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Large displacement, low rev V8 engines for F1


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#1 primer

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Posted 13 November 2009 - 18:31

Just wondering.

Let's say the rules get changed and current F1 engines are all replaced by spec, sub-7000 RPM, NA 6.2L AMG-Mercedes / GM's LS7 V8 motors. These larger displacement V8 engines will have ~2.5 times more torque compared to current 2.4L F1 engines, but power (say massaged and equalized to 600 bhp) would be 200 horses short of current high rev V8s? Let us also assume (play along) that the overall weight of the car doesn't change. Same Bridgestone tires and everything else, too.

Now, comapred to 2009 F1 cars:

  • What changes will the teams have to make to the gear ratios? Lots of torque, but not as much bhp as earlier. Will the seven gear ratios be spaced out more? Closer?

  • Will it be more challenging for drivers to avoid wheelspin? Particularly in the first few gears?

  • How much will the 'top-speed-at-the-end-of-a-straight' change? Let us take the start-finish straight of Sepang as an example.

  • How and how much do you see the laptimes changing? Is it possible for these hypothetical F1 cars to be quicker around some circuits (Monaco?) but slower on 'power tracks' like Spa? Or will these new cars be slower than 2009 cars on all tracks?

  • Will the torquier engines give these cars an advantage when accelerating through a certain speed range? I mean, will they take less time while accelerating from 100 to 200 km/h compared to their 2.4L versions?


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#2 Fat Boy

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Posted 13 November 2009 - 19:59

Just wondering.

Let's say the rules get changed and current F1 engines are all replaced by spec, sub-7000 RPM, NA 6.2L AMG-Mercedes / GM's LS7 V8 motors.



Wow, let's not.

#3 saudoso

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Posted 13 November 2009 - 21:47

Just wondering.

Let's say the rules get changed and current F1 engines are all replaced by spec, sub-7000 RPM, NA 6.2L AMG-Mercedes / GM's LS7 V8 motors. These larger displacement V8 engines will have ~2.5 times more torque compared to current 2.4L F1 engines, but power (say massaged and equalized to 600 bhp) would be 200 horses short of current high rev V8s? Let us also assume (play along) that the overall weight of the car doesn't change. Same Bridgestone tires and everything else, too.

Now, comapred to 2009 F1 cars:

  • What changes will the teams have to make to the gear ratios? Lots of torque, but not as much bhp as earlier. Will the seven gear ratios be spaced out more? Closer?

  • Will it be more challenging for drivers to avoid wheelspin? Particularly in the first few gears?

  • How much will the 'top-speed-at-the-end-of-a-straight' change? Let us take the start-finish straight of Sepang as an example.

  • How and how much do you see the laptimes changing? Is it possible for these hypothetical F1 cars to be quicker around some circuits (Monaco?) but slower on 'power tracks' like Spa? Or will these new cars be slower than 2009 cars on all tracks?

  • Will the torquier engines give these cars an advantage when accelerating through a certain speed range? I mean, will they take less time while accelerating from 100 to 200 km/h compared to their 2.4L versions?


This is a very dangerous thread to start :eek:


#4 Bill S

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Posted 13 November 2009 - 22:01

It was sort-of done in the 70's matey ....

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#5 desmo

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Posted 13 November 2009 - 22:09

If F1 is going to spec engines- and it seems to be by steps- I actually like the idea of using pushrod SBCs. There's no reason to go to any lengths to obtain high specific outputs or low weight in a spec engine series, use whatever is cheapest to buy and hits your hp target.

#6 OfficeLinebacker

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Posted 13 November 2009 - 22:53

If F1 is going to spec engines- and it seems to be by steps- I actually like the idea of using pushrod SBCs. There's no reason to go to any lengths to obtain high specific outputs or low weight in a spec engine series, use whatever is cheapest to buy and hits your hp target.

carburetted! carburetted!

LOL :rotfl:

#7 DOF_power

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Posted 13 November 2009 - 23:11

Electric engines.

#8 Scotracer

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Posted 14 November 2009 - 01:10

Just wondering.

