Subframe/vlsd swap

[deviousKA]

This is a great community for a serious 240sx owner. You guys have helped out a bunch before and hope you can clear this up for me. my s13 240's open diff output seal is leaking and my car has high miles so most of the rear subframe and suspension bushings need to be replaced. i am looking for a vlsd equipped 240 to get the whole subframe with diff. besides 91-94 vlsd equipped models what is compatable with my car? s14? i will be sure to grab the driveline as well

[Dousan_PG]

no matter what you need a s13 subframe. or s15.
i DONT THINK s14 will fit

vlsd can be
z32
j30
s13
s14
s15
aftermarket unit in one of the above pumpkins


eveyrthing else might need to be changed slightly (rear vlsd cover/axles) to fit.

its a straight forward job.

[j240sxna]

Been there tried that stuff. You need to stick with a s13 subframe. S14 and s15 are interchangable. A bit wider compared to the s13 subframe. Diff from a s14 can be installed in a s13 provided you have the proper spacers. I have posted in detail about this on freshalloy a while back.

Jeremy

[Dousan_PG]

are you sure s15 doesnt fit? i recall a few Japanese companies using s15 subframes on 180sx
iirc, yashio factory was one. i might be confusing it though..its been awhile.

[j240sxna]

Positive. You might be able to get it to work by using offset subframe bushings but that is a serious pain for no real benefit.

[Dousan_PG]

im pretty sure you can change it, great for drifting
can you read japanese? if you can it would help, i'll scan it righ tnow

one sec, ill scan it up and have it posted in about 5 mins

[AKADriver]

A US-spec S13 VLSD rear subframe is, 99 times out of a hundred, going to have SuperHICAS.

If you want an LSD, I see people selling complete JDM rear subframes all the time, look into one of those. Ask the importer for a (RP)S13 rear subframe with a 4.08 VLSD and no HICAS. Should be farly easy to get.

[Dousan_PG]

somebody translate it!




pics #140 and 141

[j240sxna]

Geez, why doesn't everyone just go buy a s14 subframe and try it. That way you can find out the same thing I did. You need offset bushings and you need to weld on the s13 exhaust hangers. Useless swap if I may say so. What do you really gain???????


Jeremy

[Dousan_PG]

Originally posted by j240sxna
Geez, why doesn't everyone just go buy a s14 subframe and try it. That way you can find out the same thing I did. You need offset bushings and you need to weld on the s13 exhaust hangers. Useless swap if I may say so. What do you really gain???????


Jeremy

NOT S14, i was talking s15 the whole time.

[j240sxna]

As I mentioned before the s14 and s15 are the same dimensions!

[SaintlyCharBoy]

do any of y'all know about similarities between the z32 an ds14 subframes?

tia

[j240sxna]

z32 is way wider! Geometery seems visually the same between all of the subframes. In fact the s14 and s13 upper and rear lower arms are the same length and have the same angles. Using a s14 subframe you could still use a s14 upper arm to make sure it clears the strut.

-J

[Ozone240]

You can force the s14 subframe onto a s13. Probably not the best idea, but the stock bushings will flex enough to do it. If you are replacing the subframe bushings with poly or solid ones, then no, you will need offset ones like Jeremy was saying.

The s14 and s13 subframes are different, enough to make a big difference???? not sure. Here they are though:

1. The rear diff in s14 is isolated using rubber bushings (poly bushings are available), solid mount in s13.

2. The rear lower control arm is mounted at a different angle. If you look at the two pics posted (thanks dousan36) you can see the s13 lower control arm front mount is slightly above the subframe arm. On the s15, and s14 (just checked with mine in the garage) is mounted lower. I have heard that it is for more anti-squat. I am not a suspension engineer, so I can't validate that.

There is more bracing/stronger shaping of mounting points on the s15/s14 for the forward link and the upper control arm, can't see the toe link one to compare. As far as how much better (which is a relative term) this all is, who knows.

kevin

[j240sxna]

I have both subframes and still don't see a big enouh change in the reinforcement to make a difference. Isolating the diff was the main reason I wanted to do the swap.

As far as the lower arms being different angles. They might be slightly different angles. The one with the more tilt may be the one with the most squat from what I can determine. Weight transfered rearward more easily translates in a direct path.

Also the s14 has a longer wheel base so the angle might have also been designed for that. To really determine you could always look at a jun subframe and see what makes it hook up so much better off the line.

-J

[ruf]

Less antisquat. Makes the rear end much more predictable.