ca gearbox ratios
 

what are the gear ratios for the et ca s12 and s13 gearboxes? are they in the manual?

Also does the s13 use a different size diff to the s12?

84-86 S12
1st 3.592:1
2nd 2.057:1
3rd 1.361:1
4th 1.000.:1
5th 0.821:1
Rev 3.657:1

86.5+ S12
FS5W71C Warner
1st 3.321:1
2nd 1.902:1
3rd 1.308:1
4th 1:000:1
5th 0.759:1
Rev 3.382:1

are they both ca18et S12 gearbox's, 1 which is mk1 and the other mk2?

the fj box also has a different ratio, i think shorter first 2 gears and a longer final drive

whats the diff ratio? prob 3.92

what, on the fj dave.

with it being an NA engine and a sporty car i would say 3.9 / 4.1

the lower the ratio (diff) the longer the gear

the first one is the MK1 and the second one is the MK2 tranny.

You cant use the S13 crown wheel/pinion in the s12 case.

are you a vampire mart ?

No, my name is Buffy and I kill them for a living?

I dont want to.
can anyone help answer the question :)

im after the s13 ratios now and want to know if the diff ratios are the same

The info is on sxoc.

The S14 box is an option to consider as well

we need the info on hear, not to go searching the sxoc.

and why does it say sxoc, i thought it came up as a swear word lol.

xoc was in the filter for a while, not sxoc or zxoc. We had a lot of problems with spam posts with that url title Shaun.


Ive been trying to find it on sxoc and havnt found anything as yet.

From what magnum says the mk1 and mk2 boxs have different ratios. Is this definatly right. I wasnt expecting that. i just want to compare the s13 ones to the s12 ones

Just look at the S13/14 downloadable manuals for the data.

mk2 s12 and s13 are identical box ratios (in the uk anyway). S14 box can be used to replace any car using an s13 box if the S13 CA style belhousing is used rather than the s14 SR type. Straight swap, 20 mins for the bell housings.
As Martin said, s13/14 ratios are on the downloads, but essentially the s14 box gives longer 1st and 2nd, almost the same 3rd, identical 4th (1:1) and slightly shorter 5th. Its essemtially a 'close' ratio version of the S12 mk2/s13 boxes. There are afew variants of each of the boxes. I have had 2 different s12 mk2 boxes, 3 different s13 boxes and 2 different s14 boxes, but they are detail changes and only some parts are interchangable.
Ultimate box design is the last s14 boxes which have a 'trapdoor' design (similar to winged anti surge engine sump pans) on the centre steel bearing carrier that stops oil starvation to the bearings and gears on hard accelertaion and G loads.

I found a excel that mention 200 SX se 1987, the 5Th ratio is different that on mk2 ratios said before:

1st 3.321
2nd 1.902
3rd 1.308
4th 1.000
5th 0.838 instead of 5th 0.759:1

Final gear ratio 4.111

Perhaps it's an american difference.

http://www.mediafire.com/?8ctjqadnujd

What do you think about it?

The final ratio is in the rear diff. Changing this would have the best effect.

Manual - 3.7
Auto - 3.9
FJ20 - 4.11

3.9? Are you sure? i mean all sources tell 4.11 and 4.111 on R200 Ca18et :confused:

Manual CA18ET is 3.7

Auto CA18ET is 3.9

FJ20 is 4.111

Maybe the Euro 8 spark cars had different diffs

Would an ca s13 gearbox fit my mk1 s12 if i use my mk1 bellhousing?Or are the propshafts or selectors in different positions, I need to know weather to keep it as a spare or not

the s13 boxes are the same design but different length (longer) than a mk2 silvia box, the mk1 box is a lot different and a slightly different length too. Changing to and s13 box does mean a wider range of boxes available and possibility of a close ratio version if you use the s14 box with the s13 bell housing. Im 90% sure that the mk2 silvia box bellhousing is teh same as the s13 tho.

Did you have to change the length of the prop when using the S14 box, and was the shift in the same place? Was the gearbox mount transferrable?

I'm thinking of trying to find an S14 box. I already have 2 S12's and an S13 box, but if the prop length is the same as S14 then i'll use the S13 box till a decent S14 box comes up.

my car had an S12 mk2 box originally fitted. after breaking a couple i bought an s13 and s14 box. the s13 box, and s14box when fitted with the s13 CA bellhousing, are 50mm longer overall (in the tailhousing section actually), than teh S12 Mk2 boxes. it required the prop shortening by 50mm, but the gearbox mounting points on the box are in the same place and take the same mount as the Mk2 so its only the prop that you need to get shortened (cost me £40 inc balancing iirc).

the gearlever position is moved back 65mm though so the tunnel will need modifying too.

