Tranny Q...

  • Thread starter Thread starter Sage
  • 11 comments
  • 417 views
Sage

Sage

Staff Emeritus
Messages
12,533
United States
United States
Messages
GTP_Sage
Okay, n00b question by me: :p

When you set the gear ratios wider, does that mean it takes longer for you to get to the optimum shift points (Basically, faster in the long run, but slower acceleration)?

Also, how does the Final Ratio work into the equation? It seems weird, because when you change the Final Ratio, the gear ratios don't change, so how does it work?

Thanx! :)
 
Ok, the wider you set the auto settings the higher top speed you have, but it takes a while to get ther. If you set it sportier you get a faster acceleration, but lower top-speed (you get maxed out on straight-aways)

Final Gear is a finer tune of auto settings. The closer you get to 0 the more top speed you'll have, but you give up acceration, and vise-versa.

The final gear is suppose to be set after you've determined your autosettings.
 
The wider you set the gear ratios, the higher the difference between your engine speed when you change out of one gear and your engine speed when you change into another gear. So, if the ratios are set narrow, you might be at 7500rpm in 2nd, then you'll be at 6800rpm in 3rd. If you set the ratios wide, you'll leave 2nd @7500 and go down to 5000 in 3rd.

This makes a difference because at 5000rpm you'll have less power, and a longer gear, so the car will struggle to pick up speed. However, since each gear is further apart, your spread (which directly determines your top speed) is greater, and therefore you can attain higher top speeds, subject to the car's power.

The final gear affects the overall speed of the car. Imagine this:

Engine speed: 8000
Gear ratio: 2
Final drive: 2
Wheel speed (in rpm): 2000.

If you change the final drive to 1, the wheel speed will be 4000, i.e. twice as fast. Remember, you're thinking in ratios here, so the number determines the amount by which the engine speed is divided to get output speed.

Hope that helps! :)
 
Yeah, I think you're definitely on the right track. Love the last post in that thread, by the way.

Here's my guide for ultimate gear-ratio setting:
You want the car to be on the rev-limiter as you reach the braking point at the end of the longest straight.
You want the car to have about 5-6000rpm on board in 1st gear at the apex of the slowest corner.
If it's a twisty track with lots of slow corners (Cote d'Azur), you want to have the gears nice and close. Also, if it's a track with a lot of quick corners (Laguna Seca), you want the gears nice and close too. However, if it's a track with a nice long straight, and lots of quick corners (Grand Valley), you want nice long gears.

Now, in your practise, you have to set the gear ratios so that you have the correct balance between the slowest and fastest speeds. The final drive should be used to adapt to the circuit's overall speed characteristics (i.e. low for Laguna, High for Cote). Remember, by altering the final drive, you're changing the ratios of all the gears.
 
Okay, I'm starting to get it now...

However, why does the Final Ratio work vice-versa of the gear ratios? (Gear Ratios: lower=faster acceleration, while Final Ratio: higher=faster acceleration) Isn't that kinda... odd?
 
Originally posted by youth_cycler
Okay, I'm starting to get it now...

However, why does the Final Ratio work vice-versa of the gear ratios? (Gear Ratios: lower=faster acceleration, while Final Ratio: higher=faster acceleration) Isn't that kinda... odd?
Click to expand...
Erm. The lower the ratio, the less work the engine has to do.

With gears, the closer the gears are, the faster the acceleration, but this does tend to lead to lower top speeds due to shortening the range of gears.
 

Latest Posts

Back