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-   -   FD transmission solution for 500+ hp (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/fd-transmission-solution-500-hp-905977/)

Howard Coleman 05-28-10 03:12 PM

FD transmission solution for 500+ hp//see post 210 for new clutch info
 
http://img714.imageshack.us/img714/5307/006me.jpg

let me start w the caution that while the rotary is simple the $s start adding up as you add more air and fuel.

my transmission solution is not inexpensive but it is stout, and provides significant gearing advantages. while i will offer for sale the adapter plate, the other items will need to be acquired independently and there is a modest amount of machine shop time.

so why go through all the effort and expense?

the FD arrived on the showroom floor producing 184 SAE foot pounds of torque.

500 SAE rwhp FDs produce 400 foot pounds and lots of stripped 3rd gear teeth and twisted mainshafts. if you really crank up the boost and are drag racing you will be replacing trans as often as changing your oil.

then there's the gearing

yikes!

a 3.483 first gear? great for pulling stumps. not great for doing anything but getting into second. and second? what's w a 42% drop in revs?, third a 31% drop and then the really long drop to 5th which is pretty much an economy run gear.

plainly stated the gearing sucks.

practical alternative trans options do not abound. there are all the racing trans options but they do not have syncros and after living w that type of box in my real racecar for 6 seasons, trust me, you don't want to be anywhere near one for the street. they are also really expensive. and you will eat up interior pieces and get to know the nice people at the trans shop far too well.

there is the fairly high dollar Toyota box. Getrag. nice gear spacing, nice syncros, stout but generally available around 4K just for the box.

i zeroed in on the Tremec T56. modern engineering, available at a junk yard near you for between $800-$2000. (there is the totally redone new T56 called the Magnum which sells new for less than 3K which is a bargain).

the T56 is often found in F body Camaros and later in the GTO. lots around. the Camaro has better ratios and the GTO has better syncros. i have a 99 F body Camaro trans that i am purposely installing to see how the syncros actually work at 8000. and for the ratios.

//////UPDATE.... just as Jered (GTO box) found... my junkyard $1000 F body T56 shifts fine at higher RPM. at the Oct 2013 Texas Mile i shifted out of first at 9000, second at 8800 as well as third and fourth. zero problem for this old junkyard dog. i really like the F body as it has better ratios...//////////////////

i am totally in debt to Jered Olson (IronMdnx) for alot of the engineering on the project. the T56 is just a touch too wide to clear the starter so he figured by using the auto bell housing the starter would point forward and clear the trans. one smart solution from a very very smart guy. WTG Jered.

so i had the benefit of his initial install which he kindly shared.

so here's how i did mine...

auto rear iron. necessary (i think) to mount the starter.. maybe you could do some mod work on the standard rear iron if you were creative.

auto rear bellhousing. machine .25 of an inch off the rear face to move the input shaft further into the stock pilot bearing. machine a small opening on the driver's side for the 2 dash 3 hydraulic clutch actuator bearing lines.


bolt on my adapter plate ($350.)

http://img338.imageshack.us/img338/4335/007if.jpg

find an auto trans flex plate for your flywheel (and an auto starter).

call QuarterMaster. talk w Geoff Tickes (847-540-8999 ext 250) tell him Howard suggested you call.

you will need a button flywheel(less than $200), the 8.5 double disc(less than $900) , a driveshaft (around $3-400) and a small button to flywheel adapter and the TriLight clutch release bearing (around $300). i am uncertain on exact pricing. that's between you and QM, i am just trying to be of help.

here's the clutch release bearing. custom setup for proper clearance w the pressure plate.

http://img63.imageshack.us/img63/637/002kjr.jpg

the clutch is neat. clutch spring pressure is your call between 1800 pounds and 3000. it depends on your app. i don't drag race but needed a clutch to hold 600 rw so i am running, initially 2250 spring pressure which is the same as my wonderful Exedy cerametallic that wouldn't work in this app. unlike the racing apps my clutch has thicker friction material... the "rally" option. the clutch has 18% more frictional surface than my old Exedy. more surface, less spring pressure. win win.

