jimmydanny

First:
FD upper intake manifhold, is that usable on the FC? I would like that because it will give better airflow from an FMIC than the stock FC one do, since it is made for TMIC.

Second:
What diff housing can fit the FD torsen, and what stubs and axles fits that again? I have asked this before, but I never seem to get a proper answer, even though people have done this multiple times.


I have an S4 N/A cab (open diff originally, USDM), with an S5 TII engine. The gearbox is swapped, but I don't know if the rest of the drivetrain is swapped, and if it is, I don't know what diff might be on the car anyway.

Jim, Norway

The faster you answer the faster I can decide what to upgrade next

jimmydanny

I have confirmed, I got the Cab N/A diff, that is open in the US I guess? If so, that is what you have to count in when considering my question.

misterstyx69

iTrader: (142)

Well if you have a TII engine,the Best setup would be to Have the rest of the drivetrain in..like Trans,driveshaft,differential and half shafts.
The N/A Transmission is really not suited for the extra power that the TII can put out,and frankly either is the Differential.
I have heard of People putting the FD Torsen into the FC TII Differential housing..
...and the N/A Rear End??..it comes in OPEN and LSD..
Drop a strip of rubber and you can tell which Back end you have...the Open Diff will leave one Tire's worth,..the LSD will put both tires layin Rubber...Burn out time!!!
......................
FD manifold: you know that you are gonna need a spacer or get some porting done to match the runners on the inside of the manifolds Right?..also the TPS will have to be used from the FD and wired in to operate.
..TRY THIS: Hit SEARCH,,,look for "FD upper on an FC"..Thread is by ME.(misterstyx69)..is has alot of info,and even has wiring info on the TPS.
...............
Really you can plumb in the Piping for an FC just as good as having an FD upper.Use a Greddy Compression tube and a bit of Imagination.(you can retain power steering BUT you may have to relocate Battery).
I put my Piping through the Holes in each corner of the Front,behind the Lights.You have to get rid of the Windshield washer tanks to do this.
The Greddy Trust Intercooler will allow you to Retain power steering but the pipes are run BOTH on the passenger side of the car..Look up that setup too..
.............
You See?.The more that you Decide to Modify the car for After market parts,the more stock parts will either have to be Moved or relocated.MY Power steering was Lowered 4 inches with my FD upper on.My Battery in the passenger Storage bin.
It is really a give and take..Your decision though..Good Luck.STYX.

jimmydanny

The FMIC is not my first pri, the Diff is. I know people swap FD torsens into FCs, but I have heard both into the open diff housing and LSD housing. I don't know here really.

Also, I got TII trans, axle is modded, I guess swapped with a Mazdatrix custom one, so it is good enough.

The torsen from mazdatrix, what car does that come from? MZTX-TORSEN1 it is called. As I got N/A diff, axles and shafts, that will fit straight in, if I just could find a used one.

Thing is, I dont wanna swap axles and shafts if there is a solution out there for me.

EDIT: I got Vert N/A diff, so I got 3.91 in ratio, as far as I understood it. Does this mean I need the torsen from a 13B-REW automatic, as they got the same ratio, or can I swap the gear here?

jimmydanny

Or... is it the Miata Torsen that fit into the N/A open housing maybe? I am really unsure now..

jerd_hambone

Pretty sure Aaroncake proved that the N/A transmission and rear can hold a lot more than you would expect.

jimmydanny

I got the S5 TII tranny, so np there.

My problem is what LSD (pref torsen) fits into my housing, and is compatible with my ring and pinion, so I can swap my ring over to the torsen one without having to play mechanic while not being one.

The problem wiht the clutch type is that I have to rebuild, it costs much more, and the torsen fits my occasional sideways driving. Normally I drive straight forward, which makes the torsen good enough.

Also it helps me in the snow here in Norway

kungfuroy

iTrader: (6)

The FD torsen will only fit the t2 Diff housings and you will have to get the S4 stub axels for them to work, then t2 halfshafts to your wheel hubs.

arghx

iTrader: (3)

pretty sure Aaroncake proved that they are glass on high horsepower boosted cars, just like everyone thought. the n/a transmission and diff are weak. I have blown both of them up on an actual n/a car, although I was pushing them pretty hard. they are time bombs. If you drive easy they will last a while but it's only a matter of time before a failure.

FD torsens are weaker than T2 clutch type diffs. they can still hold up power but the T2 diff is considered an upgrade for a high horsepower FD because it is stronger.

jimmydanny

Well, problem is then I would need a T2 diff, axle, stubs and so on. that would be in the high 1500s, which is way too steep.

