does anyone know what at what MPH it caps out on each gear? ie 1st gear max speed 40, 2nd 70, 3rd 100 etc.

Stock F type R rwd if it matters, im sure if you have increased red line it will change.

 

It is indeed different for each of the different models as they have different gear ratios (transmission specific) and differential ratios (model specific). I never paid attention to the top speed in any gear, but rely mostly on engine sound and sometimes the tach when pushing it.

 

You can check it yourself by using S and the paddles - no automatic upshifts so just see where the engine cuts the throttle. Checking 8th might be a challenge ...

 

You can check it yourself by using S and the paddles - no automatic upshifts so just see where the engine cuts the throttle.
Checking 8th might be a challenge ...

 

yeah figured so, im currently in the process of getting my time in stock, tuned only, and tune with mods, i mean i can figure out 1st-3rd just driving it, but getting info on 4th to 6th would be down right dangerous!

 

Which model and tranny do you have? I can provide the gear ratios for you to calculate the top speed on each of the gears if you have the top speed for any of the lower gears. Be certain to use the Dragy or Waze speeds (not speedo) for true speed. I found my speedo over-indicating until I put 305 tires on the rear.

 

im using dragy, i found the speedo to be dead on with oem or vrdstein summer and pirellie winter in same size. Ima go for a drive now and let you know top speed in 1st and 2nd.

 

U can always take the speed at half of redline rpm and multiply by 2...much safer.

 

The tachometer is not particularly precise, and probably not accurate enough anyway. A datalogger would be the only way I can see to get quality results.

 

I tested it and 1st gear was capped at 44mph.

 

7th and 8th are overdrive gears so you only need to check up to 6th

 

I found my speedo over-indicating until I put 305 tires on the rear.[/QUOTE]
Do you have 305’s on your stock wheels?

 

Do you have 305’s on your stock wheels?[/QUOTE]
I did, but I now have them on 11” VS03s.

 

So how do you calculate top speed with gear ratio? I found the ratio on wiki and 1st gear is capped at 44mph, no idea how to run the math though.

 

Top speed is not just gearing (MPH per RPM). The engine might run out of power/torque due to wind resistance before red line is reached....

Back when many road magazine tests actually measured top speed, they often told you the RPM and gear at which top speed was recorded.


Anecdote: When I was a teenager, I purchased my first old, used sports car (50's Porsche). It had dicey, old tires on it. So, I decided to play it safe and see how fast it would go in 3rd (it was a 4-speed). Turned out, top speed was only attainable in 3rd. YIKES.

 

I recall a time when some "ordinary" cars (Vauxhall) had a specification list that included the speed per 1000 rpm in each gear, so you could work out the theoretical max.

 

Here's the formula:

[V(mph)]=[rpm] / [final gear ratio] * [tire diam.(in.)] / 336.1352
305/30-20 diam. = 27.2"
295/30-20 diam. = 27.0
max rpm will differ based on tune.


Diff. ratio 2.56
Gear Ratio Final
1 4.71 12.0576
2 3.14 8.0384
3 2.11 5.4016
4 1.67 4.2752
5 1.28 3.2768
6 1.00 2.5600
7 0.84 2.1504
8 0.67 1.7152

You'll hit top speed with any of the AT V8 F-Types in 6th gear.

 

Using Unhinged details of gear ratios and standard 295/30 × 20 inch tyre with 27.0 inch circumference

 

Thanks exactly what I needed.

I made something similar. theoretically with a slightly larger diameter tire and a trans tune, you can hit 130 without going into 5th, saving one less shift from quarter mile or 60 to 130 time, hmmmmm

 

you might cut a fraction of a second with one less shift, but that will be more than offset by a loss of average power over the shift ranges. To maximize acceleration you want closer ratio rather than taller.