Acceleration: F40, F50, Enzo, CGT & Veyron

Yes, 20 years. Thats what separates the cars. Honestly if the Enzo wasn't better than the F40 in every category, it would be regression, not progress. Its superior performance is not a surprise, in fact its fully expected. It would be much more legitimate to compare the Enzo with a car of the same era, not one from 2 decades ago. For example the Bugatti Veyron, which blows the Enzo away at every stage of acceleration.

 

The Enzo as it approaches VMAX cranks out down force as does the Veryon.

Down force lowers VMAX as the aerodynamic devices (movable in the Enzo's and 458's case) such as wings and fences that create it induce drag.

Momentum is determined by Mass, (Mass X Velocity) and in the case cited a horizontal force.

VMAX is determined by having sufficient HP to overcome aerodynamic drag.

For those interested in the effect of aerodynamic devices/down force and drag I recommend:

http://www.ferrarichat.com/forum/showthread.php?t=232922&highlight=fences

 

Any car can catch air. Downforce puts it back down on the ground. I caught air in the 599 at 160+ last week, and it got shoved back down nicely, nose first, then tail. Rear downforce is very important, but front downforce moreso in corners and rough pavement. Breaking the surface to car vacuum generally kills the downforce from underbody aero. Hence blow-overs (see LM CLK) and likely the lift generated by the Enzo causing the problem. Straight line vs curve does not matter. Duration of time airborne/lacking downforce does matter, likely contributing to Enzo mishaps.

Absence of a conventional wing does not mean the car does not have a wing. It isn't "just a design difference". And going back to our wind tunnel discussion, rolling road tunnels make underbody aero tuning possible. Every car "needs" downforce, as much as possible balanced with the losses due to drag, to develop Vmax. Veyrons use a "low-drag" mode for Vmax, requiring key activation, drops ride height and retracts spoilers, even with 1000 bhp.

Tire sidewalls have also limited downforce use for a long time. Heat and pressures can cause catastrophic sidewall failures. Veyron tires case in point. I've got lots of data references for sidewall construction over the last 20 years, even in the same tire line, and varying with tire sizes, but that would be an entire thread.

Many have been dyno'ed( http://www.youtube.com/watch?v=JlXohkJ7BQo http://www.youtube.com/watch?v=FybrIDAyavA&feature=PlayList&p=F79339C2525542BE&playnext=1&playnext_from=PL&index=5 )Then we can start the "dyno vs. dyno" argument, and "flywheel vs. rear wheel" bhp correction factor argument to nullify that data. Data > anecdotes

Downforce increases downward acceleration (duh) and counters lift. Weight is not much of an aerodynamic force unless you have a dog named Toto. We discussed this in the other thread, remember how Pf used their tunnel and computers to track lift and drag? Road-hugging weight was an ad slogan, not an aerodynamic design tenet. Aerodynamics is not a "personal matter". It is mathematics and engineering. Is dispassionate a euphemism for ill-informed?

Torque influences acceleration, BHP influences VMax, as does Cd and CdA. Veyron has 922 lb-ft of "torques" to quote Jeremy, and 1001 bhp. Seems like a lot compared to F40 (426 lb-ft)or Enzo (484 lb-ft). We've posted about that before, you should read it sometime.

 

That's for the info!

Regarding torque:

HP = (TQ x RPM)/5,252

So, you could kind of ignore TQ and just ask, "How much power (HP) is the car generating at each MPH?" The more power it can keep generating, the faster it can accelerate and the higher the top speed. Too bad we don't see HP vs MPH graphs in the Owner's Manual. That would pretty much replace HP, TQ, and gear charts. Here's one I made for the CGT. Engineers use these all the time when designing powertrains. You can make one for any car, but you need all the powertrain data to do so.

At 30 MPH, the CGT is generating nearly 450 HP in 1st gear. The Enzo is even more. This assumes the car is shifted at redline. If not, the total power over time is lower.
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I was also aware of that. I knew the words of R&T. But 515 HP are not been proved.
That's the problem.
Take a look of C&D result from 1/4 mile to KM. The same gear ratio of EU cat.

