Solution for transmission(turbo setups)
#26
have you seen a turbo-II manual S4 transmission? Mounting points look very similar (2 bolt holes at the bottom of the transmission). If that fits, all you would have to do would be to cut the shifter shaft short and move the shifter housing forward.
#27
No respecter of malarkey
iTrader: (25)
you would have to do more than that, for starters the FC used a chassis trans mount not a PPF and the list goes on from there ....
just had a 5 spd RX8 trans offered to me, thinkng of buying it to hang out with the crowd of 6 speed boxes I have stacked up
just had a 5 spd RX8 trans offered to me, thinkng of buying it to hang out with the crowd of 6 speed boxes I have stacked up
Last edited by TeamRX8; 01-07-2013 at 09:04 PM.
#31
Hey everyone, I started re-building a new transmission today that will solve many people's problems. This transmission is actually and RX7 FD unit, although it's a 5-speed, I think the ratios are much better than the 6speed. This is actually kind of a info-DIY thread. The problems with the FD trans is that:
1.) the ppf frame has a slightly mounting point for 2 of the screws, you would have to alter the ppf. Forget about it...
2.) the clutch is inverted compared to ours, you would also need to alter the clutch line, new slave cylinder unit. No need...
3.) the shifter is in the wrong location. No problem...
Here in Europe we have a low power model with 192hp(basically your automatic version) to lower the cost. This version is offered in automatic and (only) a 5-speed manual. The 5-speed is the generic R15M-D which is also used in the RX7 FD. Now I'm not saying that it's the exact same gearbox, I don't know about the internals, and how strong they are. From what I know it's just the MX-5 equivalent, which is crap. So, I got a used damaged unit from the low power RX8 and switched over the parts. The outer casings(minus the bell housing and rear end) are the same, it's the same transmission layout. So the bell housing fits perfectly and has the clutch style that we need. The rear casing which houses the shifter also has the same location that we need and also the correct ppf mounts. Like I said, the is the perfect setup since those parts are from the RX8. I'm not 100% sure about this but, it can now use a FD short shifter upgrade or those el-cheapo versions that are found on ebay for like $40.
1.) the ppf frame has a slightly mounting point for 2 of the screws, you would have to alter the ppf. Forget about it...
2.) the clutch is inverted compared to ours, you would also need to alter the clutch line, new slave cylinder unit. No need...
3.) the shifter is in the wrong location. No problem...
Here in Europe we have a low power model with 192hp(basically your automatic version) to lower the cost. This version is offered in automatic and (only) a 5-speed manual. The 5-speed is the generic R15M-D which is also used in the RX7 FD. Now I'm not saying that it's the exact same gearbox, I don't know about the internals, and how strong they are. From what I know it's just the MX-5 equivalent, which is crap. So, I got a used damaged unit from the low power RX8 and switched over the parts. The outer casings(minus the bell housing and rear end) are the same, it's the same transmission layout. So the bell housing fits perfectly and has the clutch style that we need. The rear casing which houses the shifter also has the same location that we need and also the correct ppf mounts. Like I said, the is the perfect setup since those parts are from the RX8. I'm not 100% sure about this but, it can now use a FD short shifter upgrade or those el-cheapo versions that are found on ebay for like $40.
#32
Hi
Apologies for resurrecting an old thread, but I hope you good people can provide the info I need.
I'm trying to learn about mazda transmissions, in order to work out a viable engine swap.
I have a schematic showing the m15m-d and r15m-d gearboxes. Dimensionally and externally, they look very similar. Are they the same physical dimensions?
If so, will a bellhousing from an M15m-d bolt straight on to a r15m-d gearbox?
If yes, then do the M15... and the R15... use the same input shafts, in terms of length and no. of splines?
I have a truck with a 2.5TD engine and a r15mx-d gearbox. I want to fit a petrol v6 - in South Africa, this was an option with (I believe) a m15mx-d gearbox. Before blowing money on parts, I'd like to know if the bellhousing would fit my gearbox, and if it would be the same input shafts for both variants.
can anyone enlighten me?
Thanks!
Apologies for resurrecting an old thread, but I hope you good people can provide the info I need.
I'm trying to learn about mazda transmissions, in order to work out a viable engine swap.
I have a schematic showing the m15m-d and r15m-d gearboxes. Dimensionally and externally, they look very similar. Are they the same physical dimensions?
If so, will a bellhousing from an M15m-d bolt straight on to a r15m-d gearbox?
If yes, then do the M15... and the R15... use the same input shafts, in terms of length and no. of splines?
I have a truck with a 2.5TD engine and a r15mx-d gearbox. I want to fit a petrol v6 - in South Africa, this was an option with (I believe) a m15mx-d gearbox. Before blowing money on parts, I'd like to know if the bellhousing would fit my gearbox, and if it would be the same input shafts for both variants.
can anyone enlighten me?
Thanks!
#33
Back to the subject, I finished the trans today, and everything went great except for the shifter. I also had to use the main shifter rod from the 8's since it's a few inches shorter and I didn't want to cut anything. The problem with the short shifter is that the movement is restricted by the shifter housing, but nothing a little milling won't take care of. I'll try and finish that up tomorrow.
