So in the 40 year saga that is my Datsun 1200 I've always simply cobbled together the best bits I had or used what ever I could get cheap. The only other rule I had was the car must remain reliable
Close ratio gear sets are available for the standard 56 series gearbox but they are fragile (I broke two) and so I went to a beefier 60 series street box which unfortunately has a huge gap from 2nd to 3rd.
On my current home track I absolutely have to use 2nd gear in one corner. The gap between 2nd and 3rd finally wore on my nerves, so I sourced a 5.13 ring and pinion with the goal of eliminating the need to use 2nd gear
When I redid my gearing chart I was a bit shocked at what it told me. The lower gearing means the car will be coming off every corner 10-12hp higher in the powerband. The trap speed at the end of the short chutes are such that I won't need to upshift so I won't be losing out the time gained.
Well duh Captain Obvious gearing does matter..............my not doing this 10 years ago is especially silly considering when I was road racing a 125cc bike I would make gearing changes if the wind increased 3mph.
10-12hp may not sound like much but in the 1200 this is a 12-15% increase in power.
