Lots Of Gearing Information for Sierras

[greg]

Hi All,

Got a bit bored at work today so I took the time to whip up a spreadsheet with a few calculations on it.

Please note that if i haven't covered your particular setup you can let me know and I'll add them in.

To follow will be all the obvious gearing setups I've thought of and their affect on:
1. Crawl Ratio
2. Engine Revs (5th Gear at 100kms only)
3. Speedo 'out of whackness'

Cheers,
Greg

[greg]

Here's the figures that all the formulas were based on:

Setup Transfer Case Diff Gears Final Ratio % Over Stock

wt x-fer + wt diffs 1.45 3.70 5.38 n/a
wt x-fer + nt diffs 1.45 4.11 5.98 1.11
wt x-fer + 5.12s 1.45 5.13 7.45 1.39
1L x-fer + wt diffs 1.59 3.70 5.88 1.09
1L x-fer + nt diffs 1.59 4.11 6.54 1.22
1L x-fer + 5.12s 1.59 5.13 8.15 1.51
RH1 + wt diffs 1.58 3.70 5.85 1.09
RH1 + nt diffs 1.58 4.11 6.50 1.21
RH1 + 5.12s 1.58 5.13 8.10 1.51
RH3 + wt diffs 1.63 3.70 6.04 1.12
RH3 + nt diffs 1.63 4.11 6.71 1.25
RH3 + 5.12s 1.63 5.13 8.37 1.56

If your combo doesn't exist here let me know and i will try to add it.

Note: I presume all of these combinations can be achieved - but no doubt some would take a fair amount of work.

Edit - updated with 1L and NT details

[grimbo]

What about my combo of 6:1 t/case, 4:1 diff gears

[greg]

What about my combo of 6:1 t/case, 4:1 diff gears

If you can tell me what the stock 1L 1st Gear is, and what the Low and High range for the 1L is, i will consider adding it for you

[grimbo]

but mine was a 1.3 with 4:1 diffs but now has a toyota gearbox with a 3.55 1st gear

[greg]

Crawl Ratios:

Crawl Ratio is quite simply a calculation of multiplying you 1st Gear, by your Tranfer Case Low Gear, and then by your diff Gear Ratio.

This does not accurately tell you how fast your car will travel, as this will also be affected by your tyre diameter. It does however determine how many rotations your engine will complete a rotation per each time your wheels will complete their rotation

Setup = Widetrack 1st x x-fer x diffs = Total Crawl Ratio
wt x-fer + wt diffs = 3.652 x 2.268 x 3.700 = 30.646
wt x-fer + nt diffs = 3.652 x 2.268 x 4.111 = 34.050
wt x-fer + 5.12s = 3.652 x 2.268 x 5.125 = 42.449
1L x-fer + wt diffs = 3.652 x 2.557 x 3.700 = 34.551
1L x-fer + nt diffs = 3.652 x 2.557 x 4.111 = 38.389
1L x-fer + 5.12s = 3.652 x 2.557 x 5.125 = 47.858
RH1 + wt diffs = 3.652 x 4.100 x 3.700 = 55.401
RH1 + nt diffs = 3.652 x 4.100 x 4.111 = 61.555
RH1 + 5.12s = 3.652 x 4.100 x 5.125 = 76.738
RH3 + wt diffs = 3.652 x 6.129 x 3.700 = 82.817
RH3 + nt diffs = 3.652 x 6.129 x 4.111 = 92.017
RH3 + 5.12s = 3.652 x 6.129 x 5.125 = 114.713

Note: If someone supplies me with the 1st Gear for a 1L I can put these up too.

[N*A*M]

1L numbers: low 2.557 high 1.590 diffs 4.111

[greg]

Engine Revs

These figures require me to have a starting figure to work with, so since i don't have one I have supplied all the other parts of the calculation and you can work out the rest for yourself

The calculation is simple, find which setup you are going to change to, and then the setup that you have now. Divide the new setup by the current setup and this will give you a figure. Take this figure and multiply it by your current Rev's to work out what your new revs will be.

