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Date: Sat, 29 Aug 1998 00:30:16 +0800
From: Justin Chan <>
Subject: Switchlogic...Installed! (Long, slushbox, sorry)

Matthew, for you, a repost of something that went out a few months back:

A couple of people have asked about the Switchlogic. I installed this earlier this year. In the UK, it is a vendor-install only. Same thing in Singapore. What I did was to purchase a unit from the UK at some savings (no labor $$$) and installed it myself. Here's the down and dirty, followed by a few comments.

Four major steps:

  1. Remove your tranny computer and place the new tranny chip in.
  2. There is a wire that connects to the back of the new chip.
  3. This wire has to be threaded out of the tranny box and into the passenger compartment.
  4. This necessitates drilling a small hole in the back of the tranny box.
  5. Pass the wire through the hole; plug it into the chip.
  6. Don't replace the box yet - see Step 2.
  7. Run the wire into the passenger compartment and to the steering column.
  8. The instructions recommended running the wire along the firewall in the engine compartment from the computers compartment to the master brake cylinder on the right side of the car.
  9. Instead, I noticed that on the back of the computers compartment there is a little rubber grommet that, if pushed out, becomes an opening into the passenger compartment. Right behind it is part of the airconditioning vent ducts; but there is a gap for you to push it down behind the ducts and into the area beneath the dashboard. Threading cable is useful. If not, nimble fingers. If you replaced the computer already, you can't get to the grommet (see step 1.e.)
  10. Remove lower dashboards.
  11. On LHD cars - you're there.
  12. On RHD cars - you need to thread the cable behind the center console towards the steering column. Threading cable imperative.
  13. Now remove the lower steering column shroud (couple of screws).
  14. The shroud is hard to remove. First time I did it it took me about 40 minutes because I didn't want to crack it. If you feel around you'll notice it is hooked to the upper shroud by clips that come undone if you push the lower shroud inwards towards the steering column gently. You'll get there - be patient.
  15. You need to prep the shroud by sawing a little hole in it for the new shifting lever to fit through. Not too difficult.
  16. Hook the cable to the shifting lever.
  17. A new lever is provided that slips onto a little socket meant for a lever made by BMW for electronic steering column height adjustment. Most people don't have this.
  18. Some wires need to be plugged into the lever.
  19. On the other end of these wires is a plug.
  20. This plug plugs into the cable you threaded to the tranny box.

Replace everything you've unscrewed over the past three to five hours and go! Your tranny chip is now hotwired to a lever at your fingertips.

To commence, change into "M" or "Snow" mode (you lose this). The S/logic takes over and you control shifting manually.

The lever flicks forwards and backwards. You can stipulate to the vendor which way is upshift/downshift. On mine it's push forward for down, pull towards for up. Easy pie. Takes about 10 seconds to learn, 5 minutes you've got it mastered.

It's basically a new car if you've suffered with an automatic. You can keep the engine right at the tip of its torque curve so it always feels lively. I downshift to take corners in second and mash the accelerator coming out without having the car shift up at an awkward moment as I come out of the bend. Downshifting to overtake or speed up or just to go up a hill is no longer operated by the kickdown button or a manual shifting of the lever. What was very awkward before - the 5/3 or 4/2 shift, is now just a couple of flicks.

The shifts are very smooth and fast. You can specify a fast-shift option for faster shifts under heavy throttle. Downshifts are smoother than upshifts for some reason.

Safety features are built in so your engine never overrevs. If you're at 80 and specify second, the engine must spin down to an acceptable speed before the gear shifts.

The difference between this and "M" or "Snow" mode are basically: greater control; faster shifts - both in terms of operation and actual shifting; safer (hands on the wheel) and I perceived the car to be much more lively than in any automatic mode - largely because of the total control you have over gear changes. You can rev up to 6000 on a light throttle if you want - on full automatic, it would inevitably shift between 3500/4500.

Finally, there is an indicator panel which tells you which gear you are in. It only works for the Switchlogic i.e. it's not for "E" or "S" mode. This costs more and is hard to install.

I would do it again. No changes to the engine, but car feels much better because it's so much more torquey, and you have much more control. Zipping through slow traffic is less of an effort and less dangerous. Being able to exercise control over the engine brake going into a corner or bend is also an added plus. Notice how often the word 'control' comes up?

Not having driven either the Steptronic (BMW) or Switchtronic (ALPINA) I can't say. But it certainly didn't make the car "un-BMW like". In fact, the 'tiptronic' style transmission should have been an option on 3ers postdating the current E39, and will certainly feature on the E46. That will have shifting done on the stick itself. I feel much happier with the lever on the steering column, F1 style. I drove for a year shifting between 2/3/4 on the stick. I like this way better.

