zach1328

I am not saying this is definately possible, nor am I attempting to start an arguement, but with these details, is it possible for a 500e to reach the 180mph mark?

A stock 500e with no speed limiter can reach about 160-165 mph. At which it will reach the 6k redline limiter.

A 6 speed manual or automatic transmission will solve this 165mph rev limiter problem. (A 6 spd should allow more along the lines of 190mph rev limit, if not more).

But at 175 or 180ish it should theoretically reach its maximum drag limited speed. But a manual transmission doesn't lose as much HP to the WHEELS. A 500e loses around 17.5-18% with the auto tranny, so more along the lines of 15-16% with a manual.

So it should have more like 270-272 RWHP compared to the stock 265RWHP. (I know at high speeds 5-7 RWHP won't make you go much faster).

But then if you lowered the car around 1.5" to 2", you will further increase the drag limited top speed to say 185mph. (Some companies/magazines have found results that lowering a car 1.5" increase top speed by around 5mph).

My question is:
Is it realistic or even possible for a 500e to reach in excess of 180 or 185mph with a 6 speed manual tranny and a 2" lowering kit?

ptoro01

I think a tail wind might help a bit too but going downhill would certainly better the odds of all this being possible, Doc!

Shoomakan

I don't think so, Zach. Keep in mind, while we do consider the 500E to be a fast and powerful car, it does only have 315 or so horsepower. It's significantly slower than a 2002 F-Body Camaro, for example. Which can NOT hit 186 mph, even with the 6th gear you're speaking about and a lowering kit.

More importantly, that Camaro has a better drag coefficient as well as more power.

Think of it another way: An unrestricted E60 M5 V10 can max out at around 195 mph, and that's with 200 more horses, 6 speed manual, and lower/stiffer suspension.

The 500E was made to cruise at 100 mph all day, back when not many cars could do so. It's not a supercar.

Shoomakan

And another thing: you've got your transmission losses wrong. The auto saps close to 25% of the engine's power, and the manual around 14%.

And I've noticed in my years of car ownership that top speed claims are sometimes unusually off. According to the world wide web of lies, a 300E-24V should max out at 235 kph. It's faster. My bike supposedly only hits 275, but I got it there keeping in mind I weigh over 300 pounds and wouldn't fit under the windscreen, thus severely increasing wind resistance. I'm sure a smaller rider could have pushed it at least another 10-15 kph.

RBYCC

The stock 500E does not have enough power to reach the speeds you suggest.
The only 124 that had enough power was the "Hammer' which attained a top speed of 186MPH with about 75HP more then the 500E.

Shoomakan

And I'm sure it still took it a while, relatively. Ed, maybe with your engineering background you'd be able to explain this to Zach better than I can, but I remember some ballpark formula/theory or something that someone told me once about wind resistance at speed. Something about needing 9 times more power to add your top speed by 1/3 of it or whatever.

If there's a formula or name so I can read up on it I'd be happy.

ptoro01

But perhaps, jet fuel, skinnier tires and the front & rear windows removed are necessary as well.

My next drastic suggestion will include a parachute, all or nothing!

RBYCC

Zade

Go back to the 1700's and Swiss mathematician Daniel Bernoulli's equation.
Just about every modern aerodynamic calculation is based on his equation.

You are correct in that the horsepower required to push an car at higher speed is not linear but exponential.
Every time the speed doubles the HP required to overcome the drag force is increased by 8 times !!

Easier to visualize and understand with the linked calculator and tables.

Online calculator :

http://www.bgsoflex.com/aero.html

Tables for frontal area and cd for most make cars:

http://www.mayfco.com/tbls.htm

Ed A.

Shoomakan

Thank you!

Zach, you should also be able to answer your question with this information!

ptoro01

A 6.0 500e sounds like the solution in this case. An extra liter should add 100 horses. Or a w210 e55 brobus koompressor..

But there is always the straight pipe, afterburner/flamethrower, NOS and 1.21 gigawatts of electricity but then things could become pretty unpredictable.

zach1328

Actually AMG quoted the Hammer's speed as 190 MPH. Actually I believe their official report said "over 190 MPH".
Now yes the AMG Hammer did have a Cd (Coefficient of drag) of .25. It also had an additional 70hp and torque or so.

But a 6 speed tranny easily allows for a rev limited top speed of over 190MPH, so after the 6 spd tranny the only thing you need to worry about is the drag limited top speed.

From the factory I believe Mercedes tested the Drag induced top speed to be somewhere around the 175MPH mark. The manual transmission will also put more HP down to the wheels.

The lowering kit and additional 5-10WHP would allow for an additional 5mph onto the 175mph drag induced top speed.


I'm sure most of you guys know much more about cars and how they work then I do. I just feel like the evidence is there to support the fact that a 500e can reach 180mph.

But what is the Cd on a 500e? Around .31, right?

