Pagoda SL Group
W113 Pagoda SL Group => General Discussion => Topic started by: mdsalemi on June 28, 2006, 06:01:04
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For those interested, the current issue of Car and Driver (should have arrived in U.S. Mailboxes within the past few days) has a test report on a 1971 280SL from the Classic Center in Irvine. There is no apparent link or text on the C&D website, but the issue is August 2006, with the M-Coupe vs. Cayman on the cover. The article is entitled, Convertible Currency, Part 2: Recycling a 1971 280SL at 2006 prices by Aaron Robinson. Page 80
0-60 in 8.6 seconds? Hmmm...maybe its time to take mine to Irvine for a tuneup...yep, that's what I'll do as soon as I get that *&^% distributor fixed.
Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored
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Michael I've been meaning to visit Classic Center in Irvine to see what their SLs look like. In the CandD article did they mention the asking price for the 71?
Agree 0-60 in 8.6 sounds awfully fast!
Pete
69 280SL 4-speed
US spec, blackwalls
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quote:
Originally posted by ivorysl
Michael I've been meaning to visit Classic Center in Irvine to see what their SLs look like. In the CandD article did they mention the asking price for the 71?
Agree 0-60 in 8.6 sounds awfully fast!
Pete
69 280SL 4-speed
US spec, blackwalls
don't quote me exactly as I put the magazine away--but I want to say the $80,000 price range for this perfect (so they say) example.
Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored
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Got mine today but haven't had a chance to read it yet. It's nice to finally see the Pagoda make to Car and Driver!
1969 280sl 5 spd
Gainesville, Fl.
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It was an original and very low mileage car, as well. Wasn't it Michael?
You know, $80k probably isn't so crazy for an excellent and UNrestored car, I think.
Will look for this article, a good find! Thanks.
I sure wouldn't want to try to make this 40ish year old car do 8.6 secs, whether it could do it or not -- no point in blowing it up.
1967 230SL (Manual, rustless driver)
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This sounds like the $80,000 car discussed in this thread:
http://sl113.org/forums/index.php?topic=5391
When I was at the Classic Center in February it was the only 113; don't know if they've gotten any others.
Hard to believe they would let Car and Driver thrash such an original car enough to achieve 8.6 seconds to 60.
Chris
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They could not get to 8.6 seconds if they dropped it off a cliff. The best of the 113 cars barely get under 10 seconds. This can be verified by looking at the acceleration runs for 113s at the various MBCA national events over the years. C & D numbers have always been bogus. Don't put much faith in them.
Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex
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According to Road and Track June '63 test the 230SL did 0-60 in 9.7 sec. I have no data on the 280 SL but suspect there is not a major differance
Daryl
'64 230 SL
Serial # 508
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I've got to think that the equipment for testing this kind of thing today is dramatically different from 1963, so you can't really compare C&D's earlier stats with today's stats. In fact, I've got to think it's not even fair to compare one magazine's (or manufacturer's) stats to another.
Douglas Kim
New York
USA
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Ok. First thing in the morning, I'm going drag racing. Want to see what 0-60 is 43 years later...
(I would now but the cab is kickin' in ... :| )
James
63 230SL
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J.-- Don't forget the nitrous kit.
D.--By equipment/technology being different, do you mean a starter signal and stopwatch? On board race clock?
The difference is about/over one whole second.
1967 230SL (Manual, rustless driver)
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Hey, I agree that the acceleration time quoted seems optimistic, but my point was that you've got to put this number into perspective. Here's how Automobile Magazine describes the discrepancy in these tests:
"Since there is no industry-wide standard for car testing, every maker has its own pet procedures. Some test with less than a full tank of fuel, some with two passengers and luggage aboard. Doing our own tests is the only means of leveling the playing field."
I'm no engineer, but I've got to think even aside from methodology, you've got to factor in huge incompatibility when comparing old numbers to new numbers. If they're not using the same method, you can't truly compare the numbers.
Douglas Kim
New York
USA
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If there is anyone out there with a stock M-130 getting 8.6 seconds, I want to talk to him. That's gotta be a typo. Think about it, 170HP and 3,000 lbs. I love my car, but it only goes that fast in my dreams. Maybe they meant 10.6.
