Gullwing anomaly

[berfinroy]

It has been commonly noted that, with proper gearing, a "standard" 1954-57 300SL was capable of a top speed in the range of 150 MPH. What is less commonly known is that the actual dynamometer measured horsepower of its fuel injected M189 engine was about 180, not the exaggerated 220 "gross" horsepower often attributed to it.
I know the aerodynamics of that model were pretty good for its day, but it doesn't possible that such speeds were attainable with that amount of power.
What am I missing here?

[t walgamuth]

I was under the impression that it would do 165. Horsepower is one thing, torque is another.

[fonzi]

Check automobile-catalog.com

240 gross, 212 net HP. Supposedly 146mph top speed. I didn’t check their theoretical top speed though.

the race cars of the day had to be different than the road version, and I’m assuming you are talking about the road version.


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[berfinroy]

FONZI: The horsepower figures you cite are the generally published ones for a "stock" car, although it should be noted that different states of tune were available. This was a limited production exotic car, after all.
That being said, it should also be noted that the 1958 300 series of sedans (the D Adenauer, S roadster and SC Cabriolet) had the same basic M189 fuel injected engine that were rated at 160 hp, and even with longer intake runners, higher compression ratio (although still only 8.5) and more aggressive cam, its a long way from 160 to 212, let alone 240. The 180 hp figure I suggested cam from an episode of Jay Leno's garage, wherein his shop rebuilt a 300SL engine and could only get 180 on their dyno. He called a number of 300SL experts to find out why, and was told that 180 was in fact the real number!

T WALGAMUTH. Yes, torque is another thing, but is much harder to come by than horsepower. More displacement or forced induction are pretty much the only way significantly more of it. The M189 3 liter in the 300SL that is generally said to have 212 HP is said to have 203 ftlb of torque, which is about all you are going to get out of a naturally aspirated 3 liter, which did benefit from "ram" intake manifolds. That doesn't seem like enough to get a 2851 lb car with a cd of .38 (very good for the day) up to 150+.....

[t walgamuth]

from wikipedia:

The Mercedes-Benz 300 SL (chassis code W 198) was a two-seat sports car produced by Mercedes-Benz as a gullwinged coupe (1954-1957) and roadster (1957-1963).[2] It was based on the company's highly successful 1952 racer, the W194, with merchanical direct fuel-injection, a first on a production vehicle, boosting power almost 50% on its 3-litre overhead camshaft straight-6 engine.[3] Capable of reaching a top speed of up to 263 km/h (163 mph), it was both a sports car racing champion[4] and the fastest production car of its time.[3]

The 300 SL was inspired by Max Hoffman, Mercedes-Benz's authorized United States importer at the time, who correctly perceived a large American market for such a car. The company introduced the 300 SL in February 1954 at the International Motor Sports Show in New York instead of in Europe in order to get it into U.S. buyers' hands sooner. Nearly 2,700 were sold, at triple the price of an average American sedan.

Regarded as an automobile icon, the 300 SL was voted the "sports car of the century" in 1999.[5] SL is the short form for "super-light" in German,[6] Mercedes' first use of the designation, referring to the car's racing-bred light tubular frame construction.

It claims 240 hp at flywheel.

[Benz Dr.]

There was a special version NSL engine that's basically the same unit placed into the later roadsters. I've worked on these engines and can tell you they're not like anything remotely similar to any other car.

Gullwings are terrible cars. No interior room, no head room, hot, noisy inside, rough riding, and very heavy steering. Almost impossible to get in and out of. The roadster is a better looking, better handling car, that's light years ahead of the coupe.

[Tony H]

What was the final drive ratio? Pretty tall to be in the 150mph range. Agreed the roadster is better looking. I got to talk to a couple from BC Canada driving a roadster down the coast last year and checked it out for a bit.

[t walgamuth]

Originally Posted by Benz Dr.

There was a special version NSL engine that's basically the same unit placed into the later roadsters. I've worked on these engines and can tell you they're not like anything remotely similar to any other car.

Gullwings are terrible cars. No interior room, no head room, hot, noisy inside, rough riding, and very heavy steering. Almost impossible to get in and out of. The roadster is a better looking, better handling car, that's light years ahead of the coupe.

