Electronically Limited Top Speed

[mbenz76]

The E350 CDI I am waiting for (patience is definately not one of my virtues ) has a top speed of 155mph (to which it is electronically limited).

My question is what do people think it could actually achieve were it not limited?

Just curious really at how conservative these limits are.

I assume they are there to protect parts which aren't engineered for higher speeds even if the engine can manage it.

 

[HumberMart]

Prob not that much more for an E350. I'd be surprised if they'd get up to 160.

 

[LTD]

I haven't hit the limiter in mine yet

 

[BTB 500]

I assume they are there to protect parts which aren't engineered for higher speeds even if the engine can manage it.

Nope. M-B, Audi, and BMW voluntarily imposed a 155 mph limit on their cars to head off potential legislation in Germany to restrict top speeds.

 

[st4]

I haven't hit the limiter in mine yet

You will

 

[Will]

(boring thought)

155mph = 250km/h

 

[johny5_uk]

Although I am extremely interested surely no one is going to give an accurate answer here?
Maybe you could work out a rough estimate by hitting the rev limiter in 6th?

 

[Howard]

Bobby Dazzler has a program that take into account track , width , power , Cd , and a few other bits and it will work out the theoretical top speed of your car ...

My CLK 430 is electronically limited to 155 , but if the limiter was removed , would ( theoretically ) run to 167 mph ... I have no reason to doubt this.

Send him a PM and ask if he would work it out for you , you will need some specs handy though. These can be got easily off the net.

Good luck.

 

[Dryce]

Just curious really at how conservative these limits are.

Well you might decide to manufacture a car that can go up to 140. Then state it's 'limited to 155'. From a marketing perspective it could imply that the car is capable of a lot more.

I assume they are there to protect parts which aren't engineered for higher speeds even if the engine can manage it.

No.

It might allow them to stick on cheaper tyres.

But the real reason is to give the manufacturer an aura of social responsibility. Somehow limiting the car to over twice the speed limit in many countries makes the company appear more responsible and keeps the more self-righteous MPs from actually legsilating something.

A similar sort of thing happened with motorcycles in the 80s. They were limited voluntarily to 125bhp.

 

[A210AMG]

theoretical top speed....


All good pub talk but does it take into account, wind, road surface, weight in your car at the time you 'max' out...

also...

It would be a little sad sat in your C63 / E55 / RS6 etc and a Focus RS flashes you out of the way and carrys on in the distance................

 

[Howard]

I beleive it does.

Bobby Dazzler spent some time working on this program for a previous employer i beleive ...

Having just found the original post , it seems i was wrong , the 430 CLK is only good for 166mph.

This is what it takes into account ... ( for the CLK 430 )

transmission losses 18%
engine power (at the flywheel) 279 BHP
engine power (at the wheels) 229 BHP
vehicle track 1.506 m
vehicle height 1.371 m
maximum vehicle cross section 1.86 m*m
vehicle mass (weight) (kg) 1555 kg
drag coefficient 0.31

Calculated theoretical top speed is 166mph


http://www.mbclub.co.uk/forums/862363-post41.html

 

[BenzedUP]

Where did the Torque figures go? don't you put that into account? Also wheel size can effect the top end speed? etc..

My 2004 320 Cdi has 267bhp and 410ibft and weighs about 1730Kg, Height 1450mm so what's the top speed of that?

 

[CE230]

A similar sort of thing happened with motorcycles in the 80s. They were limited voluntarily to 125bhp.

Swines. I had to get an imported full power V-Max because of that but it didn'[t last thankfully.

 

[Diesel Benz]

Strange, the E350CDI top speed was initially reported as 248 km/h but now the MB site says 250 km/h, electronically limited. The latter sounds right because already the 221 S320CDI makes 250 km/h and the power difference is not significant (173 kW versus 170).

The E350CDI would not reach top speed on the seventh gear, the theoretical speed at max power rpm (3800) is 272,9 km/h if I calculated it right. At the same rpm the 6th gear gives 242,9 km/h and this must be the gear for top speed. Gassers would do 250 on fifth gear likely.

 

[Howard]

Where did the Torque figures go? don't you put that into account? Also wheel size can effect the top end speed? etc..

My 2004 320 Cdi has 267bhp and 410ibft and weighs about 1730Kg, Height 1450mm so what's the top speed of that?

Ask BD , not me ....

I gather they are all worked out on standard trim and rolling radius.

BD will be able to explain it better than me.

You'll need to come up with the cross section , track and Cd too ...

 

[orangeboy]

What would a 2005 E320 CDI go up to?

When you approach the higher speeds I don´t get the feeling that it will go and go.

 

[thebook]

The E350 CDI I am waiting for (patience is definately not one of my virtues ) has a top speed of 155mph (to which it is electronically limited).

My question is what do people think it could actually achieve were it not limited?

Just curious really at how conservative these limits are.

I assume they are there to protect parts which aren't engineered for higher speeds even if the engine can manage it.

This video shows the E350CDI hitting the limiter:

YouTube - Mercedes E350 CDI Coupé at top speed (limiter)

It is not mine I hasten to add!

 

[Howard]

We're talking about top speeds if limiter was removed.

I like your car .... you're fairly local too ( i'm Teddington ) maybe see you at MBWorld at a GTG ?

 

[thebook]

We're talking about top speeds if limiter was removed.

I like your car .... you're fairly local too ( i'm Teddington ) maybe see you at MBWorld at a GTG ?

My office is based next to MBW so I get to go there quite often a GTG sounds like it could be fun.

Appreciate we are talking top speed unlimited but some insinuated the 350 might struggle to reach the limiter so I thought I would add the link

 

[lynall]

350 diesel must be good for a genuine 155 no problem, especially the power of modern diesels, may be slow the last bit but i reckon not by much.

Ive done 155 in my car a couple of times and the last 10mph is quite slow in comparison if you see what i mean.



Lynall