S52B32US (formerly: M50) automatic swap

[The Dark Side of Will]

Shortly after I got my E34, my dad found an '88 325is autotragic for my mom.

They recently took a day trip and the car returned 25 mpg. Think that it's a fairly small car and a fairly small engine, my dad was disappointed with this.

Since both of us are hot-rodders, the natural response to this is to contemplate an engine swap.

I assume that since the M50 has 10.5 compression and the M20 has 8.8 compression, the M50 will get much better mileage.

Pretty much all the info I've found relates to M50 swaps with manual transmissions, but this car must remain an automatic for my mom to drive.

So I've found that the M50 needs the E34 pan and pickup to fit in the E30 body, so I looked for 525i engines. There is a '90-'92 engine close enough to pick up for $500 and a couple of '93-'95 engines within about a 30-45 min drive for $600.

If these questions have been answered before, please point me to those threads.

What is the difference between the two year ranges? Anything interesting?

RealOEM says the automatic trans use is:
E30: 4HP22-GA
E36: A4S 310R-LN
E34: A4S 310R - RH/MX

This website http://www.bokchoys.com/differential/GearRatios.htm
says that the ratios for the A4S 310R were:
2.86 / 1.62 / 1.00 / 0.72

This website http://e30world.com/specifications/BMW-E30-specs-table
says that the ratios for the 4HP22 were:
2.48 / 1.48 / 1.00 / 0.73

Is this correct?

Is the wiring for the automatic part of the engine harness or are the auto transmission signals routed through the body harness? Is the harness routing different between the E34 and E36?

What's involved in swapping the A4S into the E30 as far as mounts and driveshaft go?
Would it be "better" (whatever that means) to keep the 4HP22 and tilt it to match the M50?

I'm assuming that the A4S is an electronically controlled transmission and that the 4HP22 is a hydraulic transmission that could be used with an M50 running manual trans DME. Is this correct?

Thanks!

[James Crivellone]

4HP22 is hydraulic/manual so you don't need any electronics to run the thing. Personally I think the A4S 310 is a stouter transmission.

In terms of electronics, the tranny harness is a seperate component of the engine harness, however, at least on E34 NVM50's the engine harness has automatic provisions (not sure on manual equipped M50's) via a connector that is right next to the DME. Not sure on E36 generations.

Assuming you had a kickdown button, the EGS Tranny computer, and the harness the thing should plug in fairly easily, plus with the factory harness you could pull EGS codes via any DIS/Inpa diagnostic setup.

[The Dark Side of Will]

Interesting. So the DME and EGS are separate units?

Does an OBDII A5S EGS computer talk the same "language" as the OBDI A4S EGS?

IE, could I use an A5S and EGS with an OBDI M50 DME?

[The Dark Side of Will]

As the change in title indicates, I've acquired some more definition on this potential swap.

I have a line on a '97 M3 S52B32US engine for a good price. My dad is interested in it. He wasn't very excited about going from 165 HP to 190 HP, but he's much more excited about going from 165 to 240.

The car is still my mom's to drive and still has to stay automatic. RealOEM only shows an automatic transmission for the OBDI E36 M3's. Will the OBDII DME capable of running the VANOS talk to the OBDI EGS?


Also ran across this thread, but haven't had time to read it yet: http://www.r3vlimited.com/board/showthread.php?t=232038

[DesertBMW]

The car is still my mom's to drive and still has to stay automatic. RealOEM only shows an automatic transmission for the OBDI E36 M3's. Will the OBDII DME capable of running the VANOS talk to the OBDI EGS?

Best way is to get a whole harness from 1993-1995 325i because wiring harness is integrated for both ECUs. Do the GM 4 speed transmission it is much better than the ZF 5 speed one from 95 M3. OBD2 EGS will not work on E30 because it needs constant signal from OBD2 anti lock brake system.

[The Dark Side of Will]

What applications got the GM transmission?

Thanks for the info on the OBDII EGS. Will the OBDI EGS work with the OBDII DME?
Does the OBDI EGS communicate with the DME? Does it piggyback on the DME sensors or does it have its own (IE, trans needs to know throttle position, engine load and RPM)?

[DesertBMW]

What applications got the GM transmission?

Thanks for the info on the OBDII EGS. Will the OBDI EGS work with the OBDII DME?
Does the OBDI EGS communicate with the DME? Does it piggyback on the DME sensors or does it have its own (IE, trans needs to know throttle position, engine load and RPM)?