http://img248.imageshack.us/img248/6894/018bd.jpg


auto flywheel counterweight 4.02 pounds
auto flywheel 4.8 pounds

ACT lightweight FW 9 pounds plus CW = 13.02

QM pressure plate w button 18.8 pounds.
Exedy single cerametallic 27.6 pounds

http://img143.imageshack.us/img143/1571/014cn.jpg

you will need to buy a short clutch master cylinder. .75 piston. Willwood, Tilton AP take your pick. about $100.

whether you use an F body or GTO box you will need to get the GTO linkage assembly. it situates the shifter rearward 2.5 inches and locates it exactly in the center of the Mazda rectangular shifter hole.



you will need a rear trans mount. i spent some time on this as i didn't like anything i saw. i want nothing sticking down underneath my car. so all trans mounts that bolted across the tunnel were out. secondly i wanted no interference w my exhaust. i ended up w a very short (9 inches or so) mount that sits high under the tailshaft. it angles higher on the pass side to clear the exhaust. i will have a 4 inch by 4 inch stainless steel plate on the interior of my car which will be the sandwich plate. i could have ripped out the carpet and mounted it under the carpet but that was too much work for me. i have no problem w a tidy stainless plate in the car. you may feel otherwise. feel free to have at it.

the FD driveshaft has always been a source of irritation. no option to replace worn U joints? are you kidding me? the new driveshaft has replaceable joints and is good for 1000 hp. it weighs 12.6 pounds V 15.

rebuildable...

http://img686.imageshack.us/img686/1425/019fi.jpg

http://img404.imageshack.us/img404/4797/022xf.jpg

then there is the PPF and what to do. i am extremely happy w my solution. after looking at all kinds of torque arms etc i decided i wanted none of them. bulky, heavy and stressing things i didn't want further stressed... trans tailshaft and trans mount. i called Justin Samberg and he had exactly what i wanted. he delivered his usual masterpiece on time and on quote. around $500. it solved all my problems and installed in 30 minutes. i also hear from the FDV8 guys that the Samberg subframe hooks up (launch not love) significantly better than the torque arm options. PPF weighs 4 pounds more than the Samberg subframe.

http://img541.imageshack.us/img541/6...subframe03.jpg

that's pretty much it from a hardware aspect. i just have to reassemble my motor and bolt everything in.

one of the more challenging items was the adapter plate. the quick summary is that it took almost 2 months and a grand to get it exactly right. it is so centered that the input shaft has about a thou clearance to the FD bearing and you can turn the crank without turning the input shaft! this will all make contact once up and running of course but it is dead nuts. to promote deeper penetration of the input shaft into the pilot bearing the adapter plate is 3/8.

you will want to grind a couple of tabs off the trans. (you can see this in the pics.)

a Dakota Digital convertor box will zero in the speedo. ($75)


back to gearing:

let's assume we shift at 7800:

we reach

............................................FD.... .......................T56 F body

second gear at...................4512......................... ..5219

third gear...........................5384............... .............5696

fourth gear.........................5607................. ...........6000

fifth gear.............................5608............. ...............5772

who do you think wins the race?

FWIW, i have designed my ports so i make 400 SAE rwhp at 5000. the rotary makes great power up top but if when you shift you could be driving a Yugo you have a problem. the T56 plays right into the rotary by supporting midrange power.

horsepower under the curve wins races. the T56 gearing puts the curve better into the narrow powerband of the rotary.

finally, that's how i did it. feel free to do it differently, maybe better.:)



that's it for now. road reports when we actually get it going soon.

howard

Force13B 05-28-10 03:17 PM

Howard great thread as always. What was your final $$$ for all this? Also do you have a pic of the new PPF installed?