My options are:
Miata/FD torsen=180-300$
Kaaz (bolt on)=1178$
T2=1500$

The obvious choice is the Miata in any case, which anyhow only came on the turbo miata afaik?

jerd_hambone

From what I gathered from the info given, this is a stock turbo motor. Not a high hp boosted car. Aarons car lasted quite a long time before his full-out build, and also a while after.

And yes, they do give out with time, no mechanical part will last forever. So basically, it's a matter of time before anything gives out. All depends on up-keep.

To Jimmydanny: What driveshaft do you have? Custom, or the one Mazdatrix sells?

jimmydanny

I think I got a Mazdatrix TII trans to N/A diff. but I have to check it up on wednesday when the PO gets home.

As for the boost, I got TII tranny, no worries there, also I am aiming for a max of 300hp when money starts rolling in. That might be a year from now, or five.

jerd_hambone

I'd say get the Miata torsen for the time being. Then upgrade to a nice TII diff and get a torsen for it.

jimmydanny

Okay, what torsen, T1 or T2? Wanna scan fleabay fast for me?

arghx

iTrader: (3)

.

jimmydanny

Useful info there arghx.

There are loads of miata Torsens out there. But some are overpriced, some are priced so low you gotta think hard before you consider them.

My problem is that I live in Europe, so a price of 600 wouldnt be bad, without shipping, but when shipping is needed too, I can't come much over that price combined really.

But the torsen from Miata, again. T1 or T2? And can a normal workshop adjust the backlash and everything, or do I need a special workshop for this? Differentials arent exactly the thing you change so often that your regular mechanic is an expert on it

arghx

iTrader: (3)

you might want to make a thread in the 3rd gen section. There are more people in that section that would know the ins and outs of this, as rear end swaps are comparatively rare on 2nd gens. FD owners more commonly switch out diffs for drag racing or road racing.

jimmydanny

Problem is, my housing is unique to the open diff. So I must have a Miata diff, which the 3rd gen guys cant help me with. If I had a TII LSD I could have used the 3rd gen diff. But Im not that lucky, Im afraid

RotaryEvolution

iTrader: (30)

why is it $1500 used for a TII diff?

the miata will only fit the n/a case as you mentioned so it's a bit of a waste of time IMO if you plan on upgrading the power level of the car. so you really need either a TII diff or an FD one, both with half shafts. alternately you can just find an n/a LSD(S4 GXL and i think S4 vert/GTU/GTUs had it also) and run it until you break it.

jimmydanny

The TII diff:
Axle
Shafts
Diff with housing in good condition.

If I find a N/A LSD (which are rare), it will be steeply priced. I saw one some time ago, went for a good 500-800 I think. In the US, so the freight.. dont wanna mention it.

The Miata solution is just as good as the N/A LSD, and cheaper too, and the torsen will do the work just as well as the TII diff for time being.

When (which I mentioned, can be tomorrow or in two years) I start to consider upgrading, it will be done in stages like this:
Haltech ECU with proper map
Then Turbo, injectors, fuel pump, whatever is needed.

I have no need for more than 250hp in the start. If I go higher, the Kaaz diff will be the best solution I think. But if I afford a new turbo and injectors, I can also afford a Kaaz diff

But as I said, for now, the torsen one is the best for me.

Problem is: What needs to be done, and do I need T1 or T2 diff?
I know I can drop it in, swap the ring and pinion from my open one. Problem is that backlash thing, which I got no idea what is really?

RotaryEvolution

iTrader: (30)

try calling rancho mazda recyclers in california, they had about 10 FCs last i was there so they gotta have an n/a LSD, although they are rather pricey they won't be THAT pricey. i found an n/a S4 clutch LSD up the street at the porsche/mazda recyclers for $125 used.

backlash is how the case sets in the carrier, it can be adjusted from side to side which meshes the gear teeth. if it is set out of place it will cause the gears to run off one another and cause noise/wear, same if it is too tight instead they will be clashing though. since all you need to do is replace the ring gear on the new case then all you need to do is have the case preload/backlash adjusted properly, the pinion won't be moving anywhere as it should be left untouched.

jerd_hambone

Any reputable shop should be able to set it up for you. If not, then a good trans shop, or performance shop.

jimmydanny

Haha, it lives 23000 people in this region :P

The closest shop would be either 200 or 300km away, depending on which city actually got it.

But a regular workshop with a mechanic older than 20 years should have someone with this knowledge.

Especially the polacs working here. They got those Polski Fiat to work on, RWD, must have some knowledge

jimmydanny

http://cgi.ebay.com/ebaymotors/JDM-M...Q5fAccessories

This one, this is a torsen that fits straight into my open diff housing, right?

Also is the helical geared version, I think that is the better one of the torsens from the Miata?