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  #46  
Old 11-22-2008, 03:42 PM
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Quote:
Originally Posted by jt20 View Post
I think you nailed it right there, Jim.

The only thing I couldn't find mention of in this thread was the match between the differential and the turning radius. It seems related to oversteer since the car is being pushed at a different trajectory, but on slow turns that should not normally impose a loss of traction, I have noticed that giving the car a good push from behind when turning at close to max radius causes slippage in the front end.

Is this a design flaw?
Not in MB's opinion. They view that as safer than to have the machine swap ends if the rear lets go first. All MB's are intended to have understeer at the limit. Jim
__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)
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  #47  
Old 11-22-2008, 04:11 PM
t walgamuth's Avatar
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I have always found them to be pretty neutral at the limit, and very very safe and enjoyable to drive fast in.
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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual. It still needs upholstery redone...I also have a 427 Cobra replica with an aluminum chassis.
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  #48  
Old 11-22-2008, 04:25 PM
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LOL...I can't believe you guys are discussing the handling limits of a W123. It's definitely not a sports car, it's a huge heavy brick with hardly any horsepower and a HEAVY engine over the front wheels. It's an understeering pig. I can't go more than about 10MPH at full lock without the car just going in a straight line lol.

My 560SEC on the other hand, handles quite well, but you have to be awake because it can oversteer very easily if you don't treat the throttle like it's made of glass.
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  #49  
Old 11-22-2008, 04:53 PM
t walgamuth's Avatar
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Quote:
Originally Posted by johnathan1 View Post
LOL...I can't believe you guys are discussing the handling limits of a W123. It's definitely not a sports car, it's a huge heavy brick with hardly any horsepower and a HEAVY engine over the front wheels. It's an understeering pig. I can't go more than about 10MPH at full lock without the car just going in a straight line lol.

My 560SEC on the other hand, handles quite well, but you have to be awake because it can oversteer very easily if you don't treat the throttle like it's made of glass.

I have driven probably a half million miles or nearly so in a 123 and probably well over 120,000 in a 126 mostly in an SEC. I find your statements not to match with my experience.

The 123 is neither heavy, nose heavy nor a brick (at least not a really bad brick).

In fact the 123 and 126 are very close in weight with the 126 being a bit heavier.

All benzes I have owned from 123 onward have been very well balanced. I had a 115 body 300d which felt heavy in the nose though.
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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual. It still needs upholstery redone...I also have a 427 Cobra replica with an aluminum chassis.
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  #50  
Old 11-22-2008, 05:13 PM
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Quote:
Originally Posted by johnathan1 View Post
LOL...I can't believe you guys are discussing the handling limits of a W123. It's definitely not a sports car, it's a huge heavy brick with hardly any horsepower and a HEAVY engine over the front wheels. It's an understeering pig. I can't go more than about 10MPH at full lock without the car just going in a straight line lol.

If you read Jim's statements as well, you would understand what it was designed to do. In this case, its LIMITS are a success.
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  #51  
Old 11-22-2008, 05:18 PM
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The W123 is actually not nose heavy at all. I put mine of 4-wheel race scales a few weeks ago. With a full tank of fuel the car weighed 3400 lbs on the nose with a 53/47% front/rear weight distribution.
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  #52  
Old 11-22-2008, 05:34 PM
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I lost a pissed off 20 year old in a mitsubishi galant once after a chase halfway around town at 2 in the morning. I was driving the SD
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  #53  
Old 11-22-2008, 06:31 PM
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Quote:
Originally Posted by bgkast View Post
The W123 is actually not nose heavy at all. I put mine of 4-wheel race scales a few weeks ago. With a full tank of fuel the car weighed 3400 lbs on the nose with a 53/47% front/rear weight distribution.
Well, people have to understand the W123 is a sedan and it is intended to offer a superior compromise of handling characteristics at all design loads. So, a 53/47 ratio front to rear is very good without passengers or bags in the trunk. If the W123 exhibits any handling characteristic compromise that might be improved upon, it is the tendency to tip or roll at the initiation of a turn, which is significantly more pronounced with this chassis than the W115. The old chassis cornered much flatter, and was much better in transients, but was not as capable loaded.

In its day the W123 was head and shoulders above any other daily driver/taxicab favorite sedans on the market, and, to this day offers exceptional road manners for every day driving - meaning don't take it to the track and expect to out perform a W124 or later MB or other similarly balanced car, but excercise its solid dynamics in real world driving situations and the result is rewarding.

