a combination of 28 years service and turbo system upgrades (often also due to 28 years service) place great strains on our transmissions. there are many threads throughout rotary land as to finding a fix, and as usual, there are many options.

in 2013 i switched gears, literally and figuratively, so as to run the Texas Mile. my objective was/is to run over 200 with a 13BREW fixtured as a dual purpose, street and track. wastegated into the downpipe. i figured about 575 would get it done as another club member did 196 with a 550 swapped in V8. one of the issues was a weak 5th gear in the stock trans. i did not want to shred a gearbox anywhere near 200. another trans issue for me has always been the gearing... a really short first gear and pretty wide spacing after first..

just like spring rate is the trump card in coil overs, gear ratios is the number one factor when considering transmission options.

i zeroed in on the Tremec T56. a club member had mated it to his 20 B which gave me much of the initial info.

before we get to that let's compare ratios:

assume we shift at 8800:

FD 1st gear 3.483, 2nd gear 2.015 5104 rpm, 3rd 1.391 6072, 4th 1.0 6336, 5th 6336

T56 1st gear 2.66, 2nd gear 1.78 5896, 3rd 1.3 6424, 4th 1.0 6776, 5th .74 6512 6th .5 (forget it)

obviously the T56 wins the race. combine the better gearing with 450 ft pounds of torque capacity and newer design syncros at an attractive price and you have a viable trans option. there was lots of internet scuttlebut that the trans wouldn't shift at higher rpms but the 20b swapped setup had no problem. i bought a 50,000 mile 1999 trans from a boneyard for a grand. i added an automatic rear iron to my motor and acquired an auto bellhousing and starter.

the reason for the automatic items is that since the Mazda auto trans is wider than the manual trans the starter is mounted towards the front to eliminate a clearance issue.

i worked with an large industrial metal shop in Milwaukee and created a simple adapter plate with 18 drilled and tapped holes. simple yet precise as the input shaft needs to be dead center to the pilot bearing. i called my friends at Quartermaster and they delivered a very nice aluminum driveshaft. a huge bonus here is that i am scrapping the Mazda driveshaft that has U joints that are NOT replaceable. if you ever have your driveshaft out of your car rotate the U joints and you will very quickly realise they are fully amortised. i ditched the PPF and swapped in (a 30 minute install) Samberg's rear diff subframe. i used a 2004 Pontiac GTO external shift mechanism which located the shifter in exactly the correct position. back in 2013 my clutch options were a bit limited but this has turned around and my clutch is one of the most pleasing aspects of the project. Mcleod's RST double disc is organic sprung and can hold 800 ft pounds. it is also very easy on the leg with a Tilton short 7/8 master cyclinder amd a Tilton 6000 release bearing. amazing!

i found my T56 shifts fine at nine/9000. in prep for the 2013 Texas Mile we did a dyno run to 205 mph which was 8604 rpm in 5th. i wasn't crazy about not being able to use 6th as at the end of the course as you are close to steady state (not much acceleration at 200) and having the motor and clutch at that rpm could be a bit dicey. perhaps fortunately i melted a fuel pump fuse on the second run so never found out.

i enjoyed the T56 in my FD from 2013 til 2021 when in prep for my second TM attempt i decided to jump on Tremec's newest 6 speed offering, the Magnum F. the Magnum F has the same exterior dimensions as the older T56 but has all of Tremec's 2021 engineering. 700 ft pounds, really advanced syncros and is a bolt in replacement for the aging T56s. the big thing for me is that it has a .80 5th and a .63 6th. which means 200 is 7000 in 6th. Perfect.

i was having just a slight reverse engagement issue with my T56 and believed it was the aging external GTO shift mechanism. after doing some research i discovered what appeared to be a 21st century replacement from Sikky. i also discovered a bronze insert from Tick Performance that replaces the plastic fantastic OE insert. executive summary: it shifts like a sequential. night and day better than the GTO setup. almost my favorite thingy on my car.

probably the biggest impediment for the swap is finding an auto rear iron (no longer being made by Mazda) as well as an auto bellhousing and,starter. There needs to be a better solution. Grannas, and perhaps others, have machined away enough of the Tremec case so as to use a 12A rear facing starter with a Quicktime bellhousing. I have a better idea and will explore it next week at the PRI with the relevant party.

i just want to make a pitch for the Magnum F here.... perfect gearing, fabulous syncros, fairly inexpensive for what it is around $3400. quiet, smooth, fits in the tunnel like it was made for the FD as the Magnum F places the reverse lockout solenoid forward which fits the wider tunnel area...

the Magnum F is the modern trans solution. maybe Tremec should rename it the Magnum FD.

here's the trans with a Spicer 1350 to 1310 U joint and Sonnax yoke that is unique to the Magnum F


ready to install with a Mazda auto setup


awesome Sikky shifter



Mcleod rotary flywheel for RST clutch package custom lightened by 6 pounds for me


Mcleod RST clutch. easy driving in stop and go traffic



Samberg subframe... locks down diff

 

Howard, would you say this is a pretty close to "buy these parts and bolt this in" setup? Or is there still some fab work?

