Lee,

So, does it mean if I want to modify my '92 400SE, which rated 282hp/302 lb-ft, I can sqeeze more power out of the engine then say, a '93-'94 400SEL(279hp/295lb-ft) or '95 on S420s(275hp/295lb-ft)??

Thnx...

Akry,
As for how much can be extracted is limited by your budget and the tuner's talent. j/k MB was more forthcoming with power specs on W140's than the W124's for some reason. You do get more power out of the box with the earlier cars. If you look at Renntech's W124 page http://www.renntechmercedes.com/w124.html You will notice that the early 500E's can be modified for power much easier than the later cars. Both cars can be taken to the same level it just costs many thousands more to do to the later cars. ex. a stage 1 6.0 engine is $19K on the early cars, $27.5K for the later cars. Since such grand upgrades are likely out of the question for most of us mortals it would more specifically fall to chip tuners and the like. Since everyone who tunes MB software is different (and secretive!) it is hard to say. It would stand to reason that the earlier cars could be tuned to a higher output number. Keep in mind, they are faster to begin with.

I do suspect that the difference is bigger than MB says it is. Ex. MB claims 93 500E's had 315HP and 347lb-ft while 92's had 322HP/354lb-ft. Having driven both 92 and 93 cars the difference is bigger than 7HP and 7lb-ft. On 3700-3800 lbs that amount should be negligible. If I had to guess I would say that the 93's did make 315/347 but the 92's made quite a bit more than 322/354. I'm talking about a difference you can easily feel and measure. I was feeling/noticing the difference long before I knew of the "feature".

I have noticed that the later cars are more stable in their performance. No matter the outside conditions, they perform about the same. The earlier "hot" versions seem "turbo" temperature sensitive. I have measured up to 1 full second difference 0-60 on the 400E. That was between a 40 degree F evening and a 100 degree F afternoon.

Hmmm...if those early cars are that sensitive there has to be a way to trick the computer into thinking its colder outside than it really is! That is about all I can say on this matter...

Lee

Lee,

Thnx for such a thorough answers. MB usually is conservative on their spec figures. I always feel that my '92 400SE makes more than 282hp. It says OFFICIALLY that 0-100km time for 400SE is 8.6sec. But no matter how many times I measure it, it will be some where around 7.4-7.7sec.(hey, maybe they put a 5.0L V8 in mine by accident....J/K).

As for the temp. sensetive issue. I did notice that when the day is hot, the car seems to "loose" couple HPs.

Well, anyways, thnx for your time to answer my Qs.

Akry,
Your welcome. I'm always glad to help out a fellow enthusiast. MB has something of a rep for "underestimating" or "under-rating" their cars from that generation. As tight as things are today with BMW and Lexus, I'd guess their numbers are more accurate. The 400E was rated at 7.1 to 0-60 but I could consistently pull 6.5's. (6.2-6.4 on a cold night) I have not timed the 500E but I can tell it is MUCH faster. The 500E was rated at 6.3 but I know that was about a second high. There is a particular stoplight and later a bridge near my house. If I floor it when it goes green I could be at 60-65mph by the time I reached the bridge in the 400E. In the 500E, I am at 90+mph.

There is the old addage of 1% power for every 10 degrees change in ambient temp. The 94+ cars seem to hold pretty close to that. I've seen some of the pre-93 cars just "fall on their ass" when the temp got up over 100F and conversely "run like a raped ape" when it was just above freezing. In the normal swing of temp for a day you should only gain/lose 3-5%. That translates into about a 14-15HP change for the V8's. As big a difference in performance as I've seen it has to be closer to twice that.

It could be said the fuel/air/ignition maps are a bit too conservative when it comes to temp changes. I've heard that a smart tech can trick a temp sensor into thinking it is cooler than it is. The ECU would then *theoretically* turn the power up. That is the only trick to combat the high-temp power loss I can think of offhand. If any of you have found something really trick, do tell!

Lee