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Discussion Starter · #21 ·
One imo striking point of attention is the front vs rear spring rate/frequency.

TRD springs are front 100 vs 200% rear.

Most/all after market is about 100 vs 150% like the standard spring rates.
7 kg and 10 kg not even that.

The purpose of the relative rate is the response rate to directional changes; the time the rear suspension ´lags´ behind the front wheels.
As the fronts are steered and the rears not, the rear suspension always is going to be adjusting to a directional change later* and having a higher frequency reduces the delay. The TRD set up is thus quicker; making the car more responsive to directional changes.

* the ´Scandinavian flick´ is based on this
Could also be preference and driving style. I ran faster times on my coilover setup vs my strut setup but ive also never felt the trd.
 

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Could also be preference and driving style.
Everything can be but the engineering principles following laws of nature still apply. Regardless of preference, style, habit, it is a good thing to understand the how/why even if one pérsonally is more happy/quicker with a scientifically less optimal set up or setting.
We can see this in racing at the top level continuously.
Take a very obvious one: Max Verstappen and Sergio Perez with Red Bull in F1. Max is quickest with an oversteered car, Sergio with undertsteer/neutral whereas téchnically quickest is somewhere between the two.

Anyway, quickest track set up is séldomly the best/quickest on the real world roads. US auto-x being yet anóther extreme.
This applies to the damping/springs, ARBs and tyre width alike.
Just about the only thing applying everywhere alike is mass. Less mass = quicker. Even safer as shorter stopping distance. Good compliance and less mass. On the road more so* than in racing and more important too.

And back on the topic. As you state; only véry stiffly sprung and with heavy duty ARBs so the wheels travels little, the wide 9" don´t rub.

Now, for those interested in the relative front/rear spring rates/frequencies, do look up the ´Scandinavian flick´ and the search for some videos of MPS or 4x4s. That will make clear how the rear suspension lags behind the one on the directly stééred wheels. The effect on the directional progress of the car is obvious.
For a proper understanding; it is nót about the spring rates persé but about the front vs rear: A 10 kg rear spring will settle faster than a 4 kg one.
That 10 kg will however lag more behind the front 7 kg one than the 4 kg one behind the 2 kg front spring.
What a particular driver prefers is another thing just like the use.

* because of rougher surfaces and the other users of the public space
 

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Discussing spring rate frequency at spring rates approaching 10kg on a 2,200 car is like discussing "sprint rate" frequency on a go kart.

Jokes aside, Petrus, what is the offset of your 7" wheels that are rubbing, what width tire is mounted on them, and what camber are they set to?
 
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