Gear ratio guru's

Mudgey · Post by **Mudgey** » Mon Jan 06, 2014 1:35 pm

Dont forget to multiply your gear ratios by the final drive. You can see that the CTR's FD is 11.6% greater than the majority of the preludes, therefore for the same flywheel torque you would see a 11.6% increase in torque at the hubs per gear at the expensive of 11.6% reduction in max speed per gear.

CTR kurb weight is approx 1250kg,
Type S: 1310kg
UK Prelude: 1380kg.

Thats quite adifference on its own!

mynameisowen · Post by **mynameisowen** » Mon Jan 06, 2014 1:53 pm

Adding to the debate:

Torque at wheels = Torque at Crank * Gear Ratio * Final Drive Ratio

Fag packet calc:

E.g. 200Nm at Crank * 3.307 (M2B4 1st gear ratio) * 4.266 (M2B4 Final Drive Ratio) = 2821Nm at wheels

The car which accelerates quicker will have more torque at the wheels for a longer time, all else being equal.

Factors which affect the acceleration of the car are:
1. Vehicle Mass
2. Wheel&Tyre radius
3. Losses due to drag and friction

Pre-emptive QA:

1. Why dont we have a gear ratio of over 9000 so that we have a bazillion Nm at the wheels??

Because then we'd be changing gear every millisecond and have to have a bazillion gears.

2. All this torque of talk, y no power?

Very simply Power = Rate at which torque is applied. So more torque for longer = more power = more acceleration.

By applying more torque for longer (nice wide torque band or lots of tight gears) you are inherently producing more power for longer = more acceleration. All else being equal two cars with one peaky high hp engine and one fat yank torque engine with the same power output will accelerate at the same rate given the correct gear ratios and number of gears to ensure that the same torque is applied to the wheels.

/

mode

Post by **Donald** » Mon Jan 06, 2014 5:14 pm

I liked the DBZ bit

Post by **GreenyUK** » Mon Jan 06, 2014 8:53 pm

Oh my gosh lol some clever people on here. Think I'll need to read this agian a few times

I'm up a bazillion gears I change gear in a millisecond on a daily bases anyway

And wow I can't believe a 4g prelude weighs that much! Lol I though they were light lol.

prelude91 · Post by **prelude91** » Mon Jan 06, 2014 8:58 pm

3g's are knocking 1400 kgs. cars have got heavier over the years, such is progress

Post by **RattyMcClelland** » Mon Jan 06, 2014 9:03 pm

GreenyUK wrote: And wow I can't believe a 4g prelude weighs that much! Lol I though they were light lol.

Mudgy was on about 5th Gens. But they arnt 1380kg. A UK VT 4ws is around 1350kg. A uk 4th Gen 4ws is around 1330kg
And the BB3/BB4 with a sunroof and AC are around 1260kg.

prelude91 wrote:3g's are knocking 1400 kgs. cars have got heavier over the years, such is progress

3rd gen Prelude?

The 2.0i-16 4WS weights in at 1150kg and the normal 2ws EX is 1050kg since its got no electrical wiring/injectors etc.

prelude91 · Post by **prelude91** » Mon Jan 06, 2014 9:11 pm

b/h ratty, you know your stuff, off the top of my head, I thought the 3g was kissing 1400, will check my manual later, but I stand corrected

Post by **GreenyUK** » Mon Jan 06, 2014 9:52 pm

ah ratty ok that sounds more like it. So if mine is a bb1 the only difference between that and a bb4 with sunroof and ac is the 4ws does that really weigh 70kg

I can't wait to get rid of it all I'm not a lover of the 4ws any way

Plus 4g bonnets seem pretty heavy to so bet there's a bit to save there also.

mercutio · Post by **mercutio** » Mon Jan 06, 2014 9:53 pm

and the sunroof that weighs around 40 kg if I remember right and its the worst weight as its high up

Post by **RattyMcClelland** » Mon Jan 06, 2014 10:15 pm

4th and 5th gen boonets are around 12kg and carbon fibres are around 7ish kg.

Pretty insignificant IMO. Battery is 18kg though and a very small area up front. Ac is around 20kg, sound deadening 12kg.

But yes the 3rd gen 4ws is 1150kg. Mine was and my EX was 1050kg.

Lude Generation

Gear ratio guru's

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