911 3.2 G50 Gears

[davidtran]

Hi everybody 

I have a 911 3.2 G50. 

Does anyone know the gear ratios and top speed for every gear? Or where I can finds this information

David 

[OZ930]

Owners manual

[davidtran]

3 hours ago, OZ930 said:

Owners manual

Thanks for that. 

I am going to practice a heal tow/rev matching with the rennline pedals that I purchased. It's been a while since I've been on the track, so will give a go to refresh on the street. Then I just got curious about over revving. 

Hypothetically providing I stay under 100km/h, is it possibles to over rev? Worst case would be going from 5th to 2nd gear at 100kmh, because 1st would be locked out and that would would still Hypothetically be under redline? 

This chart shows top speed of 2nd gear is 69mph/111km/h or 64mph/103km/h. Can't tell which is correct. 

Anyone able to confirm my thoughts makes sense?

 

[LeeM]

 Well I wouldn't be going from 5th to 2nd for a start mate, especially on a track, as you're just asking for trouble in my opinion.

Use your gears when downshifting, as it's not a PDK GT3RS 😁

[tomo]

10 minutes ago, LeeM said:

 Well I wouldn't be going from 5th to 2nd for a start mate, especially on a track, as you're just asking for trouble in my opinion.

Use your gears when downshifting, as it's not a PDK GT3RS 😁

Yep and G50 box is like a rifle bolt selecting gears very precise. 

[davidtran]

42 minutes ago, tomo said:

Yep and G50 box is like a rifle bolt selecting gears very precise. 

Won't be intentionally going from 5 to 2 obviously. 

More of a hypothetical to know and understand the risks of overreving if I don't exceed 100km/h. So while I'm on the street I can practice gearing without the risk of overrev if that makes sense. 

As per above i don't think you can enter 1st until your speed is low enough on G50. So 2nd gear being the next lowest and 5th being the highest. My question is, is there a risk of overreving if I do not exceed 100km/h?

[LeeM]

 To answer the question, hypothetcally yes, I think there would be the chance of overreving it, and/or the chance of gearbox damage.

 

[911]

1 hour ago, LeeM said:

 To answer the question, hypothetcally yes, I think there would be the chance of overreving it, and/or the chance of gearbox damage.

 

I don't agree with that.

If second gear is capable of doing 100km/h - based off of the charts. I think you'd simply go up to the redline in 2nd, with no chance of any gearbox damage or over-revving.

Over-revving would occur if you exceeded 64mph and dropped into 2nd with a lightning quick gear change. 

I found this on pelican parts, which is for US G50 cars, but id say our ratios are the same? 

Engine speeds in top gear:-
30 MPH = 1262 RPM 40 MPH = 1682 RPM 50 MPH = 2103 RPM 60 MPH = 2524 RPM
70 MPH = 2944 RPM 80 MPH = 3365 RPM 90 MPH = 3785 RPM 100 MPH = 4206 RPM

Top Speed in 1 gear = 38.041 MPH
And changes into 2 gear at 3706 RPM dropping 2594 RPM
Top Speed in 2 gear = 64.670 MPH
And changes into 3 gear at 4312 RPM dropping 1988 RPM
Top Speed in 3 gear = 94.488 MPH
And changes into 4 gear at 5030 RPM dropping 1270 RPM
Top Speed in 4 gear = 118.350 MPH
And changes into 5 gear at 4978 RPM dropping 1322 RPM
Top Speed in 5 gear = 149.784 MPH

[LeeM]

1 hour ago, 911 said:

I don't agree with that.

If second gear is capable of doing 100km/h - based off of the charts. I think you'd simply go up to the redline in 2nd, with no chance of any gearbox damage or over-revving.

Over-revving would occur if you exceeded 64mph and dropped into 2nd with a lightning quick gear change. 

 That's fine mate, though it was a hypothetical answer to a hypothetical question.

 Hypothetically you COULD damage your gearbox, and you COULD also have compression lock and spin you're arse around ending up in a cement wall, yet these are hypothetical scenarios.

   If someone was stupid enough to find out what would happen if they changed from 5th to 2nd at 100kph in an old car, then that's up to them to find out, yet I'd expect a report back as to whether it went ok or the gearbox exploded into a million shards of metal 😁 👍

[spiller]

You are over thinking this. If you find yourself calculating what engine speed you will potentially be at based on gear ratios whilst trying to threshold brake and downshift on a race track, your mind is not on the job and you will likely make a mistake. Down shifting in a braking zone is based on having an understanding and “feel” for what your car is doing at any given moment. You can’t calculate your way through this situation and if you’re worried about overrevs, don’t go on track or buy something with PDK.

[911]

49 minutes ago, LeeM said:

 That's fine mate, though it was a hypothetical answer to a hypothetical question.

