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#16
03-05-2003, 02:00 AM
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Kevin,
so you checked your speedo with a mobile gps and it is nearly perfect. Both photos you show here indicate that your 300E has a 3.27 diff maybe from a euro 300TE: 6400rpm at 140mph and 4450rpm at 100mph. But on both photos the economy gauge reading is low, too low for the given speed. You wrote that you just got off the gas to take the photos - and that's the point I don't understand. In a 1986 (and in all other years) 300E you have a 722.3 transmission with a hydraulic converter withOUT mechanical converter locking. Converter locking was a feature first introduced with the electonic switched 722.6 transmission, that was never available in the W124. If you are under full power at high speed like shown in your first picture the engine pulls the car and the converter is nearly locked (at 98%), slip is at minimum. Economy gauge will read at the right end indicating WOT. Vehicle speed and engine revs fit - supposed you have a 3.27 diff in that car. If you get off the gas for whatever reason, what will happen? Economy gauge will read somewhere in the middle, indicating some underpressure in the intake because the throttle is partly open. The car will now push the engine so the force through the converter goes from the transmission to the engine and the engine revs will drop. You can watch this at any speed, if you release the gas, the revolution will drop immediately. Now that the car is pushing the engine through the converter, engine revs and vehicle speed will no longer fit (the calculation assumes that revs before and after the converter are nearly the same) because of the slip inside the converter. The gauges will show a revolution too slow for the given speed. That is the point where we need a new explanation for the gauge readings in your pictures.  I don't want to offend you personally and beg your pardon in advance - but I think these pictures might be taken with the car (or at least the rear axle) in the air (on some kind of lift) and not on the street pulling hard at 100mph or 140mp. You will get these readings (low power but high revs and speed) with a lot less throttle with the car on a lift than on the street, as indicated by the economy gauge.  In case I'm wrong with this explanation: please enlighten me  bis denn, Christian 1989 300TE 
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#17
03-05-2003, 04:11 AM
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Chris,
I have to say that you certainly know your stuff about these cars. Myself being between a beginner and intermediate level of knowledge, I have no technical say above yours. I will say however that I garuntee you that as somewhat suggested (although I know you mean no offense) that both shots you see are 100% legit. Personally I have no reasons or motivations behind staging photos of my car driving at high or top speed. Honestly if I were to go out to my garage at 3AM and jack up the rear of my car and rev it to 100mph+ (which is dangerous as well) to take a picture to post then I would really be a laughable person to say the least. I have nothing to prove or make point of on this thread, I just happened to get to my car's max speed after a year and a half of owning it and I figured I'd put in my part for those who might wonder what the top speed of their 300E or similar w124 is. Then again, this situation has seemed to have turned more unique than I expected. Like I had mentioned, I am no MB tech, I have limited knowledge on my car although I am eagerly learning (I am more of an american car guy) and beyond what I have mentioned I don't have any explanations or excuses for my photos. My economy guage (from the way I perceive it) almost seems to run off of a vacuum type source or module. For me, when I leave it at idle its usually just a tad (maybe 1/8) above the full (black)economy side. From there it's completely dependant upon how far my foot is pushing on the pedal and whether I am moving or not. At 45mph I can cruise at steady speed with the meter all the way on the black economy side with the pedal barely pushed and just holding speed. The second I depress it, it sinks right over towards the red, depending on how fasr of course but full red comes on at maybe 1/2 throttle or so (maybe a little past). But then again, the second I take my foot off the pedal to where there is no pressure, the meter flips back over to the black as seen in my 2nd photo. I don't know what the tendency of other people's gauges are, but it doesn't matter what speed I'm going it, if I let off the throttle completely then it goes all the way over in the black. As previously mentioned, in the first photo the photo was taken just after the rev limiter (fuel cut as you mentioned) had kicked in and the guage instantly dropped from full load (red) down to where you see it in the picture. Now I assume this is due to the pumps cutting and manifold pressure dropping in turn is possibly where the economy guage is fed from? That's my assumption on it. As for the second photo, I had actually gotten up to maybe 107-108 mph but I had let off to bring the camera up to take the picture. At that point it had slowed to 100mph which was not planned... infact I wasn't trying to get any specific speed captured but I was trying to get a good high speed photo to show a few people. As I had mentioned above, the tendency of my guage is that when I let off the gas at any speed it will sink back to black. Isn't this the tendency of all of them? I mean, if you're doing 100mph and your foot isn't pushed on the gas, aren't you getting good economy? Sure it's sucking the gas to feed an engine at high rpms but it's like the difference between driving at 45mph up a hill and driving at 45mph on a straight or down a hill. The engine speed is still the same but of course you're going to be getting worse milage going up hill because you have to push on the gas harder which wastes more gas getting worse economy, therfore pushing the meter into the red. Now on the flat you down't have to push the gas very hard which probably puts the meter into the low or mid-range, and on the down hill you don't have to push at all which puts it on the lowest part of the meter. Are you telling me that your gauge would stay the same in all of these situations despite throttle position? As