CA16DE/CA18DE FWD Clutches

[mdb4879]

Hey, I was wondering what the differences are between the CA16DE and the CA18DE FWD clutches and flywheels. As I remember it's just the splines in the clutch disc, but I'm unsure. Are the flywheels basically the same? I ask because a CA16DE Spec Satge 3 just won't cut it for the next phase of my Pulsar and was wondering if I could use a CA16 clutch disc with a CA18DE(T) pressure plate for a stronger clutch? I know a CA18DE(T) clutch can't be used with an RS5F31A transmission, and visa versa with an RS5F50A transmission. But a transmission swap would be pointless in this car considering my plans. Any input?

[boost_boy]

CA16 clutch and transmission stuff is in the family of the SR20/GA16/E16. The CA18 is in the family of RS5F50 to include the maxima, stanza, the Pulsar SE with CA18DE, etc, etc. It's for heavy duty use and will not break so easily. The FWD SR20 trannies fall apart even with stock power and the CA16DE's transmission mated to CA18DET is "end game" for that transmission as it will let go. Go get yourself a complete CA18 clutch set-up and abandon any thoughts of using anything clutch related used on a CA16 whatever. To answer the question "No" and stop being a [email protected] . CA16...lol (you got jokes )

[mdb4879]

So what I gatherd from your post, Dee, is that ANYTHIING SR related is not for heavy-duty use... sounds about right although I do take offense to the E16 part. That's my baby, lol.

To my memory the common problem with the RS5F31A is 5th gear pop-out, which is caused by the engagement on the shift collar being too short making the engagement teeth wear out abnormally fast. Nissan made a revised fifth gear kit that changes the engagement from 1mm to 2mm and a pop-out fix kit is available that replaces the collar, fifth gear on the input shaft, and the seals and gasket that you'd be stupid not to replace while you're in there. Granted, I'm not saying it isn't a weaker transmission, because it definitely is, just to my knowledge the 5th gear pop-out is the main reason for getting rid of them.

But my point is that I'm waiting to find a good '88 Pulsar to use for my monster build, and when I do the transmission is staying in that car. Right now I'm just planning to get my current N13 back on the road, but with a few added goodies. So in the mean time since the RS5F31A is an inferior transmission and essentially worthless to us, and since I have a spare in my storage unit that already has 5th gear out so I REALLY don't care about it, why not see what it takes to make one of these pop . Plus I don't really drive the car a lot, and when I do I have a hard time really putting it through any abuse that most others would (Idk, I just have a fear of breaking stuff. I'll put on the throttle without a worry, but I can't bring myself to drop the clutch from 43,000rpm and power shift every gear everywhere I go. Even though it is just a toy.)

So anyways, just to clarify, I'm unsure exactly what you answered, Dee. Did you say "no" I shouldn't bother, or "no" a CA18 pressure plate won't bolt up to a CA16 flywheel?

[mdb4879]

I did a little poking around and found some info on the differences between the clutches (thank you Exedy). The CA18DE clutch has a 215mm diameter disc with a 24T spline, 1" diameter input shaft. The CA16DE clutch has a 200mm diameter disc with an 18T, 13/16" diameter input shaft. The disc diameter is the important factor for what I was wanting to know. I would think that one might be able to get away with using a smaller disc than the pressure plate was made for, but more than likely the results wouldn't be fantastic and with my current plans for the car there's no reason to try.

On another note, from looking at the input shaft specs I would definitely say the RS5F50 series transmission (CA18DE) is made to handle more power

[Liquid_Neon]

Its a tad old school by now, but back in the day When i was researching everything i could read I heard of multiple sr20 fwd turbos shredding their trannys. splitting cases, stripping stuff, and losing 5th gear

Sniff around on the exa board archives and you will hardly read of grenaded trannys. They take abuse and keep coming back for more. ca16 trannys suffer a lot of the same fate as sr20 fwd stuff and tend to have lot of clutch slip problems.

[mdb4879]

To my knowledge the gearsets are the same if not interchangeable between the RS5F31A transmissions. Whether it be E, GA, SR, or CA16. They make two different pop-out kits with different 5th gears so idk if it wold matter which one was used if someone wanted to fix the problem. Luckily mine still has 5th gear, and I hope it stays that way for personal reasons (not DET build related). But if it goes out at some point, oh well. I may try to fix it or not. Not entirely sure.

I can only imagine the clutch slip issue is because no one makes a clutch for the CA16 transmission that will hold a substantial amount of torque. A Spec stage 3 is only rated for 210ft/lbs and the stage 4 for only 225. That's nothing. What do you think it would take to reach that? 14psi on a good tune, 16psi on a stock type tune? I made 160wtq with a holdable spike to 12psi if my gauge was at all accurate. Idk what the equates to at the crank, but it should be nearing the line. Regardless it doesn't matter since the transmission can't take the abuse. I guess the clutch is a good safeguard, lol

[livelyjay]

Just check out the difference between the two transmissions. Besides the obvious size difference, the RS5F50C transmission weighs a hell of a lot more than the RS5F31A. The axles that go with it are also a lot beefier than the RS5F31A axles. It's meant to take abuse. The clutch, flywheel, and pressure plate that Dee sent with my engine weigh probably twice as much as the OEM CA16 components. I was floored by the difference in flywheel weight.


I had heard that you can take the guts from the RS5F50C and put them into the RS5F31A case, but I'm not sure it can be done, and you'd still need axles.

[mdb4879]

Damn that thing is huge. I know the clutch is the same as a RWD CA. Idk about the flywheel, but if it then I just bought a RWD CA swap and it's flywheel is huge. From memory it's a fair bit bigger than my CA16's flywheel and enormous compared to the K20 flywheel I just pulled. I wonder how the RS5F50C and it's axles compare to a 2006 Civic SI's drivetrain.

[livelyjay]

Why are you curious about the Civic Si drivetain? What are your plans?

I did the transmission swap as a test for my swap. If I could do it, then I could maybe do the full engine swap. Dee said the OEM trans couldn't handle the power, and my OEM box was having pop-out issues and bad syncros. So I gathered up all the parts and did the conversion. I should have just bought a donor car, but there wasn't anything available until I had already purchased everything.

[mdb4879]

No big plans (at least not in the likes of what you were thinking ). I haven't ever seen the RS5F50C drivetrain in person. But I just did a clutch in a 2006 Civic Si so I do know what that looks like, and it looks pretty stout. Just from speculation from image comparison I would think the CA18 transmission would be stronger. The transmissions themselves look about the same size and while I haven't seen the axles and the input shaft is slightly smaller, the Si transmission is also a 6 speed. So if they are indeed roughly the same size dimensionally then I'd figure our transmissions should have larger, stronger gears. Knowing the Si trans is decently stout, and knowing what Dee has in front of his I'm pretty certain the RS5F50C is a behemoth, especially considering the car it came in.