Rear spoiler on a W123 - PeachParts Mercedes-Benz Forum

William73 · #1 06-10-2006, 11:33 PM

What benafits could be expected from a rear spoiler on a W123? I know that in theory it would provide down force. If you only had one of those trunk lip "duct tail" spoilers, at what speed would it do any real good?

mercmad6.3 · #2 06-11-2006, 09:01 AM

i have had a few cars back in the 80's with the rubber deck lid spoiler,and in one graphic example I had BMW 3.0 with one,After I had fitted it I noticed two things- the rear tyres wore very quickly and the rear springs sagged,They start having an effect from 50 MPH onwards, I frequently had that thing over 130mph,and yes they do work!.

William73 · #3 06-11-2006, 02:37 PM

Awesome! Did you notice a change in fuel economy? I've heard that the big wing on the Dodge Charger Daytona would push the back of the car down a few inches when it got up to speed. I'm surprised that a little one would have such an effect. Would you need a front spoiler if you had a rear one? I don't think you would want the front higher than the rear at 130mph.

t walgamuth · #4 06-12-2006, 12:29 AM

first, my bavaria 3.0 bmw wore out the tires and the springs sagged without a spoiler.

second, i never saw more than 115 in mine. i know the 3.0 had a bit more power. but...

third a small spoiler might help fuel mileage a bit. maybe 1" or so. i am just guessing on this based on the fact that some economy cars have a little one.

and fourth, what 123 car will top 130?

unless heavily modified.

tom w

William73 · #5 06-12-2006, 09:28 AM

Quote:

a small spoiler might help fuel mileage a bit. maybe 1" or so.

So I might go one more inch per gallon?

Veloce300DT · #6 06-12-2006, 01:34 PM

Spoilers arent really effective at lower speeds, and are more of a vanity when applied to most passenger cars. Many cars have been designed with small spoilers with the thought in mind of increasing cleanliness and/or efficiency by reducing drag- being placed either at the top of the rear window, at the bottom of the rear window, or on the trunk.... think Porsche 944, Saab Turbo's, Some station wagons, and some other assorted import cars.

A spoiler placed at the top of the window is meant to reduce build up of soot and other vision marring surfactants that can build up on the rear window by changing the air flow over the window at higher speeds.

And of course, a spoiler at the bottom of the window (common on some hatch-backs) and spoilers on the trunk create downforce with minimal drag, which naturally enhances high speed handling and rear tire grip. But for most motorists to feel any benefit would require frequent high velocity traveling speeds. The W123 is a capable high speed cruiser... fitted with a 617.952 is can pack some bite at its high end... at 85mph there is gobs of torque to use. they really become different cars at higher speeds. BUT, a trunk spoiler really wouldnt change the handling dynamics of the car much at all in a noticeable way unless you were traveling at 130mph as mentioned above. I have never seen a 617 carry itself that fast, and it would be near impossible to sustain a constant speed above 100mph with all of the traffic on the roads now. Night time driving is another story

I love driving at night, within reason.

A spoiler on a W123 car, be it a gasser or diesel, would serve primarily as a vanity feature. W123 AMG cars were often fitted with a small trunk spoiler that sat on the top edge of the trunk, spilling down onto the rear fascia of the trunk, hugging the star emblem. They look good when the entire AMG package has been fitted to the car- lower side mouldings, front spoiler, and the must have AMG Penta wheels.

t walgamuth · #7 06-13-2006, 08:48 PM

Quote:

Originally Posted by William73

So I might go one more inch per gallon?

a one inch tall spoiler.

more i think prob will hurt economy. just a gut feeling. (you should see my gut though)

tom w

William73 · #8 06-13-2006, 10:50 PM

My gut feeling is that it would hurt it also. You don't get many forces for free. Gravity is free but to create down force would take energy.

duxthe1 · #9 06-13-2006, 11:22 PM

Back when I was on the Saabnet fourums spoiler talk was rampant. I remember someone posting about a comparison of factory spoilers. The basic premise was that the only factory spoiler that generated any appreciable downforce was the porsche "whale tail" spoiler, which was asolutely huge. None of the other makes that offered spoilers had anymore measureable downforce than their non-spoiler counterparts. It was noted that all spoilers created drag that hurt fuel economy regardless of make. So unless you go crazy huge with it, a spoiler is nothing more than cosmetic. (and usually in poor taste)

Veloce300DT · #10 06-13-2006, 11:24 PM

I would agree... on a car with the profile and shape of a w123, I cant imagine it would help reduce drag and positivley affect handling and performance in any way unless the car had a monster engine under the hood and is capable of 150mph + which would in turn created the energy via windforce to produce a decent amt. of downforce. but then who cares about fuel efficincy if u are running a monster engine!

Spoliers are funny like that. Vanity? or Performance? on smaller economy cars that are of a shape and profile that accomodates a small spoiler purely for economy, I can see it working. theres a smaller power to performance ratio, and efficency can be affected, altered, and enhanced much more easily by careful small additions. Im sure manufacturers also apply spoilers to economy cars to make the cars appear more sporty too.

t walgamuth · #11 06-14-2006, 08:01 AM

my late uncle, the manufacturing engineer, used to say "if you drop a feather on an anvil, the anvil will deflect. it will be hard to measure, but it WILL deflect."

so even a little 1" spoiler will make some downforce, but it will be hard to measure.

a little cleaning of the airflow with a very small one might improve economy. but i bet it would be hard to measure.

and for myself, i wouldnt want to perforate the paint and risk a place for rust to start.

tom w

BobsterMan · #12 06-14-2006, 11:37 AM

When my youngest daughter was about three years old, she had determined that a "sports car" was any car with a rear spoiler, which she would identify by ascribing it with a swoop of her hand.

I'm not sure how she had determined that, but it probably involved the same cognitive processes as others who feature the adornment on their sporty cars.

I suppose I'm waiting for the designers wind tunnel test data on a full-scale model. The rear spoiler, in my opinion, will result in greater speeds when you can drive away in such an a manner as to leave it behind.

Now except that old Dodge... that was all performance and class.