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It occurred to me that you will not be able to answer any of this, but I’m going to write down what’s going through my mind anyway.
The bore diameter that I ended up at on my setup is 7/8”, but It just came to me that this may be irrelevant due to two main factors.
1. The RX-7 system uses a fork and has a mechanical advantage/lever action which looks like a 3:1 ratio (guesstimating). Or in other words, for example, the slave must extend 3mm for every 1mm at the throw-out bearing. The concentric system is obviously direct 1:1. It looks like the concentric system would be much more sensitive to input.. if not to consider the second factor..
2. I really don’t think there could be a simple bore diameter measurement for a concentric slave cylinder; being that it’s hollow in order to straddle the input shaft.. This means area would have to be calculated based on the inner ID and outer ID of the “bore”. Without those two diameters, and without knowing the exact mechanical advantage of the factory fork, it appears I cannot mathematically compare these two setups.
Is the slave you use in this kit a Nissan part? I may have to get one to dissect.
Last edited by R_PROWESS; Jan 25, 2019 at 08:58 AM.
It occurred to me that you will not be able to answer any of this, but I’m going to write down what’s going through my mind anyway.
The bore diameter that I ended up at on my setup is 7/8”, but It just came to me that this may be irrelevant due to two main factors.
1. The RX-7 system uses a fork and has a mechanical advantage/lever action which looks like a 3:1 ratio (guesstimating). Or in other words, for example, the slave must extend 3mm for every 1mm at the throw-out bearing. The concentric system is obviously direct 1:1. It looks like the concentric system would be much more sensitive to input.. if not to consider the second factor.
I believe this to be the case as well. Also, most concentric slave cylinders impart force much more evenly across the face of the pressure plate than a fork/collar lever bearing. This translates to roughly 1/4 - 1/3 of the pedal pressure being exhumed on just getting the bearing collar ears to slide into position on the fork ends as the pressure evens out across the pressure plate. Surely that accounts for some of the feel when being pressed. I believe that is the reason a lot of high performance kits are going that way too. It's just far easier, and AP and Tilton have been supplying these bearings for that reason for quite a long time now. OEMs are only now catching up (with the exception of Saab and a few others, who have been doing it since mid to late 80's)
Originally Posted by keithrulz
2. I really don’t think there could be a simple bore diameter measurement for a concentric slave cylinder; being that it’s hollow in order to straddle the input shaft.. This means area would have to be calculated based on the inner ID and outer ID of the “bore”. Without those two diameters, and without knowing the exact mechanical advantage of the factory fork, it appears I cannot mathematically compare these two setups.
Precisely why I said it's matched to a 5/8" master cylinder, as that is the only way of identifying what it's for. I believe with that in mind, and the factory slave being similar, and the pedal pressure being directly actuated as soon as the pedal is pressed- that is the reason why it feels like a normal HD clutch in the current race car setup. (Slightly different bearing, however, but works the same)
Originally Posted by keithrulz
Is the slave you use in this kit a Nissan part? I may have to get one to dissect.
It is not. The factory Nissan bearing is tiny, and it's also absolute ****.
This whole kit started because I got a practically brand new transmission because of a 370z owner who demanded Nissan change his transmission after his slave cylinder took a **** before 15,000km. I got the transmission out of it.
I can take my spare bearing apart today and measure the ins and outs and let you know what it looks like.
The bearing also has a fluid diffuser built into the base to help with bleeding, I assume.
yes all year rx7's and rx8's are stock with 5/8" clutch masters and 3/4" clutch slaves from my research while developing this kit.
the slave supplied in the kit is matched to a 5/8" clutch master and a 13/16" clutch slave in all years before they switched to the supplied internal hydraulic bearing. before and after the slave style switch, every model uses the same clutch kit regardless of type of release mechanism.
There is a post in the thread that keithrulz posted stating that someone bored their own factory cylinder to 21mm to achieve the results of a larger bore that FEED sells: https://www.rx7club.com/3rd-generati.../#post12308372
Another user mentioned that there is a Jeep model slave that fits an RX7. I did find some 0.880" jeep clutch slaves, which is 22.35mm or so.
So the hydraulic bearing in the kit is most likely an already larger "effective bore" than the stock rx7 slave cylinders, and should operate as good or better on most, if not all clutch kits.
Also, I have another bearing that is slightly smaller that moves the bearing contact face closer to the center of the clutch diaphragm to enhance leverage on the release mechanism, but have not tested the effectiveness of this unit on "stock" style RX7 pressure plates. It seemed a bit too small when test fitting, so it might work great for the multiplate clutch units which make use of a Datsun 510 bearing (which I have as well to compare) but I have no multiplate units to test.