Ceylon 05-28-10 04:00 PM

Nice write-up Howard! I fancy doing something like this in a couple of years. Those kind of gearboxes are less common this side of the pond though....Perhaps someone will have made a kit by then :)

MakoRacing 05-28-10 04:12 PM

Awsome, one more thing to buy... ;)

Howard Coleman 05-28-10 04:14 PM

"one more thing to buy"

you know it never ends...

Force13B 05-28-10 04:55 PM


Originally Posted by Howard Coleman CPR (Post 10024808)
"one more thing to buy"

you know it never ends...

You have to tell yourself just one more thing. If you made up a huge list it would be depressing.

MakoRacing 05-28-10 05:15 PM


Originally Posted by Force13B (Post 10024882)
You have to tell yourself just one more thing. If you made up a huge list it would be depressing.

It'd go from depressing to suicidal once you add up the costs of everything on the list. :D
Back to the thread...lol. One thing that's cool about this is all the weight savings, especially in the flywheel/clutch/drive shaft area.(yay for less rotating mass) Howard, did you weigh the T-56 itself vs a stock trans?

GoRacer 05-28-10 05:29 PM

Sweet, except GTO's are as rare as FD's. I like the synchro choice better but the Camaro trans would be alot easier to find. :worship:

Prometheus 05-28-10 05:35 PM


Originally Posted by Howard Coleman CPR (Post 10024692)
one of the more challenging items was the adapter plate. the quick summary is that it took almost 2 months and a grand to get it exactly right. it is so centered that the input shaft has about a thou clearance to the FD bearing and you can turn the crank without turning the input shaft! this will all make contact once up and running of course but it is dead nuts. to promote deeper penetration of the input shaft into the pilot bearing the adapter plate is 3/8.
howard

Is that tolerance so tight to prevent the misalignment @ high RPM's

That was the only drawback of going to a push type Vs a pull type clutch IMHO.

Also, I wonder if it might serve profitable to sand cast a special bell housing that mates the 13B REW to a T56 (eliminating the removing & replacing of the rear plate)

this might also allow the user to retain the readily accessible GM starter Vs the expensive and much more difficult to source Mazda starter.

The T56 swap has always been on the back of my brain, but there is so many damn parts to source,that the average consumer just sticks with whats easy.

I planned on doing this swap Vs the GETRAG from the supra (because it is an American product)

American = Possible last minute sourcing of parts, comparatively cheaper prices for what you are buying, knowledge is more readily accessible (many more T56 transmission builders than GETRAG & OEM FD tranny builders)

MOBEONER 05-28-10 05:36 PM

Howard what are you building, a drag racing car or a autocross car or just an all out super car?

Howard Coleman 05-28-10 05:42 PM

"did you weigh the T-56 itself vs a stock trans?"

yes, the stock trans weighs 92 and the T56 120. given the 400+ foot pounds of torque coming from the hopped up 2 rotor or 600 from a 20B i will gladly should the burden of 28 pounds given much of it is made up of really strong gears.

i frequent the LS1tech board and a few others and find that GTO trans are almost always avail ($1300- 1800) as well as F body. also the Cad CTS V trans is another T56 varient. i saw one offered for $1500.

as to syncros, i admit it remains to be tested, but i see lots of small block drag Camaros running 9000 rpm and powershifting stock T56 boxes... we will see. the GTO has a shorter first gear.

hc

Howard Coleman 05-28-10 05:48 PM

"sand cast a special bell housing that mates the 13B REW to a T56"

maybe. Quartermaster routinely makes really neat special bellhousings and depending on demand they might offer something.

they also make beautiful flywheels. Geoff showed me an RX8 FW they made... complete w the cast in balance weight. it had two bolt patterns. one for the OE pressure plate and one for the PP i have (8.5 inch double disc).

they could easily do a FW. BTW, they make great stuff. i ran their clutch on my racecar. they are also only an hour and change away from me. face to face is good.

hc

proz07 05-28-10 06:00 PM

sweet iv been waiting for this write up for quite some time now.....

