my9thtry

Does anyone know a company that makes final drives for the M2B4.

Mfactory's wont work and i dont see why any others will if they are designed with the open diff bolt pattern.

Thanks Joe

1qwklude

I dont think they make a higher final drive for the M2B4 but im not 100% positive.

vinuneuro

Houseman can make you a custom fd, but that'd be some $$.

my9thtry

houseman? i thought mgags had an m2b4 with a 4.71, but his trans was a frankenstien

NirVTEC

Youre wanting to change the FD but are going to keep the stock LSD?

vinuneuro

Clint, don't think he has a choice with the lsd as iirc an a/m diff won't fit in the m2b4 case.

NirVTEC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vinuneuro &raquo;</TD></TR><TR><TD CLASS="quote">Clint, don't think he has a choice with the lsd as iirc an a/m diff won't fit in the m2b4 case.</TD></TR></TABLE>
If he's looking into replacing an FD(for what reason who knows) I would think he'd want to go the best route possible and use a Quaife in a Non-LSD case.
I would think it would be simple to find someone to do a partial trade with.

What is this car being built for out of curiousity?

my9thtry

Who is houseman again?

Keeping the stock diff in there would be ideal. No reason to spend 1k on another torsen when i have one that works perfect.

Main purpose for the car, right now, i would say is the strip. If some where down the line i have the oppurtunity to take it on a real road course i would.

Shifting at 8300 i dont even come out of third in the 1/4 running 97-98 mph traps. Its just geared too tall.

The car has plenty of power with a/c ps cat and full 2.5 inch exhaust it puts down 215/165.

I need to fix my belt throwwing issue first but that wont be until february when i get back from afghanistan.

The car is more powerful then the traps are telling, i couldnt even launch hard without shooting off a alternator belt. But right now i am just looking around for options

A Blue Lude

Are the Prelude LSDs actually torsens though? I remember the big discussions from a few years back, but not the conclusions.

PirateMcFred

I remember that thread. *link for reference* I am still unconvinced that there are any viscous LSD in the Honda world particularly the M2B4. I have an M2B4 sitting in my garage ATM too. Maybe this weekend I'll have to split the cases again and compare the M2B4 LSD to a spare open diff I've got.




<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NirVTEC &raquo;</TD></TR><TR><TD CLASS="quote">If he's looking into replacing an FD(for what reason who knows) I would think he'd want to go the best route possible and use a Quaife in a Non-LSD case.</TD></TR></TABLE>

I guess that's tricky nowadays. There's a surplus of used Quaife ATB diffs in the US for various Honda apps. but now the only new LSDs you can get from Autotech is the "wavetrack" that's of an unproven design but is supposed to have the same style warranty. It's not any cheaper either.

Pirate


Modified by PirateMcFred at 6:44 AM 9/26/2008


Modified by PirateMcFred at 7:18 AM 9/26/2008

my9thtry

I wish i could see thos pictures to help identify my dif but big brother doesnt let you play too much on government computers.

I guess the best thing to do its sell/ trade what i have ....

Where is mgags in this thread i'd like to find out what was done to his to make it fit

PirateMcFred

These are Mgags' Custom 4.7 FD/OEM torsen LSD M2F4 pics:



I think I have most of the images saved from that thread for a basis for comparison.

M2B4 left, Quaife right (first hand experience)


M2B4 (first hand experience)


Advertised as an M2B4 I cannot say for sure:


Advertised as an M2B4 I cannot say for sure:


Old Accord SiR LSD gearbox with a potenitially aftermarket diff. install



I can upload more when I find them.

-Pirate


Modified by PirateMcFred at 11:09 AM 9/26/2008

vinuneuro

Which trans is Matt's torsen from?

PirateMcFred

dunno. You'll have to ask him and he might not even know as his gearbox was all sorts of customised by some drag racing outfit.

Added more pics to my last post.

vinuneuro

The one on the right is from Matt's trans right? The case design looks bang-on to the one used in the dc2 ITR. What diff is on the left in this pic?

MLBZ521

iTrader: (6)

I have Matt's Transmission now.. Just had it installed during the summer with a swap since the old engine blew..

I had all the work done by Scott @ Collective Racing down in Tucson, AZ.
When I told him what I was getting and the Spec's of the Trans he wasn't sure it was right..
I believe he said that an aftermarket Final Drive will not work with M2B4 Transmission.
I told him who I was getting the Trans from he knew who I was talking about and wanted to check it out when it came in. Which I didn't mind, as I had read some of that old discussion that had no real conclusion..