Ray
'68 280SL 4-spd Coupe
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quote:
Originally posted by Chad
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D.--By equipment/technology being different, do you mean a starter signal and stopwatch? On board race clock?
The difference is about/over one whole second.
1967 230SL (Manual, rustless driver)
Maybe it was the ol': "eins, ally-gaytah. zwei, ally-gaytah. drei ally-gaytah..."
James
63 230SL
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Nah - the xx-ally-gaytah would provide an unacceptable time for zero to sixty. I was: Eins, Zwei, Drei. But we have here a nice, long down slope: I'll try to obtain some data.
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I remember reading this portion of a post by Joe A. within a thread comparing the Euro vs. US w113 powerplants -- the textbite seems on-point somewhat here as well perhaps, the thread was from three years ago.
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"If you compare the 0-60mph (0-100kph) times in the Mercedes technical data books you will see that the times range from 9.0 seconds to 11.l seconds. Rear end ratio and transmission made the biggest difference not the engine type. Only ten kilometers per hour variation at top speed for all the models and all combinations!
Joe Alexander
Blacklick, Ohio"
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1967 230SL (Manual, rustless driver)
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Well, the results of my first time trials are in! The hardest part was finding a flat straight-away around here. My timer was a small second & minute stop watch. So results are rounded off to the second. (Second hardest part was hitting the go button and stepping on it at the same time...)
My average was 0-60 in 4 to 5 seconds. Oh, that was Kilometers. :oops:
My best 0-60 MPH was 11 seconds. That was a Euro 3.75 automatic 230SL shifting thru the gears manually. I shifted at about 5500 RPM I think. Felt like a rocket to me, since I rarely step on it like that. Kinda fun. I plan to do a few more runs if I can find a decent stretch.
James
63 230SL
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OK.... 0-60 test coming up in next 3 days.... tank 3/4's full, without a new tune-up or setting timing or gaps, but I'll make sure my tires have the right pressure... and on the high side). 250SL, 4 spd... I recently figured out I don't need to start from standing in 1st.... so I've already beat my normal time from the stop-light to merging onto freeway in morning by a healthy margin... I measure by looking at my speed when I pass the first sign after merging... and I accelerate to about 5500... 5700... using 2nd from standing start instead of 1st I hit 75 at the sign still in 3rd gear, instead of ~68 mph (< 70). I always wondered why 1st was geared so low.... turns out it was for starting up from standing on a hill... or using engine to brake on a steep down-slope at very slow speed. I read this recently in my blue manual ---- clutch is slipping a little in 4th at ~4000 when I stomp the pedal to the floor... so I was looking for what kinds of things (besides getting oil on the pressure plate) might be causing it.
Anyway... back to topic... I can find any number or country roads near here to test 0-60... I'm guessing under 10 sec's though.... but time flys when you're having fun, so maybe it's really closer to 12. I'll use a stop watch (a real one --- I used for timing at swim-meets... to hundreths of a sec.... not that a few hundreths is significant... repeatability of human timers is no better than +/- 5/100s at best anyway).
Side-topic... I kinda wish our CA freeway speeds would dip a little... like 70-75 since my milage at 80-85 mph is starting to get outta-hand. Of course I could drive in the slow lane with the trucks, but something inside me still has a healthy dose of the adolescent... so I end up in the fast lane on a 4 lane freeway (8 lanes both ways).... zinging along at 85... accelerating to 90 - 95 from time to time. Feels good though.... so I go by the ol' motto, if it feels good do it.
Longtooth
67 250SL US #113-043-10-002163
95 SL500
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OK, let's get real here. I quote from the original Car and Driver test of the 1964 230sl (4sp):
"This is either the most substantial solid light car, or the quickest most agile heavy car we have ever driven. The driving sensation, particularly as related to the seat design with its almost chair-height, and the angle of the steering wheel, are exactly like the Mercedes sports coupes-the 220-SE and 300-SE. The only important difference is that the 230-SL feel very tiny, and very [italics are the magazine's, not mine]. The driver's impression is kind of whimsical - as though a big, plush Mercedes touring car had been toouched with a magic wand and transformed into a lithe, impatient thoroughbred without losing any of its town car-reapectability.
The road test in 1964 shows 0-60 @ 9.9 secs., standing 1/4 @86 mph with 4sp and hard top on.