S14 ratios are better for my car anyway, and the latest s14 box i have has the anti surge trapdoor design too to stop the oil rushing away from the gearset asnd filling the tailshaft section.

Is there a difference in length to the S13 box and an S14/13 bellhousing combo?

ie, if I fit the S13 box will I need the prop shortened when I eventually get an S14/13 combo?

Have you considered going for an os giken gearset?

certainly the 3 s13 boxes and two s14 boxes (when fitted with CA bellhousings) i have had, are all the same length, so you will need to shrten the prop anyway to fit s13 or S13/14 hybrid.

i have considered the OS Giken stuff, but my gerabox failures (to date:D ) have been selectors rather than gear sets. In my opinion, i could run 20-30% MORE horsepower than a 200SX and not break the gear sets or tailshafts due to the lower weight of the car. Its torque that kills the gear sets and bearings and im not dragging a 1200kg tin car about, but 750kg of plastic pig instead! so the loads are less, and the box is subjected to those loads for less time due to the quicker acceleration of a much lighter car. Trouble is by the time you have a Giken box built up, its nigh on 2 grand and it uses stock selectors and H pattern.

I toyed with a Quaife sequential box for a while, but i just couldnt justify £6k for a box, even if i could afford it. The more i looked into it, it wouldnt fit anyway as theres a dirty great lump on the drivers side of the box that just wouldnt go into the chassis (see Brens pics of his S14 monster build). The HKS sequential box that i saw at the Autosport show would fit however as its all in a std size casing:D

If i do buy a race box, and it wont be in the next 18months as it would probably require a class change, i would probably go for the HKS or more likely the PPG dog box with possibly an Ikeya shifter.

Cheers Craig, I'll prob try to fit the S13 box first off then going for an S14 combo as and when.

What is it you do to break the lever arms (selectors) then, are you just too heavy handed with the box?

id like to say its a design weakness, but i suspect its because im a heavy handed mutha funker:D
i tend to stamp on the clutch and slam the lever into gear which breaks the cast 5th/reverse selector. Proper usage i reckon theyd last forever!

i'm not 100?% sure on this one but i thought if u got an early s13 box it was shorter than the later ones! i'll be able to tell ya for sure tommorow coz gonna try fitting a Greg s13 box into my mk2!

i have heard that too but all mine were longer than mk2 silvia. i suspect that the earlier s13 boxes are the same as the mk2 s12s anyway (they share the same FW part number accoring to FAST iirc.
why not measure the overall length from bell housing face to end of box, not including tin cup shit shield thingy? I have mk2 s12 box here from a mate that i can then measure up.

will have a look when i get to work tomorrow! hope it is a straight fit coz wanna get my wagon back on the road again by saturday!

Sounds like you see red craig on the track. One of our Marcos drivers always snaps his and couldnt work out why when all the other 8 drivers never had problems. We put a new gearnob on it with a bolt head on the top holdin it on( on his request) and sure enough it wore right threw his glove and his hand in a half hour race lol. He has actually even snapped the whole gearbox ally top cover completely in half once :p . Animal!

I aint there to make up the numbers:p
i managed to pull an ebay quickshifter outta the box at Curborough!:D
ive now bought a B&M shifter from Apex and its just the best shift ever on the nissan box, well impressed. makes accurate sweet shifts every time, i dont have to slam it into gear to ensure itll go in and not miss. havent broken a box since:) its a bit like the quaife shifts on the ford boxes if you are familiar with them? sweeeet.

like ya trick with your driver tho, very good idea.
a mate runs a race team, they run GTs, porsches and vipers, radicals and the odd Formula BMW and they often tell their drivers all sorts of bull to get them to do what they want. Special pads, softer tyres than the next guy, all bollox of course;)

The marcos box is pretty much identical . dog boxes with Quaiffe gears and really easy to rebuild.


As for the bullshit that gets told. Id love to comment but its a public forum ;)

my s13 box was longer!

Il sell my s13 one then

bit annoying really coz i read somewhere that the early 1 was a staight fit and bob from gbh told me it should be the same! unless some1 had fitted a late box to the s13 i got it from!