Great info, this is a good way for people pushing big HP to have a trans that holds together!

How is the weight compared to the stock FD trans?

Dale

 

Very interesting. I can't seem to find any information on this Samberg Subframe. Is there any alternatives? Also, I'm assuming you used a different, stronger differential. Is that the case, or is the stock diff good enough? Mine has over 200k miles on it so I'm looking to upgrade before I grenade it and get stranded in the middle of the desert.

 

https://www.roninspeedworks.net/ is the latest company to pickup and carry the torch on this mounting equipment.

 

" I can't seem to find any information on this Samberg Subframe"
perhaps no current website but... you can contact Justin @
https://www.facebook.com/RX7v8/

always good stuff.

i am running the original diff with a FC Turbo 2 plate type lsd. i never do drag starts and am easy on my equipment so the stock diff has worked fine for me. i do have Driveshaft Shop 300 M axles as you do not want to break an axle and go sideways at 200. the OE lsd is a Torsen and as such has modest strength due to the spider gears.

Ronin is a go to if you want to swap in a beefier rear end but i don't think ATM he offers anything re trans adapters. there is an excellent biz opportunity for someone to make an adapter kit for the Magnum F.

here is my run to 205 on the dyno with the T56... fifth gear at 8604:


you will note in the bottom left 330.1 KPH which is 205.1 mph. around 11 seconds in fifth at 575.

as to Dale's question... nope as to a bolt in. i kind of whittled away til i had it worked. someone should pick up the wrench here as this really is the trans for the FD.

:

 

here's my original T56 with the external GTO shifter circa 2013. love the Hurst 6 speed shifter ball



and the driveshaft:

 

2x the cost of a CD009 from the Nissan dealership, but at least it’s worth rebuilding rather than tossing and buying a new one


ps: there’s no aero drag on a dyno .

.

 

"ps: there’s no aero drag on a dyno ."

would there be anyone here that doesn't know that? appreciate you pointing out the obvious.

 

"How is the weight compared to the stock FD trans?"

FD trans is between 90 and 100 dry without bellhousing.

Magnum F is 128 without bellhousing.

for detailed info such as part numbers for the yoke, clutch package etc see my website section entitled "Magnum F transmission solution" BTW, i am not selling anything here, just sharing an option for FD owners.

 

Thanks for the detailed review. Good to know another option exists, albeit with some work required

 

well it’s too bad you didn’t make it to the Texas 1/2 Mile to see how close to that number it would come then.

Did they announce where the new site is for 2022 yet?

 

So what are the thoughts on this compared to the CD009? Is the tremec gearing better?

 

Coincidental timing, Sadev were spamming their tremec replacement the other day, if anyone was keen on a 37kg(?) flat shift seq. They're showing it at PRI.....which might get a deal on display stock on Saturday afternoon!

 

Howard,

I worked with Silver Sport Transmission (SST) to develop their T56 kit. They are a large Tremec dealer in TN. They took my car and 3d scanned the underbody. They tried the Magnum F and so did Grannas, albeit with a manual rear plate and QuickTime bellhousing. They don't fit well due to having to cut the tunnel, which most people won't do. They went back to a T56 Magnum and upgraded to carbon synchros.

Silver Sport developed the best T56 kit that I have seen to date. They use a Wilwood 3/4" Master Cylinder with their firewall adapter kit, Tilton ToB, QuickTime Bellhousing (they all suck and need modified or corrected because they're all off. SST custom makes offset dowels like for other platform like jeep, so they did that in house), WOSP 2kw starter that can be clocked, SST trans mount, SST shifter (destroys the junky sikky shifter), and I purchased a SPEC 8.5" twin disk clutch. Since I had a built stock diff (OS Giken LSD, HPP 2n1 Cradle, DSS Axles) they developed and adapted all the bracing to incorporate the PPF. I have tons of pic of the development and install. Everything was 3d printed, test fit, and then produced. Amazing setup. I could send pics if desired on FB if you are interested.

Mark Shoaf

 

Tremec gearing (the close ratio spec) is excellent in FD with around 4.77 final gears, the first 5 ratios are very close to the OS-G gearset for the factory box. They are stronger than the CD and bolt on fabricated or machined steel bellhousings are far safer than alloy casting.

