R200 and R230 Ratios

[cyrus]

Q45

 

"G50 - Up to 96 - R200V LSD 3.538 ratio"

 

"FY33 - Second series with 4.1L - R200V LSD 3.692 ratio"

 

"F50 - Current Model - R200 2 pinion open 3.133 ratio"

 

 

300zx R2304.09

 

300zx TT R230 3.69

 

Does't a 2.76 and a 3.11 exist???

 

Is the R200V as strong as a R230? WHat's the difference?

[Brad-ManQ45]

The Armada has either a 3.36 or 2.98...

[Doug71zt]

The Z32 N/A is a R200V with a 4.09 ratio, not an R230

 

The difference between the two is basically the size of the ring gear, which is also a rough indication of the strength of the diff. An R200 has a 200mm dia. ring gear (7.9 inch) while the R230 has a 230mm dia. ring gear (9.0 inch). The case and internals of the R230 are also quite a bit heavier to match the increase in ring gear size. You'll know the difference if you try to pick up the R230 - it's a big hunk of iron.

I haven't heard of an R230 failing due to input power, the ring gear is the same size as the famous Ford 9 inch, but in a much stiffer housing, which increases power handling.

Matt (Cheftrd here) recently reported that one of his customer's cars chewed up the ring and pinion of an R200. It was a Cefiro sedan running an RB26, I believe putting out around 600 hp. It also took a couple teeth off of a gear in the transmission.

 

Doug

[cyrus]

Thanks for the info, but then all this info begs the question: If the old R200 has the same strength as the later R200, then why bother? Unfortuately I need a ration around 3.00 for my V160 trans.

[Doug71zt]

Well, a lot of the old R200's had only 2 pinion gears, which was the weak point. The later Z31 units had 4 pinions and late 87 and up had clutch lsd. The short-case R200V is used because it's cheap and available. As far as I'm concerned, it isn't any stronger, the internals are all the same, it isn't worth the work to put it in. The old R200 has 3.36, 3.54, 3.7, 3.9 and 4.11 ratios available from cars supplied to the N America market. To go lower, I think you could use the new series Q45 unit (3.133) and slip an LSD into the case. Or the Armada R230, although I don't know if its an IRS unit, as I've never looked at one.

 

Can you go taller in tire size to change the effective ratio? What size tires are you running now?

 

Doug

[cyrus]

Supra 6 Speed V160

 

1st - 3.827:1

 

2nd - 2.360:1

 

3rd - 1.685:1

 

4th - 1.312:1

 

5th - 1.00:1

 

6th - 0.793:1

 

tire 245/40/17 ~24.4" tall

 

Final drive wanted 2.96

 

present drive is 3.55 and the engine is tached up to 2800 on the freeway. Desired is 2300 rpm.

 

I am concerned about axles strength if I use the old R200 case...

 

That sounds good, but the the axles are not up to snuff. How strong are the 280zxt?

[Doug71zt]

Have you considered stuffing the Supra pumpkin into the Z rear suspension? If you could get it mounted in there, you would just have to get some custom CV shafts to mate the Supra inner CV to a set of Z31 outer CV's and use Ross's adapters. Maybe his billet stub axles also....As I've never played around with a newer Supra, I don't know what that would entail. Probably about the same amount of work as a R230 install.

As a side note, for the latest Q45 diff with the 3.133 ratio, you would have to put a short-nose R200 in there, as that ratio is only available with the short-nose pinion.

So - no matter what, you are stuck building another driveshaft and adapting the mounting and CV shafts. Maybe sticking a S14 240sx subframe under there would be the way to go......

 

Good Luck

 

Doug