And that is why 4wd was outlawed in both Indy cars and Formula one? I don't think so. You guys have not done your homework.

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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.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

If we are only talking about a steady state turn at the limit of lateral grip, then Brian is right and AWD doesn't present an advantage. However, that situation makes up a very small percentage of driving, on a race track or in any other situation I can think of. AWD allows more power to be applied sooner after the apex, and will cut lap times, provided the power available is enough to offset the weight penalty of having power to two more wheels.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

I respectfully disagree with that.

Those are race cars that often time have a minimal weight to compete. they often include ballast weights to bring it up to minimum weight. they also use race tires as well as a lot of aero dynamic tricks. This cannot be compared to street cars.

Also i believe there is a limit on the engine type, but not the HP so its drive trainloss can be negated.

with the same minimum weight (1415lb) the AWD car theoretically will turn/brake and accelerate as fast as the RWD car (assuming race tires have the grip necessary for both). with the added benefit of possibly gaining any additional traction on loose surfaces.

In this specific example it does not include any of the downfalls of a typical AWD street car.

I never believed AWD to provide more grip, the handling at and over the limit are different and you get on the throttle at a different time. personally to me the downfall has always been the weight associated with them.

since you autocross - i also had a 99 miata which i miss everyday!!

S2000's dominated Bstock, same class as the Subaru WRX STI's. despite having AWD and more HP. but in BSP where they can crank up the HP and add a lot of tires they dominate - however i think S2000's are in A Stock now?

now i have been at an event where it rained half way through and all the AWD cars were dominating.

i dont mean to be rude or anything, I also agree with everything Brian said, i just want to bring some real world examples.

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198? 300D ???K - Future DD
1989 300TE 285K - traded in '12
1984 300SD 186K - Sold in 08
1978 300SD 330K - Died in 05

Because of the high number of douche bags and lesbians??

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On some nights I still believe that a car with the fuel gauge on empty can run about fifty more miles if you have the right music very loud on the radio. - HST

1983 300SD - 305000
1984 Toyota Landcruiser - 190000
1994 GMC Jimmy - 203000

https://media.giphy.com/media/X3nnss8PAj5aU/giphy.gif

Agree'd, and on a race car that you have to add weight to bring up to minimum weight the AWD may have advantage.

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198? 300D ???K - Future DD
1989 300TE 285K - traded in '12
1984 300SD 186K - Sold in 08
1978 300SD 330K - Died in 05

OMG IS THAT A REAL AD?

the other day i told my wife we have a lesbian neighbor. she asked why and i said "well she drives a Subaru Forrester"! she didnt think that was an actual thing! i must show her this ad!

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198? 300D ???K - Future DD
1989 300TE 285K - traded in '12
1984 300SD 186K - Sold in 08
1978 300SD 330K - Died in 05

I saw that posted here somewhere, but apparently Subaru has been courting the lesbian market since the late 90's when they ran ads featuring Martina Navratilova...


A quick search for that first ad led to this site...http://www.adrespect.org/common/Adlibrary/AdvancedSearch.cfm

43 similar ads....

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On some nights I still believe that a car with the fuel gauge on empty can run about fifty more miles if you have the right music very loud on the radio. - HST

1983 300SD - 305000
1984 Toyota Landcruiser - 190000
1994 GMC Jimmy - 203000

https://media.giphy.com/media/X3nnss8PAj5aU/giphy.gif

I guess you have not noticed how the Subies dominate the stock classes they run in. Heck they aren't even very well balanced, very nose heavy. If they were balanced theyd be even faster. I am not aware that any subies fit into BS or AS and run head to head with s2000s. It may be different other places but I doubt it.

At Indy in the late sixties the stp turbine cars ran 4wd. Their cars were heavier and had less horsepower than the other cars and (I just read an interview with Parnelli Jones yesterday in Racer magazine) the gearing was such that he ran out of acceleration about half way down the straightaways. He made it up in the turns. That was in 1967. They ran the tires on all four wheels that the rear drivers ran on the rear.