This is factory 5 speed with 4.1 diff vs the close ratios & 4.77 diff, in metric road speed.

 

https://www.rx7club.com/rotary-car-p.../#post12495176

.

 

just discovered the additonal posts in this thread. i am about to leave for my friday foray at the PRI so don't have time to properly address various items ATM.

thanks to all posting. to be clear, my primary purpose here is not to trash other trans options but to just offer my setup.

my Magnum F fits perfectly into the tunnel (like it is OE) with no modification. further, my Sikky shifter is wonderful.

as to next Texas Mile, i emailed them and will share when i receive the date. the biggest reason i am in Indianapolis today is to determine which turbo to run...

 

The sikky is functional, but every sikky I've driven feels like a truck. The SST shifter is one of their core competencies and purchased by shops all over. This is an example of perfect design and fitment.

 

just returned from a very fruitful trip to the PRI. while there was the ususal mind bending assortment of beautifully fabbed and creatively engineered machinery on display this caught my eye... a twin turbo C8 corvette. i am wondering how the rear glass is going to fare up next to the turbines...




Browellbellhousing.com / Lafayette, Indiana may solve the rotary/MagnumF mating issue.

they have done a significant number of rotary to whatever trans you wish using a 3/8 inch plate w the (manual) rotary bolt pattern adapting to a number of bellhousings. the BH adapts to a forward facing starter. they often use some sort of Chev BH and a Tilton starter but there are numerous BH options. i didn't get into too much detail or pricing but i did get what i think was a pretty good gauge on one of the key guys (Scott) who does lots of the engineering. if you go to their website you'll find they have done it all and at a high level.

 

glad to hear your travels went safely

would like to understand more about the McCleod twin clutch you’re using. Not purposely trying to pollute your thread, but somebody mentioned that McCleod can provide it for a 13B fitment with the CD009 disc spline as well as this Tremec application. Since you’re using it with this trans then it seems relevant to discuss. TIA.
.

 

Since 1/2 mile and 1/4 mile roll racing is the current trend, I feel the CD009 trans in my FD with the 8.8 and 3.73 is the way to go.
I input all of my specs right down to tire size (275/40/17) and shift RPM.

I considered the 4.10 ratio but with the power level we are shooting for (between 750-800hp) first and 2nd gear need to be "usable" in distances that short. A 175+mph half mile trap speed should be perfect and realistic.

 

^^we should probably start a different thread for getting into the details on a different trans, but we can link back to this one as well so that people can decide for their self which one suits their need better.
.

 

Those splits aren't as good as the close ratios on the tremec.

 

How do you figure that?

Here is a side by side of the Tremec Howard just switched to with his final drive (4.77) and the CD009 with my final drive (3.73).

The notable difference here is the lower rpm "shift to" at 2nd gear, which will help me with traction. Also, the CD009 has the final 3 "shift to" rpms above 7000rpm vs just 2 for the Tremec.

These two setups are very close to each other.

 

i run the OE FD (manual) final drive ratio.. a 4.1, not a 4.7.

again, i am just sharing what i currently run. other options currently exist and will broaden over time. others may be wanting to do different things w their FDs and therefore might find different solutions.

my objectives are to have a trans that delivers proper ratios for my motor which has peak torque around 6300, really good syncros, has a clutch that is stop and go friendly, provides a top gear that is 200 mph happy and has 21st century engineering.

i especially love first gear... the FD first is really short and almost unusable. that's why, with the better 5th and 6th (versus my old T56) i said the Magnum F ratios are "perfect." all 6.

here are the current 3 transmissions...

...............FD................................. .................................CD009............ .................................................. ....Magnum F

1st....3.483...................................... ............................3.794................. .................................................. .2.66
2nd...2.015......5104............................. ........................2.324......5394........... ..............................................1.78 ......5896
3rd...1.391.......6072............................ ........................1.624......6160........... ...............................................1.3 ........6424
4th...1.............6336.......................... ...........................1.271......6890........ .................................................1 ............6776
5th....719........6336............................ .........................1.............6952....... .................................................. .80.........7040
6th............................................... .............................. .794........6952.................................. .......................63...........6930

The Magnum F fits like it was designed for the FD tunnel. zero, repeat zero need for a hammer. zero need to modify the trans for fit or for my Sikky shifter, other than the bronze Tick Performance insert. (see pic in an earlier post). an earlier post commented negatively re Sikky shifters. i don't discount his observations but on my Magnum F my shifter is almost my favorite thing on my car as it shifts precisely/easily/quickly into every gear with no drama. LOVE IT.

full disclosure here since it may sound like i am a sales rep for Tremec, i paid $3400 for my trans