I have a euro V8 trans computer for use with the E/S switch that in effect does exactly what you're intending to do-- it shifts at exactly 7 mph without a spirited push of the pedal form a stand still. I dunno if it's easier to start from scratch or check out the innards of an older trans 'computer'. Any euro V8 W126 should have it.

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1987 560SEL (210,000 miles)

In the 420 when you click it over to the right you can hear the solenoid engage the whole time unless you click back out, if you take off quickly it will stay in first a while, if you keep the shifter engaged over to the right it will take 1st to redline....not sure if it will just stay there or if it will shift on its own....never tried it, don't intend to either. Highest I've gone with it in that slot is about 4500rpm....and it shifted to 2nd as soon as I released it.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

You could always reverse-engineer the PCB on a BergWerks unit, if you could get your hands on one ...

Back in 2008, I posted about doing this on my 500SEL. Do an advanced search on my name 'pmckechnie' and 'first gear start' and and you should be able to fine it. This is using a controller from a 500SEL and 1 wire and 1 switch. It gives switchable first gear start for almost nothing. Look and see if it helps. By the way, It still works great after 4 years.

Paul

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84 500 SEL (307,xxx miles)

$250 is a bit more than I was going to charge for the device I came up with and that device does a bit more than mine is going to.

My original intent with this was to build it for Hit Man X in exchange for some parts.

I suppose I could come up with an interface for setting the shift speed as well. That's not that difficult at all considering the controller has a USB interface. At that a 0-60 time device would be easy too but largely not useful for core functionality.

As 97 SL320 mentioned my biggest issues so far are:
1) investigating solenoid life and duty cycle.etc.
2) filtering, attenuating speedometer input signal for the controller.

Function List
-First Gear Downshift/Up-shift at Preset/User Determined Speed
-Disable Switch to resume second gear starting
- ?

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Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k

Well since we were looking into this for the I6 cars AND the component cost is about $30, it makes some since in this instance to 'reinvent the wheel'.



I have the ECE V8 box around my house somewhere if you want it Kris. I think it is only about five wires. I have no clue why no one built a kit for the I6 cars. Hell, maybe it is not possible or no one felt there was a market.



Factory FGS module? (002 545 41 32)

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]