Feel free to send me questions if you have any.

I do know Dinan has put these on one of their 8ers. They may or may not be agents for Racelogic. But if it's good enough for Dinan, that's pretty good.

Justin Chan

And an update sent to Brian Kennedy yesterday:

>> [JC] You can (as I did) actually specify at what point you want the tranny
>> chip to match your EPROM.

>You can specify the redline? Or you can specify the top shiftpoint
between each
>pair of gears? How do you do that? Special tools? EPROM writer?

Well supposedly (though I've never tried) the computer is supposed to automatically shift up for you when you exceed the rev limit. So if I had specified 6000 as the rev limit, it would have automatically shifted at 6000. I specified a rev limit of 6750, short of the 7000 warned against by Jim C and others. I usually flick the lever at 6500, giving myself a narrow margin to play with. Whether in the microsecond between 6500 and 6750 the electrons travel down the hotwire and instruct the tranny chip, or the chip takes over and shifts automatically, I don't know. But it does shift there. I chose 6750 because I originally intended to install a pair of Racing Dynamics camshafts, which peak HP is found at 6600 RPMs.

You can probably specify a higher 'autoshift' point, let's say a dangerous 7500. The tranny would shift there, but your main EPROM, I think, would override and cut out power at 6000-6500 (I believe the stock rev limit, stock HP peaks at 6000) so, as you say, the specified autoshift point is pointless (pardon the pun) until the rev limit is removed or revised.

>> There is also a fast shift option which will
>> instruct the transmission to shift faster than stock. Apparently this
>> shaves 0.2s off the normal shift.

>Cool. I suppose that makes the shifts a bit rougher?

Not really. Not being mechanically minded, I can't explain it in full, but according to the VP of Racelogic, the tranny shifts "conventionally" under a light load, and "faster" under a heavy load (wide throttle?).

To be honest, I can't tell the difference between a 1s and a 0.8s shift time (can you!?!). But they said is was an option and I chose it. The shifts are as smooth as in normal auto, in fact I would say even more so, because there isn't that split second of hesitation between your mind saying "why aren't you shifting now?" and the autotrans saying "ok, I'm going to shift now". With the lever, the communication is immediate, and a nice feel. In some respects, I prefer it to a stick shift, especially when doing fast road driving in an urban setup. It gives me an extra 15% attention to pay to the driving environment, and allows me to risk maneouvers I might not have tried if I had to worry about dealing with a clutch.

>Sounds like you're happy with it. Great!
>Have you had any problems with it?
>Any drawbacks whatsoever?

Nope, not really. The shift lever comes either black or with a fake carbon fiber sticker. I took the sticker, but didn't like it, so got hold of a piece of carbon fiber, fashioned it to the shape of the lever, sprayed it with clear coat paint and stuck it on, It melds much nicer with the Milos' trim I have installed.

The car really behaves very normally, it still feels "stock" in Switchlogic mode...any complaints would be probably that I think the car can afford to be geared a little wider between 3rd and 4th now, as I usually don't go above 80 in urban, and I would like lower revs when cruising in 4th. That's an OEM fault. The gears were probably a bit closer so that the engine didn't feel so lackadaisical in ordinary E mode, but with the Switchlogic, that consideration really falls away.

Tall passengers may find the lever a bit intrusive on leg room. I'm short, about 5ft6 so I have no problems.

>Back to the 4hr install -- Did it require special tools? Anything

If you can (1) access your ECU compartment (1a) know how to rechip your car and (2) can disassemble the lower dash, you're 50% there. One hard part is removing the tranny ECU without bending the supporting brackets...I did...and replacing the ECU took much cajoling and the better part of an hour.

The only other hard parts are threading the cable from the tranny ECU into the passenger compartment, and for me, because I drive a RHD, through the center console and into the steering column. US users will haver an easier time with the steering column on the same side as the computers. Also tricky is disassembling the steering column shroud/trim without breaking anything. It feels like it is going to break, the clips are flimsy, and require tugging in a very unconventional/counterintuitive direction to facilitate removal. I've written instructions in case anyone is interested.


Sure, no problem. One of the few enthusiasts with a slushbox on the digest. My S/logic is probably the performance equivalent of a BL/SS or an ACS/SS for you other guys out there. It costs about $600 if you buy from a distributor in Australia, close to $1200 if you buy from the UK...don't ask why. So it's somewhere smack between BL and ACS - but honestly, probably transforms the automatic more than the SS transforms the manual...having shifts vs having shorter shifts...!


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