For 1968 Lotus designed all new four wheel drive cars which were lighter and (if possible) handled even better) but USAC limited the intake size and restricted them to the smaller tires on all four wheels that the rwd cars ran on the front, hoping to make them uncompetitive. They made up some of the lost power by running white gas instead of jet fuel and still dominated the race.

After that usac reduced the intake even more... effectively banning turbines, and later went so far as to outlaw 4WD altogether when folks started showing up with it in piston engine machines.

4wd was banned in every major form of racing it was introduced in because it effectively made all the 2wd cars obsolete.

I suspect the ruling bodies also may feel it is more boring since with the added stability there are not as many crashes.

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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.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

like i said, Subaru WRX STI and S2000 run in B Stock

http://scca.cdn.racersites.com/prod/assets/2013%20Stock%20by%20manufacturer.pdf

the national results shows that ALL rankings are by lightweight RWD cars. top 8 are S2000's. are you going to tell me that ALL of the Subaru STI's decided they are going to skip this class or that you were wrong about subaru's dominating the class they are in?

http://scca.cdn.racersites.com/prod/assets/results/2012%20Solo%20Nationals%20Final%20Results.pdf

i don't think i can comment much on this as it was way before my time, and these are far from street cars. sounds like the car in your first example was geared lower than the rest to make up for the weight and HP difference? also you said it ran all 4 tires the same as the RWD ran in its rear? so it would have more rubber under it? depending on the course and how much are straight and how complex the turns are this may be good or bad.

I tried convincing my coworkers about this, and you are much older and wiser than them so i don't think i am going to convince you in your life time.

a tire, no matter on which end of the wheel can only do 100% of 1 thing, do you want to stop, go or turn? you cannot stop and turn at the same time and expect 100% stop and turning. To me what some pro-awd people thinks that the front driving wheels somehow negate this fact and let the front tires perform @ 125%

Do you at least agree that a lighter car will perform better than a heavier car? (you have to this is the basis for autocrossing!) and that an AWD drive drain typically add weight to a car? and that an AWD drive train has more drivetrain loss?

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198? 300D ???K - Future DD
1989 300TE 285K - traded in '12
1984 300SD 186K - Sold in 08
1978 300SD 330K - Died in 05

Don't waste your time on this. The people arguing with you do not understand the physics and do not want to understand the physics. They simply want to argue their autocross experiences, which are all well below the cornering limits because they are not (probably cannot) be skilled enough to keep the tires at the cornering limits at all times. This is also due to widely varying friction conditions on a millisecond basis.

The only way to make the argument is on dry pavement with constant friction. If they agree to discuss with that as a premise, then the physics can be applied uniformly and the answer will be obvious.

Anything else is a waste of time.

Where is your evidence, Brian? All you do is rattle on. Pull out your engineering books, and show us all the evidence. Post a link, do something other than rattle on.

Here is a quote directly from twalgamuth's post 244. (AND, YES, IF YOU READ MORE CAREFULLY, he is talking exactly the same subject, and if you want me to point out the words, I am happy to do so.)

Unlike 100% anti-dive, 100% anti-lift (or more) is common in road cars, or in production-based road racing sedans and sports cars. Cars that react rear brake torque through a simple trailing arm or semi-trailing arm generally have more than 100% anti-lift. Examples include C2 and C3 Corvettes, many BMW’s, Porsche 911’s and 356’s, and all but the first Mazda RX-7’s.

Yes, twalgamuth, this guy is a consultant to race car drivers, but right here he states that "100% anti-lift (or more) (ie. a car where the rear end squats in braking) is common production-based road racing sedans." He specifically lists cars that are similar. I don't know how more specific one can be.

Brian, if you are an engineer, it is for the Burlington, Northern & Santa Fe Railroad. Since you contantly hold yourself out as an engineer, tell us what your credentials are. What college did you go to and did you even graduate? And what do you currently do to earn a living? And please explain why you ignore everyone that points out false facts that you post (ie; YOU SAID, "the rear brake calipers are always forward of the axle")? Talk about a fountain of misinformation.