awsome
z

Prometheus 05-28-10 06:47 PM


Originally Posted by Howard Coleman CPR (Post 10024994)
"sand cast a special bell housing that mates the 13B REW to a T56"

maybe. Quartermaster routinely makes really neat special bellhousings and depending on demand they might offer something.

they also make beautiful flywheels. Geoff showed me an RX8 FW they made... complete w the cast in balance weight. it had two bolt patterns. one for the OE pressure plate and one for the PP i have (8.5 inch double disc).

they could easily do a FW. BTW, they make great stuff. i ran their clutch on my racecar. they are also only an hour and change away from me. face to face is good.

hc

I looked up their custom bellhousings @ various online distributors.

they range in the ballpark from $400-$500

That is a fare price that would allow customers to not have to remove their engine to swap out the rear iron

Delete the need for the auto starter & flex plate. & retain the GM starter.

This swap sounds awesome, the process just needs to be simplified, in order to become common practice.

Even if it comes at a higher cost financially.

+ this would get your buddy some more business on those awesome looking PPF supplements.


Now all we have to do is creat a tubular rear subframe that would allow a more readily available/ robust Diff/ diff case & axle combo...:lol:

no_more_rice 05-28-10 06:49 PM


Originally Posted by Howard Coleman CPR (Post 10024808)
"one more thing to buy"

you know it never ends...

Exactly....if I had it to do over again I would have started with a $4000 roller, you end up replacing everything anyway

Great post Howard.

RotorMotor 05-28-10 08:13 PM


Originally Posted by Howard Coleman CPR (Post 10024994)
"sand cast a special bell housing that mates the 13B REW to a T56"

maybe. Quartermaster routinely makes really neat special bellhousings and depending on demand they might offer something.

they also make beautiful flywheels. Geoff showed me an RX8 FW they made... complete w the cast in balance weight. it had two bolt patterns. one for the OE pressure plate and one for the PP i have (8.5 inch double disc).

they could easily do a FW. BTW, they make great stuff. i ran their clutch on my racecar. they are also only an hour and change away from me. face to face is good.

hc

Howard, if you produced a "kit"... bellhousing, driveshaft, tranny mount, and any other part that needs to be custom made, I would be the first in line with many people behind me I'm positive. I know how much people like bolt up solutions, and having only to decide on a clutch and find a transmission (in addition to ordering a "kit" from you) would make something like this MUCH more palatable for the average consumer out there, which I've found is the majority of people out there. :icon_tup: :nod:

-Heath

Howard Coleman 05-28-10 09:00 PM

"Howard what are you building, a drag racing car or a autocross car or just an all out super car?"

yes.

"Delete the need for the auto starter & flex plate. & retain the GM starter" w a custom bellhousing.

the problem is in order to use the manual starter the flywheel would need to be of a significantly larger diameter that might fall outside of the bolt pattern for the block, which of course wouldn't work. the starter needs to be forward. that said you could still do a custom bellhousing w the mazda auto starter. or perhaps another more readily avail starter. QM makes starters from scratch.


"Howard, if you produced a "kit"... "
i primarily just build engines because i love to. i am happily retired after a 37 year career on Wall St and don't want to get too busy. the purpose of this post is just to share info. anyone else is welcome to pick up the ball. i do appreciate the fact that if there was a kit/package there would be a larger interest.

"if I had it to do over again I would have started with a $4000 roller, you end up replacing everything anyway"

think that comment is funny? i think it is one of the more accurate pieces of advice in the forum... and funny.


"a more readily available/ robust Diff/ diff case & axle combo"

IMO, if you replace the fragile Torsen LSD w a clutch type diff, if you replace the big rubber diff bushings w nylon as well as the front bushings on the lower longidinal link i think the rear is good to go. axles are a different matter and do need to be replaced. w the Driveshaft Shop setup.

it never ends.

hc

thewird 05-28-10 09:44 PM

So whats the total cost excluding the transmission? I'm thinking of getting this Tremec TR6060 (magnum) and put a 4.4 rear end gear. What you think? Do you know if we need the Electric or Mechanical Speedometer version?

http://www.ddperformance.com/shop/pr...7cPath=107_124

Check out the gear rations :D...

