2014-2020 Formula One 1.6l V6 turbo engine formula

[ringo]

With respect to the engine, there was one thing i forgot to mention.
For the constant power engine, the boost has to go up the lower the engine speed is.
The higher the boost pressure, the higher the boost temperature.
The engines ability to have constant power will be limited by how much heat the intercoolers can draw from the hot intake air.

If the engine makes max power at 4,000 rpm with the give fuel flow 27.8g/s
The boost temp will be 231 degrees celcius!!

So unless there is a way to cool that to 40 degrees, then i don't think the engine will make the constant power to begin with.
The most sensible compromosise for constant power is between 8,000 rpm with 140 degrees and 12,000rpm at 95 degrees i guess?

What type of boost temperatures do some race cars normally see before the intercoolers?

[machin]

OK, I've done my own graph and performance prediction based on my own software. car details:-

640kg + 150kg fuel
2.3m wheelbase
0.25m cg height
60% of weight over rear wheels
Overall ratio (one gear) of 4:1
13" wheels, 450 width, 25% section
Engine Output -constant 600bhp

Results?

It produces 670kg of downforce at 100mph.
Top speed is 170mph at engine rpm of 10,400rpm.

It is traction limited right up to 101mph (this is equivalent to 6200rpm at the engine).

0-60mph in 2.15secs
0-100mph in 3.7secs

Here's the tractive effort curve -the light blue curve shows grip at the driven wheels, dark blue shows the resistance curve, green is engine output.



So the engine only needs to be constant power from 6000 to 10500rpm.... adding more gears doesn't do anything for the acceleration or top speed.

[autogyro]

I suppose you could slip a clutch from stationary with this constant 600 bhp engine. It would need to be the size of a wind turbine though.
Anyway slipping clutches defeats the fuel efficiency target.

The estimated rev range originaly given for the flat power curve was 4,000 rpm to 12,000rpm.
If you stick to something at least feasible and then draw the graphs, it would be nice.

[ringo]

OK, I've done my own graph and performance prediction based on my own software. car details:-

640kg + 150kg fuel
2.3m wheelbase
0.25m cg height
60% of weight over rear wheels
Overall ratio (one gear) of 4:1
13" wheels, 450 width, 25% section
Engine Output -constant 600bhp

Results?

It produces 670kg of downforce at 100mph.
Top speed is 170mph at engine rpm of 10,400rpm.

It is traction limited right up to 101mph (this is equivalent to 6200rpm at the engine).

0-60mph in 2.15secs
0-100mph in 3.7secs

Here's the tractive effort curve -the light blue curve shows grip at the driven wheels, dark blue shows the resistance curve, green is engine output.



So the engine only needs to be constant power from 6000 to 10500rpm.... adding more gears doesn't do anything for the acceleration or top speed.

Well add another gear, maybe a 3.5:1 and see what happens to your top speed.
secondly where's your final drive and wheel diameter?
You top speed might be cut in half with a half decent final drive.

[machin]

You can see on the graph that the top speed is power limited (see the green force line is lower than the dark blue resistance line above 170mph). Lengthening the gear won't increase the top speed.

If we tweak the ratio a bit I can get the required constant power rev range to 7100 to 12000rpm... how's that for the intercooler temperatures?

[machin]

Anyway slipping clutches defeats the fuel efficiency target.

You don't have to give it full throttle when slipping the clutch!! And you only need it for the start, and then 1 or 2 pit-stops...

[machin]

secondly where's your final drive?

I said; overall ratio of 4:1.

and wheel diameter?

I've given you the tyre specs -you can work it out from there....!

[autogyro]

Anyway slipping clutches defeats the fuel efficiency target.

You don't have to give it full throttle when slipping the clutch!! And you only need it for the start, and then 1 or 2 pit-stops...

With one ratio from stationary to max speed, you will have to slip the clutch at least to 60 odd mph to keep the engine in any kind of feasible power output rpm range anywhere near your suggested (4,000 to 10,500).
If you do not the acceleration will be dismal.

[ringo]

Oh i just say the tyre specs, i was focusing on the other stuff.
a diameter of .5525m

Well put it this way, if i put more gears in between, it will still have an advantage. The argument that it makes no sense has no mathematical grounds.

