Project V8 RX-7 Choosing a Transmission!  Tremec T56 Magnum

Project V8 RX-7: Part 5 - Choosing a Transmission, the Tremec T56 Magnum!

By Mike Kojima

When we were contemplating the buildup of our E-ROD powered RX-7, we planned to bolt up the same T56 six speed transmission that we had in the car when it was LS1 powered.  This plan went to crap shortly before we decommissioned the 7 for the E-ROD swap when while driving under normal conditions--nothing abusive or even brisk for that matter--the transmission got itself jammed in 3rd gear and no amount of muscling could free it.  Online forum research gave us the clues, but not until we pulled and disassembled the transmission did we reveal the culprit, a broken 3-4 gear syncro key. 

We were dismayed to find that the syncro keys were flimsy stamped sheet steel.  To fix the transmission we replaced the keys with billet steel parts and replaced the aluminum 3-4 shift fork with a beefy steel part and bronze shift pads.

Project V8 RX-7 Choosing a Transmission!  Tremec T56 Magnum
These stamped syncro keys in the T56 are flimsy and can easily break in normal driving causing the transmission to get jammed in gear.  We replaced these parts with solid billet steel parts to fix our tranny.

Although this would fix the transmission's immediate problems, we didn’t feel that the T56 was a good long term solution with our new more powerful LS3, considering that we might do some other things to it in the near future.  The transmission also lacked that buttery smooth shifting we enjoyed back when the car was a rotary.  We did a little research and decided for the money we should get the Tremec T56 Magnum.

Project V8 RX-7 Choosing a Transmission!  Tremec T56 Magnum
We replaced the aluminum shift forks with stiffer steel parts with bronze shift padsAlthough these parts fixed our transmission, we still did not like its rough notchy shifting,

We could not convince Jeff to let us tear his brand new Magnum apart so we had to steal photos of the internals from 5.0 Mustangs and Super Fords since they did a bang up job of photographing the tranny's guts.

Project V8 RX-7 Choosing a Transmission!  Tremec T56 Magnum
Welcome to our replacement transmission of choice, the Tremec T56 Magnum.  This tranny is a beefed up T56 built to take 700 lb/ft of torque, 60% more than a old T56 with refinements to smooth and speed shifting.


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Thursday, October 27, 2011 3:42 AM
Wow, I know that its a brand spankin' new super well-made transmission, but I'm still surprised that genuine MotoIQ staffers managed to resist the urge to apply WPC treatment to every contact surface in sight! I suppose that would be flat-out overkill, what with increasing the strength of an already-might-as-well-be-unbreakable gearbox.

Oh I know! It would reduce temps in the transmission, reducing parasitic power loss as heat. Pick up a couple of tenths of a horsepower at the wheels! Hahahah.

Seriously though, The T56 magnum looks the business. I only ever knew the original T56 as the unpleasantly notchy but generally capable Corvette gearbox. The T56 Magnum looks like a whole different animal. If it can take 700 ft/lbs stock then it should be possible to beef it up to low quadruple-digit horsepower drag-racing spec with relative ease. Throw chryo-treating, WPC, the whole kitchen sink of non-invasive component improvements at the damn thing. I bet you would wind up with one extremely capable piece of equipment; the sort of thing you would bolt into a car like Hennessey's new Venom GT without worrying about it.

Schweet. Can't wait to see it as part of the finished project.
Thursday, October 27, 2011 4:01 AM
I'm very glad to see this project back in action.
Dusty Duster
Dusty Dusterlink
Thursday, October 27, 2011 5:25 AM
The T56 is originally a Borg-Warner design. They make transmissions in addition to kick-ass turbochargers.