When the Transmission came in though, the case was beat up pretty badly and leaking. So now it HAD to be ripped apart..
I was so busy (with moving myself and the family I was staying with down there, along with other things) when the swap was being done I didn't even ask him what he found when he took it apart. And it had so many problems after the swap that had to be fixed or replaced. I was just excited to get the car back and drive it again after almost 5 months without a car.

So now this thing has another piece to add to it's hybrid state.
From what Matt knew about it:

M2F4 Gearing/Case
M2B4 LSD Unit
4.7 Final Drive
Newer* Micro Polished Syncro's & Newer* Differential Bearings

And now it has the gear box casing of an M2S4.. But thankfully still shows the M2F4 Sticker.

I need to contact Scott and see if he remembers what was in there and if he took any pictures like he was wanting..

cool2073

Would anyone know whether diff from M2B4 would fit and perform in M2S4 92-96 Prelude Si (H23A1), please.

my9thtry

cool2073

Read the post above yours.

Well i guess i am SOL, with the M2B4.

I have an M2S4 thats in good shape i guess i could use the gears from the B4 and get a better diff and FD if i cant find someone wanting to trade.

PirateMcFred

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cool2073 &raquo;</TD></TR><TR><TD CLASS="quote">Would anyone know whether diff from M2B4 would fit and perform in M2S4 92-96 Prelude Si (H23A1), please.</TD></TR></TABLE>

Only half of the transaxle cases will work. The side that mates to the engine will have to be modified to fit the differential.

Short answer: No.

megomaniac

So what's the long answer then, can a non lsd case be modified for a oem lsd(die grinder?)from a m2b4?

megomaniac

I'd sell the m2b4(I've seen them selling for1000+) and get like a m2f4, get the new mfactory lsd(I've preordered mine,free shipping 585 i think ) and the final drive you want, mfactory too. If you find a cheap tranny maybe you'll break even..

PirateMcFred

M2B4 ("P16" engine-side casting):

M2S4 ("PX5" engine-side casting):


You can see at least one difference in the casting. There's a little 45˚ notch in some webbing that surrounds the M2B4 differential (and the M2F4 [also a "P16" enigne-side casting] for that matter) that is not in the M2S4. You'll have to cut the cast "baffles" down a bit to fit the OEM differentials. There could be other differences but I only know of the main casting interference concerning the M2S4 and similar gearboxes.

I suppose I could see if I can swap out the guts of my spare M2S4 into the M2B4 I have but I don't want to spend the time... There's no incentive. I already have my M2F4 with Quaife installed in the car.

Pirate

*updated casting info*


Modified by PirateMcFred at 6:12 AM 9/30/2008

A Blue Lude

Huh, I can see now the part of my T2W4 diff that is broken (the issue that you advised me on Pirate, which was very timely and helpful BTW )

The exposed gears on Matt's LSD make it pretty plain that it's a Torsen style. Good to see all the pictures again!

cool2073

Many thanks!!!

PirateMcFred

Here are some more.

I took the M2B4 apart anyway just to satisfy my own curiosity:

Anyone ever notice how thick the material is that the ring gear's bolted to?


It's the full width of the ring gear...


And you can see that there's some extra guts inside that are held in place with giant circlip and a couple torx screws (under the bearing). I am not going to disassemble it but I'd bet a bunch of money that if you try to take the ring gear off the differential will actually split in two and allow access to the clockwork inside. Another neat thing is that the diff rattles like it's got a bunch of gears in it (still not believing it's a viscous unit ). The outside of the diff casing is perforated with all sorts of holes to let fluid go in and out.



Anyway, I got out the calipers and discovered that the M2B4 LSD differential is very close to 10mm wider from taper bearing to taper bearing (141mm vs 131mm) and that's another big reason why the OEM LSD (of this particular type at least) is incompatable with M2F4 and M2S4 cases. You can however run an aftermarket Quaife or Kaaz in the M2B4 if you shim the crap out of it to line up the ring gear with the countershaft.

M2F4 case left, M2B4 right


It's subtle, but you can see that there's an extra centimeter material between bearings of the M2B4 differential. There's an extra step down from the flange to the taper bearing.

So there. Some Tech for the Prelude Forum. This concludes a very informative threadjack.

Pirate


Modified by PirateMcFred at 6:03 AM 9/30/2008