Porsche 914 gearbox for your VW 1200

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This is a guide on how to replicate a Porsche 914 gearbox for your VW 1200.

Background
A Porsche 914 gearbox was used in some of the Salzburg Rallye Beetles that Porsche Salzburg entered in European rallies between 1967 and 1974. More info on those cars at this link.

Accuracy and gearbox theory
In short: The Porsche 914 had a wide range of gearboxes available. The Salzburg Rallye Beetles used a short ratio gearbox, but because the engine used in those cars could reach 6500 rpm while our VW 1200 can only reach just above 4000 rpm I'm going to opt for a taller gearbox, just so that we don't hit the rev limiter at a too low speed. For this reason, the tune is not an exact copy of the Salzburg Rallye Beetles, but rather inspired by it. The gearbox settings I'm using still matches a stock 914 gearbox, it's just a different version than the one used in the Salzburg cars.

The gears used in the 914 gearboxes are denoted by letters: A to ZD, where A is shortest and ZD is tallest. Which one(s) that were used in the Salzburg Rallye Beetles is unknown to me, but judging by the top speed mentioned in the article on the blog (see the link under Background above) it seems like a short ratio version was used and the only stock gearbox configuration that fits to that description uses the gears B, HA, M, R, V. That gives a top speed of 110 mph at 6500 rpm.

However, if we equip that to our 1200 Beetle with 4000 rpm, we'd get a top speed of 68 mph, which even for a Beetle is a bit too slow. So instead I'm going with a taller version of the gearbox, namely: A, F, N, V, ZD. This does not only give a higher top speed, but the first gear is also shorter (A, compared to B), giving faster acceleration from a standing start. Unless you want to equip your Beetle with a turbo, it's going to have less power than the Salzburg cars, so going with the A gear instead of the B gear is probably a good idea.

If you want to play around with the gear settings yourself rather than just following me, you can find more information and a great Excel tool here: http://www.914world.com/specs/regearing_901.php

Accuracy and calculation: If you've peaked through the Excel file you'll probably notice that the numbers doesn't match the settings used in my tune. That is because the exact gears used in the 914 transmission aren't available in the customizable gearbox in GT6. However, in effect the gearbox matches well, because the effect is derived by multiplying each gear with the final gear, for instance:

914 gearbox:
Final gear: 4.43
1st gear: 3.09

3.09*4.43=13.7

My tune:
Final gear: 6.000
1st gear: 2.281

2.281*6.000=13.7

So if you want to try another 914 gearbox configuration, just use this formula to translate it to what ratio you need in GT6:

X=A*B/Z

Where:
X= Gear ratio in GT6 (the number you want to know)
A= Gear ratio IRL
B= Final gear IRL
Z= Final gear in GT6

Example: A gear have a ratio of 2.89 and the final gear is 4.43. In GT6 we're using a final gear of 6.000. The calculation then is:

X=2.89*4.43/6.0=2.134

So 2.134 is the value you want to use.

The tune
Follow the steps below:
  1. Purchase a fully customizable gearbox

  2. Select the final gear and set it to 3.384

  3. Set top speed to 340 km/h (maximum value)
    Note: This is not going to be the final top speed of the car, it's just so that the game loads the gear sizes that we need.

  4. Set the gears:
    1st 2.281
    2nd 1.395
    3rd 0.930
    4th 0.687
    5th 0.524

  5. Select the final gear and set it to 6.000

Power recommendation
For this gearbox I recommend somewhere between 60 - 70 BHP. That's about half of what the Salzburg Rallye Beetles had, but because their engines could reach higher RPM's they also got a higher top speed. Since our car will hit the rev limiter at about 160 km/h I think it's nice to give the engine just enough power to achieve that speed. If you want more wheelspin at the rally stages, feel free to go higher or even add a turbo :)
 

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