RX-7 vs. Supra SZ-R: why so different?

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hessi

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Gents,

while driving the new Japanese 90's Seasonal I had a look in my garage and my eyes caught two eligible cars which I usually don't drive:

Supra SZ-R '97
éfini RX-7 Type R-S (FD) '95

Both FR, both within the comparable 400-420 PP range. Both Coupes, close in age, not too far apart in weight, either and somewhat similar dimensions, as well.

And then I drove them. What the hell? This might have been the biggest difference I've ever encountered between two cars so "similar" on paper.

The Supra: moderate understeer, a very slight hint of oversteer on extreme change of direction. More or less: boring.

The RX-7: Friggin' hell, what a car. Change directions by braking and thinking about the way and the front just slides in the right direction. Perfectly controllable oversteer, good for drifting and fast overtaking on the outside of a corner.

Now, I know this is a stupid question, but what makes these cars behave so fundamentally different?
The RX-7 weighs less, has a perfect 50:50 balance and the front springs are softer. So I changed both accordingly to "emulate" the other (as close as possible), but although the RX-7 lost some of its awesomeness it still is completely different to the Supra and vice versa.

Once again, I know these are different cars and it's like comparing Apples and Oranges, but I'm just curious: Are these cars so different in reality, too? What is it that makes them so different?
 
Rotary engine.
 
The only thing it occurs to me is that the RX-7 is lower, making its center of gravity closer to the ground totally affecting the handling.
 
Small details like wheelbase and the location of weight over the tires makes a big difference. Also, Supra is just a bigger bulkier car.
 
Rotary engine.

What does that have to do with anything?

As to why the cars are different, cars are complex. Depending on how detailed GT5's physics engine is, there could be 100's or 1000's of variables that are different between the cars. It's a lot more than hp, weight, balance, and suspension settings. Too much to cover here.

Go look for a book on race car dynamics.

Race Car Vehicle Dynamics by William F. Milliken and Douglas F. Milliken is a good one. 465 pages.
 
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