2.66, 1.78, 1.30, 1.00, .80, .63

thewird

Howard Coleman 05-29-10 06:55 AM

"2.66, 1.78, 1.30, 1.00, .80, .63"

yes, those are the best. 5th and 6th are Ford. 1st thru 3rd are F body. a 20 and 21% drop into 5th and 6th:). i plan to swap a Magnum in w those exact ratios after the Texas Mile.

the .8 5th would be too short to do 200 but the .74 should go thru the lights close to 8000 w a 3.90.

BTW, i talked to a Tremec engineer and the Magnum is really high tech. lots of new thinking on the syncros, the gears are completely different size-wise etc. whil it is a dead ringer on the outside, and is a T56 bolt in it is really diff on the inside. you can buy them from Summit.

this is not meant to diminish the regular T56 which is a well engineered trans.

as to speedo, almost all have electric like the FD.

thewird 05-29-10 09:32 AM

By installing a 4.4 or even maybe a 4.7, you could make that 0.63 gear usable in your texas mile and at the same time be tightening up your gears on your powerband.

Let us know when you put the tr6060 in so we can know what type of adapter you use to make it line up with the stock shifter location :)

thewird

Howard Coleman 05-29-10 10:26 AM

i wouldn't want to run 600 thru 5 gears w a high ratio FD gearset as the pinion becomes really small/fragile.

there is no diff installing the 6060 as to adapter or shifter (GTO).

staticguitar313 05-29-10 11:21 AM

This is all good steps towards a better trans solution, but some of these sacrifices are a little too much for me. The having to replace the rear iron on manual cars with an auto one. Yes I want to take apart my WORKING rotary and re stack the keg after port matching another iron. Whats the deal with the auto flex plate setup. I'm not well informed on how the clutch is attached to the flex plate.
Cost is also a big issue for some people.

Speed of light 05-29-10 11:38 AM

What does the forward facing, auto starter do to quick and easy spark plug access (from below).

Prometheus 05-29-10 12:33 PM

I wonder if te transmission tunnel on a manual FD can be modified to use the standard T56 starter (light pounding or cutting of the tunnel)

also wondering if it might be better to start with an auto FD shell (for those who have not yet bought their FD's (cheaper than a manual & automatics usually have a larger transmission tunnel)

possibility of rotating the transmission counterclockwise, to tilt the shifter twards the driver (moving the starter to a lower position on the tranny case)

then make a custom short shifter arm that compensates for the transmissions new angle.

Howard Coleman 05-29-10 01:42 PM

"sacrifices are a little too much for me" (auto rear iron)
"Cost is also a big issue for some people."

the first line of my thread:

let me start w the caution that while the rotary is simple the $s start adding up as you add more air and fuel.

i might further point out that you don't need the trans upgrade until you are making over 500 rwhp. if you want to talk money add up what 500 costs. (lots) what's a few more thou?

finally, there are lots of other ways to get it done, many costing significantly less.

"rotating the transmission counterclockwise"

outside the box thinking. way outside. you won't be able to rotate it enough to clear.

"What does the forward facing, auto starter do to quick and easy spark plug access"

great question. i was very concerned about the lead #2 plug also. amazingly, even though the starter is there somewhere it is nowhere near the plug!:)

"transmission tunnel on a manual FD can be modified to use the standard T56 starter"

perhaps i misunderstand, but the tunnel is fine (lots of clearance, you'd swear it is OE). it is the body (width of the trans case) and there is nothing you can do about it. it occupies the space where the manual starter resides.


"with an auto FD shell"

never heard of an auto tunnel being any diff than a manual tunnel but i am always interested in learning something new.

hc


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