It would be interesting to see the road tests for the W113 as it grew in displacement and weight through the model history, but I don't believe the 0-60 ever got much better.
Also, I recall reading somewhere (wish I could put my hands on the source) that the bhp/liter for this engine was the highest of any production engine of its day. Hard to believe, would love to learn more.
Best,
g
'64 230sl, fully sorted out...ooops, spoke too soon
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oops, I left out the full quote, it reads
"very fast"
g
'64 230sl, fully sorted out...ooops, spoke too soon
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Greg:
I think many cars of the era had higher bhp/liter displacement than these Mercedes. The italian sportscars almost universally did. Even some Giuliettas I've had with the little jewel of a 1297cc engine pumped out great power and a throaty exhaust.
For example the Alfa Giulietta Spider Veloce had the 1300cc engine I4 -- about 90-100hp. This was somewhat better than the 230/250/280 series. Just one example.
And thank you very much for the Injection system PDF file!!! I am reading it now.
Thanks
1967 230SL (Manual, rustless driver)
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I saw the C & D issue with the very, very, did I say very, brief article on the W113. The time quoted is NOT for 0-60, but for a rolling start 5-60. This makes a huge difference. Add at least 1 second, pbobably more like 2 seconds for a standing start 0-60 time.
Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex
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Did my 0-60 test... full tank, without hard-top, but with my 260 pound passenger son with the stop-watch... '67 250SL 4-spd... engine rebuilt (long block) , injectors, etc. about 10k miles ago. No tune-up, but timed with new points and plugs about 3k miles ago. Shifted at or slightly above 5500.
11.5 sec's avg of 3 trials... 11.6, 11.3, 11.4 rounded to nearest 10th of sec's... but discovered my clutch is slipping a wee-wee bit nearing 5000 - 5500, so it'll do better when I get that fixed.... and letting my 260 lb. son watch from the side-lines.
I also tried doing this starting in 2nd instead of 1st.... thinking like my rolling starts from stoplight to freeway, I'd save time and reach faster speed without the extra shift. Didn't work.... 14 sec's starting in 2nd instead of 1st.... same conditions as above.
I don't think I'll get below or even down to 10 sec's though... boo-hoo. Considering though, that the top end acceleration in 3rd and 4th is spectacular... say from about 4000 to 5500, what do I care with the standing start 0-60 time? I like the high speed acceleration at 75 - 95 mph more anyway.... nice rationalization, huh?
Longtooth
67 250SL US #113-043-10-002163
95 SL500
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Hi there Longtooth
You shoudn't shift at 5500 RPM, but should try to accelerate with the RPM around your maximum torque. I'd say shift at ~4700 or whatever gives you most "average" torque on either side of the torque maximum. In theory accelerating around maximum torque will give you better performance than up to max HP.
Keep us posted.
Enjoy
Ulrik
'67 250 SL Papyrus White 113043-10-000023
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Nice car ,but gee I like to talk with CAR & Driver and see what methods they used to arrive at their conclusions of 0 to 60 MPH times. I have one of thoses gagets you attach to your winshield to do the results of off the line drag racing and time trails very good write up on this one and I meet the engineer who designed it.
My point is to conclude a 0-to 60 in 8.6 seconds seems like a typo to me. Someone needs to conclude this with a good old fashion time trail at lions speed way, who wants to volinteer to do a 0 to 60 run against CAR & DRIVEr and the Classic Centers 280SL?
Bob Geco
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oky-doky Bob G.. good point. I'll try shifting at peak torque next time.. right after I get my oil heat exchanger leak fixed.
By the way, my big blue book says the acceleration, 0-100 kph is
230SL with 3.75 rear end = 11.1 sec's
230SL with 4.08 rear end = 9.7 sec's
250SL with 3.92 rear end = 10 sec's (same with 3.69 rear end)
250SL with 4.08 rear end = 9.7 sec's
All the above listed for full tank with 1 passenger, but not whether with or without hardtop, and all with +/- 7% caveat (applies to 4 spd transmission).... and variation includes permissible engine output and variations in tire conditions.