The new 6-speed manual transmissions in the 5.0-equipped Mustangs were based on the T56, as well. Apparently the 6-speed automatics are designed by the German company ZF and assembled in Michigan.
Thursday, October 27, 2011 8:09 AM
sorry but the Getrag unit is nothing like the magnum at all!
The unit is only goog for 285foot lbs in 4th gear [the strongest] vs the Magnum 700foot lbs in 1ST gear! The Ford / Getrag unit has had numerous complaints against it. Fords own recomendation is a $3500.00 replacement from Tremec & Frod racing.
Der Bruce
Der Brucelink
Thursday, October 27, 2011 9:00 AM
I guess not all t56s are created equal! I never knew Jeff's car before Motoiq, so I don't know where his LS1/t56 combo were sourced from? I thought I'd heard that some of those earlier camaro t56s weren't as strong as the c5 Corvette or GTO t56s. Is the old t56 maybe headed for this secret vq35 project where you guys have been seriously considering bolting up a t56 behind it?!?!
Jeff Naeyaert
Jeff Naeyaertlink
Thursday, October 27, 2011 10:27 AM
Der Bruce: The old LS1/t56 combo was sourced from an '01 Camaro. I'm not sure what all the improvements were but i do know the vette and gto t56's had double and triple cone synchros on all forward gears with carbon blocker rings--the blockers supposedly increasing durability and the synchros definitely improving smoothness.

I donated the old LS1/T56 to the cause (read: Mike) so I'm not sure what he has planned for it. last I heard I think it's going into a rocket car...
Der Bruce
Der Brucelink
Thursday, October 27, 2011 12:20 PM
"It's for the cause"...John Tuturo....You don't mess with the Zohan......anybody?

Thanks for the Heads Up Jeff! A rocket car huh? Dude, I'm not so secretly hoping you can stream some sweet pictures over here next week at SEMA, in the same vane that you and Martin brought GTA info ASAP to us from down under!
Jeff Naeyaert
Jeff Naeyaertlink
Thursday, October 27, 2011 12:49 PM
don't worry, we'll have plenty of people at the show this year! We can probably task someone with updating our facebook feeds on a regular basis, Will will also be along doing MotoIQ Radio!
Der Bruce
Der Brucelink
Thursday, October 27, 2011 2:32 PM
Facebook? I've heard of this thing people are calling Facebook :\ In mathematical terms Motoiq > Facebook!
Thursday, October 27, 2011 11:05 PM
Sorry Mike (Kojima), I know you're big fan of LS's, but this is really getting out of control. I love the tranny choice, but the engine !!!

These days, no matter where you look on the net, there are people doing LS's swap, I think it's pathetic. Sure they're compact, reliable, fairly light, have great aftermarket support and what not.....but where is the think-outside-the-box mentality?

Dave (Coleman) please stick with your Miatabusa and bring some more weirdness into this tuning scene.
I believe everyone has something unique to offer, if everyone swap LS's into every possible car.....this is turning into something lame, I don't know how else to explain it.
b drecksage
b drecksagelink
Friday, October 28, 2011 4:15 AM
JDMized: everyone doesnt have the engineering skills/access to cnc machines/budget/friends to pull something off as dave coleman does with the miatabusa. Name a better swap for the fd rx7. Also, this isnt mikes car, so its not his choice of what engine goes in it. Also, the rx7 already had a ls1 swap, they're just updating it with better stuff now. What are they supposed to do? take a reliable car and start swapping in a powerstroke diesel just to be different?

also, i love the miatabusa idea just as much as i love a 430hp ls3 in a fd that has a warranty.
Friday, October 28, 2011 8:53 AM
Ok 1st off I work for 1 of the 10 elite Tremec dealers in the world so thats where this info is coming from.

The t56 was used in many vehicles from Gm /Ford / Astin Martin / Holden ect
When the new camaro / charger / mustangs were released they had a new 6 speed the TR6060 it has no parts related to the t56s of old. The Magnum is the aftermarket version of the TR6060.

With the availability of many different bellhousings from different manufacturers it can be made to fit a variety of engines easily
Mike Kojima
Mike Kojimalink
Friday, October 28, 2011 9:02 AM
JDM, as an engineer, I like the LS swap in a PRO DRIFT car. I have no sentimental attachment to what sort of engine or components a car used for professional competition has. I am concerned with getting the most performance potential for my customers end use with the budget I am given. My other main concern is winning.

