Andrew's S54 Swap

[Asbradley21]

on the subject of E-throttle control - some interesting stuff has come up recently. Apparently, the US S54 tune doesn't open the throttle more than 75% until after 4000rpm. It doesn't reach 100% until 5000rpm. The solution is to use the EU tune or the CSL tune which are both much, much more aggressive.

the thinking is the US tune was limited to 75% throttle for emissions reasons.

Still seems to me like more reason for manual throttle. The one from bimmerworld claims to have solved the sticky modulation issues of the other manual setups, appears to be a different design than VAC and Sunbelt Link

[Andrew325is]

Thanks for documenting your swap thoroughly. Will be referring to this thread for guidance.

I didn't go into too much detail about anything, so if you have any questions don't hesitate to ask.

[Andrew325is]

on the subject of E-throttle control - some interesting stuff has come up recently. Apparently, the US S54 tune doesn't open the throttle more than 75% until after 4000rpm. It doesn't reach 100% until 5000rpm. The solution is to use the EU tune or the CSL tune which are both much, much more aggressive.

the thinking is the US tune was limited to 75% throttle for emissions reasons.

Hmm, that's interesting. Everyone should make sure their tuner flashes their ECU with the latest version of Euro software then. :)

[nando]

on the subject of E-throttle control - some interesting stuff has come up recently. Apparently, the US S54 tune doesn't open the throttle more than 75% until after 4000rpm. It doesn't reach 100% until 5000rpm. The solution is to use the EU tune or the CSL tune which are both much, much more aggressive.

the thinking is the US tune was limited to 75% throttle for emissions reasons.

[ohthejosh]

Thanks for documenting your swap thoroughly. Will be referring to this thread for guidance.

[Andrew325is]

Yeah basically. I've heard from people it was better (instant is the word), but I haven't driven a Z4M myself.

[nando]

eh. I doubt you would even notice. most likely, it's for emissions. I can't see the extra cost and trouble being worthwhile, unless MSS70 is considerably easier to tune than MSS54.

I can't recall ever hearing anyone complain that the throttle response of an S54 was slow, or there was any detectable lag.

the S54 in the Z4m makes the same HP right?

[Andrew325is]

why is it so much better? I mean it's faster, but.. what does that really mean? did injector timing accuracy increase by 1000%? did ignition timing accuracy increase 5x?

you learn as you really get into standalones and stock computers that faster doesn't really mean a whole lot. there are some things that are good to have better precision/faster processing for but they are also diminishing returns.

if you tell me the fuel map is 2x the size, I'll yawn. :p

What's faster is the throttle response when pressing the accelerator pedal due to the increase in processing power: 64 million calculations per second. Compare that with the MSS54 which is capable of 25 million calculations per second, which is just slightly more than the older MSS50's capability of 20 million calculations per second. BMW claims in their Z4 M Roadster press release the faster processing, "helps to improve emission management," then goes on to talk about the double-VANOS, so I assume that operates faster as well. Of course neither ECU compares to the MSS60 & MSS65 (E90 M3 & E60 M5) which are capable of 200 million calculations per second. :)

[nando]

why is it so much better? I mean it's faster, but.. what does that really mean? did injector timing accuracy increase by 1000%? did ignition timing accuracy increase 5x?

you learn as you really get into standalones and stock computers that faster doesn't really mean a whole lot. there are some things that are good to have better precision/faster processing for but they are also diminishing returns.

if you tell me the fuel map is 2x the size, I'll yawn. :p

[Andrew325is]

If you can find a tuner that can flash an MSS70, I have one on the shelf for sale.

That really would be the ideal ECU. There's got to be someone who can do it since people are putting S85's in their E30's and the MSS65 is similar as far as I know.

[gobuffs]

If you can find a tuner that can flash an MSS70, I have one on the shelf for sale.

[Andrew325is]

Someone asked me some questions about the electronic gas pedal and throttle. I'll post my response here in case the info is useful to anyone else. :)

How do you mount the electronic gas pedal?

To mount the electronic gas pedal, first of all you'll just need to remove the E30 pedal (which can be a real PITA) and unscrew the pedal stop behind it (if its still there). The pedal stop is 8mm which is the same as the upper bolt for the electronic gas pedal mounting bracket. Use a high strength plastic epoxy (such as Devcon Plastic Welder) on the base of the bracket and secure where the base of the old pedal was and then screw in the upper mounting bolt. Let that cure overnight. In the morning, loosen the clamp that holds the steering column tube against the firewall so you have room to slide the pedal onto the bracket. Just rotate it out of the way and re-tighten it. The pedal should then slide onto the bracket. It might be kind of a tight fit. Make sure you attach the connecter on the the pedal before snapping it into place.

Why is the manual throttle an issue?

Manual throttle is an issue first of all because the S54 was not designed to utilize a manual throttle. The geometrical design of the throttles were designed with an electronic throttle motor in mind. As such, the torque required to open and close the throttles is not linear as one would expect in a cable operated system. This makes the throttles rather difficult to smoothly modulate. There have been several companies trying to make manual throttle kits for this engine over the years. Some have continually tried to improve their product but they have not succeeded very well. I've tried Sunbelt's kit which was probably the best. It would probably be okay for a professional driver racing at high speed on the track, which is what it was designed for, but it felt very touchy off the line and took a lot of practice to use without making the car jump. It was not a comfortable driving experience. I had to push quite hard before it would move and then suddenly it was too much. You could quickly find yourself in a dangerous situation. In my opinion it is a no-brainer to go drive-by-wire with the S54 if you intend on using the car on the street. It's a very smooth and refined system. Also, the throttle motor probably already came on your engine so there's no additional expense. The response time is very good. It's even better if you use the MSS70 ECU (Z4M) which processes data much faster (I don't know if there's a tuner who can flash it yet).

[Andrew325is]

Here's the last video I took driving the car the day before I sold it. It had logged 4,500 miles at this point with the S54. Perhaps not very impressive, but keep in mind I did not shift lower than 4th gear while driving on the interstate.

http://youtu.be/a0hoyiMvY38

[Hatem]

anybody has idea about swapping e46 LCM on E36?
Thanks,
Hatem Reyad

[Andrew325is]

Are you related to Wayne Gretzky by any chance?

lol umm maybe? :)