Close ratio gears?

tvfreakazoid · 01-19-2009, 12:35 AM

HA, I see thanks guys. So, cars like enzo's and lambos, are the gears close and further apart for 5th to 6th gear? How are those type of cars set?
So if someone wanted to modify there cars to have a higher top speed, then will they have to set their gears apart further?

Quote:

Originally Posted by RCZ

tvfreakazoid,

If you have any questions about how the mechanical parts of cars work, check out HowStuffWorks - Learn How Everything Works!
That will answer just about everything you need to know. The direct link to the gearing section is HowStuffWorks "How Gear Ratios Work"

Once you read that then read my following comment.

Close ratio gears just means that there is less of a difference between the size of the gears (gear ratios). The result is that gears are shorter and that translates to faster acceleration. There are two problems when gears ratios are too close. 1) You limit your top speed and 2) You have to shift more often and therefore any time you gained in acceleration is nulled out by the time it takes you to do all that shifting. The opposite occurs when the ratios are longer... you will have less acceleration, but a higher top speed.

Crash · 01-19-2009, 03:23 AM

Quote:

Originally Posted by tvfreakazoid

HA, I see thanks guys. So, cars like enzo's and lambos, are the gears close and further apart for 5th to 6th gear? How are those type of cars set?
So if someone wanted to modify there cars to have a higher top speed, then will they have to set their gears apart further?

Yes, exactly. But you can have the best of both worlds if you have enough power. For both top-end speed and fast acceleration, you can do 1st-3rd close ratio, then make the spread from 3rd-4th more drastic. From there 4th-6th (7th or even 8th in some cases) can be more drastic. In the end, your top speed will rely on these things:
How much drag your car creates
How much your car weights
How much power you have
Your final gear (the gear size of your differential)
And your last gear of your transmission.

Assuming that weight and drag didn't have anything to do with it, theoretically, to increase your top speed, you can make the ratio for the final gear smaller, or make the ratio for the last gear in your transmission smaller.

To give you an idea of why power, drag, and weight have to do with it, the 2004 Corvette has 6 speeds. It has 350HP and 365Lbs/Tq. The final gear is a 3.42, and the 6th gear is a 0.5 while the 5th gear is a 0.85 (I believe). In this case, the top speed in the Corvette is achieved in 5th gear, not 6th because the car doesn't have enough power to push it that fast when it's in 6th gear due to drag. If the car was moving at 190MPH and then shifted into 6th gear, it would slow down to about 150MPH even with the throttal at 100%. However, theoretically, if the car had enough power to max out the RPMs in 6th gear, the Corvette's top speed would be around 250MPH.

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