Again, willing to work with anyone who is using that setup on this. Though it will take a bit of back-and-forth.
so to recap:
RX7/RX8 cars: 5/8" master + 3/4" slave (19.05mm bore diam)
Kit parts: 5/8" master + 13/16" approx. slave (20.6375mm bore diam) [before they switched to a concentric slave cylinder, but still used the same clutch kit components]
Last edited by Careless; Jan 27, 2019 at 10:42 AM.
I can take my spare bearing apart today and measure the ins and outs and let you know what it looks like.
The bearing also has a fluid diffuser built into the base to help with bleeding, I assume.
I measured the 3 cylinders I have here, and will message you to have a discussion about this and then we can reconvene with our findings here later, as I don't want to mud up this thread for a somewhat off-shoot discussion.
I'd definitely be interested in buying a kit from you in a month or two if you have any left or whenever you do a second run. Either way i'll be following this thread for sure!
I'd definitely be interested in buying a kit from you in a month or two if you have any left or whenever you do a second run. Either way i'll be following this thread for sure!
Hi,
Sending 4 out today. Have about 3 or 4 remaining. Have to double check.
I figure a lot of the interested parties are awaiting tax returns, so I expect that these 3 or 4 will still be here when you decide.
Not sure when the second run will be complete, but a lot of the production delays will be ironed out in the second run, so delivery time will be sooner.
Will keep you guys posted and answer any questions you may have either here on in direct messages.
Thanks for your interest.
Here's what the packaging looks like (This is the stack of 4 boxes + misc items).
And this is what you get inside (minus the packaging filler material, which is well packed too):
Steps may change with instruction manual updates, but I'm still working on making it bullet proof.
sending 4 out today. Have about 3 or 4 remaining. Have to double check.
I figure a lot of the interested parties are awaiting tax returns, so i expect that these 3 or 4 will still be here when you decide.
Not sure when the second run will be complete, but a lot of the production delays will be ironed out in the second run, so delivery time will be sooner.
Will keep you guys posted and answer any questions you may have either here on in direct messages.
Thanks for your interest.
Here's what the packaging looks like (this is the stack of 4 boxes + misc items).
and this is what you get inside (minus the packaging filler material, which is well packed too):
steps may change with instruction manual updates, but i'm still working on making it bullet proof.
I also received my kit a few days ago. Starting with the packaging, it arrived in a neat box with many boxes inside it. Each cut perfectly to fit against each other for no rattles and neatly labeled with printed stickers. All the components are top notch quality and I was especially impressed by the starter mount’s beauty. Every single edge on all parts has a nice bevel so it looks very high grade. The entire thing from packaging to product looks very professional and on par with some of the best in the industry. Can’t wait for my car to be up and running!!
I think in the future if Careless developed/offered a shifter adapter and crossmember for FC/FD this would complete this kit and people would start buying it like bread!
Other than that, I want to point out that the OEM shifters from these transmissions feel great and Z’s are one of the few cars that not many people get short shifters.
That being said, most shifter relocation kits for this trans convert it to a short shifter. Which is not desirable for me personally.
Mazworx seems to make a nice relocation kit that keeps OEM shifter AND seems to be perfect length for the FC chassis. I’ll be going with that for now.
how are making out with this kit and where again I can get the shifter to fit a turbo 2 fc.
I have one more available on this run, but I have to wait a week to see if the last package I sent was lost by UPS in shipment.
If it is found and ends up in the purchasers hands soon, then the last kit will be available for purchase. Otherwise, I will be producing a second run, and that should be something like 4-6 weeks depending on machining time- which is something I can't quite control if they're busy. I will be contacting people in the order in which they contacted me and will see who is actually interested in buying vs. who is on the fence.
I will keep you guys posted, but another run of 16 more complete kits will be available soon if I have to send another one due to UPS, and I will get lead time on the machining. The rest of the parts I have in stock, minus a few fasteners and the custom clutch lines which take a few days to have made.
Hi guys! I’m happy to say the car is finished with the swap and is driving out and about!!
While this is doable with the engine in the car, I strongly suggest you guys to pull your engines and mate the trans while it’s outside the car so you can see easily all the clearances and the way things are bolting together.
I have an FC chassis, had to cut off the little “ears” for the stock trans in the tunnel. Then I took a 4lb hammer to it to widen it a bit to make ample room for movement. I’m using an ACT Xtreme pressure plate with ACT SR20 6-pick clutch disk. The 6-puck sprung disk is very driveable I might add. The SR20 disk works perfectly as it has the 24-spline for Nissan shaft while being 240mm wide as the FC Turbo clutches. Using an ACT Streetlite flywheel which worked well with Careless’ supplied spacer and hardware.
The bleeder Careless provided has absolutely perfect placement to just screw in your FC clutch hose into. Bleeds well too.
Custom driveshaft was a breeze with the help of a local driveshaft business.
