300km+

[drift_dingo]

allo all,

ok, so I has a long term project. to build a 300km/h+ Skyline.

What I have to work with:

Stock r33 '97 GTST, 98000k. now I think the diff ratio are 4.11 (granted its had the whole rear cradle replaced so I'm not entirely sure whats in it...) <-- any way to find out?

my main question, who makes a/m diff's for these things with tall ratio's? aka 3.9/3.7 ? i'm kinda iffy about getting s/h diff centres, not something I want going crunch...yesh, it won't be much chop on a stock engine, but I'm looking at a rb30/25 with a t04 in the long run as well.

[bubba]

This is what I did when I wanted taller ratios..

-Sourced a second hand auto S13 complete diff which is 3.9:1 (you need the whole things as the crown wheel has to match the pinion gear)

-Ordered a Nismo 2-way

-Gave S13 diff and 2-way centre to my diff guy to set up

-Collect new diff

-Put car on hoist and swap complete old diff for complete new diff

I vaguely remember coming across a 3.7:1 diff but can't remember what it was out of.. I recommend doing some searching as I think various ratios and what they came from was discussed.

[N1GTR]

Where do you plan on doing 300kmh?

Cool project

[zebra]

Leave the diff and just rev the thing to 9000rpm

[N1GTR]

Is the goal to just see 300 on the speedo/readout or do you want more? If so change the diff and then you don't have to rev the crap out of it

Here's another option to consider, if you're going to get a gearset for the gearbox, get a custom 5th gear made and leave the diff alone.

[R31Nismoid]

From memory a factory GTR ratio (gearbox & diff) will get to just over 300km/h (7500rpm+) provided you have the power to get there of course.

That would then mean, given the ratios are the same in GTS-t, you should be fine.

Nothing would require alterations at all really.

For the 3.7, pretty certain that was from the old Z stuff, but that is longnose R200, not sure of the dramas that might surround that.

Although in this day and age im sure there is someone that probably makes a off-shelf type thing anyway.

[NYTSKY]

Stock GTST diff ratio and gearbox ratio with 17inch wheels, max speed is 256km per hour at 7000rpm.

[PLYNX]

How about getting a six speed gearbox and fitting all the normal ratios up to fifth that the standard five speed has and then getting a lower ratio gear cut for sixth gear ? Probably around 0.6 ratio. This way you get relitavly normal driving and that way you dont have to change diff ratios.

[PM-R33]

From memory a factory GTR ratio (gearbox & diff) will get to just over 300km/h (7500rpm+) provided you have the power to get there of course.

That would then mean, given the ratios are the same in GTS-t, you should be fine.

Nothing would require alterations at all really.

Nah they won't unfortunately Ash, they fall quite short on stock gearing unless revved to 8000+. As Dave says sounds about correct. There was a similar discussion in this thread:

http://www.skylinesaustralia.com/forums/Pr...tr-t331234.html

Edited August 22, 2010 by PM-R33

[Ten Four]

You needs getrag. 335kmh I believe

[Deano 1]

farout where do u plan to go 300km? you doin a trip to the salt lakes?

[PM-R33]

Pfft, trip to do some grocery shopping, right?

[iseekool]

Something from an Aussie car.... 3.08:1 (Holden VR/VS) - might have to get something custom.....

[R31Nismoid]

Nah they won't unfortunately Ash, they fall quite short on stock gearing unless revved to 8000+. As Dave says sounds about correct. There was a similar discussion in this thread:

http://www.skylinesaustralia.com/forums/Pr...tr-t331234.html

lol, reads more like theorising as well

Perhaps the car im thinking off had a different gearset.

I'll have to dig up some info - this is going back quite a while.

[PM-R33]

Lol I had some estimates to back up my claims

From a bit of quick math with a Nissan Skyline 5th gear ratio of 0.75 and a final drive ratio of 4.111 and a common set of tyres such as 255/35/18 used, you would need approximately 8000rpm to hit 300km/h. 7500rpm would only give around 288km/h.

Where as a R34 GTR on same tyres revving to 8000rpm would hit around 340km/h due to its 6th gear ratio of 0.79 and final drive ratio of 3.55:1.

However this is only theoretical

Edited August 24, 2010 by PM-R33

[conan7772]

farout where do u plan to go 300km? you doin a trip to the salt lakes?

trouble with the salt lakes it the 70km of shitty dirt road you have to cross.

Here's an idea...

Get a couple of mates who wanna do it too.

Find a nice quiet 3km straight stretch of road in the country with no houses around and good phone coverage.

Go out with 3 cars and phones. Scope the straight then put a car 2-3 km's past the start and finish.

Wait for the all clear...

Go for it.

[Ten Four]

What PM-R33 said, you need getrag

[N1GTR]

If only we had that test track Bugatti use here in Oz

[nuclear_skyline]

How freakin awesome was that Bugatti... 431km/hr ZOMG!

[PM-R33]

Speaking completely hypothetically, to achieve 300km/h you really don't need that long of a stretch of road. Numerous highways in Australia would EASILY accomodate for such a speed and im sure have. Shame it is illegal to do so though and therefore should not be done.

But yeah 431km/h with that Veyron was insane!