EU cat: 9.2 secs
USA: 9.3 secs

I think, if US car had more power, we would have noticed it. And this is true.
30-40 hp are verifiable by naked eye

 

1. A Euro F40 with Euro cats has the same gear ratio as a US F40 with US cats (evidence is both cannot exceed 200 mph).
2. A Euro F40 is faster than a US F40 (evidenced by R&T and other tests).

My guess is a Euro F40 with Euro cats is generating more HP than a US F40 with US cats. Yes, the Euro F40 is a bit lighter, but the acceleration differences imply power differences rather than weight differences.

I don't think Ferrari could get more HP from the US cats without increasing boost past what they were comfortable doing. And then why not do that for the Euro cars as well?

Euro F40 with no cats probably have the most HP, and I wouldn't be surprised if Ferrari upped the boost on those cars as well because of the better flow.

 

I agree with your position. Because, it's all written.
We have 4 miles per hours tests (I have some others KPH tests) and are simple to verify the figures.

The US car is the heavier. If it's the powerful, its numbers should change, expecially from 100 to 170 mph. From the 1/4 mile to the KM trap.

Paul Frère was saying that his F40 was able to 11.7s on the QUARTER and 20.9s on the KM.
C&D car was able from 12.1s on the quarter to 21.4s on the Km. With the same gear ratio.
We know that here weight is less important that the real power. So, how is possible to confirm more HP for the US cars?


Take a look here:
http://www.nicksforzaferrari.com/f40powerchip.pdf

 

I wonder where the Murcielago LP670-4 SV, Zonda F, Koenigsegg CCX fit into this (he said mischievously)...

 

Bill:

Here is what I have as it relates to gear ratios for USA F40s versus Eu cars.

First gear - 1:10.707 (USA), 1:10.069 (Euro)
Second gear - 1:6.628 (USA), 1:6.262 (Euro)
Third gear - 1:4.745 (USA), 1:4.463 (Euro)
Fourth gear - 1:3.724 (USA), 1:3.501 (Euro)
Fifth gear - 1:2.965 (USA), 1:2.787 (Euro)

Bill/ F40 Le Mans: You are suggesting that the "Euro F40 with Euro cats" shares the same gear ratios with the USA F40, correct?

 

The gear ratio you are mentioning for the EU, is non-cat version, I mean.
You are refferring to a 2.727:1 for final.
Is 2.90:1 for all the cat cars.

 

Interesting about Tire Sidewalls and how they effect VMAX.

Because of the Veyron's massive weight (Not VMAX down force which is minimized) the tire sidewalls are under enormous load at VMAX. So much so that if you turn the steering wheel over 15 degrees they could over max so if you do the car starts to shut down the engine. In addition because of the tires limited ability to withstand these loads the size of the gas tank is limited so that you can only run VMAX for 15 minutes.

 

Anyway, not ignore the EU-spec. There is an ocean between them.

The Lambo and Paganis are not problems for the ENZO. And no worries for the EU-spec too.

http://www.evo.co.uk/carreviews/cargrouptests/238351/lamborghini_miura_and_murcielago.html

Performance LP 670-4
0-30 1.6
0-40 2.2
0-50 2.6
0-60 3.2
0-70 4.2
0-80 5
0-90 5.8
0-100 7.3
0-110 8.4
0-120 9.6
0-130 11.5
0-140 13.2
0-150 15.4
0-160 18.2
0-170 21.2
1/4 mile secs 11.4
1/4 mile mph 129



http://3.bp.blogspot.com/_BpMYqnBeSQ8/SspvYgBQQfI/AAAAAAAAAp8/troRRSBDQCs/s1600-h/SV+Page+4.JPG
According with R&T results. The SV is a fast car. BUT

0-30 1.2 s
0-60 2.8 s
0-100 6.8 s


The Enzo is faster at any speed, and the EU-spec F40 can match it from 30 mph to 160 mph.

