Georonimo

I'm certain that there is a FAQ topic some where on this board covering this swap into the RX7 but I can't seem to find it. I have in my possesion one low mileage rx8 trans that I have been wanting to stuff into something small and british (MGB) along with a 13b. I have established that that the bolt pattern is the same, but I'm not sure what clutch setup would be required. Any thoughts or a link would be appreciated.

RotaryRocket88

iTrader: (7)

Well, it is mentioned in the 2nd gen FAQ here: https://www.rx7club.com/showthread.p...49#post5131249, but since the RX8 transmission is different length & has weaker gears than TII transmissions, virtually no one would swap it into an RX7. Your case is obviously different.

I did some searching around, and it looks like RX8s use the same 225mm clutch disk as NA FCs. The input shaft splines are apparently the same too. So, if you're using an NA 13b engine, the existing flywheel and clutch should work.

Georonimo

Thanks for your help. Would this transmission be out of place in a first generation Rx7?

Turbo8

iTrader: (17)

The RX-8 actually used the same size flywheel and clutch as the FC Turbo and FD transmissions (240mm).

The RX-8 transmission is basically a modified Miata gearbox, the 04-08 transmissions are notoriously weak (bad shift forks and half shaft) and there are few options for stronger rebuilds that make economic sense.

VICEdOUT

iTrader: (1)

Turbo8 is correct, here is a link to Racing Beat's page:

Rotary Tech Tips: Transmissions

VICEdOUT

iTrader: (1)

Anyone know any other clutch slave cylinders that will work with the 6 speed on the FD swap? Since the Rx8 cylinder is too long and hits the 7's engine oil filter.. There has to be an easy swap to a shorter different slave cylinder that matches the bolt patters of the 8's tranny and does not hit the oil filter on the FD.. I will have to mix and match cylinders until I find the right fit if no one knows of one already..

VICEdOUT

iTrader: (1)

After looking for clutch slaves that look alike and might fit, I bought a slave cylinder from a 2005 Mitsubishi Eclipse 2.4 L and "Made it fit" (just hasn't been tested as of yet) but looks like it aligns properly just have to see if it will hold the pressure since the two mounting holes had to be drilled out bigger to match the mounting threads and it needed to be spaced upward unevenly to the right angle, it needs to use the 8's slave cylinder push rod as well...

73rx313b

iTrader: (40)

2005 Mitsubishi Eclipse huh??? I will have to remember that! I used one from an early 90's Honda on my rx3 6speed conversion. It may actually fit a little better than the Eclipse one because I didnt have to use the spacer bolts but good job finding one that worked!!! I like it!

VICEdOUT

iTrader: (1)

What model and year clutch slave cylinder did you use to be specific ? Post up some pictures, this is the perfect thread to do so. I might have to try your choice of cylinder if this one does not work out for me and everyone else will have some reference and starting points if they decide to go 6 speed..

73rx313b

iTrader: (40)

I will have to dig up the part# and info on it but it seems like it was a 91-92 Civic but dont quote me on it just yet. You can check my build thread for pics... I think there are a few in there.

kiwipwr

Did you manage to track down the part number for the honda slave cylinder mate?

Sgtblue

iTrader: (16)

Not certain of exactly what your dealing with or clearances you need, but GReddy (and possible others) make an oil filter relocating kit.

VICEdOUT

iTrader: (1)

It would hit the adapter assembly as well I believe, it's the lower part of the pedestal that will hit as well as the bottom of the oil filter.. I tried the early 90's Honda slave cylinder actual part number that you or someone else gave me in a different thread about the 6 speed to FD setup and it did not look like it would fit either, I went to Auto Zone and asked for it and looked at it next to the 8's cylinder and it has the banjo bolt for the clutch reservoir line stick out the back as well so I didn't even bring it home to test fit.. So far the 2005 Eclipse cylinder is the shortest, best fit for it with some modification of the mounting holes.. I would like to believe there is a perfect direct bolt on clutch slave cylinder out there that would work even better but has not yet been discovered ? ? ?

VICEdOUT

iTrader: (1)

Just refreshing the thread for a little bit of informative facts, Hey 73rx313b, the Autozone Duralast part # 13090 Cs2162 Slave Cylinder fits perfectly thanks again ! Altho the Eclipse Cylinder worked good too as far as pushing the rod in far enough, the one 73rx313b mentioned works and fits much better for anyone doing the 6 speed FD swap. On another note, I could not get it into gear with the engine running, after a long hybernation period, I finally started my FD engine and it fired right up, reved up real nicely too, but would not go into gear, with the engine off it does, but with engine on it does not. It seems as if it is pushing the rod in TOO much and I could feel the pedal max out before hitting the metal, I've played with the clutch pedal adjustment screw too with no luck. Maybe my combination of Rx7 and Rx8 clutch components did not work but I have a 93 FD Rx7 engine with 04 Rx8 Tranny, with FD Pressure Plate, Rx8 Friction Disk, Fidanza Aluminum Flywheel I had since my Rx8 engine (which is the exact same Fidanza flywheel used for either FD or Rx8) and the Rx8 Throwout bearing with an Rx7 Pilot bearing in the Eshaft. I'm guessing the setup does not like the FD's Pressure Plate and I was going to re buy another Rx8 Pressure Plate to try that, the Rx7 PP's arm splines seem like they are sucked in, compared to the Rx8 PP arm splines are longer and stick outward more, perhaps I need to use a Rx7 throwout bearing instead but I will try the Rx8 PP first.. What clutch components and setups are you FD with 6 speed tranny guys running ? Any thoughts or insight in the matter would be greatly appreciated.

ghost1000

iTrader: (1)

I'm using
ACT flywheel
Exeedy rx8 clutch kit.
1997 Honda civic slave.

have you fixed the problem yet? There are so few of us who used this setup.