Here are the figures:

wt x-fer + wt diffs 1.00
wt x-fer + nt diffs 1.11
wt x-fer + 5.12s 1.39
1L x-fer + wt diffs 1.09
1L x-fer + nt diffs 1.22
1L x-fer + 5.12s 1.51
RH1 + wt diffs 1.09
RH1 + nt diffs 1.21
RH1 + 5.12s 1.51
RH3 + wt diffs 1.12
RH3 + nt diffs 1.25
RH3 + 5.12s 1.56


Okay, for example:

I currently have a stock wt setup and am going to upgrade to a RH3 + 5.12's. Lets say that currently to do 100kms / ph I need to do 4000 rpms.

The calculation will be ( 1.56 / 1.00 ) x 4000 = 6240rpms

And the second example:
I currently have an RH1 and just want to put 5.12's in it. Currently i am doing 4500rpms to do 100kms ph.

The calculation will be ( 1.51 / 1.09 ) x 4500 = 6233rpms

Notes:
This calculation assumes a few things:
1. You are not changing tyre size
2. You are still driving your car in the same gear

EDIT: Added some more figures for 1L setup

[greg]

1L numbers: low 2.557 high 1.590 diffs 4.111

Thanks NAM... I'll add those into the figures

[greg]

but mine was a 1.3 with 4:1 diffs but now has a toyota gearbox with a 3.55 1st gear

sorry grimbo - i'm only listing upgrades, not downgrades

[Kirkv]

Ok everybody I found that chart about the suzuki gear combos.

This is assuming that you have a stock gearbox whyich has:

1st gear - 3.652
5th gear - 0.864

This will expain everything about any off the shelf gear combo available for a Sierra. Please note that the speed quoted in this chart is in miles/hour as it is a US site.

http://www.off-road.com/suzuki/reviews/sumogears.htm


If you want to go a bit further with some custom calculations try these.

Miles Per Hour = Kilometers Per Hour x 0.62137

Kilometers Per Hour = Miles Per Hour x 1.60934

MPH = RPM x Wheel Diameter (in) / Total Gear Ratio x 336

RPM = (MPH x Total Gear Ratio / Wheel Diameter (in) x 336

Horsepower (hp) = Kilowatt (hp) x 1.34

Kilowatt (kW) = Horsepower (hp) x 0.746


Hope this helps clear up the gearing confusions

Cheers

[bigsteve]

Hi All,

Got a bit bored at work today

Hey mate if you are that bored at work and you feel the need to crunch numbers can you do my Tax return??

[greg]

Hi All,

Got a bit bored at work today

Hey mate if you are that bored at work and you feel the need to crunch numbers can you do my Tax return??

I've still gotta get mine done actually... Getting a bit stressed about it now

[bigsteve]

Hi All,

Got a bit bored at work today

Hey mate if you are that bored at work and you feel the need to crunch numbers can you do my Tax return??

I've still gotta get mine done actually... Getting a bit stressed about it now

How could you leave a possible chance at more money for mods??

[greg]

How could you leave a possible chance at more money for mods??

I know man - it's criminal isn't it

[greg]

Speedo Out of Wackness - Tyre Size vs Diff Ratios

Note: this calculation assumes you are using a widetrack x-fer case, widetrack instrument cluster and widetrack speedo cable - i believe all of these will affect your reading if you mix and match these items.

Note 2: The figures shown are a percentage of how correct your speedo will be. So to get your speed, just multiply your speedo speed reading by the figure shown (per your tyre size) and you will know how fast you are really going.

For example: If you are running stock wt diffs, with 30" tyres, you speed when doing 100kms ph on the speedo will be (1.15x100km) = 115kms.

If you want the speedo reading for a given road speed, get the road speed and divide it by the same figure (100kms / 1.15) = 87kms.

Simple

[greg]

Speedo Out of Wackness - Wide Track running stock diffs:

Tyre Size - vs Percentage of Stock

26" Tyres 1.00
27" Tyres 1.04
28" Tyres 1.08
29" Tyres 1.12
30" Tyres 1.15
31" Tyres 1.19
32" Tyres 1.23
33" Tyres 1.27
34" Tyres 1.31
35" Tyres 1.35
36" Tyres 1.38

[greg]

Speedo Out of Wackness - Widetrack running Narrow Track Diff Ratios (is that possible?)...

