W58 supra gearbox conversion

[Sargeant_Khan]

I've driven 3 fc's and one with the supra box. All the stock fc boxes drove like shit, hard to shift at high speed and really sloppy in the shifter. Go to the ausrotary forum and search up the topics on gear oil. They're always debating what oil makes the gearbox less shit. Supra box and aftermarket box's are a popular mod on the rx7.
:beer

Glhf finding a rx7 box for 550 in gc...second hand rx7 gearbox's have all been flogged, just like the cars. How to lose with a $1000 reconditioned supra box?

[thrash]

The supra box feels odd to me.. but I think it's just a matter of getting used to the clutch. And the one I have, the difference between 1st and 2nd, as well as 4th and 5th gear is a bit too tall for street use.. sometimes i find myself struggling to choose between 1st and 2nd, and usually it's because both just feel wrong for some particular speeds and inclines. Being on 90km/h means I have to stay in 4th at about 2900rpm.. 5th becomes 2100-2200, and the car doesn't wanna climb even a slight incline at that rpm in 5th. Would be ok at 110 highway speed though :)

As far as the shifts are concerned, when I drove tom's car, the shifts felt smoother than they do in my car.. not sure why. maybe it's just me.

Also, the shifter sits just a tad too far forward for my liking.. might get the lever shortened, or get a short shifter down the track. Can't get into reverse gear with the handbrake up.

Definately a different feel to the starion box though.. the shift from 2nd to 3rd is EXTRAORDINARILY better. While with the starion box, when you're in gear, you can't move the lever much. The supra box on the other hand, has a lot of freeplay of the lever in any gear. It has less movement in neutral than the starion box though lol.

Oh, and in terms of getting the speedo accurate, it turns out most automotive instrument shops can easily make a ratio box for you, but they aren't cheap. The one that MRC told me about was in Lidcombe, Sydney.. and they will not just send you a ratio box - they want you to take the car to them, where they put it on their own calibrated dyno, and give you a ratio box based on their own calculations. Mind cost 240 bucks. Haven't had it installed yet. Will let you know how I go.

[Adriano]

DO the blokes in lidcombe put it on a dyno now. WHen i had one done we just took it for a drive over a marked km with a "counter"fitted to the speedo cable.

[greenstaz82]

the w58 in mine shifts smooth as , takes punishment up in the rev range .

[Lummy]

Yep, another vote for a W5* gearbox.

My car only does circuit racing - so it's whole life is hard. I haven't had a problem since swapping over to the Supra box.

It's not massive power (about 300HP at the wheels), but it does have crap loads of torque and that's what normally snaps gearboxes. This thing is holding up really well.

[thrash]

DO the blokes in lidcombe put it on a dyno now. WHen i had one done we just took it for a drive over a marked km with a "counter"fitted to the speedo cable.

lol.. yeah they got a dyno now. it's sort of embedded into the shop floor. No strapping the car in or anything.

[MR Bender]

love the supra box in my car its awsome!!
the only thing i would like if 2nd and 3rd where closer together! but apart from that its really good

[thrash]

mind you, according to dellow, you cannot tell the W5* boxes apart from each other by looking at them.. the only differences is in the ratios within. In light of this, I would say different people would have different experiences with the gearing in their supra box conversions.

I believe mine is actually a W58, as the difference in ratio between 1st and 2nd is the largest in this box, which is what I'm feeling when I drive, and the difference between 4th and 5th is also the largest in the W58. Tom had told me he thought this was a case, but dellow also say that W58s are rather rare and most of them are W55 or W57s.

Bender, You may find that you have the W59 if you have a wider-than-normal gap between 2nd and 3rd..

Following is a list of ratios I saved - info is gathered from dellow and projectzerog:

[thrash]

Looking at the numbers, I came to the conclusion that the W55 was the best box suited to the starion in terms of ratios, but this is a fairly useless conclusion since you can't tell if you have a W55 until after it is being driven on (or you take it apart and can count the ratios I suppose..)

[MR Bender]

the funny thing is that i was told that my box is a w55 box but i dont know?
and maybe im not reving it hard enough in 2nd i really need to get my tacho fixed!

[thrash]

some driving and calculations will allow you to figure it out ;)

This might be of some use:
http://www.projectzerog.com/files/gearR ... ulator.xls

But the W55 has almost the same ratios as the standard starion box, except for 1st gear.. so if you're feeling a larger gap between 2nd and 3rd, i don't think it'd be a W55

[MR Bender]

yer i dont know? :D
i mite take it for a drive and try and figure it out
thanks for the info thrash. :beer

[TomVR4]

I made an excel spreadsheet last year when I was thinking about putting a pajero diff centre in it. You can put in the diff ratio, gear ratios, shift rpm, wheel dimensions and it will give you a graph of speed vs rpm. its pretty messy though, I just made it when I was mucking around. If you want it pm your email address

[MR Bender]

I made an excel spreadsheet last year when I was thinking about putting a pajero diff centre in it. You can put in the diff ratio, gear ratios, shift rpm, wheel dimensions and it will give you a graph of speed vs rpm. its pretty messy though, I just made it when I was mucking around. If you want it pm your email address

that would be great mate!
pmed Tom

thanks

[MrBishi]

mind you, according to dellow, you cannot tell the W5* boxes apart from each other by looking at them..

Not strictly true. The W58 has a steel sandwich plate between the case and extension housing. Others have alloy (which can't be told apart).
The pick of the bunch would be the 2nd gen W58 found behind N/A 2JZs. Newer and apparently 'better'.