850Ci M73 Steptronic M Gate - Upgrade to M/S Gate - Sport Drive Mode - DONE Wonderful

[Timm]

Get a whole new shifter with it: https://www.ebay.co.uk/itm/193665473...Bk9SR4KS4tK-YQ

[Auraraptor]

Unfortunately, I just need the boot, not the whole assembly.

But wait is the boot the same between left and right hand drive?

[m6bigdog]

Unfortunately, I just need the boot, not the whole assembly.
But wait is the boot the same between left and right hand drive?

That I am aware, the UK right-hand drive cars have a lot of special parts and unfortunately, the steptronic console trim/boot is one of those pieces.
Now, don't let Tim try to talk you into converting your 8 into right-hand drive... just because he has a lead on a bunch of parts on an island somewhere in a the Atlantic.

[MParallel]

Unfortunately, I just need the boot, not the whole assembly.

But wait is the boot the same between left and right hand drive?

It's asymmetrical, so unfortunately, no.

[rmchurchdc]

FWIW,
8 Sport Drive TCM's installed. A few owner feedback replies in this post.
A few SD-TCM's are still available, I have a few TCM's that need to be upgraded and once that is done, I will put my 8 back together soon.
So, when I sell out the current batch of GS9.22.1 TCM's upgraded to SD, it will be awhile before I upgrade more!!

Do you have any TCMs left for sale?
Thanks!

[m6bigdog]

Do you have any TCMs left for sale?
Thanks!

PM me: oops - new to forum.. that won't work!!
need a way to communicate.
I could put one on eBay?

Yes, I still have some available.
More info - Post in the E31 "Parts For Sale" section" link below..
https://www.bimmerforums.com/forum/s...rogram-Finally

[rmchurchdc]

PM me: oops - new to forum.. that won't work!!
need a way to communicate.
I could put one on eBay?

Yes, I still have some available.
More info - Post in the E31 "Parts For Sale" section" link below..
https://www.bimmerforums.com/forum/s...rogram-Finally

Yea, no way to DM on here. Email me?
rmchurchdc at gmail

[Rich8]

I got this great upgrade for my 1997 850Ci a couple of months ago. Installation and learning was so simple....a non-event. for my M73, and it's a real joy.
I got the SD-Shift Profile - 2.81:1 - Final Drive gear ratio version
.
Driving in D mode is still good but now with the option to use 1st gear if I floor it. But it all gets better when I move to DS mode; the box immediately shifts down one gear and if I'm in a hurry, I can move the lever over into DS and immediately pull back, and now I have two quick downshifts, with just one action on the gear lever.
And while I'm in the 'spirited mentality', then I have 1st gear anytime on demand. When I'm driving in DS auto-mode, I can be rushing through the mountains here in AZ, and the box doesn't go up into 5th (unless requested), it just goes between 1st and 4th.
.
It really is a joy to drive now......thanks Rod, for seeing the project all the way through.

[m6bigdog]

Got requests for another SD-TCM-315 and I was all out.
So, I burned some EPROMS and tested more units, both the 281 & 315 versions.

Currently, I have 8 ea. 281 and 2 ea. 315 available to ship.
Unsure when I'll do another production run, so hopefully these will make it through the summer.

I'm going to put my 8 back together (the test mule), do some additional CSi rear suspension upgrades and maintenance; that way, I can enjoy the new found Sport mode for myself.

[m6bigdog]

Drove my 8 yesterday and what a difference with SD.
Summer is close.

[Auraraptor]

Got requests for another SD-TCM-315 and I was all out.
So, I burned some EPROMS and tested more units, both the 281 & 315 versions.

Currently, I have 8 ea. 281 and 2 ea. 315 available to ship.
Unsure when I'll do another production run, so hopefully these will make it through the summer.

I'm going to put my 8 back together (the test mule), do some additional CSi rear suspension upgrades and maintenance; that way, I can enjoy the new found Sport mode for myself.

