E30 M3 S62 Build - Loads of queries about 4x4 drivtrains

[craiggroves91]

Pics or its not happening

[The Dark Side of Will]

Yes I looked at this, but how do you mount the box to the engine? which clutch would you use and with which flywheel? how would the starter work?

If only I could find something v8 with a t case already mounted.

Seriously, read my thread on E30Tech.

http://www.e30tech.com/forum/showpost.php?p=1240811&postcount=44

http://www.e30tech.com/forum/showpost.php?p=1261232&postcount=258

And a post in another thread that's linked from mine...

http://www.e30tech.com/forum/showpost.php?p=1261654&postcount=164

[nando]

If you used a ZF 5-speed, you could also use a 525ix transfercase. It's got an electromagnetic clutch - with some clever electronics, it wouldn't be that hard to control (you'd need wheel speed inputs and a PWM output). You can definitely get them in the UK, for not all that much.

You can get the rear housing of the 525ix transmission for about $200 and convert any ZF 310/320 to mount a 525ix transfercase to it. It would require a U-jointed shaft of course. the 525ix transfercase is a little beefier internally than the 325ix (bigger chain, bearings, gears), and the 325ix transfercase really doesn't have trouble with 300-400 ft/lbs of torque so a 525ix transfercase should be just fine.

[The Dark Side of Will]

the 525ix transfercase is a little beefier internally than the 325ix (bigger chain, bearings, gears),

Source for this info?

and the 325ix transfercase really doesn't have trouble with 300-400 ft/lbs of torque so a 525ix transfercase should be just fine.

Just how big is the pool of 400 HP E30 iX's? I bet I can count them all on the fingers of one hand. Don't forget that in stock configuration, the front diff is the "fuse". When used with the stronger 168mm front diff, the next weakest link will rapidly become apparent.

[nando]

There are limited pictures online of the E34 transfercase. I was hoping to use parts of it, but it became apparent that although similar, it's really different inside. the gears are much bigger as is the chain.

torque.. forget about HP, that's a function of how fast you're turning at a given torque level. torque breaks stuff. :p

I've *never* heard of a turbo guy breaking a transfercase. I've heard of countless front E30 diffs breaking though. If you've heard of one, you'd be the first. ;)

[Kershaw]

there was a guy on here with a turbo ix (in norway, derp) that went through 6 or 7 transfercases.

but he had something like 700-800hp.

[The Dark Side of Will]

There are limited pictures online of the E34 transfercase. I was hoping to use parts of it, but it became apparent that although similar, it's really different inside. the gears are much bigger as is the chain.

torque.. forget about HP, that's a function of how fast you're turning at a given torque level. torque breaks stuff. :p

The torque/horsepower debate is only relevant if you're comparing engines with very different RPM ranges. A 400 HP turbo M20 and a 400 HP S62 are going to have similar torque because they make peak power at similar RPM.

This is *NOT* the 180 HP Caterpillar vs. 180 HP Yamaha comparison.

What pictures did you find of the E34 T-case? What is its designation?

The E30 T-case is the ZF A-95

http://www.garlington.biz/Ray/BMW/325ixDriveTrain.htm

http://www.garlington.biz/Ray/BMW/325ixDriveTrain.pdf

[nando]

there was a guy on here with a turbo ix (in norway, derp) that went through 6 or 7 transfercases.

but he had something like 700-800hp.

he broke front diffs, not transfercases..

[nando]

The torque/horsepower debate is only relevant if you're comparing engines with very different RPM ranges. A 400 HP turbo M20 and a 400 HP S62 are going to have similar torque because they make peak power at similar RPM.

This is *NOT* the 180 HP Caterpillar vs. 180 HP Yamaha comparison.

What pictures did you find of the E34 T-case? What is its designation?

The E30 T-case is the ZF A-95

http://www.garlington.biz/Ray/BMW/325ixDriveTrain.htm

http://www.garlington.biz/Ray/BMW/325ixDriveTrain.pdf

drivetrain components are still rated by torque, not horsepower.

http://boards.bmworg.ru/viewtopic.php?t=2835

[The Dark Side of Will]

Driveline components are rated for a lot of things, including vehicle weight.

*THIS* is exactly what I'm concerned about regarding BMW T-cases:



The pinions in the center diff don't inspire confidence either...

[nando]

Driveline components are rated for a lot of things, including vehicle weight.

*THIS* is exactly what I'm concerned about regarding BMW T-cases:

this is a lubrication and maintenance issue. also, you can extend the splines at least another inch to give more contact area. BMW still uses this same basic design. The U-jointed transfercases still have that splined section, only there's a flange for the shaft to bolt to, instead of a one-peice shaft/spline.

The pinions in the center diff don't inspire confidence either...

why? have you EVER seen one damaged? they're basically the same size as the ones used in the diff, and transmission, and anywhere else in a BMW drivetrain.

[The Dark Side of Will]

this is a lubrication and maintenance issue. also, you can extend the splines at least another inch to give more contact area. BMW still uses this same basic design. The U-jointed transfercases still have that splined section, only there's a flange for the shaft to bolt to, instead of a one-peice shaft/spline.

And if it didn't experience torque, it would never wear...
That's exactly why I want to convert it to a fixed yoke front output.

why? have you EVER seen one damaged? they're basically the same size as the ones used in the diff, and transmission, and anywhere else in a BMW drivetrain.

They're small and narrow and there are only three of them. Six pinion planetary sets are pretty standard in high output two speed applications.

[nando]

i wonder if the splined output flange on the E46 has the same # of teeth. The biggest problem with extended splines is removal of the shaft.

that's all well and good that some have 6 and BMW uses 3 - but I've NEVER seen a damaged BMW planetary gear. Unless perhaps the transfercase was run for a long time bone dry. the gears in my 275,000 mile case look brand new! remember, only 1/3 of the torque (approximately) is going through them.

[Turk]

so are we saying the back end of an e30/e34 gear box (below) will fit on the e34 v8 5 speed or maybe even the e39 m5 6spd?



Or will this need to be spaced out from the back of the tranny, i.e. having it welded onto the back?

[The Dark Side of Will]

remember, only 1/3 of the torque (approximately) is going through them.

100% of transmission output torque (4.2x engine torque in the case of the S5D) is delivered to that planet carrier.

so are we saying the back end of an e30/e34 gear box (below) will fit on the e34 v8 5 speed or maybe even the e39 m5 6spd?

http://www.325ix.com/photos/index.php?action=resize&file=2011/S54ix/11-05-2011/DSC00278.JPG

Or will this need to be spaced out from the back of the tranny, i.e. having it welded onto the back?

The component pictured will fit on the back end of the ZF 5 speed but not the Getrag 6 speed.