before, I had let off to take the picture, therefore I was slowing down and I was at 100mph when the picture was taken. Previous to the photo the guage was reading full load due to the fact that I was accelerating to overcome wind resistance and increase inertia. When I let off, the guage drops which is what you see there. On top of all of that you can even see two street lights and the dark sky, as well as a few stars in the 2nd photo. Notice the blurred light and that black isn't my windshield, its the sky. If you really look close you can see 2 bright stars and a couple more dim ones on the left... and no those aren't spots on my windhield. As for the first photo, I didn't capture the road at all.. I wasn't really concentrating on backround, I was just trying to keep my car straight and hold the camera at 144mph. As for the gearing... you honestly have me baffled. I don't know a damn thing about the gearing on these cars but it seems you have indicated a 3.27 ratio on mine. I had no awareness of this and I didn't change any of this out myself so I guess if this car didn't come factory with it then the previous owner must have changed it. It still seems odd though because to my knowledge he never modded anything else, it seems bone stock to me. I honestly don't care who believes my photos or not, I didn't expect to have anyone question them but I did not come here to prove anything or mislead anyone, I just wanted to share my experience. However, I am still wondering about the whole economy guage thing. Can anyone else chime in and tell us the tendency of your guage? To me the way mine acts makes sense as I had voiced further up, but somehow I guess I could be wrong. Once again, I'm not trying to argue with you, I'm just trying to defend my part to the best of my knowledge. Thanks for the info and replies, it is nice to have a experienced person around. P.S. Let me know if there's any more pictures I can take that would help clear things up. I don't mind doing some experiments like I did earlier today, so just let me know and they will be delivered upon request...
__________________
-Kevin Last edited by KNanthrup; 03-05-2003 at 04:18 AM.
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#18
03-05-2003, 04:47 AM
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Oh by the way that 2nd picture was actually taken during a night (morning) out on the town (Seattle), and I had 2 witnesses with me.
Here is the full sized shot for further examination: http://home.attbi.com/~knanthrup/images/dash_large.jpg and not that it proves anything but heres a shot that was actually of a friend of mine in the passenger seat taken by a friend in the rear seat about 6 minutes before I did that 100mph run which is indicated by the clock on the left which I have blown up for easier viewing. basically im just trying to show that i was infact out and on the road since i was with friends unless of course you think id sit in a garage with 2 friends with my car jacked up revving to 100mph  her face has been blanked out for privacy reasonshttp://home.attbi.com/~knanthrup/images/nightout_2.jpg i wished i had better photos for proof that night because i took a bunch of my friends but that was the only one lucky enough to catch the dashboard
__________________
-Kevin
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#19
03-05-2003, 05:15 AM
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Kevin,
I'm very limited in expressing inter-human things in English because English is not my mother tongue. So these things are becoming difficult for me and again: no offense intended. Since the readings (speedo, tacho, economy) all together don't make sense to me I tried to find a technical explanantion for these situation and - after thinking twice - finally I wrote what came into my mind. I will not repeat it. In case I'm wrong please accept my apology. Maybe someone else will find a sufficient explanation of your photos. Best regards to you wherever you live, bis denn, Christian 1989 300TE
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#20
03-05-2003, 09:05 AM
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Uh, Chris, for someone that says "English is not my mother tongue"... your English is better than most Americans! I'm not kidding... spelling & grammar included!
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#21
03-05-2003, 12:30 PM
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Dave,
thank you very much for your compliment. kind regards, bis denn, Christian 1989 300TE
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#22
03-05-2003, 03:59 PM
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Chris,
I understand what you're saying and I guess I don't blame you for your questioning. Like I said I am no expert or tech on these cars so I do not have great technical answers for your questions although I wish I did. Again, I honestly didn't expect any controversy to start over this, I'm simply a guy who caught a few photos and decided to post and share them with the community. The questions and comments caught me off guard because as I said, this is the bahvior of my car that I drive every day and I don't see anything wrong with it because I'm so used to it. Obviously my car and guages contrast from yours and probably others but I am not able to explain why because I fail to see the flaws within. My rear end ratio is set at what you see in any case whether the car is on the road or whether it's on a jack or something... atleast that's the way I see it. As for the economy guage, I guess this will be a continuing controversy. I was hoping someone else could input their experiences with theirs because I really do fail to see problem again. I'm just an inexperienced guy with a camera, but I wish I could offer more. Once again I thank you for your input despite any misunderstanding. It has been helpful for you to give me information regarding my car, especially on the differential ratio because I actually had been wondering about that. In best regards I apologize for our contrast and I hope you didn't take any of my replies offensively. And by the way you english is excellent, I wouldn't have known you weren't native to it
__________________
-Kevin
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#23
03-05-2003, 08:52 PM
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Chris: Gauge needles can sometimes do very funny things.
