View Full Version : PAR gearset/Nismo LSD ratios

Leroy Peterson
30-10-2015, 02:02 PM
my 32a gearbox has 1st-5th PAR straight-cuts (synchro) and a Nismo 1.5 mech LSD.
I'm hoping to work out the gear ratios and final drive.

The website says custom ratios are available: http://www.par-engineering.pl/index.php?option=com_content&view=article&id=48
After plugging some figures into a calculator, the closest figures (from my driving experience) are listed here on PGA: http://www.users.on.net/~paullus/pulsarorgau/tech_essentialgearboxinfo.html
PAR straight cut gearset:
1st 3.1
2nd 1.93
3rd 1.28
4th 0.956
5th 0.810
Final 4.167:1
Where did these figures come from? is it most commonly recommended by PAR, even though it differs from the PAR website?

But my 5th gear is long as fark.
The previous owner once said it was longer than N14 5th gear, and ive done 220-240 (speedo accuracy, is there such a thing?) in 5th gear at no more than 5,500 rpm. Even with lots of power its just doesnt gain much speed in 5th.

what would the likelyhood of the final drive being changed when the gearset or LSD were fitted?

nameplate 4.1:

30-10-2015, 03:06 PM
PAR make numerous gear and final drive ratios - so anything could be in the box

The ratios you've listed:
1st, 2nd and 3rd are custom
4th, 5th and the final drive are basically same as stock

You'll be able to work out the overall gearing for each gear by feeding engine RPM and road speed through some maths in Excel
If you don't know what the final drive ratio is it will be hard to work out the individual gear ratios

Leroy Peterson
30-10-2015, 03:12 PM
yeah, and to add to the complications are the speedo errors. I guess recording rpm in each gear at speeds less than 80km/h should help narrow it down a bit.

Whats PAR's philosophy on the crown and pinon shaft? is it just a strengthened version of stock or does it compliment the gearset?

Boosted VLAD
30-10-2015, 04:30 PM
I've got a stock ratio 5th gear on my PAR gear set, it's 0.755

Boosted VLAD
30-10-2015, 04:39 PM
PAR have changed their ratios a few times and have done custom ratios for people, but here are mine anyways, maybe this info can help you

1st 3.11
2nd 1.846
3rd 1.235
4th 0.956
5th 0.755 (Stock)
Final 4.176 (Stock)

I know these are my ratios for a fact because I've put the teeth through a gear ratio calculator

Tooth count on each gear and opposing gear:

1st 9/28
2nd 13/24
3rd 17/21
4th 23/22
5th 45/34
FD 71/17

When I got the box it had a PAR pinion shaft which I snapped and replaced with a Nissan one, the ratio for the PAR one was 4.428, 62/14 teeth, this and the stock ratio is what most people have gotten with their PAR boxes

Boosted VLAD
30-10-2015, 04:44 PM
I would get a gps and get a friend to write down the speeds at A SPECIFIC RPM in each gear,
Go to a website that accounts for gear ratios, final drive and tyre height and have a play around and see if you can get a match,

You can obviously find out your tyre size and you have 2 likely final drives to play with on the calculator,

Unless you want to go pulling the box apart, which I doubt you would just to figure out the ratios.....

Leroy Peterson
30-10-2015, 06:28 PM
Hmmm thanks for the info.
I need ratios and final drive for my ecu. The more accurate the better