If I take out 7% from the above, then the 10 sec for the 250SL goes down to 9.3 sec's and the 9.7 sec's with the 5 speed tranny goes down to 9 sec's. Presumably, then, it's potentially possible to get to 8.6 sec's with some additional tweeks.... no passenger, no hardtop, near empty tank.... provided the engine's output is a peak levels (compression, injection and spark timing. If the SL's anything like my '65 Chevy 327, advancing the timing for max acceleration and using a dual point centrifugal advance makes it accelerate like a rocket compared to single point vacume advance and standard (driver use) timing. In that case though, my 327 won't idle without boosting the engine speed waaaay up.... and it'll back-fire a lot too.... gurgle, gurgle, bang, bang.... not to mention dieseling if I keep it that way for awhile.
So I'm guessing the 8.6 sec's isn't a typo now... it was just done with engine and test conditions set up for max acceleration.... possibly with a 4.08 rear end and 5 speed tranny?
Longtooth
67 250SL US #113-043-10-002163
95 SL500
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I haven't seen the C & D article yet, but Vince's post says the time quoted was for 5 to 60 not 0 to 60? Don't be disappointed if you can't get to 8.6 from a standing start.
All of this 0-60 info is interesting comparison for us. Now that I have my suspension sorted out, I want to time mine. Just not sure my 2nd gear synchro is up to it.
Ray
'68 280SL 4-spd Coupe
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Sorry Longtooth, but just to put it right. You should shift after max torque, which is 4200, say shift at around 4600, landing at ~3900-4000 going up to 4600 again and so forth. The point is that you should maximixe the area under the torque-curve, to use a mathmatical expression.
BR,
Ulrik
'67 250 SL Papyrus White 113043-10-000023
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As Dennis Zanone pointed out in another thread, here's the article now online:
http://www.caranddriver.com/features/11283/features-review-1971-mercedes-benz-280sl.html
(Vince: the stats show 0-60 as well as 5-60 acceleration times.)
Douglas Kim
New York
USA
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mulrik,
just an engineering point... maximizing the area under the torque curve results in using the entire torque curve! So, what I think you meant was to maximize the integral of torque/unit time... which means, in effect to use the rpm range that maximizes it... and that's from a given lower torque value, past the peak torque rpm to the rpm at the same level of torque at which you started on the lower side of peak torque. The question becomes only to find the starting and ending points of torque values that minimize the cumulative time.
The real engineering problem solution requires knowledge of the time rate of change of torque/change in rpm... or since torque's a given fixed function of rpm, the solution ends up requiring knowledge of the time rate of change of rpm... dRPM/dt as function of rpm, to be specific.
The only reason this measure is required though is because you can't accelerate at constant torque... namely at peak torque as a constant. Therefore some range of torque is required ... and that range which requires the least time per change in rpm on either side of rpm at peak torque produces the fastest elasped time between 2 speeds... 0 - 60, 5 - 60, 50 - 80, etc.
Because the requisite dRPM/dt isn't a known & published quantity (outside the engine development/design engineering team), the next best solution is to do time trials.
You're original suggestion is still approx. correct anyway... shift at rpm y where y is greater than peak torque rpm, such that when engaging next higher gear, the drop in rpm below peak torque rpm is minimized. What you want to do is maximize the time spent nearest peak torque rpm thru all shifts, and minimize the time spent at rpm's where torque is furthest from peak torque.
none of that will get me under 10 sec's though, I don't think... we'll see right after I try it this week-end.... lone in the car,top down... I'll try the 5-60mph time too.
Longtooth
67 250SL US #113-043-10-002163
'02 SL500 Sport
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I just reviewed the C&D article posted by Douglas, and I'm wondering too, it a misprint occurred. If you look at the quoted times, the 0-60 time is less than the 5-60 time, which doesn't make sense. Maybe they really did mean 9.6 or 10.6 for the 0-60 time.
Craig
'70 280SL Euro, Manual, Leather
Silver/Black
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Longtooth,
"... maximizing the area under the torque curve results in using the entire torque curve! So, what I think you meant was to maximize the integral of torque/unit time..."
So if I remember my calculus the area under the torque curve would be the "acceleration of torque" is that right? And I would assume you would want to shift when the torque acceleration is at zero?