Brian, you should also explain your totally stupid comment about technology that was invented almost 50 years ago when you said to me, "You really ought to patent this invention as the automobile manufacturers would be highly interested in understanding how it works. "

If anyone leads in the TOTALLY STUPID COMMENT SECTION, it is Brian Carlton. Brian, do you want more examples?

Better to keep your mouth shut and be thought a fool than to open it and remove all doubt ----- Mark Twain

I posted this as an example of a technology that our illustrious Brian Carlton says doesn't exist and that I should patent it. All I said, is that my 280S dipped in the rear end, keeping it flat in normal braking.

Do you have cast iron rotors and organic pads in your two mercedes?

Any vehicle, by definition, with semi-trailing arms (not just trailing arms) has certain attributes, such as an independent rear suspension including a fixed differential, axles with CV joints, and trailing arms that are angled down and out to the hub. Many also have a rear subframe member like the W123. Further, the cars are the same vintage as the 1980s W123 OR EARLIER.

• Independent Suspension
  

• Trailing arm and Semi-trailing arm suspension
  
  Compare with the following rear suspensions, Trailing arm / Semi-trailing arm suspensions are rather old. It was commonly used in nearly all mid-price to high-price sedans before multi-link rear suspension became popular in 1990s. From '82 BMW 3-series to Mercedes 560SEC, even the Porsche 911, trailing arm / semi-trailing arm suspensions dominated half the world. Trailing arm suspension (the upper picture) employs two trailing arms which are pivoted to the car body at the arm's front edge. The arm is relatively large compare with other suspensions' control arms because it is in single piece and the upper surface supports the coil spring. It is rigidly fixed to the wheel at the other end.
  Note that it only allows the wheel to move up and down to deal with bump. Any lateral movement and camber change (with respect to the car body) is not allowed. Nevertheless, when the car rolls into a corner, the trailing arm rolls for the same degree as the car body, thus changes camber angle (with respect to the road surface). Now, you can see both wheels lean towards the outside of the corner, thus lead to understeer. Because of this reason, pure trailing arm was forgotten by car makers long long ago. Instead of it, they adopted semi-trailing arm.
  Semi-trailing arm suspension (the lower picture) has the trailing arm pivoted at inclined angles - about 50 to 70 degrees. Otherwise are the same as trailing arm suspension. Apparently, the semi-trailing arms are half trailing and half transverse. You can analyse it by splitting it into two vectors, one is the trailing component and another is the transverse component. The trailing component leads to understeer, as already mentioned. On the other hand, the transverse component is actually equals to a swing axle suspension. Now, you may remember that the swing axle suspension always introduce oversteer due to body roll. As a result, the two components cancel each other and result in near neutral steering response.

At least one or two of these cars has a suspension almost identical to the W123. So, how is it not the same or very similar?

whoops getting a little bit heated for my taste! OUT

__________________
198? 300D ???K - Future DD
1989 300TE 285K - traded in '12
1984 300SD 186K - Sold in 08
1978 300SD 330K - Died in 05

I have asked this question or brought it up several times. I believe people in this forum do not have cars that are up to specs. I know most have carbon steel rotors (most commonly sold) and most have ceramic brake pads. Your car likely had cast iron rotors (which are softer and offer a lot more grab when you first brake), and I know it had organic brake pads. Organic brake pads really bit into the rotor, and made a lot of dust. The most effective pads have a limited lifespan. Organic pads only lasted about half the mileage the newer ceramic pads last. I bet the ceramic pads and carbon steel rotors only have about 75% of the initial braking grab of the original mercedes setup described above.

Do you have cast iron rotors and organic pads in your TD?

If a motor cycle does this, it takes little imagination to understand that it can be engineered into a car. My bet is the motor cycle copied the auto technology.