When we were first doing LS swaps in drifting we were outside the box. Now JDM fanboi's like to bash us because they cannot defeat us. Bring it :) Call me pathetic but call us champions too.

ovr bst, where were you when I had to write this! I had to go off my notes taken from a sema conference! I could have used your help.

Yes this is Jeff's car and the decision to not be a rotard is his. He just sucks at writing.
Friday, October 28, 2011 11:59 AM
I am not bashing, but this became clearly a trend. It's like EVERY other engine out there are no good no more.
Just the other day I saw two FD's RX7 with an LS swap. Last week I saw a BMW E46 with an LS swap and I yesterday I saw a Subaru bug eye with an LS swap !
After checking on tuning companies's website, it seems quite a few of them are gonna bring the "original" project to SEMA with an LS swap.
I am not going (to SEMA), you might. If you are, you'll witness yourself.
Friday, October 28, 2011 12:05 PM
@Brandon Drecksage:
I guess you work with what you have (or they have), which is ok. I would have left the 13B in it, and work out the bugs (known reliability issues with oil consumption and apex seals).
Friday, October 28, 2011 2:11 PM
You would have left the 13B in it, you would have attempted to work out the bugs, and compared to the LS3 you would have failed.

There's just no way to make a 13B as powerful and reliable as an LS series V8 for the same amount of money. Or a K24, or a B18 or an SR20 or a VQ35 or any of the other motors that import tuners love to wank themselves over. Every last one of them is less reliable and more expensive than an LS V8.

Everyone complains about the ubiquity of LS swaps. Hell, I complain about it. But you know who isn't complaining? The owners of the V8 swapped cars. They aren't complaining because they get a smooth, fat, torquey power-band all day every day without having to worry about being careful not to cook the turbos or watching the oil temp and A/F gauges like a hawk. They get to jump in the car and drive. And they get to do that without spending 5 hours in the garage fixing the car for every 1 hour they spend driving and enjoying it.

I personally love fast cars with unusual configurations. The more obscure and bizarre the power-plant the better as far as I'm concerned. I love seeing other people's cars with rotaries, flat 12s, diesels, straight 8s. Datsun, Mazda, Studebaker, Mopar, Mercedes, all those name-plates which have made great-but-obscure drive-trains. But that's the trick. I love seeing OTHER PEOPLE'S cars set up this way. As for my own car? I prefer a cast-iron-stove reliable common block Chrysler 2.2 turbo. It is not weird or exotic or interesting in the least, they made millions of the damn things. I prefer it because I can get in it and drive fast whenever I want without having to worry about blowing anything up. I can just go out and hammer on the thing over and over without remorse. That is the exact same thing that the owners of all these LS-swapped cars are getting; just with WAY more power and speed than my little 2.2.

For us car fans the trend of LS swaps does take a bit of the fun out of SEMA and such similar events. However for the OWNERS the trend is bringing in a whole new era of usable, easy-to-maintain, crazy-fast tuner cars and I'm sure they are loving every minute of it.

Look at it this way: what if nobody EVER did LS swaps? What if they only ever used import motors that are more 'appropriate' for their car? Do you know what would happen? Cars wouldn't get built at all.

If you told Mike he could only have his RX-7 with a rotary do you think he would keep it? No! He'd ditch the thing and get a different car. What would you rather have: a V8-swapped RX-7 or no RX-7 at all? Because that's pretty much the choice here. Mike just doesn't have the money, time, expertise and everything else needed to make a powerful rotary engine run like clockwork. The same is true for many car guys. I would personally much rather see a BMW, Mazda, Subaru, Nissan or whatever else on the road with a LS under the hood than for that car not to get built at all.