Shoomakan:
The automatic transmission in the 500e does not reduce the HP from the crank to the wheels by 25%.
A stock 500e with the 92 ECU is 322hp to the crank. They usually put down 260-265WHP or so.

If it lost 25% a bone stock 500e would be around 240HP to the wheels. Its got a decent bit more.

And a manual tranny loses more than 14%.
My friends Mustang GT is is 290 hp at the crank and 242 RWHP.
Thats about a 16.5% loss. I know a 500e will be different depending on the type of tranny and all. But my point is, 14% is a ridiculously low number. Just as 25% is way to high.

More realistically the 500e is losing 20% with the auto tranny.
322HP/5 (the 5 represtents 20%/100%) = 64.4 HP loss
This would put a 500e at 257.6 RWHP. Much more realistic.

neanderthal

The AMG Hammer had a comprehensive aerodynamic package that a 500E doesn't.
The .28cd figure figure that people quote for the W124 is for a base model 200E/D with skinny 185/65-15 section tires and steel wheels which came with hubcaps, and no passenger side mirror.

zach1328

Yes, although advances in tires and rims today should allow for a little less Cd than those old 1986 tires and rims from the 200d.
And also, I said the 500e was .31 or so, not .28.
But regardless, a .31 or even a .30 is pretty high when compared to the AMG Hammer's .25 Cd.

The 500e might even be slightly less than a .31 Cd because when you consider the .28 from the 200d, the 500e rides about 1" lower. But it has the wider tires, and widened fenders, as well as the handy passenger side mirror.
Lets not forget the 500e came with some aerodynamic upgrades from its lesser models. For example its more aerodynamic front bumper.

Take my 2008 535i for example:
Its top speed is around 170MPH and has a very similar power numbers to the 500e. Its also a little less aerodynamic than a 500e (especially with the 18x10 tires on the 535i) and its 58" height compared to a 500e's 55" height.

The 535i is quotes as 300hp and 300 tq but is really more along the lines of 320hp and 340tq. Almost the exact same as a 500e.

So the 500e is more aerodynamic, just as powerful, etc. The only thing it lacks compared to a 535i is the 6 speed tranny.
Oh and I almost forgot. The 535i has an axle differential of 3.46 which will kill the top end. The 500e has a 2.82 which should allow for even greater speeds than a 535i.

Shoomakan

Zach, you make too many assumptions.

Also, past a certain point, it doesn't matter what size diff in the back since you're DRAG LIMITED.

neanderthal

I hardly doubt your 2008 535i is less aerodynamic than a 124.036 when it's several generations newer and this page lists a previous generation 5er as having a cd of .27. Why would BMW regress on a newer model?

Internal and mechanical friction losses are much lower on a newer car than an old car. Newer cars can run very easily on 0W30 oils whereas a 500E needs something like a 15W40. Couple this with advancements in metallurgy that reduce friction on cylinder walls/ pistons, crankshaft bearings, big and small end bearings etc. Even the new transmissions are more efficient than the old ones. All this boffinry frees up more power on the newer car for propelling the vehicle, making it more efficient and enabling it to go faster as less power is lost in the drivetrain.

The most aerodynamic rims are those that are as flat as possible and cover as much of the wheel as possible. An old school Mercedes 15 hole alloy would be more aero dynamic than a new AMG 5 spoke, no matter how much newer the wheel is. And a plain Mercedes wheelcover as seen in this image is probably just as good if not better. The laws of physics don't bend for the latest in style, fashion and technology.

Stop assumptionating.

Shoomakan

You literally wrote everything I wanted to write before I thought the better of it. And you added some more. :P

I didn't want to waste my breath/fingers/keyboard explaining those to someone who's as convinced as Zach.

Hey Zach, my mom's old 2005 Honda Civic 1.7 was FASTER than a 5 litre V8 Camaro. Do you think it would have hit 160mph? :P

All jokes aside, I'm trying to illustrate to you how a modern economy car is as fast or faster than an older sport model. So imagine how much worse it is when you compare old and new sports cars.

RBYCC

Once again a sixteen year old like Zach demonstrates how talented he is by talking out of his "****"...

He doesn't even know that the MB factory did no testing on the Hammer as they had naught to do with it's build !!!

He quotes drive train losses to RWP but doesn't know "F-all" about chassis dynos and the different types...

Hoping he would leave after he trashed what was once a perfectly good Benz and now was given a BMW by his parents...

He's never truly experienced a thing in his short life other then obsessive mental masturbation about that which he "Googles , but yet speaks as if he is an oracle....

190E 16V

Ed, funny that you use the word "masterbating". That's whatcame to my mind, too. :-)

Hopefully the guys on the BMW forum will indulge his fantasies for awhile.

Jim's500E

Funny thread...

