What are the merits of a short ratio box on a track?, Will it make significant reductions in lap times? Options

[nine14cats]

I've got a stock ratio G50 box in my track car. Currently I'm using 2nd through 4th at Infineon, Buttonwillow, Laguna Seca and Thunderhill. I haven't been to Reno-Fernley yet but will be there later this year.

Would it make a significant improvement in lap times to shorten the gearing between the 2nd through 5th gearsets and take advantage of the 5th I'm not using? I wouldn't do it during the season, as I'm still getting used to the car and my RPM' (and speeds) entering turns should go up as I gain more experience in the car. But I just don't see getting into 5th pretty much at all on any of the tracks....

Thanks,

Bill P.

[lapuwali]

The current fetish for more gears in street cars is, IMHO, purely marketing. A 6-speed in a 9000-rpm car like an S2000, ok. A 6-speed in a Corvette, however...

Remember that shifting more means you're going slower, since each shift is going to take some time (0.1 sec to 0.5 sec, depending on how fast you can shift). That's time when you're not accelerating. So, shifting less is always a good thing. On an engine with not only a lot of torque, but a nice flat torque curve, you shouldn't have to worry so much about what gear you're in, so you should be able to reduce the number of shifts you make to a minimum.

That said, besides helping to keep you in a narrow powerband if you have such an engine, a close-ratio box may be useful if you visit a lot of tracks with wildly varying layouts, because you won't have to regear from track to track. You can simply use the gears in the 'box as you need to: 2nd, 3rd, 5th on Track A; 2nd, 4th, 5th on Track B. A close-ratio 'box may also be useful in situations where you're regularly fighting traffic and having to adapt to another driver's speed for a few corners, and you may find yourself between gears in your usual pattern from time to time.

Back when I raced bikes, though, I leaned towards bikes with broader powerbands, and there were a few I had that required fairly little shifting. One only required two gears at Sears Point, which has a pretty wide variety of corners. I'd only have to downshift once for the hairpins at each end, and could remain in top everywhere else.