switching differentials......

[Victor Laury]

Anyone hear of an R190 diff? I have a friend who boasts he has a rare, JDM 190 LSD diffy from a Skyline. Is he full of poo or set up?

[HS30-H]

The R192 diff ( for some reason usually referred to as an R190 in the USA ) was kind of like an R180 on steroids.

It was standard equipment on the PGC10 and KPGC10 Skyline GT-R and on the PS30 Fairlady Z432 and PS30-SB Fairlady Z432-R.

On an S30-series Z, its a straight bolt-in swap for the R180.

As fitted to the above cars, it came with LSD from the Factory. On the 432 and 432-R it came with a 4.44:1 ratio.

In the USA, Datsun Competition used to sell them as a performance upgrade.

Alan T.

[Victor Laury]

Do you have one for your 432 project, Alan?

[2ManyZs]

There was an R-190 on Ebay a few weeks ago with 5:88 gears and LSD..... he didn't get any bids with a Buy It Now of 750, so he ran it again and I think it sold for about 450...

Not a bad price for the R-190.... but with those gears, it would only be good for auto-X's....

[HS30-H]

I saw that on eBay, and got involved. It ended up as a bit of an argument.............

In fact, the R192 / R190 was never made with a "5.88:1" gear ratio, and the lowest ratio it came in was 5.125:1

I was convinced that the vendor actually had a 4.875:1 and was mis-describing it.

I told him so, and he bit my ear off with some choice language in reply

He told me that the 510 Auto-X'ers in California "use them all the time". I won't repeat the four letter words he added to spice things up...........

I told him that I might be interested in it if he could PROVE what gear ratio it had in it. All he had to do was open it up and take a photo of the stamping on the Crownwheel. Needless to say, he could not be bothered. That's eBay for you.

Either the person that eventually bought it KNEW that it was being mis-described, and had a fairly good idea of what he was getting, or he is in for a surprise. Mind you, I don't know what kind of event he would need a 5.88 diff ratio for, unless there are

wall-climbing events that I don't know about

I have a few R200's with LSD units fitted, and in several ratios. A 4.375:1 will get me close enough to the 4.44 ratio that would have been correct for the 432-R, so that's good enough for me.

Alan T.

[zed240au]

what the hell would you want a 5.88 ratio diff for hell the car would pull stumps it would be like a three speed gearbox unless you worked the motor for some big revs

I just fitted a 4.9 to my rx4 it works great but i got 9000 rpm to play with (too bad the welded centres cant handle the sticky tyres and 4.8 ratio blew two centers in one weekend not happy first dnf in along time)

Would think a 4.8 would be as low as you would need in a zed as for the r180 diffs i swear by them have been running one with lsd behind my v8 for years never given a hint of trouble

Mick

[texasz]

Only reason I could see that someone may want to run a 5.88 in a Z would be for some of the hill-climb races that are around. Something like the July 4th climb to the clouds (I think it's called, and I think that's the date) that runs up Pike's Peak in Colorado Springs, CO. That's one big hill with a huge elevation change...I have read how hard it is to tune the cars for the race due to the change in elevation...the peak is over 14000 feet. To add to the difficulty the last 2/3 of the road are not paved as I recall.

[HS30-H]

This is all academic, as the 5.88:1 ratio DOES NOT EXIST in the R190 / R192 - or the R180, or the R200.

Biggest numerical ratios were 5.142, and the 5.125 offered as a Sports Option ratio for the R190 / R192.

5.1 is quite adequate for almost any use - even with the biggest rolling circumference tyres that can be fitted under the standard wheelarches.

I'd like to hear from the guy who actually bought that "5.88" diff so that we can hear what it REALLY was.

[2ManyZs]

I'm wondering if it might be a 5:88 r&p from one of the truck diffs?

I guess it's possible to mix and match some of the ring and pinions if you have access to the proper tools to do the machine work. The only 5:88 I see in the Nissan Motorsports listings are for the H190 and the H233B diffs.

I wouldn't have bought it without seeing the ring gear stamping....If it wasn't a 5:88 I'm going to be kicking myself for not bidding on it....

[zed240au]

i know with the mazda's its just a matter of changing crown wheel and pinion from a mazda van into a rx series diff housing as no factory rx came with 4.4 or 4.9 only mazda vans does not require any machine work simple bolt in bolt out

Mick

[HS30-H]

If it were a custom-built / adapted R&P set then I'd be very worried indeed about how well the machining had been performed.

The vendor implied in his answers to me that it was a Factory combination in the R190 / R192 - which I know is not true.

I suppose anything is possible when you go custom.