I bought mine from RHDJapan. It got here as fast as anything from Japan does.

 

Yup, RHDJapan, it arrived pretty quick, like a few days if I remember.

 

Over here, you'd get the slave bored and honed to 13/16" for around $60, kit would be around $20. I'm surprised some enterprising individual over there couldn't do it as cheap or cheaper if people wanted to buy them in bulk exchange, rather than pay what I expect is over $US250 landed, just for a slave.

One of the blokes here used an off the shelf 7/8" mazda bus slave to the same effect.

 

R Magic also offers an overbored slave cylinder:

???? | RX7/RX8 ?????????? R Magic?????????

 

Bringing this back up with a question-
I hear a lot of improvements with from this cylinder with regards to the Exidy twin plate, is anyone running this with an ACT HDSS? I'm looking into new clutches and like the HDSS, but want to mitigate increased pedal force. I guess specifically, would you still get enough motion to fully disengage/engage a single plate clutch like the HDSS with this part?

 

After reading Speed of Light's comment, I found an old slave cylinder in my parts pile and bought a 98 4Runner slave from Rock Auto, and I shopped around looking for a machine shop to bore it out. So many turned me down, but I finally found one that would do it. Unfortunately, I forgot to ask how much it would cost.

Then I remembered the comment about a Jeep slave cylinder. I looked on Rock Auto and found one for an 86 Jeep Cherokee and it looked almost identical, down to the angle of the port for the line. I was hopeful the bolt holes were the same spacing apart and it used the same thread pitch, and neither of those is the case. The bolt holes aren't too far off, but it uses a 7/16-24 inverted flare rather than the stock M10x1.0 inverted flare. The rod is quite a bit longer, but it looks like I can use the original one with it, and use the boot for the Jeep slave, even though the FD rod just barely sticks out the end of the Jeep boot. The bore of the Jeep slave is around 0.88", so it should make a pretty big difference. It's a bit longer than the FD slave, but with the FD rod in both slaves, they're pretty much the same length. And it's about double the weight of the FD slave.

So long story short, the modifications to be made are as follows:

1. elongate or enlarge mounting holes
2. make a new line with a M10x1.0 inverted flare on one end and a 7/16-25 inverted flare on the other end.
3. swap over FD rod.

That's not too bad for $10-25.

It sticks out a little further past the flange, but the piston is around the same spot in the end due to the C clip.

The rods are about the same length when pushed back against the pistons.

The Jeep boot is a bit long, but should still work.



With the bolt threaded into either hole, the cylinder is pushed all the way to one side, so the holes will need to be enlarged or elongated.

This is with it pushed mostly to the other side.

 

Just ordered one of the Feed slave cylinders. Don't want these to become NLA before I need a replacement.

 

OK that's great. I might try the Jeep solution until I have all the 8hp bits

 

Just a little update:

I elongated the mount holes pretty easily. They're not pretty, but you can't see anything once it's bolted on, and it's under the car anyway haha. I also ground a bit of the flange to make room for the socket. The grinder got a bit out of hand a couple times lol.


I started making the line after that, luckily I have a transmission in pieces so I can use the bell housing for reference. I flared the slave end and put the first bend in the line, then realized the flare isn't making contact inside because the threads inside don't go down all the way and the fitting reaches the end of the threads too early. So now I need to either get an adapter (I haven't found any that go from M10x1 to 7/16-24), or maybe try to find a tap that goes all the way to the bottom, and that's fairly impossible since the flare at the bottom would keep even a flat-ended tap from reaching all the way down, and I haven't yet found any specialized taps for this. Or I could try to find a fitting where the center extends down a little further, or try to modify the fitting I have by taking off a few threads at the bottom. Furthermore, a 3/16" line is MAYBE just big enough to cover the opening at the bottom of the flare, so an adapter might be needed anyway. I've found a 7/16-24 to 3AN, so I'd maybe need to make a line with M10x1 on one end to 3AN on the other. Ultimately, whatever it is needs to be cheap enough or this all becomes a waste of time and money, and you should just buy the FEED slave or get a stock one bored out.

I still haven't heard from the local machine shop to see how much it's going to cost to bore out the stock slave.

 

I picked up the old slave cylinder that I had bored out by the local company. They charged me $231.75 lol, so I could have just bought the FEED slave and wouldn't have cost much more, and actually probably breaks even considering I had to buy the 4Runner slave also. Although a lot of that cost is because they had to fab a jig for it, and I'm getting quotes from them on how much it would cost to for 5 or 10 at a time.


I was able to clean the rust off of it pretty well, but I did run into one issue that I hadn't even thought about. After I had pulled the one out of the car (and I didn't think about capping the line because I was planning to be right back under there installing it, and I didn't realize so much fluid spilled out) I discovered that the bleeder screw for the old one was a different thread pitch than the newer ones. I was planning on swapping over my speed bleeder real quick, but it was too small. The old slave had a bore of M8x1, and I think the newer ones are either M7x1 or M6x1, I forget which. So I capped the line and found a regular bleeder screw for it from Napa. I took the car out last night though and boy it made a huge difference. It practically feels like a stock clutch now, although engagement does feel a bit ambiguous. With the stiffer clutch, you can definitely tell when the pedal starts engaging, and I have what feels like an inch of play at the top before it engages. But with the new one, it's so much easier that it makes it feel like there is much more play, so I guess I'll adjust the pedal, if I have any threads left.

I can't imagine how much lighter the Jeep slave will feel, probably like an 80s Camry lol. I drove my dad's Camry years ago and was amazed at how easy the clutch pedal was. It will probably be winter before I try that slave cylinder though. I'll report back when I do.