Look at your picture, especially your vaccum gauge: JackD
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#24
03-06-2003, 06:29 AM
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Kevin,
Quote:
All I am doing here is trying to find answers for questions, to help other people solving their problems or at least giving some food for thoughts. When I wrote my theory of which circumstances might lead to the given readings all I wanted to express was: this is a possible explanation. Like in all scientific discussions an axiom is valid until the contrary is proven. I was aware that my posting could be missunderstood as some kind of a personal attack and I tried to avoid that. Maybe I was not 100% successful. Quote:
Quote:
If only my old teachers could read this I was really bad in school in foreign languages - but I learned a lot during the last years of practicing (mostly) technical english. And I have to admid that altavista helps me from time to time :p have a nice day, bis denn, Christian 1989 300TE
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#25
03-06-2003, 06:33 AM
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Jack,
nowadays you can easily photoshop or fake whatever you like. What you show is your picture and not my photo. :p bis denn, Christian 1989 300TE
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#26
03-06-2003, 10:38 AM
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Chris: The picture I have shown is really your picture but slightly modified using photoshop. (Vacuum gauge)
The explanations you have given earlier were very valid and your technical analysis of the situation was totally logical. I have no doubt your photo was authentic, mine (yours modified)was obviously not. I have tried a high speed run this morning (although I only reached 155Km/h for a very short period du to traffic conditions). Lifting the gas pedal at this speed brought the vacuum gauge down to the middle of the gauge, which confirms your suspicion and explanations. What could have happen with the first picture? I don't really know. But it is strange. jackD
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#27
03-06-2003, 11:23 AM
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Jack,
Quote:
Quote:
Did you realise the engine revs dropping significantly? Yes / No / How much? Quote:
bis denn, Christian 1989 300TE
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#28
03-06-2003, 12:01 PM
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Chris: You are right, your photo became my photo after I played with it. But let me assure you I will not be using it for any other purpose. When I stepped off the gas, the vacuum gauge still read halfway and the revs. did dropped significantly (from about 4800 to about 3800RPM, These numbers are approximate). This is quite normal and should happen as my car does not have a locking torque converter. (260E). I wide opened throttle, the vaccum gauge should evidently be pegging at the top. Unless the car was put in neutral gear at those elevated speed, the vaccum gauge should still read higher than it is shown in the previous picture. An other explanation could be that the gauge is defective.
JackD
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#29
03-06-2003, 12:19 PM
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Jack,
>You are right, your photo became my photo after I played with it. >But let me assure you I will not be using it for any other purpose. No problem, I didn't think of that! >When I stepped off the gas, the vacuum gauge still read >halfway and the revs. did dropped significantly (from about >4800 to about 3800RPM, These numbers are approximate). Thank you very much.  >This is quite normal and should happen as my car does not >have a locking torque converter. (260E). confirmed >An other explanation could be that the gauge is defective. Yes, defective gauges are a possible explanation since the readings from Kevin's photos still don't fit together. best regards, bis denn, Christian 1989 300TE
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#30
03-06-2003, 07:13 PM
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That is definately interesting Jackd, thanks for running a test for us. I really wish I could get a photo capturing everything that's going on just to confirm my side of things. It would seem unlikely that an economy guage is defective, but I guess anything is possible right?
I could take 20 more photos of my dashboard doing the same thing at varying speeds around 100mph but I doubt that would prove anything to anyone of course. I suppose it would require a photo showing the dash, the road, and my foot off the pedal in order to make things more valid (although my 2nd picture did kinda show the road...not too well though). This would be hard to capture every aspect of it but I will possibly try to borrow a friend's video camera which would be much easier to show everything in one quick scene. It's just a matter of running that speed again, which I am not real fond of doing for safety reasons but I am definately considering doing it just to hold my own ground since I seem to be alone in a corner here Let me know if you guys have any other ideas... I simply want to earn your trust here by backing my part, although I could care less about proving something over a message board, I do have respect for everyone as people and I do value the way people look at me because I'm part of this community.
__________________
-Kevin
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