 

http://www.evo.co.uk/carreviews/cargrouptests/235489/lamborghini_murcielago_lp640_v_jaguar_xj220.html

Here you are another great comparo:

THE FACTS Lamborghini LP640 Jaguar XJ220
Layout Mid engine, four-wheel drive Mid engine, rear-wheel drive
Engine V12, 6496cc V6, 3498cc, twin-turbo
Max power 631bhp @ 8000rpm 542bhp @ 7200rpm
Max torque 487lb ft @ 6000rpm 475lb ft @ 4500rpm
Actual weight 1841kg 1512kg
Power-to-weight 348bhp/ton 364bhp/ton
Weight distribution 42:58 front:rear 42:58 front:rear
Basic price £192,000 £403,000 (1993)
PERFORMANCE Lamborghini - Jaguar
0-30 1.7 - 1.9
0-40 2.3 - 2.5
0-50 2.8 - 3
0-60 3.4 - 3.6
0-70 4.5 - 4.6
0-80 5.4 - 5.5
0-90 6.3 - 6.5
0-100 8 - 7.9
0-110 9.3 - 9.3
0-120 10.7 - 10.8
0-130 12.6 - 12.6
0-140 14.6 - 14.9
0-150 - - 17.4
1/4 mile secs 11.6 - 11.7
1/4 mile mph 125.3 - 125
Top speed mph 211 - 213

 

Performance LP 670-4:
60-100: 4.1 sec
60-130: 8.3 sec

 

While I have read this to, it was never proven. Doesn't really matter though, since even if it had a "secret" little power boost it wasn't enough to overcome the extra 250 pounds. Since the Euro cars are still a little quicker.

 

FYI, the test by "Auto" magazine was a Euro car with cats. It hit 202.0. Pretty close to the 202.6 and 202.8 tests of non catted Euro cars.

 

Maybe you could order a Euro car with cats with the same gear ratios as a Euro car without cats? I don't know if there were 3 gear ratios you could select from.

 

Showing therefore hardly any material top speed difference between cat & non cat cars.

 

Auto, Italian magazine, tested a non-cat car. I've that article. Here the picture of the engine.
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Here is a very interesting chart: HP vs MPH for the CGT and F40. You can see:

1. The power delivery in the F40 is much more steady than that in the CGT when shifting to redline in each gear.
2. The CGT's performance is affected much more from short shifting than the F40s.
3. The F40 has nearly 100 HP more than the CGT at 50 MPH! This helps make up for its lower HP at 30 and 40 mph. Both cars have nearly identical HP at 10 and 20 MPH.
4. Over 60 MPH, the CGT HP greatly exceeds the F40 HP. This helps explain the large difference in the 60 to 130 times.
5. Over 130 MPH, the additional downforce (and drag) on the CGT start kicking in and although the CGT has much more HP, the F40 can make up for some time with its smaller drag (and lower downforce).

Bottom line? The CGT really needs revs to make its HP while the F40 can get away with a little short shifting.
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Was this your chart Bill? And if so, was the data achieved on a dynamometer on a single run or an average of multiple runs?

 

I made this chart using data newly published in this thread by F40 LeMans. It's based on the US F40 SAE HP as measured by POWERCHIP with linear interpolation between measured values (see below). It also assumes the US F40 max speed in each gear at 7,750 rpm:

1st = 54 mph
2nd = 88 mph
3rd = 122 mph
4th = 157 mph
5th = 197 mph
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Hum, guess I was thinking of another test then. I know I read a test of a catted Euro car that broke 200 like all the non catted Euro cars....

 

Wait. You are talking about HP...

when you want compare the perfomance, you must compare for TORQUE...
so, TORQUE/gearing..... plus the weight difference.

If you compare for HP/gearing you ave the diffrences in power... but the car performe for its TORQUE really, so is not the same thing..

With your example even the F50 generate in the grafs more power than the F40 during the speed crescendo. But why the F50 is slower?
Cause of TORQUE difference. The F50 generate a lower torque/gearing during the speeds (it's heavier for the EU-spec F40 and higher drag force).

 

Example number two: Why a EU-spec non-cat F40 with only 500 hp can match the CGT?

The garfs you are saying could be shown only 500 hp, where the USA car is only 475 hp.
So, how is possible match really with a 600 hp car?

That's explained by the torque/gearing and weight one more time...

The Hp/mph chart shown only the power of the engine in relation of the speed. BUT not really the real perform of the car, from torque, to gearing, to the weight.

All that explain why a only 470 hp like the USA F40 is little faster than a 513 hp F50...(EVEN in the 60-130 mph time: 9.3 vs 9.6s).

And why a EURO 500 hp F40 can match really well with the Carrera GT