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      05-09-2012, 06:10 AM   #410
GoingTooFast
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Drives: fat cars are still boats
Join Date: Jun 2007
Location: compensating a fat car with horsepower is like giving an alcoholic cocaine to sober him up.

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What kind of Toyobaru did EVO test?!

Subaru BRZ 6-speed automatic, Limited trim.

BRZ........... MT (Premium trim)..... AT (Limited trim)
Weight....... 2762 lbs (1255 kg) ... 2822 lbs (1280 kg)
Gear Ratios
1st............ 3.626:1................... 3.538:1..............
2nd............ 2.188:1................... 2.060:1..............
3rd............ 1.541:1................... 1.404:1..............
4th............ 1.213:1................... 1.000:1..............
5th............ 1.000:1................... 0.713:1..............
6th............ 0.767:1................... 0.582:1..............
Final drive... 4.100:1................... 4.100:1..............


The significantly taller gear ratios of the automatic transmission, the automatic transmission itself, the combined weight of the AT (+47 lbs or 21 kg) and the Limited version (+14 lbs or 6 kg) all these things togheter but mainly the gear ratios difference don't make for a 'good engine feel' and more driving involvement, I reckon.

However, the very fine car balance must still be there. This time you just don't have the same ability to change it with the throttle as easily as you would with the MT. The chassis and steering feel from corner to corner, I am most certainly, still remain VERY good though!

Let me ilustrate this with the above example and formula [mph = (rpm x tire diameter) / (gear ratio x 336)]:

40 mph in 2nd gear with the MT the engine would be revving at 5033 rpm and just inside the 5000 - 7000 rpm engine's power band.

With the AT still 40 mph and in 2nd gear the engine would be revving at [5033 rpm * (2.060 / 2.188 )] = 4731 rpm


As you can see with the automatic transmission the engine would be revving outside its power band (5000 - 7000 rpm) where the torque cuve is higher and flatter and wouldn't therefore pull as hard.

Last edited by GoingTooFast; 05-09-2012 at 02:41 PM.
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