Tyre Size vs Percentage of Stock

26" Tyres 0.90
27" Tyres 0.93
28" Tyres 0.97
29" Tyres 1.00
30" Tyres 1.04
31" Tyres 1.07
32" Tyres 1.11
33" Tyres 1.14
34" Tyres 1.18
35" Tyres 1.21
36" Tyres 1.25

[greg]

Speedo Out of Wackness - Widetrack running Vitara 5.12's

Tyre Size vs Percentage of Stock

26" Tyres 0.72
27" Tyres 0.75
28" Tyres 0.78
29" Tyres 0.81
30" Tyres 0.83
31" Tyres 0.86
32" Tyres 0.89
33" Tyres 0.92
34" Tyres 0.94
35" Tyres 0.97
36" Tyres 1.00

[Beastmavster]

Here's the figures that all the formulas were based on:

Setup Transfer Case Diff Gears Final Ratio % Over Stock

wt x-fer + wt diffs 1.45 3.70 5.38 n/a
wt x-fer + nt diffs 1.45 4.11 5.98 1.11
wt x-fer + 5.12s 1.45 5.13 7.45 1.39
1L x-fer + wt diffs 1.59 3.70 5.88 1.09
1L x-fer + nt diffs 1.59 4.11 6.54 1.22
1L x-fer + 5.12s 1.59 5.13 8.15 1.51
RH1 + wt diffs 1.58 3.70 5.85 1.09
RH1 + nt diffs 1.58 4.11 6.50 1.21
RH1 + 5.12s 1.58 5.13 8.10 1.51
RH3 + wt diffs 1.63 3.70 6.04 1.12
RH3 + nt diffs 1.63 4.11 6.71 1.25
RH3 + 5.12s 1.63 5.13 8.37 1.56

If your combo doesn't exist here let me know and i will try to add it.

Note: I presume all of these combinations can be achieved - but no doubt some would take a fair amount of work.

Edit - updated with 1L and NT details

What about 4.6 vit diffs? You have 5.12's but not 4.6's....

[Gutless]

WOW! Did you do anything at work today

what about 4.55 yota diffs, 3.65 sierra 1st gear, and 6.1 transfer??? That wasn't in there.

Bout 101 Final drive

Can you work out my percentage overdriven/underdriven? I run 33's.

[cj]

Here is a gearing spreadsheet for Zooks
http://autos.groups.yahoo.com/group/off ... -%20Excel/

[munga]

NT 1lt 4spd Sj410 sierra gears:

1st 3.163
2nd 1.954
3rd 1.421
4th 1.000
rev 3.321

4hi 1.590
4lo 2.716

diff 4.111

3.163 x 2.716 x 4.111 = 35.316 crawl ratio



ps: can we put this at the top of the gearing section of the sierra bible?

[largesuzy]

NT 1lt 4spd Sj410 sierra gears:

1st 3.163
2nd 1.954
3rd 1.421
4th 1.000
rev 3.321

4hi 1.590
4lo 2.716

diff 4.111

3.163 x 2.716 x 4.111 = 35.316 crawl ratio



ps: can we put this at the top of the gearing section of the sierra bible?

certainly can

[munga]

LJ80 / LJ80V gears:

1st 3.835
2nd 2.359
3rd 1.543
4th 1.000
rev 4.026

4hi 1.563
4lo 2.571

diff 4.556

3.835 x 2.571 x 4.556 = 44.921 crawl ratio

[Gutless]

Can someone tell me the gearing for this combo?

WT diffs, vitara 5sp box, and vitara transfer?

[munga]

1996 Vitara gears (5sp manual):

1st 3.652
2nd 1.947
3rd 1.379
4th 1.000
5th 0.795
rev 3.670

4hi 1.000
4lo 1.816

diff 5.129

(4sp auto):

1st 2.826
2nd 1.493
3rd 1.000
4th 0.730
rev 2.703

[munga]

Can someone tell me the gearing for this combo?

WT diffs, vitara 5sp box, and vitara transfer?

3.652 x 1.816 x 3.7 = 24.538

[Gutless]

hmmm. Better order some calmini gears with the tax cheque

[Bad JuJu]

I have S3+wt Diffs+wt gearbox+32" (32.6" actual) tyres .... what would my out of whackness be ???