Which gear box ?

[Devan]

Hi all,

As many other sx'ers can probably relate to I have been putting off finishing off

[Devan]

Sorry hit send by accident haha.

As I was saying been putting off finishing my 200 for a few years. Finally I have set myself this summer to get her how I want her to be or as close as the budget allows for the time being.

My question as is stated in the title, which gear box can a, fit directly to the ca18det engine and b, would people recommend the most. I want reliability more than anything else as I would prefer not to have to touch the gear box again for many years.

I will be looking for a standard used gear box, unless people recommend the standard one which I have about 3 or 4.

Thanks in advance

[Devan]

Too early, just reread last sentance. I meant to say I would only be looking to install a standard box from another car not one that costs the world unless people recommend that the original one is the one to stick to.

[GTSX]

It depends on what you want to use the car for.

A standard S13 gerabox if fine for most things and takes a fair bit of power and abuse.
You can always fit an S14 box to the CA bell housing and use that too, this will change your ratios slightly.
I think an S15 six speed works in there also, but I don't see the point.

[Jordan_200sx]

There isn't really much difference between SR/CA box in terms of strength and S15 boxes seem to strip syncro's for a passion. You option to progress from there will be a Z32 or RB25 box, or even a Z33 (350z) g'box but depends how much you ideally looking to spend

[Devan]

Thanks, basically I will be using the car as a weekend car and would like to take down the 1/4mile strip a couple of time.

No idea about bhp but from what I've been told I will be running Stage 3 taking into account the upgrades I've bought over the years and am yet to install. ( Id prefer a custom map rather than just buying stage3 chip, but that's another thread in itself)

I won't be drifting and drive sensibly.

I had a light bulb moment this morning thinking rather than just putting in my new engine to my existing box that it would be easier to put it onto a spare box I already own and swap the lot. From there if got me thinking if there was a better box.

[Devan]

Are Z32 or RB25 boxes a straight swap ?

[Jordan_200sx]

They need adapter plates and modified prop's

[Devan]

Is that easy enough to do ? Think I will keep my eye out for one.

[Actual_Ben_Taylor]

It's not really worth it unless you think you'll be running over 400bhp

Get a late S14a gearbox and have it rebuilt with a CA18 bellhousing and all new uprated bearings. This will be bulletproof on a stage 3 motor.

[alanjuggler]

given that you're at stage 3, I'd stick with a standard box either CA or SR.

the SR box is different in the later S14a boxes - they have gated oil control to ensure under acceleration that the oil doesn't move to the back of the box.

that'd be my preference given it's much easier, doesn't need new mounts welding up, doesn't need a new prop making, doesn't need an adaptor plate or any machining of the gearbox bell housing and keeps the stick in the standard position. (like the RB25/Z32 box)

[Devan]

Cheers for the input guys. Very helpful. I'm not making a completion car or anything, just want a solid car with power should I choose to stomp on someone from time to time.

Ideally July is when I want to have finished the work so I have a little time.

Pardon my ignorance but are you saying to put the SR workings into a CA18 gearbox housing whilst up rating the bearings ?

[Jordan_200sx]

The SR/CA bell housings are interchangeable dude, so put a CA bell housing on the SR Box/Main Case and it'll go straight onto your CA

[CNHSS1]

pics of an s13 CA box and a late model s14 box
right hand is CA box with just a slot in the centre plate, left hand is the gated s14




this shows the two sorts of bearing, open for s13 and rubber shielded for late s14 (again to stop oil flowing through bearings and into the wrong section, starving gear clusters)



this shows the s14 'gate' trap door to stop oil flowing into tailhousing under acceleration

[Actual_Ben_Taylor]

Aren't there aslo synchro differences?

[CNHSS1]

this is the little sprung loaded gate widget in all its glory





interestingly, PPG suggest all the holes in the centre plate be sealed up with JB Weld or similar when using one of their straight cut gearkits, and the main case filled thorugh the original filler plug and then the tail section filled through the gear lever hole

[CNHSS1]

s13 through s14 and late model s14 have detail changes, certainly some of the selectors are differing castings but all seem as tough/weak as each other (may just be me!!)

I think there are detail differences in synchros too, but ive never investigated the differences, synchros tend to get abused on track...

[green_rs13]

hi chris,
do you know how much oil PPG recommend putting in each section? as I have to swap the box currently fitted on my car so might give that a whirl as the box that's going on is a CA box and only cost me £20 so its no real bother using it as a bit of a test mule.
I keep stripping 3rd at like 280hp but really don't want to have to swap to a large casing box as I can see it costing me a grand.

[CNHSS1]

I don't know but id have guessed at about 60% main 40% tail section. If using a CA box you may need a shielded bottom bearing or it'll just move through the race.

My racers still broken :-( but the wo lads longest rebuild is using a Z32 and mazworks adaptor plate.
The current racer (road legal scimitar with 360 hp fully forged DET) has broken a selector in an s14 but touch wood the gears themselvss have stayed together with soft compound R888s. Have some wider super soft Kumhos for this season so will see if it chews the teeth off now! Lol

[green_rs13]

hmmn, in my haste I forgot about the centre bearings. don't think I can be arsed to strip it down that far just to swap those out. i guess if I blocked all the holes up and left it with the open bearings then I would run the risk of all the oil ending up in the rear.
my current solution is to just over fill it

I think it was just shock loading that killed my last one as it went as I upshifted to 3rd. not the usual clutch kick of death.