Let's say the rules get changed and current F1 engines are all replaced by spec, sub-7000 RPM, NA 6.2L AMG-Mercedes / GM's LS7 V8 motors. These larger displacement V8 engines will have ~2.5 times more torque compared to current 2.4L F1 engines, but power (say massaged and equalized to 600 bhp) would be 200 horses short of current high rev V8s? Let us also assume (play along) that the overall weight of the car doesn't change. Same Bridgestone tires and everything else, too.

Now, comapred to 2009 F1 cars:

  • What changes will the teams have to make to the gear ratios? Lots of torque, but not as much bhp as earlier. Will the seven gear ratios be spaced out more? Closer?

  • Will it be more challenging for drivers to avoid wheelspin? Particularly in the first few gears?

  • How much will the 'top-speed-at-the-end-of-a-straight' change? Let us take the start-finish straight of Sepang as an example.

  • How and how much do you see the laptimes changing? Is it possible for these hypothetical F1 cars to be quicker around some circuits (Monaco?) but slower on 'power tracks' like Spa? Or will these new cars be slower than 2009 cars on all tracks?

  • Will the torquier engines give these cars an advantage when accelerating through a certain speed range? I mean, will they take less time while accelerating from 100 to 200 km/h compared to their 2.4L versions?


Q1:

The gear ratios would likely be similarly spaced, given the current V8s have a very wide torque-band

Q2:

Work out the wheel thrust...

6.2l V8 w/ 600BHP @ 7000rpm = ~ 450lb.ft so say 470lb.ft peak torque (given a small drop from peak)

Average gear ratio will be 18,000/7,000 = 2.57 times lower than 2.4 V8 so take the typical torque of a 2.4 V8 - 220lb.ft - and multiply it by 2.57 gives you 565lb.ft which is 1.2 times higher than the 6.2 V8.

The 2.4 V8 would have more torque about the rear wheel (given same rear wheel diameter) so would wheelspin more.

Q3:

Using Q2 Speed Trap data from Malaysia 2009 you get a peak for 2.4 V8 of 304.9km/h or 189.5mph. This is with, say for sake of argument, 750BHP.

Take 150BHP off this, and given that drag squares with speed, you'd see a peak of 272km/h...assuming they've reached terminal velocity of course.

Q4:

Since it's rear-wheel thrust that actually determines the propulsive force, and since the F1 car produces more and has a very broad torque band (watch some on-board F1 footage where they will run from 9,000-18,000rpm in one gear!) I'd highly doubt the larger engines would exhibit an advantage anywhere, especially given the increased weight of the unit. If you can find me a 6.2 V8 that weights 95kg I'd love to see it :p


Edited by Scotracer, 14 November 2009 - 01:14.


#9 gruntguru

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Posted 14 November 2009 - 03:32

Q2:
Work out the wheel thrust...
6.2l V8 w/ 600BHP @ 7000rpm = ~ 450lb.ft so say 470lb.ft peak torque (given a small drop from peak)
Average gear ratio will be 18,000/7,000 = 2.57 times lower than 2.4 V8 so take the typical torque of a 2.4 V8 - 220lb.ft - and multiply it by 2.57 gives you 565lb.ft which is 1.2 times higher than the 6.2 V8.
The 2.4 V8 would have more torque about the rear wheel (given same rear wheel diameter) so would wheelspin more.

Much easier to calculate thrust from power. Thrust = Power / Velocity. No need to consider gear ratios. Notice you get 1.2 times higher thrust (1.25 to be exact) - that's because the engine has 1.25 times the power.

Q3:

Using Q2 Speed Trap data from Malaysia 2009 you get a peak for 2.4 V8 of 304.9km/h or 189.5mph. This is with, say for sake of argument, 750BHP.

Take 150BHP off this, and given that drag squares with speed, you'd see a peak of 272km/h...assuming they've reached terminal velocity of course.

I get 283km/h. (Calculated using "power required increases with the cube of speed.")