You are seeing V8 swaps everywhere because they make projects possible that otherwise could not be done given time/money/realism constraints. The V8 swaps are not "taking over" the high-horsepower import builds. People who want to build hot roatary motors are gonna build hot rotary motors, they're not gonna do anything else. You just see so many more LS swaps because it is cheap and easy and super-fun to drive the finished product. They're more common because they damn well should be, not because of dishonorable tuners abandoning the engines of import brands.
Der Bruce
Der Brucelink
Friday, October 28, 2011 2:30 PM
Drunkenmessiah: Um, Mike doesn't own the car if you read ^^ there!
Mike Kojima
Mike Kojimalink
Saturday, October 29, 2011 10:10 AM
JDM, so the LS is turning into the B18C of the new generation, who cares as long as it fills the function. I mean we were on of the originators of doing this over 3 years ago and now people like you say we are not original and copying. The LS serves it purpose it helps us win.

That being said I am starting a VQ build for myself.
Jeff Naeyaert
Jeff Naeyaertlink
Saturday, October 29, 2011 1:42 PM
I did my original LS swap into this car in the winter of 2005—6 years ago—and as far as I know was only the 2nd or 3rd to be officially California CARB legal (most guys doing it didn’t care about those technicalities). Back then after my stock rotary died I didn't want to build it up cuz everyone had already done that--and most definitely better than i would have. I was also tired of having to try to get around California smog in a city I didn't know anyone with connections to get around it in (Santa Barbara). The LS was the only way to increase power and still stay smog legal. None of those other engine combinations mentioned above or even building the rotary could be made legal. Since then I’ve grown quite fond of having 320 ft lbs of torque at 2,000 rpm and 25-30mpg “bone” stock. There’s no way around it, it’s the most practical, and most “think outside the box mentality” I could have had at the time. The wiring was probably the biggest PITA barrier to entry for making the thing run, even without making it CARB legal; but now with this new EROD kit GM has made it a cinch, so I'm just freshenin' it up! …and having Mike write about it ;)
Mike Kojima
Mike Kojimalink
Saturday, October 29, 2011 2:40 PM
Jeff was the first guy I personally knew that did an LS swap into an import and about the 3rd guy I had heard of that did it.

I gave him shit for it but loved how refined and fast the car was. One of the fastest FD's I had ever driven and so smooth effortless and unquirky.
Der Bruce
Der Brucelink
Saturday, October 29, 2011 7:25 PM
See, now I can understand why certain people, who share a similar opinion as myself, might have a difficulty with the V8 craze in Formula D considering it's a motorsport. I will say that Mike's repeated logical arguments for about the the last year or so have effectively caused a rearrangement of neural pathways aka I'm starting to come around on the V8s of FD.

BUT, I have no idea why people have a problem with it on street cars. To each their own, right? I grew up on push rods with small block to big block swaps and vice versa. Sixes swapped for 8s and so on and so forth. Difference between then and now is that the platforms of today (or 15 years ago in the case of the FD) handle WAY better than those domestics of the prior CENTURY! Granted, it's a little weird seeing the Corvette powered Civic or LQ powered GDB but hey, good for that guy. Won't handle nearly as well as an LS FD but the dude's having fun! Jeff, you're just taking things to another level :) Still think it'd be fun to take the LS up against a comparable HP 13B to really see which usable 6k rpm lends itself better on the track and see if there's any real difference in handling.
Monday, October 31, 2011 7:17 AM
I'm with Der Bruce and DrunkenMessiah. This is good info! I still want to see the "purist" camp represented but build this abomination as much as you want!
Monday, October 31, 2011 5:00 PM
@DrunkenMessiah: thanks for schooling me, (education costs money), how much do I owe you?
Seriously dude, you have your opinion, I have mine. I would have kept the 13B (even though it has notorious issues).
These days people seem to be hell bend with the HP craze, how gives a shit about HP? A good-fun car HAS to have the whole package, (chassis, brakes, suspension, AND MOST OF ALL a good driver, if you want to take advantage of the power). Anyway, that's my opinion.
I also LOVE the fact that you assume that because I have a "JDM" screen name I am one of those "wanksters." The truth is, I grew up in Japan and I no longer am in high school, thus the screen name.
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