Speed vs rpms

[CrankyOldMan]

I made a spreadsheet for my gearbox modifications to find out the different top end speeds for each gear. I also included a graph that shows the RPM drop between gears--both from 6000 RPM (6500 is the rev limit) and from the RPM that will land on 4000 (the lower limit of the power band is around 4200). The stock gearbox is pretty terrible between 1-2 and 4-5. These charts show the approximate speed that you can shift, either before redline, or to land on the sweet spot. Note that in either case, it's impossible to land on 4k in second gear due to the rev limit.

The first few times you take it up to 6k RPM, it's going to feel like it might explode, but it's still within its "intended" operating range. The way the chart works is: the numbers along the 6000 RPM line are your safe-ish limit. The numbers along the 4000 RPM line are your target shift points to maximize acceleration in the next gear.

Stock gearing:


To help reduce the RPM drop between 1-2, I'm using the Celica/Yaris RS gears for 1st through 4th and final drive. To make 5th gear less useless, I'm using a Matrix/Vibe/Corolla 5th gear set.

My custom gearbox:

[ijose 845]

Originally Posted by CrankyOldMan

I made a spreadsheet for my gearbox modifications to find out the different top end speeds for each gear. I also included a graph that shows the RPM drop between gears--both from 6000 RPM (6500 is the rev limit) and from the RPM that will land on 4000 (the lower limit of the power band is around 4200). The stock gearbox is pretty terrible between 1-2 and 4-5. These charts show the approximate speed that you can shift, either before redline, or to land on the sweet spot. Note that in either case, it's impossible to land on 4k in second gear due to the rev limit.

The first few times you take it up to 6k RPM, it's going to feel like it might explode, but it's still within its "intended" operating range. The way the chart works is: the numbers along the 6000 RPM line are your safe-ish limit. The numbers along the 4000 RPM line are your target shift points to maximize acceleration in the next gear.

Stock gearing:


To help reduce the RPM drop between 1-2, I'm using the Celica/Yaris RS gears for 1st through 4th and final drive. To make 5th gear less useless, I'm using a Matrix/Vibe/Corolla 5th gear set.

My custom gearbox:

Oh so tell me if im reading this right

1st - 31.5 mph
2nd - 58mph
3rd- 85!!???
4th - 115!!!!!

so 5 is pretty useless like you said?
If thats the case then WOW i have been babying the shiit out of my car!!
in seccond i shift at 35 and i think its going to explode. Its good to know it has more power.

[CrankyOldMan]

Originally Posted by ijose 845

Oh so tell me if im reading this right

1st - 31.5 mph
2nd - 58mph
3rd- 85!!???
4th - 115!!!!!

so 5 is pretty useless like you said?
If thats the case then WOW i have been babying the shiit out of my car!!
in seccond i shift at 35 and i think its going to explode. Its good to know it has more power.

The bigger issue with 5th gear is that it's so close to 4th that there's not much point in using it, unless you want to get slightly lower RPMs on the freeway. You'll know if you push it too far: the speed limiter cuts the throttle (fuel?) and it feels like the tires hit ice. Depending on your tire size, inflation, etc, you may have a few mph +/- on those numbers. I normally wind it all the way up getting on the freeway, but keep to about a 3k shift landing otherwise.