During physical time trials, I wonder if there is an aerodynamic benefit to having the softtop up or even the hardtop on (despite the weight) I think we need to find a large open parking lot somewhere that we can do some experiments. Maybe Moffett Field?
Pete S.
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Pete.... it would be (i.e. area under torque curve = acceleration of torque) but only if the x-axis (absissa? or ordinate?) were in time based units... and they only "sort-of" are.... being that it's rpm, but the rate at which rpm changes is the time unit needed.
As an engineer, I've always found it interesting that the technical articles and information provided by the mfg'er never shows the maximum rate at which rpm can change in each gear... which is a complex (but definitely analytically determined) function of the cam intake and exhaust opening and closing rates & oroface's, cross-section of restrictions, pressure, & volume rate of input, and volume of the combustable material, gaseous volume at combustion temperature, & a bunch of other factors I am too ingnorant to devine... but all of which are part of the fundamental engineering design of an engine and it's ability to convert energy to revolutions of the crank --- given other loads on the crank and losses all the way thru to the drive wheel's (friction).
I know for a fact that the automobile industry (mfg'ers) know the analytic and empirical forms for the variants, since one of the engineer's I worked with designed the camshaft for one of the Ford racing engines 20 years ago... it was fundamentally limited by the stiffness profile of the shaft and cams with cam loads being continously varying per rev coupled with the resonant modes of vibration in the shaft itself with multiple vibration nodes and damping. Vary complex mechanical vibration displacements with all designs done by mechanical modeling. If, in my industry we can accurately model mechanical vibrations and modes to nanometers in the few nanosecond time periods, then it's a forgone conclusion that the automobile engine/drive-train designs are done with modeling at least as refined as those we use... and I'd guess a lot more (given the billions in annual revenue and competition in that industry).
Basically, all the torque curve (torque vs rpm) provides is the efficiency of conversion of energy to the crankshaft... peak torque being the most efficient point (in rpm units).... below that point the engine is starved for energy... i.e. could convert more per unit time than it's getting in energy input... and above peak torque the engine loses efficiency of conversion... I'm guessing, but probably because thermal gradiant's develop such that local points of heat energy can't be efficiently dissipated fast enough so local expansion's increase, which increase frictional losses... not to mention the vibrational nodes that develop within the cam, the rate at which the valves can open/close without bounce, etc.
If you think about it from an engineering standpoint, there's been quite an advance in energy conversion to the crank over the last 40 years... think about the torque developed in a new 230 MB sedan compare to the 230SL of our 113 vintage automobiles.... unfortunately, however, it's taken far too long to reach that state of efficiency.... since, in actual fact there was little to force the conversion until the Japanese entered the market place and began to sway consumers in the US and force the rest of the world-wide (read US and Europe) auto mfg'ers to tow the line.
Energy conversion can be taken as fuel efficiency, or as torque & hp efficiency per unit displacement..... or a combination thereof. ... so the US focused on using it to provide SUV's... read hp to drive greater mass/unit displacement. Interesting how virtually unlimited real-estate in the US allows larger, heavier vehicles to gain consumer's, while in Europe & Japan, with vastly limited real-estate and smaller older narrower streets in towns and cities (which grew from the days of buggies), the gain of consumer's interests is in smaller more negotiable vehicles, not to mention their higher relative costs of energy. Truth be told though, MB and in earlier years, BMW, Jaguar, Bently, etc. were the cars of 'kings'... i.e. the elite class of consumer that didn't care much about fuel efficiency nor size of streets in cities. As price of energy has risen in relative terms, so too has energy conversion efficiency improved in the automobile.... the economic balance always provides the incentives.
Longtooth
67 250SL US #113-043-10-002163
'02 SL500 Sport
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The times posted in the article may just be from MB's 280SL published spec's in their Big Blue manual. My Big Blue only goes thru the 250SL's so doesn't list the 280's... and later.
Can somebody with a Big Blue that covers the 280sl, preferably thru the '71 model post the published spec's for 0 - 100 kph with various rear ends?
If the 250SL publishes 9.7 sec's 0 - 100 kph with the right rear-end, then it's conceivable that the '71 280sl manual may have picked up another second or so.... especially without the hard-top on, 1 driver (no passenger), and 1/8th tank of fuel.
Longtooth
67 250SL US #113-043-10-002163
'02 SL500 Sport