With the mirrors removed...the 500E could only reach 172mph on the test track 20+ years ago. Yes, the car's drag limits its speed. I don't think there's an official 6.0 liter E60 tested for top speed by the factory...maybe there is. I doubt it went much faster though. A stock 500E with the rev-limiter removed does about 160mph.

That's fast enough for me !

the_widebody

so just removing the mirrors gains 12 mph? so the fitting of skinny front wheels would make a big difference as well.

Shoomakan

I find that hard to believe. If it had Suburban mirrors, maybe. :P

Jim's500E

172 mph with the mirrors removed is the manufacturer's claim...not mine. Do the research, the data is available for you to see for yourselves. Yes, the car they used was stock production with the 'skinny' 225/50/16 tires on it....and of course, a euro-version w/o the US mandated speed limiter.


I saw what looked like about 157 on mine...on a downward sloping highway that we use around here to go fast. Truth is its prolly just 155 or so at the limiter with a mph or 2 for gravity (?) .

zach1328

Why would they regress?
That link you posted says the 1995-2003 5 series is 56.5" in height and 70.9" in width.
My 5 series is over 57" in height and around 73-74" wide. Close to 1" taller and 3-4" wider. Thats going to have a big effect on the Cd on a car.

A bugatti Veyron sits around 2.5" off the ground in the high speed mode, and still has a Cd of .36. Why? Because the tires are wide as hell, and the car is wide as hell.


The 2003 5series probably had 8" tires all around. I've got 18x9.5" in the rear and 18x8.5" in the front.
And the 2003 5 series its quoting probably didn't have the sport package. Mine does, which is why it has the much wider front and rear tires.

Point is, my 2008 5 series has a much larger frontal area than that 2003 5 series.
The 500e has less frontal area, probably rides slightly lower than my 535i, and doesn't have the wide *** 18x9.5" tires in the back.

Now back to the bugatti veyron. This car is a great example of why I believe a lowering kit can make a huge difference in top speed.
The Veyron typically has 4.9" of ground clearance.
When put into its high speed mode, it will lower to only 2.6" of ground clearance.
At its typical 4.9" ground clearance it has a Cd of .41. When it is lowered to 2.6" off the ground, the Cd drops to .36.

Esentially, if you lowered a 500e 2.3" (as the veyron does), you should lower the Cd by close to .05. So that would be like taking the Cd on a 500e from lets say .31 to .26 from a 2.3" lowering kit.

If removing 2 side view mirrors increases the Drag Limited top end by around 10mph, im pretty sure a 2.3" lowering kit will do a bit more.

I'll test it with my 500e when I get one. Until then you guys can sit around not believing me for all I care.

neanderthal

You know, if you're going to pretend to know what you're talking about, you should probably know what you're talking about. That's something that i'd suggest.

To whit; cd =/= cdA

The figures being quoted here are for the cd, also known as coefficient of drag. That is a static figure that is independent of the frontal area of the object in question. If you want to talk about the coefficient of drag combined with the frontal area, that metric is denoted as cdA; cd times area. Frontal area in this case.

As for your lowering a 500E to make its cd drop by .05 let me ask you this; if I lower a Land Rover Defender 90 by two inches, will its cd also go down by the same amount? Think carefully before you answer, because transposing one thing to another directly can lead to a transpositional error.

So, what was the answer? Will the effect be the same on a Landy? If you answered no, then perhaps there is some grey matter between your ears. If you answered yes, then you are an even bigger idiot than I thought. Yes, I think you're an idiot. I will continue to think so until you demonstrate that you can learn from people who know better than you.

To answer the question, the LandRover will not lower its cd by that much because it wasn't designed in a windtunnel. Same applies to a 500E. It was designed for sustained high speed running, but it wasn't designed for 200 mph or ultimate top speed. And aerodynamics plays a huge role once you start going much faster than 140mph.
Do you really think that the aerodynamics of the Veyron weren't optimised for high speed running when its entire raison d'être was to be the fastest standard car on earth? Was that the purpose of the 500E at it's inception? Or was it designed to combat the performance of the E34 BMW M5? Whose reason for existence was empirically NOT straight line performance.

By the way, the wider tires and wheels on the BMW are more than offset by the little air deflectors that are in pretty much every new car on sale today. Some are really overt (designed into the front bumper,) some are very subtle, but just about every new car on sale today has wheel deflectors.
The air around the wheel is very turbulent and smoothing or even directing the air properly around the wheels reduces drag significantly.....

Like I said; if you're gonna act like you know what you're talking about, perhaps you should do it
a) around people who don't know better
b) with better knowledge, facts and science
c) with less assumptionating.

Edit. BTW, the Veyron has an ugly cd becasue it was conceived first as a show car, then the president of VW decided it would be the fastest car. So design dictated the aerodynamics.

Like I said, know what you're talking about.

ptoro01

Huh so an AMG kit with wheel deflectors would make the car faster?? From the looks of it the Gen I kit has them.