 Hypothetically you COULD damage your gearbox, and you COULD also have compression lock and spin you're arse around ending up in a cement wall, yet these are hypothetical scenarios.

   If someone was stupid enough to find out what would happen if they changed from 5th to 2nd at 100kph in an old car, then that's up to them to find out, yet I'd expect a report back as to whether it went ok or the gearbox exploded into a million shards of metal 😁 👍

Just based off the information provided. Obviously in a real world example things can go wrong. Just based on the gearing provided above. I think if he slots into 2nd from 5th at 100km/h he will be close to the redline in second, but not over-revving. Unless I'm wrong? 

He said it was just a hypothetical. I'm guessing he wants to practice his shifting and wants to make sure if he stays under 100km/h, which is the high end of the speed limit that a misshift won't cause an over-rev. 

I'm no transmission in expert, someone else might prove me wrong. 

[davidtran]

21 minutes ago, spiller said:

You are over thinking this. If you find yourself calculating what engine speed you will potentially be at based on gear ratios whilst trying to threshold brake and downshift on a race track, your mind is not on the job and you will likely make a mistake. Down shifting in a braking zone is based on having an understanding and “feel” for what your car is doing at any given moment. You can’t calculate your way through this situation and if you’re worried about overrevs, don’t go on track or buy something with PDK.

Thanks for getting back to me. As the 911 has said I'm just asking while I practice on daily driving. I want to make sure I don't make mistakes on the tracks. I just want to know if my interpretation is right from someone who would know. 

[LeeM]

1 hour ago, 911 said:

 

I'm no transmission in expert, someone else might prove me wrong. 

 Neither am I, yet I'm not one that wants to find out either 😁

 I've done 20 odd years of bike racing, and a few years in my 911 in the hills with...let's say 'spirited' driving, so I think I may have a bit of a grasp on what would probably happen.

1 hour ago, davidtran said:

Thanks for getting back to me. As the 911 has said I'm just asking while I practice on daily driving. I want to make sure I don't make mistakes on the tracks. I just want to know if my interpretation is right from someone who would know. 

   @spiller has basically nailed it mate, as he drives a manual 996 cup car, a road GT3 and he's quick, so he's worth listening to.

 Just enjoy learning your new car, then hit the track when you're comfortable in it 👍

[911rox]

7 hours ago, davidtran said:

Won't be intentionally going from 5 to 2 obviously. 

More of a hypothetical to know and understand the risks of overreving if I don't exceed 100km/h. So while I'm on the street I can practice gearing without the risk of overrev if that makes sense. 

As per above i don't think you can enter 1st until your speed is low enough on G50. So 2nd gear being the next lowest and 5th being the highest. My question is, is there a risk of overreving if I do not exceed 100km/h?

Theoretically there is no risk of over-revving the engine per the graph if you keep it under 64mph as long as the car has the factory gear ratios and final drive installed. Gears ratios are fixed and therefore engine speed can't change in a non linear fashion. You are correct in your assumption. 

When I first started tracking, I drew the same graph for my car to determine the theoretical maximum speeds for each gear. In reality you don't use this information as suggested by others. By extending each line the same graph can be used to determine the theoretical overrev if the wrong gear was slotted... 

[OBRUT]

@davidtran Why do you think 1st is locked out?

[davidtran]

12 hours ago, 911rox said:

Theoretically there is no risk of over-revving the engine per the graph if you keep it under 64mph as long as the car has the factory gear ratios and final drive installed. Gears ratios are fixed and therefore engine speed can't change in a non linear fashion. You are correct in your assumption. 

When I first started tracking, I drew the same graph for my car to determine the theoretical maximum speeds for each gear. In reality you don't use this information as suggested by others. By extending each line the same graph can be used to determine the theoretical overrev if the wrong gear was slotted... 

Thanks very much. That's all I wanted to know. 

11 hours ago, OBRUT said:

@davidtran Why do you think 1st is locked out?

Might be wrong, but locked out maybe not the best term. I believe it's hard to get into first without jamming it in, unless you're going at low speed. Other gears go in smooth if that makes sense. 

[OBRUT]

3 hours ago, davidtran said:

Thanks very much. That's all I wanted to know. 

Might be wrong, but locked out maybe not the best term. I believe it's hard to get into first without jamming it in, unless you're going at low speed. Other gears go in smooth if that makes sense. 

It will go in easier then you think, especially with the revs up a bit. 

[911rox]

4 hours ago, davidtran said:

Thanks very much. That's all I wanted to know. 

Might be wrong, but locked out maybe not the best term. I believe it's hard to get into first without jamming it in, unless you're going at low speed. Other gears go in smooth if that makes sense. 

No worries, all good...

On track, the highest risk for a "money shift" IMO is the 4th to 5th shift. People often don't lean on the gate enough when they rush the shift and slot it into 3rd... Always feel for the shifter having gone across before releasing the clutch going 4 > 5...