Keep hearing about frame twist with 440s
Sincerely, thanks for writing all of that up. I always take your perspective and opinions seriously and every time I've applied your advice, it has served me well.
Please don't take this the wrong way but this explains pretty much the whole "debate" here:
...As far as the science that I apply, yeah, I have a degree in engineering and I built chassis' and did FEA analysis as part of FSAE teams in college. I know the science behind these chassis, even a lot of what was considered when these cars were built.
No doubt, the time that you've spent studying and working on this stuff is incredibly valuable. I give you all the credit for that...that said, I work closely with aerospace engineers of various disciplines and it's part of my daily life to listen to smart people who believe that there's only one possible correct answer, they're the only one who knows it. Christ, that seems like an exhausting way to view the world.
When I guy like Uncle Tony comes along who is totally undisciplined but likable, charismatic, funny, talented and smart as a damn whip, it MUST chap the asses of people with an engineering mindset, especially when the guy gets results. Honestly, I get that.
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And that's the biggest mistake most people make, they assume the factory did the best thing. Well, two things about that. First, they did the cheapest thing they could get away with, and only designed these cars to last about 10 years or 100k miles at BEST. Second, they were building a chassis for the time, which meant bias ply tires, super soft suspension for comfort that was the selling point of a lot of stuff in the 70's, and safety standards that would make most modern engineers shudder because that's just what they knew at the time.
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Ok so you're not reading my posts at all then.
...But that's not what your SCCA champion vs a stock miata on the back roads example was. Yes, the SCCA car still has flex. Probably a lot less than a stock Miata. But you conjectured the stocker might do better because of road conditions. And hell, it might. But that performance isn't because of the chassis at all. It's because of how the suspension is set up. The SCCA car would win handily with the suspension set up for the right tires and road conditions with the same chassis. ...
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I agree with all of that...I guess I failed to adequately stress my emphasis in that comment. The stock street driven sports car
could be quicker than a fully modified autocross car in some conditions
despite having vastly more chassis flex, depending on conditions. I didn't mean to say that it would be quicker
directly because of the flex but it's part of a system that has a degree of compliance that might prove to be advantageous. All things being equal, a stiffer stock suspension car would feel better to drive but saying that it would necessarily be quicker would demand some actual data.
A car like a Miata, especially the NA gen cars (model years 1990-1997) have immediately obvious amounts of chassis flex and cowl shake in stock form, even on stock 14" all season tires. They were also designed to be a total blast to drive and surprisingly quick despite their low power, low grip. They're also quick in some part because of their compliance. It makes them approachable and it makes a driver more willing/able to push the limits. Chassis flex is just one part of a "perfect for what it is" package. Trying to isolate that one variable becomes an exercise in hypotheticals that probably is a bit far off the rails. Anyway, that's my opinion based on my own experiences in driving many tens of thousands of miles in stock and modified Miatas and a dozen or so autocross events in these cars.
The first mods that I did to my Miatas was to add chassis bracing. The shock tower bracing in particular added a sense of immediacy to the steering input and notably reduced the cowl shake. I liked it better but it didn't make me any faster after the mod.
Yeah, my evidence is pretty much all anecdotal.
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All of that anecdotal experience is valuable and IMO, valid. But if you really think that yours is more valid than the experience of a guy like Uncle Tony, I don't know what to tell you.
If he says that a drag car with stock-like chassis flex is easier to drive and less likely to bite you and have a sudden and dramatic wall collision "incident," I have to hear him out on that too.
