Andi Baritchi
andi@airmail.net
www.Boostaholic.com
12/30/2001

Optimal shift point calculation for Rob's stock 97 TT.
This is according to his 303rwhp dyno graph (the blue graph). I'm not
using the green 315rwhp graph because that seems to just indicate a
small boost spike.

Note: The theory behind these calculations is that you always want to be
in the gear with the highest horsepower, as at any given speed that will
provide the most rear wheel torque. Hence, I've calculated what RPMs you
end up at after each shift, and found the RPMs at which the HP curves in
the "before shift gear" and the "after shift gear" intersect.

Note that Supra tachometers tend to read high by 200 RPM at redline. Thus,
I've calculated the shift points in terms of both actual RPMs and Toyota
Tachometer RPMs. For reference, my tachometer says 7000 RPM at the
rev limiter, and according to the dyno machine it is only at 6800 RPM
at fuel cut.

Summary of results found below:
** 1-2 SHIFT AT ACTUAL 6800 RPM (7000 Tach) **
** 2-3 SHIFT AT ACTUAL 6600 RPM (6800 Tach) **
** 3-4 SHIFT AT ACTUAL 6400 RPM (6600 Tach) **
** 4-5 SHIFT AT ACTUAL 6500 RPM (6700 Tach) **
** 5-6 SHIFT AT ACTUAL 6300 RPM (6500 tach) **

Calculations:

gear ratios:
3.83 first gear
2.36 second gear
1.69 third gear
1.31 fourth gear
1.00 fifth gear
0.79 sixth gear

thus the RPM shift ratios are:
0.62 1-2 shift
0.72 2-3 shift
0.77 3-4 shift
0.76 4-5 shift
0.79 5-6 shift

HP Levels at different RPMs from blue graph:
4000 190rwhp
4100 200rwhp
4200 220rwhp
4300 240rwhp
4400 250rwhp
4500 255rwhp
4600 265rwhp
4700 270rwhp
4800 275rwhp
4900 280rwhp
5000 285rwhp
5100 287rwhp
5200 290rwhp
5300 293rwhp
5400 297rwhp
5500 299rwhp
5600 301rwhp
5700 303rwhp
5800 303rwhp
5900 300rwhp
6000 295rwhp
6100 292rwhp
6200 288rwhp
6300 285rwhp
6400 280rwhp
6500 276rwhp
6600 270rwhp
6700 267rwhp
6800 260rwhp

Note:
bRPM = before shift RPM
aRPM = after shift RPM
bHP = before shift HP
aHP = after shift HP

1-2 shift
bRPM aRPM bHP aHP
6400 3968 280 190
6500 4030 276 190
6600 4092 270 200
6700 4154 267 210
6800 4216 260 220 ** 1-2 SHIFT AT ACTUAL 6800 RPM (7000 Tach) **

2-3 shift
bRPM aRPM bHP aHP
6300 4536 285 255
6400 4608 280 265
6500 4680 276 270
6600 4752 270 272 ** 2-3 SHIFT AT ACTUAL 6600 RPM (6800 Tach) **
6700 4824 267 275
6800 4896 260 280

3-4 shift
bRPM aRPM bHP aHP
6100 4697 292 270
6200 4774 288 275
6300 4851 285 278
6400 4928 280 280 ** 3-4 SHIFT AT ACTUAL 6400 RPM (6600 Tach) **
6500 5005 276 285
6600 5082 270 287
6700 5159 267 289
6800 5236 260 290

4-5 shift
bRPM aRPM bHP aHP
6100 4636 292 265
6200 4712 288 270
6300 4788 285 275
6400 4864 280 278
6500 4940 276 282 ** 4-5 SHIFT AT ACTUAL 6500 RPM (6700 Tach) **
6600 5016 270 285
6700 5092 267 287
6800 5168 260 289

5-6 shift
bRPM aRPM bHP aHP
6000 4740 295 272
6100 4819 292 275
6200 4898 288 280
6300 4977 285 285 ** 5-6 SHIFT AT ACTUAL 6300 RPM (6500 tach) **
6400 5056 280 286
6500 5135 276 288
6600 5214 270 290
6700 5293 267 293
6800 5372 260 296