GM has dual oil pans

OBD1 EGS will work with OBD2 but you will have to rewire it. OBD1 EGS does not communicate with ecu, it receives RPM, throttle position voltage, load voltage from injectors, this is why the harness is integrated for both systems. Easy way is to get it all from 1993-1995 325i

[The Dark Side of Will]

What years/models for the GM trans? All OBDI 4 speeds?

Rewiring is easy enough. So I *should* be able to run the OBDI EGS with OBDII DME (is there a calibration difference of the DME's for manual or automatic transmission?). Has such a swap been done or documented before?

How does the OBDI EGS get those inputs? Does it have parallel sensors to the DME sensors? Are the sensors "dual tapped" so that both units read the same sensor?

How'd you come by this useful knowledge? ;)
Where do I get the requisite ETM's for the rewiring?
Thanks!

[The Dark Side of Will]

Shit's on. My dad threw down for the engine today.
We know we'll need the E34 oil pan and pickup.

In doing some research, we find that the GM transmission is called the 4L30E by GM. 4 means 4 speeds, L means longitudinal, 30 is a rating of the transmission's capacity, both in engine torque and gross vehicle weight and E means electronically shifted.

There are two versions, one with a 2.4:1 first gear and one with a 2.8:1 first gear. Do we know which cars got which transmissions? IE, did the 4 cylinder cars get the 2.8 and the 6 cylinder cars get the 2.4?

We want the 2.8 for this swap as we'd like to go with a pretty tall rear end gear.

More automatic swap threads to read later:

http://forums.bimmerforums.com/forum/showthread.php?t=1652147

http://www.r3vlimited.com/board/showthread.php?t=164359

[The Dark Side of Will]

This is the engine.

It's surprisingly complete, considering the price he paid for it.

It's pretty much only missing the alternator, the A/C compressor and the right side mount bracket. There are only about half a dozen cut wires in the harness, too.

Note that the scale *HAS BEEN TARED FOR THE PALLET*

[The Dark Side of Will]

Read:

http://www.r3vlimited.com/board/showthread.php?t=232038

http://www.r3vlimited.com/board/showthread.php?t=164359

http://forums.bimmerforums.com/forum/showthread.php?t=1652147

(asshat deleted all his info last week)

I'm eyeballing a 3.23 diff from a Z3 to use with the GM transmission. I think my dad would be fine with that. My mom won't care as long as it gets her where she needs to go.

However, I still need to figure out how to pick a 2.8 first gear trans from a 2.4 first gear trans.

Edit: According to this, '94 model year was the break point for the 2.4/2.8 ratio set: http://www.bimmernut.com/forum/5-ser...n-changes.html
The .pdf version is here: http://members.roadfly.com/erichall/...veShifting.pdf

[DesertBMW]

Due to the increased spacing of first through third gears, this new version may also be referred to as the "widespread gear ratio automatic transmission." Careful selection of gear ratios and torque converter characteristics has enhanced the low-end acceleration

Just get 1994-1995 GM tranny and 3.7LSD and you will be set. If you go taller ratio than 3.7 diff then car may suffer low end power and will feel "lazy"

[The Dark Side of Will]

I really don't think that going from an 8.8:1 2.5 litre to a 10.5:1 3.2 litre will cause the car to feel lazy... We're not looking for maximum performance out of this car anyway. I have The Mule and Bad Idea for that...

According to RealOEM, the A4S 310R was used through 98ish in the E39 528i. I have not yet confirmed with www.car-parts.com whether the available transmissions are 4 speeds or 5 speeds. I was expecting to pick up an E39 528i trans based on the *@$$*umption that its internal calibrations would be for a heavier car with a more powerful engine than the calibrations used in the E36.

Also, the OBDI EGS will need to be recalibrated to make the most of the higher output enigne. Does anyone do that?

[The Dark Side of Will]

Here's a crazy idea... The 5 speed GM automatic was used in the late '90's.

Depending on how BMW specified the control interfaces, the 5 speed EGS from the OBDI M3 has at least a snowball's chance in hell of working.

I recognize that it's a long shot, but I'd like to take a close enough look at the controls to figure out if it could work or not. Where can I download the appropriate TIS's?

[The Dark Side of Will]

Back in the realm of the real world... I've read that the S50B30-US had VANOS... Which means that an S52B32 could be run using the OBDI DME... Right?

I was expecting to use the OBDII DME because I thought that the OBDI DME didn't run VANOS.