CSI shocks/springs rear and front?

[m6bigdog]

CSI shocks/springs rear and front?

No. Installed new EDC shocks a couple years ago..maintaining the M-Sport spring rates w/K-Bars GenII.
I'm doing the final-drive front bracket and rear mount bushings.
The CSi final-drive rear mount bushings are NLA, but I have some I purchased years ago.
SD-TCM, 3.23:1 LSD and traction control is giving the OE final-drive bushings a workout and I have yet to replace the OE bushings.
I will install new CSi subframe bushings when/if the small 2-227-375 come off B/O (BMW estimate 6-12 month until restock).

[Auraraptor]

Nice, good luck. The NLA rear bushings are annoying. Eventually I want to redo all mine but waiting for restock. Eventually I will start a separate thread on bushing options/alternatives

[m6bigdog]

I'm going to get a ticket in my 8 with the SD-TCM.

In SD, off the line in 1st gear is so effortless and the higher RPM shifts keep the M73 engine up in the power band.
Down shift come with less throttle to let the RPMs do the work without the need for heavy throttle or flooring it.
Truly the addition of an Extreme Sport Program Mode (with 1st gear), without changing the stock TCM features; Manual Mode and "D" position Automatic Gear Shift (AGS) programs.
Just more fun and more engine RPM performance with less throttle...
https://www.bimmerforums.com/forum/s...rogram-Finally

[m6bigdog]

Another happy 850-M73 owner...
I have a couple of the 315 and 281 versions of the SD-TCM available.
There are 12 each 850-M73's plus mine with this SD-TCM installed.

The only issue I discovered is with the earliest 850-M73 cars (1/95-3/95) that have the EKM hardware version EKM HW:6, SW:9.8.
They will display a "D" only on the IC-EGS when in "SD" mode.
For these cars everything including the Sport Drive works normally, but the Transmission EGS Display on the Instrument Cluster is without the "S" when in "SD" mode.
The EKM version can be tested using a DIS.
The solution would be to upgrade the EKM to HW:7, SW:9.8, but that maybe more effort that is is worth, as the tilted Steptronic shifter indicates the "SD" Mode and if the shifter is tapped +/- then the IC will display the Manual mode gear selected M1-M5.
The DIY EKM upgrade to HW:7, SW:9.8, is possible, but you are on your own, as there are only 30-40, 850-M73 cars that could benefit from this upgrade.
E31 Bimmerforums Discussion:
Instrument Cluster EGS Display and communications between EKM and EGS Modules
https://www.bimmerforums.com/forum/s...nd-EGS-Modules

schaefersd

• As i was reading various postings, I saw m6bigdog's post regarding the SD-TCM upgrade for the Steptronic transmission in the M73 model. It sounded good so i went for it. I can report that the performance improvement is great and the install was super easy. An added bonus is that the AGS function in the normal Drive program is also improved, meaning it adapts quicker to the driving style of the driver.

https://www.bimmerforums.com/forum/s...0#post30926720

[vgs]

I now have the SD TCM 2.81 working on my Euro-spec 03/1995 M73.

For us early Euro-spec M73 owners, Rod and I ran across an issue that we've now figured out.

The early Euro cars didn't come equipped from the factory with the Shift Inter-Lock solenoid 25161422277, and they come with a GS9.22 TCM (not the .1 revision). It seems that the GS9.22 does not see a missing Inter-Lock as an error, but the GS9.22.1 SD-TCM does and it throws a Transmission Fail-Safe Program Error.

Luckily the connector for the missing solenoid is present in the harness.

I scavenged the solenoid from a US-spec E38 and plugged it into the unused connector in the transmission harness and it worked. No more Trans Fail-Safe, and SD mode works (although it doesn't display 'SD' in the instrument cluster due to the EKM version, which was expected).

I still need to run through the shift adaptation period to give my full driving impressions... but after a short test drive so far I'm impressed and glad I did this upgrade! Thanks Rod!