to thinking it would work.
BUT, at the end of the day, it just cant put the power down and has to reduce it with slip. A normal AWD car with 3 LSDs manages to find more grip at the expense of potentially blowing all 4 tires off. But driven well, An STI or Evo on same tire as TM3 "should" be superior.
I think there's more of an advantage of traditional AWD in the dry where LSDs aren't as critical and the complete lack of front/rear crosstalk does have turning benefits. Though still a rear LSD would be huge if we could then run maximal rear bias and have full front power come in as wheel straightens.
Of course this is all pontification without testing. But my experience seems to lead me to thinking it would work.
Rodney!
Looking for a hot receptacle
I agree with both of you...
Although I ran on re71rs (my rain setup is not here yet) both my and Jeremy's M3P's were less affected by the rainy slick sealed asphalt vs every other competitors car setup. You had to have some patience on entry, but if you nailed that you could floor it and let the digital pixies to the work. Challenge workers noted how fast on exit we were vs the rest of the field.I agree that an AWD wrx/evo/etc with proper diffs and rain tires would be faster, but there was none on site last weekend. Also, the consistency of the M3P in the wet or dry cannot be ignored.
I heard lots of whining about the Tesla 3rd hand, but nobody had the pelotas to say anything to me personally. Sure, we were still doing 1.9 sixty foots, but we had to turn eventually, and that's where essentially everything is faster then this car...
Tesla is absolutely the boogeyman car right now. But its just so misunderstood. People seem to have this idea that CG is underground, its makes 1000hp, and can pull 2gs from apex to the next entry.
But its still an AWD car with 3 open diffs and and weighs over 4000lbs. It just happens to punch well for its weight class.
So weird too, when a new mustang, miata, corvette, or insert any other popular AX car comes out everyones excited. But if its the Tesla its time to freak out because (insert same handful of lame excuses)
But its still an AWD car with 3 open diffs and and weighs over 4000lbs. It just happens to punch well for its weight class.
So weird too, when a new mustang, miata, corvette, or insert any other popular AX car comes out everyones excited. But if its the Tesla its time to freak out because (insert same handful of lame excuses)
How can the inner sidewall buckle more mechanically, unless one has too much static or dynamic camber? Already heavily-loaded suspension bushings (or bearings) don't have that much give, IMO.
Its about the angle that it moves. The tire/wheel is basically a trapezium so how the tire rolls will depend on the angles of the wall and the inside wall of a pinched tire will buckle inward and upward (relative to wheel center). A stretched tire will deflect but push down as the wall moves.
In a static picture of a tire on a hypothetical testing rig where you apply a friction force along the tire tread, I can see how the inner sidewall can buckle more in the case of a stretched tire.
I just cannot visualize how can it happen on a cornering car. There's the angle between the wheel and the ground determined (to a first approximation) by suspension/lateral force/roll angle. The tire will just compress to fill the shape between the ground and the wheel.
Or the pinched/stretch setup should somehow result in different cambers under load from different bushings flexing.
On a stock M3P with zero camber, I think the inner sidewall won't collapse under lateral load regardless whether it's pinched or stretched, because the lack of camber will mean there's more space on the inside edge of the rim.
What's wrong with my reasoning here?
Its just far more complicated than us looking at it as a simple mechanical system. Have you looked at undercar videos of how much a tire squirms on track? Its A LOT.
There are several hard to explain reasons Ive come to this conclusion, but my best evidence is the tire wear on 9" wheel vs 11" wheel given my setup which is too different than anyone else to really compare static values.
I can say with absolute certainty, the 275 A052 on a 9" wheel sucks and is super floppy. And on an 11" wheel feels like the car doubled in total vehicle stiffness. Its dramatic.
There are several hard to explain reasons Ive come to this conclusion, but my best evidence is the tire wear on 9" wheel vs 11" wheel given my setup which is too different than anyone else to really compare static values.
I can say with absolute certainty, the 275 A052 on a 9" wheel sucks and is super floppy. And on an 11" wheel feels like the car doubled in total vehicle stiffness. Its dramatic.
Sweed269
Member
A stretched tire should have significantly less side to side movement under changes in cornering loads. The inner sidewalls relative to the load is already near at max stretch and the outer sidewall has to extend up against the downward pressure of the car stabilizing it. If the rim in narrow, the outer sidewall falls over and the inner has a lot of distance it can move.
Here's a pretty square rim/tire combo, yet you can see just how much it still moves.
I can only image how bad it is on a pinched tire.
I can only image how bad it is on a pinched tire.
The change from 9" to 11" on the same 275 A052 was pretty dramatic in how the car felt. Grip was up even though tires are getting pretty well aged. I'm almost down to no tread on the inside and ~2/32s on the outside. But still, they felt better than new being stretch rather than pinched.
This isn't new info, but reiterating if you're going to run A052s don't push the tire/wheel ratio.
As for the course this weekend, they were a pretty decent blend of accel, sweeper, and slalom considering the small lot. These are RAW times and PAX in XA I was 4th saturday and 3rd sunday (I think?). Not bad with all of us in the top 10 being regularly successful running National events. Especially since I have like 5 mods and tiny worn 275 tires.
This isn't new info, but reiterating if you're going to run A052s don't push the tire/wheel ratio.
As for the course this weekend, they were a pretty decent blend of accel, sweeper, and slalom considering the small lot. These are RAW times and PAX in XA I was 4th saturday and 3rd sunday (I think?). Not bad with all of us in the top 10 being regularly successful running National events. Especially since I have like 5 mods and tiny worn 275 tires.