Maybe a terrible car but a stupendous super car. They are mostly hand made. Lots of lovely details in the car. They were the fastest thing on the road in their day.

[t walgamuth]

Originally Posted by Benz Dr.

There was a special version NSL engine that's basically the same unit placed into the later roadsters. I've worked on these engines and can tell you they're not like anything remotely similar to any other car.

Gullwings are terrible cars. No interior room, no head room, hot, noisy inside, rough riding, and very heavy steering. Almost impossible to get in and out of. The roadster is a better looking, better handling car, that's light years ahead of the coupe.

I bet you never drove one or rode in it. (me neither).

Maybe a terrible car but a stupendous super car. They are mostly hand made. Lots of lovely details in the car. They were the fastest thing on the road in their day. A lot of them were amateur raced.

I had the chance to look one over really well when i twas parked in the field at the Big Auburn auction about 25 years ago, when they were still worth less than 100K. I used to see one driving around Telegraph road in the Detriot area around 1974 when I worked up there. Also earlier saw a roadster in the flesh a few times around 1966 when one of the owners of a construction company I worked for for the summer. I had no idea what it was and thought it was a little dumpy looking.

[Tomguy]

Originally Posted by Benz Dr.

There was a special version NSL engine that's basically the same unit placed into the later roadsters. I've worked on these engines and can tell you they're not like anything remotely similar to any other car.

If it has at least 270HP, I could see 150 with those CD numbers. It'd just take a while to get there. Hell, at one point I had my 4.5 almost that high indicated... sure, it was probably a good 10mph optimistic, but still. That was with the 3.5 heads and cams, it died out 10MPH slower before that mod...

[Benz Dr.]

Originally Posted by t walgamuth

I bet you never drove one or rode in it. (me neither).

Maybe a terrible car but a stupendous super car. They are mostly hand made. Lots of lovely details in the car. They were the fastest thing on the road in their day. A lot of them were amateur raced.

I had the chance to look one over really well when i twas parked in the field at the Big Auburn auction about 25 years ago, when they were still worth less than 100K. I used to see one driving around Telegraph road in the Detriot area around 1974 when I worked up there. Also earlier saw a roadster in the flesh a few times around 1966 when one of the owners of a construction company I worked for for the summer. I had no idea what it was and thought it was a little dumpy looking.

I had a ride in a gullwing once and I've done two mechanical restorations on roadsters. One roadster was a hard top only car ( Italian ) and it still had far more head room that the coupe did.
Top speed depends on what gear ratio you have. 240 HP is the most a stock engine will have. It's still a lot for a 3 liter inline 6 from the 50's.

[t walgamuth]

Cool!

I am jealous.

[t walgamuth]

I would suspect a rough ride would indicate worn shocks in the Gullwing.

[Benz Dr.]

Originally Posted by t walgamuth

I would suspect a rough ride would indicate worn shocks in the Gullwing.

Roadster was just as bad and I installed new shocks all the way around. It was like driving an old steak truck only a lot faster in a straight line. Going around corners or a big curve was a real treat. If you didn't hold on to the steering wheel carefully enough it would pull it right out of your hands. Most of the smaller cars that MB made during the same time period didn't have enough power to make you feel the kind of torque a 300 SL could produce. It would of been a great car with power steering.

I made sure to take my time working on it so that I was able to do a lot of test driving. Once I had it done the owner said, " Now I want to sell it." Guy came to look at it, inspected the car, and bought it for his client. I asked him if he didn't want to drive it first and he said no because he was satisfied with how it looked.
We went out to lunch and I let him drive the car. As we were driving I told him to open it up a bit which he did - nothing sounds like a 300 SL. He started smiling so I asked him what he thought. He said, " I never expected this thing to drive this well." And it did too. '61 disc brake car with 85,000 miles on it. Sold for 125 K about 20 years ago. Same car would be around 600 K today.

[ejboyd5]

Internet knowledge and idle speculation by those who have no personal experience with the 300 SL are an unfortunate combination when masquerading as facts.