Jim
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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)
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  #54  
Old 11-22-2008, 06:32 PM
t walgamuth's Avatar
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Quote:
Originally Posted by bgkast View Post
The W123 is actually not nose heavy at all. I put mine of 4-wheel race scales a few weeks ago. With a full tank of fuel the car weighed 3400 lbs on the nose with a 53/47% front/rear weight distribution.
With a driver in it it will be better. With four passengers I bet its biased toward the rear.

I have weighed my 84 280e euro autocrosser and it was very near 50 50 with a driver, but it was heavy on the left. A passenger probably would have balanced it right out.

The us version of the 300d is probably more nose heavy than any other model. I have not weighed a 240 but I bet its very near 50 50 with a driver.

Nose heavy is a sixties or seventies american sedan with 60% on the nose and rear wheel drive!
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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual. It still needs upholstery redone...I also have a 427 Cobra replica with an aluminum chassis.
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  #55  
Old 11-22-2008, 06:40 PM
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Simply changing from 14" to 15" wheels made a huge difference on my car. Many have said that lower profile wheels are not worth it on a 123 but I would have to disagree. Better road feel, far more connected than the stock size. I would guess that 16" would be even better. RT
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  #56  
Old 11-22-2008, 07:34 PM
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Tire selection does make a huge difference. The 240D came with 175-78/14's while the 300D came with 195-70/14's. Taking the 175-78/14's off and putting the wider tread on there was a big difference. I never tried changing the wheel diameter, but imagine it would do about what going from 16" wheels on my W210 to 18 inch wheels did. That was a huge change and made the steering feel more like a Benz of old (the W210 was MB's first rack and pinion set up and in my opinion it is a substandard effort - the old recirculating ball system was much better in terms of feel, likely due to the decades of experience MB had invested in it.

Jim
__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)
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  #57  
Old 11-22-2008, 11:11 PM
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wis wis is offline
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i like the rack and pinion in my 210. the steering feels way more precise than any recirculating ball steering i have ever driven. my 123 is lowered and has 18'' wheels and handles real well, all modern mercedes seem too soft for my taste, however even though the do roll quite a bit the grip available is amazing. the 123 does not have enough power to upset its grip in any situation i have been in, and you need to be on the throttle in the brake zone to keep a good exit speed! both of these cars responded really well to stiffer springs, better shocks and up sized wheels with performance tires. the 123 is amazing for a car of its age and the 210 is now a super sedan! the design and exicution of the suspension systems in both cars is great, but for spirited driving a little treaking really makes them more enjoyable in my opinion.
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  #58  
Old 11-23-2008, 12:22 AM
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Regarding the large body roll of the W123 over the previous chassis (W114/W115) I think the reason MB did it that way, is to give the car more yield. I saw this link on Youtube showing the handling properties of the W114 in a test video:

http://www.youtube.com/watch?v=klu1hHQA_rU

And I think the reason they gave it more yield, is to "hold" the road more as somebody stated, rather than have one wheel come off the ground and lose control. It seems that the W123 and W124 both have larger suspension travel compared to the W114/W115, but of course the W124 already has the multi link rear setup and the W123 utilized the rear suspension setup of the previous chassis.

Compare the two:
Attached Thumbnails
Handling limits of the W123?-w114.jpg   Handling limits of the W123?-w123-test.jpg  

Last edited by MBeige; 11-23-2008 at 12:28 AM.
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  #59  
Old 11-23-2008, 04:05 AM
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The only Benz I have ever been truly disappointed with the handling of is the 1960's to early 1970's 230-280SL with the pagoda hard top. The cowl shake and just crudeness of the sedan hardware in the smaller body was actually alarming.

The recirculating ball steering system is sensitive to wear, and wear is a function of power steering fluid condition. Drive one with either a new box or a well maintained one without a lot of play - the W114/5 was a very well set up recirculating ball system. With the 18" wheels and low profile tires though, the W210 handles and has great steering feel. With the stock 16 wheels it is considerably more vague and unresponsive. Just my observations, typically reinforced this time of year when I put the winter sized all season tires on the car. Jim
__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)
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  #60  
Old 11-23-2008, 07:49 AM
t walgamuth's Avatar
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The recirc ball offers a slightly progressive response to steering input. The first inch of travel does not result in a big change of direction. This makes a more stable car on the highway.

Rack and pinion offers one to one response off dead center, so it feels quicker, but is less relaxing on the highway.

The recirc ball will offer trouble free driving for a lot longer than the rack and pinion too, in my experience.

I like the quick rack and pinion in my Miata but while I am driving it on the street it requires a lot of wheel work to keep going straight as you traverse small bumps, dips and pavement textures.....never a dull moment!
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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual. It still needs upholstery redone...I also have a 427 Cobra replica with an aluminum chassis.
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