Rx8 transmission
06-17-21, 08:31 PM
#1
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Rx8 transmission
Just looking to see does anyone know anything about Rx8 transmission. Will it fit on a FD and what I will need to get it done.
your help will be greatly appreciated. Thanks.
your help will be greatly appreciated. Thanks.
06-17-21, 10:36 PM
#4
2004-2008 S1 Aisin trans is similar to the NB Miata 6 spd, 2009-2011 S2 Mazda trans is similar to the NC Miata 6-spd
the gearing is different from Miatas and also between the two RX8 versions, Miata PPF mount is on opposite side of tailhousing than the RX8, not sure how the Miata shifter positions compare to the RX8 since the tailhousings aren’t compatible. But it’s located ~3” shorter than the FD shifter position (RX8 engine position shifted further back into firewall)
They are weak compared to the FD 5-spd, the S2 version seems to be more durable, but super low 1st gear
imo you need a stronger trans if you want a 6-speed. I have at least 6 broken ones behind a 270 bhp NA Renesis engine and it really doesn’t fit wrt shifter though that might be modified to work. Unlikely that the ppf matches up either.
So overall not a good idea imo.
.
the gearing is different from Miatas and also between the two RX8 versions, Miata PPF mount is on opposite side of tailhousing than the RX8, not sure how the Miata shifter positions compare to the RX8 since the tailhousings aren’t compatible. But it’s located ~3” shorter than the FD shifter position (RX8 engine position shifted further back into firewall)
They are weak compared to the FD 5-spd, the S2 version seems to be more durable, but super low 1st gear
imo you need a stronger trans if you want a 6-speed. I have at least 6 broken ones behind a 270 bhp NA Renesis engine and it really doesn’t fit wrt shifter though that might be modified to work. Unlikely that the ppf matches up either.
So overall not a good idea imo.
.
Last edited by TeamRX8; 06-17-21 at 10:38 PM.
06-18-21, 08:16 AM
#6
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its also worth pointing out that the top gear in the 6 speed is shorter than the 5 speeds, so cruising rpm on the freeway goes up. you do get better spacing on the rest of the gears, there is one for every corner
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gracer7-rx7 (06-20-21)
06-18-21, 08:36 AM
#7
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Yep, this has been addressed in the past.
The RX-8 6-speed can't handle the power. Also the gearing is crap on an RX-8 - my bone stock RX-8 does 4000 RPM on the highway. I think they tried to gear it to compensate for lack of low-end power.
The RX-8 *5* speed that was in Japanese cars only is the same as the FD's trans. Just swap bell housing and tail shaft over. It's actually upgraded a bit as well. But it can be hard to find.
Dale
The RX-8 6-speed can't handle the power. Also the gearing is crap on an RX-8 - my bone stock RX-8 does 4000 RPM on the highway. I think they tried to gear it to compensate for lack of low-end power.
The RX-8 *5* speed that was in Japanese cars only is the same as the FD's trans. Just swap bell housing and tail shaft over. It's actually upgraded a bit as well. But it can be hard to find.
Dale
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06-18-21, 09:06 AM
#8
Yep, this has been addressed in the past.
The RX-8 6-speed can't handle the power. Also the gearing is crap on an RX-8 - my bone stock RX-8 does 4000 RPM on the highway. I think they tried to gear it to compensate for lack of low-end power.
The RX-8 *5* speed that was in Japanese cars only is the same as the FD's trans. Just swap bell housing and tail shaft over. It's actually upgraded a bit as well. But it can be hard to find.
Dale
The RX-8 6-speed can't handle the power. Also the gearing is crap on an RX-8 - my bone stock RX-8 does 4000 RPM on the highway. I think they tried to gear it to compensate for lack of low-end power.
The RX-8 *5* speed that was in Japanese cars only is the same as the FD's trans. Just swap bell housing and tail shaft over. It's actually upgraded a bit as well. But it can be hard to find.
Dale
06-18-21, 10:36 AM
#9
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we also didn't get the automatic climate control at all, until 2009 (it is possible to retrofit it)
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DaleClark (06-19-21)
06-18-21, 10:43 AM
#10
The Rx8 transmission is really only a viable option for high HP non-turbo cars, as it's designed for higher RPM ranges and low torque. Heck, RE Amemiya threw an Rx8 six speed in one of their track built FD's that was sporting a non-turbo peripheral port engine.
If you're turbocharged, I could see the Rx8 transmission disintegrating under the torque.
If you're turbocharged, I could see the Rx8 transmission disintegrating under the torque.
06-19-21, 03:24 PM
#11
The series I (04-08) RX8 6 speed manual is basically made of glass. The series 2 6 speed is better, but still unsure how much torque it can take...for what its worth I think they also used that on the Fiata 124 Spyder/Abarth so maybe it can take some torque.
06-20-21, 09:21 AM
#12
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the Fiata used the old 5 speed from the SA/FB/NA/NB/NC
06-20-21, 12:09 PM
#13
the Fiata used the old 5 speed from the SA/FB/NA/NB/NC
https://www.automobilemag.com/news/2...x5-miata-club/
Fiat pairs the MultiAir engine with the previous generation, NC Miata's six-speed box, by the way, to handle the turbo four's greater torque.
Fiat actually uses the previous-gen Miata’s six-speed gearbox to cope with the turbo’s torque.
all the problems with the 6 speeds are in the hubs/shift linkages.
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j9fd3s (06-21-21)
06-20-21, 01:42 PM
#14
For street driving on a lower powered car and a driver with mechanical sympathy, I suspect that the 6 speed will do OK - at least for a while. A few people on here have done the swap although they don't post much. Also Rotary Performance in TX did a few.
Many of the comments above are inaccurate or have way too much hyperbole so anyone reading this should do more research beyond this thread.
Many of the comments above are inaccurate or have way too much hyperbole so anyone reading this should do more research beyond this thread.
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