ClioSport.net

Register a free account today to become a member!
Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Top speed / gear ratios / calculations



jp_lcr

ClioSport Club Member
  172 Cup
Apoligies if asked before but does anyone know the standard gear ratios for a 172 Cup gearbox, tried searching but not found it?

I'm wanting to confirm max speed in each gear, think there are calculators online from gearing and tyre dimensions to work out theoretical max speed, also any easy way to factor transmission losses?

I work in data / analytics like playing with numbers and wondered whether can model the odd corner / section which is borderline for which gear, appreciate there are a thousand other factors but all other thing being equal there must be an optimum.

If I'm thinking about it in the wrong way happy to be corrected, just an idea (y)
 

mantis946

ClioSport Club Member
  LY 220 Trophy+IB PH1
Something I put together a while ago for my PH1, may be of help.

CarPowerWeightP/Wdrag coeRev limitratio 1ratio 2ratio 3ratio 4ratio 5ratio 6ratio 7FDWheel diam (M)
Clio
165​
1.035​
159.42​
0.358​
7250​
3.09​
1.86​
1.32​
1.02​
0.79​
4.07​
0.576​
MPH
38.90​
64.63​
91.06​
117.85​
152.16​
 

massivewangers

ClioSport Club Member
  Several
I've got a spreadsheet with them on somewhere (and one for 197/200). Allows you to input tyre sizes, engine speed etc. If you'd like it, send me your email address and can send it over.
 
Something I put together a while ago for my PH1, may be of help.

CarPowerWeightP/Wdrag coeRev limitratio 1ratio 2ratio 3ratio 4ratio 5ratio 6ratio 7FDWheel diam (M)
Clio
165​
1.035​
159.42​
0.358​
7250​
3.09​
1.86​
1.32​
1.02​
0.79​
4.07​
0.576​
MPH
38.90​
64.63​
91.06​
117.85​
152.16​
Was this for a 15" wheel?
 

mantis946

ClioSport Club Member
  LY 220 Trophy+IB PH1
If you add air resistance you can approx actual speed...😉
I calculated that too haha need power (In watt's I think it was) area of the car, drag and air density. Done the below based on sea level if I recall.

Power (BHP*746)
123090​
Width
1.639​
Height
1.417​
Area (Width*Height)
2.322463​
Drag Co
0.358​
Air Den
1.25​
Max speed
132.81

Surprising how much reducing drag buys you in performance, if the 172 had similar slippy-ness to a GTR you'd get:

Power
123090​
Width
1.639​
Height
1.417​
Area
2.322463​
Drag Co
0.27​
Air Den
1.25​
Max speed
145.77
 

bozothenutter

ClioSport Club Member
I calculated that too haha need power (In watt's I think it was) area of the car, drag and air density. Done the below based on sea level if I recall.

Power (BHP*746)
123090​
Width
1.639​
Height
1.417​
Area (Width*Height)
2.322463​
Drag Co
0.358​
Air Den
1.25​
Max speed
132.81
Surprising how much reducing drag buys you in performance, if the 172 had similar slippy-ness to a GTR you'd get:


Power
123090​
Width
1.639​
Height
1.417​
Area
2.322463​
Drag Co
0.27​
Air Den
1.25​
Max speed
145.77
This I like!
 


Top