Q4:

Since it's rear-wheel thrust that actually determines the propulsive force, and since the F1 car produces more and has a very broad torque band (watch some on-board F1 footage where they will run from 9,000-18,000rpm in one gear!)

Its actually the breadth of the power band that matters most. :p The lower end of the torque band (9,000 in your example) would only be used where the car is traction limited.

I'd highly doubt the larger engines would exhibit an advantage anywhere, especially given the increased weight of the unit.

+1

#10 McGuire

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Posted 14 November 2009 - 07:23

Just wondering.

Let's say the rules get changed and current F1 engines are all replaced by spec, sub-7000 RPM, NA 6.2L AMG-Mercedes / GM's LS7 V8 motors. These larger displacement V8 engines will have ~2.5 times more torque compared to current 2.4L F1 engines, but power (say massaged and equalized to 600 bhp) would be 200 horses short of current high rev V8s?


The engines would have to be severely restricted to limit them to 600 bhp. The LS7 will make 850+ hp with shelf pieces, 650 bhp with a cam and calibration change, through the cats. What's the purpose?



#11 saudoso

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Posted 14 November 2009 - 11:00

Much easier to calculate thrust from power. Thrust = Power / Velocity. No need to consider gear ratios. Notice you get 1.2 times higher thrust (1.25 to be exact) - that's because the engine has 1.25 times the power.

I get 283km/h. (Calculated using "power required increases with the cube of speed.")

Its actually the breadth of the power band that matters most. :p The lower end of the torque band (9,000 in your example) would only be used where the car is traction limited.


+1


Power requirement increases with the square of speed.


#12 ferruccio

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Posted 14 November 2009 - 12:18

Apologies for not posting to answer primer's 4 questions.

I would just like to say that large low revving V8s would not suit F1's technological(debatable of course) profile but I'm sure the engines would suit some other series. Imagine the rumble of a cross plane crank large cc V8 in a single seater..hmm.. The size of the large V8 would also compromise handling, not fitting for F1.

I don't understand why F1 won't just go back to turbos? Say 1.5L 4 cyl or V6 turbos with boost strictly regulated. The engines and the turbos would be more relevant to road cars than 2.4L V8's revving to 18,000rpm.

This to me is more attractive to the manufacturer. Can someone explain why F1 isn't going back to turbos? Forced induction are currently the preferred solution by manufacturers in meeting future emission and fuel consumption targets while still preserving power and drivability



#13 Scotracer

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Posted 14 November 2009 - 14:49

Much easier to calculate thrust from power. Thrust = Power / Velocity. No need to consider gear ratios. Notice you get 1.2 times higher thrust (1.25 to be exact) - that's because the engine has 1.25 times the power.


I'm set in my ways :p

I get 283km/h. (Calculated using "power required increases with the cube of speed.")


I used Power required increases with the square of speed which I just took from the drag force equations. I'll bear the above in mind.

Its actually the breadth of the power band that matters most. :p The lower end of the torque band (9,000 in your example) would only be used where the car is traction limited.


Well yes but seeing as they can use 9000rpm without shifting down (this was in 2nd gear - particularly noticeable at Indy 2006) I'd say that's a damn wide torque band. Of course you'll never see an F1 car shifting up and dropping 9,000rpm but I still think the torque would be within 80% of peak. Pity it's near impossible to find a torque curve for a modern F1 V8.

+1


Glad we agree on something at least :lol:

#14 dav115

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Posted 14 November 2009 - 20:11

Power requirement increases with the square of speed.

The force requirement is proportional to the square of the velocity, but the power required is proportional to the cube of the velocity (power can be expressed as the product of force and velocity).

#15 saudoso

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Posted 15 November 2009 - 11:27

The force requirement is proportional to the square of the velocity, but the power required is proportional to the cube of the velocity (power can be expressed as the product of force and velocity).


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#16 Fat Boy

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Posted 15 November 2009 - 16:54

The engines would have to be severely restricted to limit them to 600 bhp. The LS7 will make 850+ hp with shelf pieces, 650 bhp with a cam and calibration change, through the cats. What's the purpose?