As for the crossmember, don’t judge me but I just used a long 1/2” thick steel bar and drilled some holes into it. I repurposed some FC poly engine mounts as bushings for the transmission. After these pics were taken, I did make up a couple 1” spacers on top of the bushings to raise the tail of the transmission. It was hanging a little. Now it’s all level.
Also I used a Mazworx shifter which is a simple affair. Shifter sits an inch backward from stock, having to cut a notch in the interior piece so you can go into 2nd, 4th and 6th gear. No big deal. In Layman's terms:
1. Buy kit
2. Buy FC flywheel/pp and SR20 clutch disk
3. Pull engine
4. Mazworx shifter
4. Bang ur tunnel
5. Mate engine/trans
6. Drop in engine/trans
7. Buy extra FC engine mounts to use for trans mounts
8. Drill holes in a 1/2 inch steel bar and use 2 plates on top side with bolts/nuts
9. Get custom driveshaft (slip yoke that goes in trans Part# is 3-3-7091X)
10. Enjoy!
All in all, with Careless’ great communication this whole process has been relatively easy. Given the fact that I went into this totally blind as there aren’t any other FC’s with this swap other than Andrew’s car in Canada. And that car is a total race car with custom tunnel.
I want to say thank you to Careless for this endeavor and that it was well worth it!!!
Cant wait for a tune so I can start bangin gears into the summer!!
Big Brake Kit first, then this transmission kit. It’s gonna be an expensive year!
thanks for making this happen, I admire the work that it took to make it a reality.
2 questions
1. which mazworx shifter did you use? did you have to modify the location of the shifter hole on the trans tunnel?
2. what are you using for mounting the rear diff?
Originally Posted by Sash91
Hi guys! I’m happy to say the car is finished with the swap and is driving out and about!!
While this is doable with the engine in the car, I strongly suggest you guys to pull your engines and mate the trans while it’s outside the car so you can see easily all the clearances and the way things are bolting together.
I have an FC chassis, had to cut off the little “ears” for the stock trans in the tunnel. Then I took a 4lb hammer to it to widen it a bit to make ample room for movement. I’m using an ACT Xtreme pressure plate with ACT SR20 6-pick clutch disk. The 6-puck sprung disk is very driveable I might add. The SR20 disk works perfectly as it has the 24-spline for Nissan shaft while being 240mm wide as the FC Turbo clutches. Using an ACT Streetlite flywheel which worked well with Careless’ supplied spacer and hardware.
The bleeder Careless provided has absolutely perfect placement to just screw in your FC clutch hose into. Bleeds well too.
Custom driveshaft was a breeze with the help of a local driveshaft business.
As for the crossmember, don’t judge me but I just used a long 1/2” thick steel bar and drilled some holes into it. I repurposed some FC poly engine mounts as bushings for the transmission. After these pics were taken, I did make up a couple 1” spacers on top of the bushings to raise the tail of the transmission. It was hanging a little. Now it’s all level.
Also I used a Mazworx shifter which is a simple affair. Shifter sits an inch backward from stock, having to cut a notch in the interior piece so you can go into 2nd, 4th and 6th gear. No big deal. In Layman's terms:
1. Buy kit
2. Buy FC flywheel/pp and SR20 clutch disk
3. Pull engine
4. Mazworx shifter
4. Bang ur tunnel
5. Mate engine/trans
6. Drop in engine/trans
7. Buy extra FC engine mounts to use for trans mounts
8. Drill holes in a 1/2 inch steel bar and use 2 plates on top side with bolts/nuts
9. Get custom driveshaft (slip yoke that goes in trans Part# is 3-3-7091X)
10. Enjoy!
All in all, with Careless’ great communication this whole process has been relatively easy. Given the fact that I went into this totally blind as there aren’t any other FC’s with this swap other than Andrew’s car in Canada. And that car is a total race car with custom tunnel.
I want to say thank you to Careless for this endeavor and that it was well worth it!!!
Cant wait for a tune so I can start bangin gears into the summer!!
2 questions
1. which mazworx shifter did you use? did you have to modify the location of the shifter hole on the trans tunnel?
2. what are you using for mounting the rear diff?
Hi, sorry for the month late response.
1. I used the Mazworx shifter for a Nissan s-chassis. Link here https://www.mazworx.com/store/p/188-...r-Bracket.aspx
Between all brands of CD009 shifters out there, Mazworx seemed to bring the **** closest to the OEM position. It re-uses the stock Nissan lever and mechanism which feels perfect in my opinion. I had to elongate the opening on top of the tunnel by about an inch. Simple affair if you have a cut-off wheel
2. I have an FC so I'm not dealing with the Power-plant frame stuff like FD's. My diff is mounted regularly, albeit with a full catalog of the Powered by Maxx array of bushings and arms.