If i put lower gears, 1 ratio will lose on acceleration,
If i put higher gears, it will lose on top speed. Throuw 2 arbitrary gears into your graph.
I've been making graphs the whole day at your request. Return the favour.

Your downforce figures are very high by the way. too high. How did you get them?

[machin]

Wait! I've been stupid... the graph clearly shows it is traction limited from 60mph.... that's 3700rpm..... so not so good.....

[bill shoe]

Machin, xpensive, others who understand— thanks for fighting the good fight. Machin, you’re probably too patient by half (this implies you could achieve optimum patience with a final drive ratio of 0.667 ).

People who doubt machin or xpensive, here is the “John 3:16” of this discussion from machin:

"An engine making ~600BHP at 12000rpm will produce 262.5lbft of torque. Lets say it has a diff ratio such that this = 200mph. At 6000rpm (100mph) it also makes 600bhp, but now the torque it produces is 525lbft. At 3000rpm (50mph) it still makes 600bhp but now torque is 1050lbft"

It’s OK if you don’t understand this statement. However, it’s necessary to understand it before having an opinion about the optimum number of gears for a constant power engine.

Many pages ago I ranted that constant power engines would probably be banned because they lack traditional shifting noises. I think I underestimated the extent of the problem. Constant power engines will have to be banned because in a more general sense they’re not understood and therefore not comfortable to most people. Ironically, the precise method of preventing them will have to come from some engineer who does understand them.

I think this is my favorite quote this year--
“These graphs are from equations, they can't be wrong.”

[ringo]

Fighting a losing battle you mean.

I am waiting for him to realize that he needs more than one gear, for his very same example that he posted. It's plain and simple.
If you take the time to look on the graphs i posted you should be able to understand.
Autogyro hinted at the gear charts, but no one took the time realize what they represented.
1 gear ratio is mathematically inferior and inflexible. Machin has now realized this, and is searching for answers.

[WhiteBlue]

What do you guys think why they have bothered to set a max rpm? Is it really necessary when you have a fuel restriction?

[machin]

Ringo. Thanks for that. Actually I went to bed.

Bill: thanks for the kind words, I'm trying!

Here's my graph with two extra gears:-


As you can see the longer gear (red) doesn't add top speed since the car with my original gear is limited by resistance anyway.

The shorter gear (orange) loses top speed, and it also doesn't add anything at the lower end because the car is limited by grip at slow speeds anyway. (A true constant-speed machine can produce full power at 0rpm -in which case even if you had all the grip in the world more gears wouldn't increase the acceleration).

You can't see the red and orange curves below 170mph because they're exactly the same as the green curve (representing my original gear); Hence why the adding gears doesn't increase the performance of a constant power machine, assuming drag, weight etc are equal. (My personal view is that a constant power machine wll actually be too heavy and too bulky and that a "peaky" engine with lots of gear ratios is the better solution).

[machin]

OK. One more try to explain the power and torque relationship:-

F=mA right?

Lets assume that your car has lots of grip (its not traction limited), and that aero resistance (force) is zero (e.g. low speeds). You'll just have to accept that we don't have any rolling resistance in this eaxmple. (EDIT: and that the drive train is 100% efficient -please bear with it).

The mass is fixed. In order to achieve a given level of acceleration we need to provide a motive Force at the tyre contact patch (the "F" in F=mA).

In order to determine the motive Force at the contact patch at a given speed you can use two methods:-

You take the engine torque at the engine speed necessary to achieve the road speed, you multiply it by the gear ratio and the final drive ratio. You multiply this result by the wheel radius -that gives you the motive force at the tyre contact patch.

OR
You Divide the power by the road speed. (F= Power/Road Speed)

The simple solution is the second method: you don't need to know the gear ratio, the engine speed, or the tyre size. You just need to know the power and the road speed.

Don't believe me?

OK:- 200BHP at 20mph means 16615N at the contact patch.

Now you have a go at getting more force at that contact patch at 20mph using a 200bhp engine and any gear ratio and wheel size you want. You won't be able to.

I'll give you some 200BHP torque values:-
200lbft @ 5250rpm or
400lbft @ 2625rpm or
100lbft @ 10500rpm.

Pick one of them and see if you can get more than 16615N at the contact patch at a road speed of 20mph. You won't be able to do it.