#35
Uncontrollable drifter
Thread Starter
#40
Ah right, great - and all the DSC must be through the sensors also? I'm looking at putting a close ratio FD box in my 192 - so would be doing something similar to you I think? you didn't have to modify the propshaft? (which propshaft are you using?)
#41
Uncontrollable drifter
Thread Starter
Close ratio fd? If it's a stock fd transmission I suggest you DO NOT install it, your better off going with a 6 speed. Dsc has nothing to do with the transmission and I still use the stock rx8 prop shaft
#42
No respecter of malarkey
iTrader: (25)
Just for the record because the information is becoming harder to find on teh intrawebz as time passes on, but the JDM 5MT has different 3rd &5th gear ratios than the EUDM 5MT transmission
JDM 5MT
1st - 3.483
2nd - 2.015
3rd - 1.391
4th - 1.000
5th - 0.806
EUDM 5MT
1st - 3.483
2nd - 2.015
3rd - 1.484
4th - 1.000
5th - 0.762 (S1 4.444), 0.719 (S2 4.777)
these attachments are from a 2008 Mazda JDM sales brochure and a Mazda press kit for the British International Motor Show 2008 (BIMS08)
JDM 5MT
1st - 3.483
2nd - 2.015
3rd - 1.391
4th - 1.000
5th - 0.806
EUDM 5MT
1st - 3.483
2nd - 2.015
3rd - 1.484
4th - 1.000
5th - 0.762 (S1 4.444), 0.719 (S2 4.777)
these attachments are from a 2008 Mazda JDM sales brochure and a Mazda press kit for the British International Motor Show 2008 (BIMS08)
Last edited by TeamRX8; 09-02-2023 at 09:03 AM.
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dznutzuk (01-06-2020)
#43
Uncontrollable drifter
Thread Starter
Hey, so the J version has that long *** 3rd gear which is a pain in the *** even on the fd and also a totally different 5th gear. Back then I had found that the euro 5th gear was .762, I have no idea though where I found that info. Nice Team
#44
No respecter of malarkey
iTrader: (25)
I was just going to update it. Turns out the S1 & S2 UK 5MT had a different 5th gear ratio. They did update the R&P from 4.444 to 4.777 on the UK S2 5MT too though. That lowered the overall gearing and made it easier on the low power engine to accelerate.
the attachment above was for the UK S2
this one is for the UK S1:
the attachment above was for the UK S2
this one is for the UK S1:
Last edited by TeamRX8; 01-06-2020 at 03:36 PM.
#45
Boosted Kiwi
iTrader: (2)
My 2003-4 JDM 5 speed has a longer 5th than the S1 6 speed (6th) so it can't be 0.806 . Would likely be 0.762 like the EDM model .... That's the ratio I found way back when I first fitted it but can't remember where I got that info from . https://www.rx8club.com/series-i-maj...4/#post4403025
Last edited by Brettus; 01-06-2020 at 04:45 PM.
#46
No respecter of malarkey
iTrader: (25)
All I know is all the documentation and jp websites lists it as 0.806 for JDM. Maybe you got it from the UK version? Because there’s nothing from Mazda detailing any of these differences other than digging through the various official documentation and figuring it out.
this is from the original JDM RX8 press release in 2003:
this is from the original JDM RX8 press release in 2003:
Last edited by TeamRX8; 01-06-2020 at 10:04 PM.
#50
No respecter of malarkey
iTrader: (25)
I was referring to RX8s, just posted the RX7 5th gear info for reference since the RX8 bell, shifter, & tail housings readily swap over onto that same main case & internals. From what I see, all of the paired-gears are removable (not cast integral to either shaft) and should readily swap between them all. There may be some aftermarket gear-pairs available too I’d think. You also have options for aftermarket gearsets; PAR and Liberty are two I know of that are readily available. OS Giken supposedly, but a few RX7Club members have been on a wait list for almost 2 years now.
Ultimately the main case and even a stronger 3rd gear are still the weak points, but I know a 4-rotor that put 1000 hp/600 ft-lbs torque through a Par straight cut dog-ear gearset for quite a while before finally breaking the teeth off 3rd gear gear and cracking the case. Which you can get the PAR gearset with the wider straight cut gears and synchros for more civil street use. However, not cheap and you can probably do an aftermarket trans conversion for less, though then you have to adapt it to, or eliminate, the PDF. So there’s some work & cost in that part too.
.
Ultimately the main case and even a stronger 3rd gear are still the weak points, but I know a 4-rotor that put 1000 hp/600 ft-lbs torque through a Par straight cut dog-ear gearset for quite a while before finally breaking the teeth off 3rd gear gear and cracking the case. Which you can get the PAR gearset with the wider straight cut gears and synchros for more civil street use. However, not cheap and you can probably do an aftermarket trans conversion for less, though then you have to adapt it to, or eliminate, the PDF. So there’s some work & cost in that part too.
.
Last edited by TeamRX8; 01-07-2020 at 12:51 PM.