Sgtblue

iTrader: (16)

There's probably a reason for that.

BLUE TII

iTrader: (9)

have you fixed the problem yet? There are so few of us who used this setup.

There's probably a reason for that.

simple mistake

Maybe my combination of Rx7 and Rx8 clutch components did not work but I have a 93 FD Rx7 engine with 04 Rx8 Tranny, with FD Pressure Plate, Rx8 Friction Disk, Fidanza Aluminum Flywheel I had since my Rx8 engine (which is the exact same Fidanza flywheel used for either FD or Rx8) and the Rx8 Throwout bearing with an Rx7 Pilot bearing in the Eshaft. I'm guessing the setup does not like the FD's Pressure Plate and I was going to re buy another Rx8 Pressure Plate to try that

FD is pull type pressure plate and RX-8 is push type- there is no way that set-up would work together.

Needed TII FC or RX-8 pressure plate.

VICEdOUT

iTrader: (1)

^ Yes I realized that very soon after I made that post and felt like a complete tool lol ... So in order for the Rx8 tranny - FD engine setup to work, you would need Rx8 Pressure plate and Friction Disc, altho some other Friction discs might work, and the Fidanza flywheel I have works on both engines, counter weight is based on the engine so FD counterweight, the FD Pilot Bearing I believe is the same as Rx8 and an Rx8 Throwout bearing is also needed. And I am currently rebuilding my 13B-REW and porting and polishing myself, the insides of the water passages were filthy with 20 year old orange coolant / water grime so it was very much needed, something that would not just simply wash off by flushing the coolant system, I mean there were chunks of orange rust stuff.. I also thoroughly cleaned the Rotors, Irons, Housings and all seals and springs with Kerosene in the parts washer for days.. Plus I very much wanted a Large Street Port, I used Pinneaple Racing Porting templates on both the intake and exhaust ports, EP5 large turbo port template on the exhaust ports.. I will be re-using all apex, side, corner seals and springs as the engine fired right up and ran / rev'd real good I got faith in it is a good core, and if needed I will do a full all out rebuild in the future... I will be using a cheap ebay Rx8 pressure plate till I get a double or triple disc clutch and sell the Fidanza.. =D I also got faith in the Rx8 AISIN 6 Speed tranny, with the Syncro-Saver I think it will hold up to high HP very nicley, I'm still to get a short throw shifter, and IF it breaks, I will try the later 09 and up one, and if that fails, then I guess it will be big bucks on a T56 for the ultimate 6 speed tranny. I gota update and post up the latest pics of my project to my Picasa web album one of these days, link on my SIG below.. Here is a vid of the engine reving up after a 20 year off duty period, first link below. I had it idling and reving for hours, just couldn't drive it =P . Have my tune pretty decent idling and warming up and cold starts, yet to perfect it under load and WOT, and new spark plugs are probably very much needed, I used the ones from my Rx8 engine that I tuned from very rich on down to leaner AFR's..


https://plus.google.com/photos/10408...77706267380755

nlsolja123

What mods to make the 8 trans fit ? Is it bolt in ,, what about drive shaft?

ghost1000

iTrader: (1)

The trans will bolt up
Need turbo 2/ rx8 clutch setup
1996 civic slave cylinder
You have to relocate the shifter
If it's a fc a turbo 2 drive shafts will work.
My drive shafts is a aftermarket oem spec shaft and it fit
You have to make a cross member to hold the trans. I used the factor FC3S mount spaced it with extruded polyurethane. I cut the center out of the oem mount. I bolted a plate to the trans and where they met when installed in the car is where I welded them together.

The gearing is close range but 6th is really low so you want 17"-18" wheels otherwise you might find the gearing to be too low. If you run 17" you want 235/45/17 or larger.

lastphaseofthis

iTrader: (8)

my way is different, i moved the engine back and down with custom engine mounts my build is in my sig.

nlsolja123

This is for a fd, are these fd installs ?

jamesfickackerly

I like the idea of installing 6 speed RX8 tranny on my RX7 but it seems unfeasible

ghost1000

iTrader: (1)

I would love to do this to a fd, especially to a automatic FD with 3.9 diff. The fd has room for 19" wheels so the gearing isn't a issue. 18" on the FC are hard to make look good but some guys have made them look great.

Some guys say it's a week trans, people break 3rd at around 350whp in the rx8, but the rx8 is heavy. My FC is 400lbs lighter then the rx8 so I think 375-400whp will be ok. It's the turque the rips them apart, turque the meets resistance which is weight.

The plus side is the close range gearing will make the car faster, my car will probably be as fast as other cars with 50 more HP.

nlsolja123

I did it. It's in my fd. The gearing is kinda rough. I only deponent this for track . Unless you have a 3.9 rear

When you use the Honda slave cylinder. Do you use the Honda arm or Mazda. My step brother kept the Mazda arm.

Under 8-10 PSi I feel like clutch is slipping. But could also be the slave has to much tension.