For the past 15 years I've been using a street gearbox in my Datsun 1200. Prior to that I had used Nismo gearset but they were only available in the smaller 56 series gearbox. While the ratios were great these boxes are fragile.
My solution was the aforementioned street gearbox, specifically the 60 series from an 81 Nissan 210. While it's held up well there is a huge 2700 RPM drop between 2nd and 3rd gears.
My solution, which has been used by racers on a budget, was to gear the car so low that I'd only use 3rd-5th. The 5th gear is a .821 over drive.
A little over a week ago I competed at Buttonwillow and my times were 3 seconds slower than last year on this same layout The Minis I was competing against were also 3 seconds a lap slower. While that would explain the increase in lap times I was still 5 seconds slower than the Minis, same as last year.
I thought for sure with the car being 10-12HP higher in the powerband coming off corners I'd see that gap close but that just didn't happen.
The only plus side is I was no longer having to deal with the choice of revving the guts out of the motor in 2nd gear or trying to get the car rolling through corner so as to not bog the motor.
I am using 5th gear a lot so I'm thinking what I'm gain coming off the corners I give back once I shift into 5th.
Regardless I finished in the exact same spot despite what in my mind were improvements. I even put a fresh set of Hoosiers on the car.
Sigh............https://www.youtube.com/watch?v=3vPudWyYIdQ&t=785s
