6 speed manual gear ratios
- Thread starter theenico
- Start date
1.4T manual 6 speed ratios & MPH
For my 2012, I have noted that with the 15 inch wheels, at 2000 RPM
1st 10 mph
2nd 20 mph
3rd 30 mph
4th 40 mph
5th 55 mph
6th 66 mph
But according to my GPS, those speeds are indicating on the high side.
I have not see this posted before. Am I wrong?
For my 2012, I have noted that with the 15 inch wheels, at 2000 RPM
1st 10 mph
2nd 20 mph
3rd 30 mph
4th 40 mph
5th 55 mph
6th 66 mph
But according to my GPS, those speeds are indicating on the high side.
I have not see this posted before. Am I wrong?
theenico
New member
Preloader
The M32 Martyr
Is the Final drive number similar to the rear diff in RWD cars.
In other words does a higher number Final Drive translate to more acceleration in an otherwise same ratio gear box with a smaller final drive number.
The MZ0 has higher number ratios throughout, AND a higher final drive than the MZ4. Does that mean extra acceleration awesomeness?
In other words does a higher number Final Drive translate to more acceleration in an otherwise same ratio gear box with a smaller final drive number.
The MZ0 has higher number ratios throughout, AND a higher final drive than the MZ4. Does that mean extra acceleration awesomeness?
firstorbit84
New member
If I were going to build a custom geared box I'd want the shortest gears possible that would still get me to 60 at 6k in 2nd, with the lowest drop from 1st to 2nd.... yet with also the tallest 6th gear possible.
I'd have to play around with the numbers to which gears I'd want... my main concern is really the 1st to 2nd drop... otherwise the mz4 seems to be geared pretty well.
edit: it looks like the gears I already have are the tallest of the bunch. I wonder if there is a taller 1st gear out there to reduce the rpm drop... otherwise I could always put in a shorter 2nd gear, but then I wouldn't hit 60 in 2nd.
I'd have to play around with the numbers to which gears I'd want... my main concern is really the 1st to 2nd drop... otherwise the mz4 seems to be geared pretty well.
edit: it looks like the gears I already have are the tallest of the bunch. I wonder if there is a taller 1st gear out there to reduce the rpm drop... otherwise I could always put in a shorter 2nd gear, but then I wouldn't hit 60 in 2nd.
theenico
New member
I'm definitely still liking the MZ0.
Doing some math accounting for your 215/40R18 tire size as well, if your trap speed in the 1/4 is 94mph:
MZ4 3rd gear is at 6050rpm
MZ0 4th gear is at 5377rpm
In theory, your acceleration curve should be better with the MZ0, so if you can hit 100mph in the quarter:
MZ0 4th gear would be at 5720rpm
For ishts and giggles I did one more calculation. If you swapped the 4.18 R&P from the RS into the MZ0, 4th would be 6069rpm at 100mph.
Doing some math accounting for your 215/40R18 tire size as well, if your trap speed in the 1/4 is 94mph:
MZ4 3rd gear is at 6050rpm
MZ0 4th gear is at 5377rpm
In theory, your acceleration curve should be better with the MZ0, so if you can hit 100mph in the quarter:
MZ0 4th gear would be at 5720rpm
For ishts and giggles I did one more calculation. If you swapped the 4.18 R&P from the RS into the MZ0, 4th would be 6069rpm at 100mph.
klystron
Banned
I'm not sure it's always correct to say "the higher the number the better for acceleration" in all cases. If you have too short of gearing you are likely going to be shifting before your turbo spools up. It's all about the area under the curve. Turbo engines, imho, enjoy taller gearing because it's load that makes them spool up quicker.
Just my two cents.
theenico
New member
I agree. I was keeping it short and general. You can go too tall also.
Silly example: I'll start in 4th at 60mph and you start in 5th at 60. You'll spool like crazy, but I'll be walking away.
The law of diminishing returns definitely applies at a point. That's the reason I've been steering Preloader away from the MR5 in the RS. It's 1st and 2nd gears are too short for my liking, and it's compounded by that trans also having a 4.18 R&P.
Silly example: I'll start in 4th at 60mph and you start in 5th at 60. You'll spool like crazy, but I'll be walking away.
The law of diminishing returns definitely applies at a point. That's the reason I've been steering Preloader away from the MR5 in the RS. It's 1st and 2nd gears are too short for my liking, and it's compounded by that trans also having a 4.18 R&P.
Last edited:
Swordsmith
242hp/252 ft-lbs BNR EFI
But we don't dump boost between gears when doing a quarter, so does this really matter? Spool up only happens when we first drop the hammer.
(note, I don't know what I'm talking about here, so feel free to correct me... but I thought this was the idea behind NLS)
klystron
Banned
If you don't put enough load on an engine you can lose boost, too. Thenico is right in what he says about starting at 4th vs 5th, unless possibly we can spool infinitely and keep making power while doing it.
Gearing is all magic designed to deliver torque to the wheels. Remember that torque is torsional force. If the engine's crank turns over once and that corresponded with one turn in the tranny and that corresonded with one turn of the wheels, then your torque multiplier is 1 and a 100 ft/lbs engine will put 100 ft/lbs to the wheels. The shorter the gearing, the more torque you put to the wheels but the less time you have to make it before shifting. You can go 0-30 at 100 ft/lbs (assuming flat curve) and also go 0-3 at 1000 ft/lbs. Which is more practical?
I am now starting to think that it might be interesting to make a little program that determines acceleration given some engine output and gearing. This sounds like a classic optimization problem. Given a set of constraints, determine the ideal gearing required to maximize both acceleration rate and time required to go from 0-X.
Maybe we should put a CVT in the sonic.
And you will lose some boost even with NLS. In that moment of shifting the engine is putting out less exhaust (no load) so the turbo spins down slightly which will cause a hiccup in the boost level. I'd be curious how much mechanical forces buffer this effect.
If you are trying to make a 1/4 mile monster, your ideal goal should be to go through the traps right when you'd need to shift again in whatever gear you would top out at at those speeds.