The engine package that Mac has laid out here would be suitable for an Indycar, maybe. Not really my cup of tea on how to skin the cat, but it'd work and would be a hell of a lot more entertaining that their present engine package which is underpowered by a damn sight on road/street courses. That would mean that Indycar would revert to something similar to their original IRL car configuration. Big V8, although without the OHC's. Those cars would put out too much power for Indy, though, and at about 220mph the insurance companies start wanting to slow the cars down, which is how we arrived at the HP level we see now.

An Indycar is a relatively huge piece of machinery next to an F1 car, though. I don't think that many people appreciate how small they really are when you just see them on TV. They aren't a hell of a lot bigger than a FFord or F3 car. Sticking a big American V-8 in them would be the end. I can see perhaps going to Judd and getting a V-10 that everyone has to use, but that'd never happen.

When I rule the world, F-1 cars will run V-12's only. That's the only engine that makes the noise.

#17 gruntguru

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Posted 15 November 2009 - 23:45

When I rule the world, F-1 cars will run V-12's only. That's the only engine that makes the noise.


With or without RPM limit?

#18 desmo

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Posted 16 November 2009 - 00:45

It wouldn't be F1 without a rev limit or with more than eight cylinders. Bernie and Max have spoken.

#19 Peter Leversedge

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Posted 16 November 2009 - 01:37

A Sprint Car engine in a F1 car ?

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#20 scolbourne

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Posted 16 November 2009 - 01:44

It wouldn't be F1 without a rev limit or with more than eight cylinders. Bernie and Max have spoken.


Come 2013 the proposed fuel limited rules may allow various engine configurations. Then we will see whether a large V8 can really beat a high revving small engine.


I hope we get this as it should make the grid more interesting.


#21 Fat Boy

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Posted 16 November 2009 - 16:46

With or without RPM limit?


Well, let's be honest. All racing engines have rev-limiters. Damn near every racecar is faster around the lap if you burp the limiter in places....Hell, sometimes it's faster if you freakin' bury it in the limiter. The question is to whether the RPM is series limited. For the record, an 8 cylinder at X rpm does not equal a 12 cylinder at Y rpm. That's like saying a six string guitar sounds like a 12 string if you play it twice as fast. They don't. They just have the same primary resonance. Not the same thing.

To answer your question, I think an arbitrary rev limit is an inelegant solution to limit HP. If I were King, I would probably limit the amount of fuel over the course of the race, similar to the 80's. Each car gets X + 'Qual position' amount of fuel. The guy that starts 20th gets 19 liters more fuel than the pole sitter. It would allow for different strategies and encourage passing. It also makes people think, which makes them make mistakes. Refueling? I don't know, I'm on the fence. If I had to make a knee-jerk call, I'd say allow it.



#22 desmo

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Posted 16 November 2009 - 19:04

To me an interesting question is to ask if F1 were fuel limited to whatever today's engines consume per race but otherwise open in design, what would be done differently? I'm having trouble imagining where you'd go design-wise to get any real overall advantage over a current engine as they are so optimized for the current chassis.

#23 gruntguru

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Posted 16 November 2009 - 19:55

To me an interesting question is to ask if F1 were fuel limited to whatever today's engines consume per race but otherwise open in design, what would be done differently? I'm having trouble imagining where you'd go design-wise to get any real overall advantage over a current engine as they are so optimized for the current chassis.


I think if engine design was free, the fuel limit (to achieve similar lap times) would need to start at today's consumption less a factor - probably 10-15% to start then adjust from there. The fuel limits would need to decrease steadily each season.

If hybrid storage was free, the starting point would be much lower - perhaps 30-50% below current consumption.

#24 Powersteer

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Posted 16 November 2009 - 21:37

If F1 is going to spec engines- and it seems to be by steps- I actually like the idea of using pushrod SBCs. There's no reason to go to any lengths to obtain high specific outputs or low weight in a spec engine series, use whatever is cheapest to buy and hits your hp target.

Push rod are certainly not the cheapest train.

:cool: