Acceleration: F40, F50, Enzo, CGT & Veyron

Thank You Bill S and F40 Le Mans for what is surely the most informative body of work extant as it relates to F40 acceleration and performance!

 

It gives you a headache though LOL.

Honestly, unless a Euro F40 is at the same track as a CGT driven by the same driver we will never know for sure what one is a little quicker.

 

That's what TEORICALLY could be AUTO figure with exactly the same 60-100 mph of Fast Lane. Yes teorically, we have not other perfect data.
Considering some differences should be justified for the different gearing beetween both cars.
Porsche repeatedly escapes but Ferrari reaches..

The C&D CGT is a very fast car, but Euro F40s are NOT SLOWER cars
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You can try again, but don't change the result.

The tests you have yet. The fastest was FastLane but we have not some data.
Not existing a fast test for the very fast, we must make a mix of data from AUTO and FL.

 

We are able to know how many HP has your car in the 7.6 sec run behind your PerformanceBox calculations?

 

So after reading this whole thread who can send me some VBOX data on their F40 or one they have tested ?

I do this as a job and would like to look at the information provided. Will provide detailed feedback for anyone who provides me with any Race Logic files.

[email protected]

Thanks

p.s. I have been using the F40 as a performance base on my own car and have many threads on these engineering topics (power, weight, performance and proper testing) Here is some of my equipment I use http://www.riceracing.com.au/vbox-iii-testing-tuning.htm

 

Congrats on starting this thread btw.

If you need any help with your VBOX and getting the best from it feel free to get in touch with me

Here is my own thread on VBOX little off topic but its worth a read hopefully
http://www.ausrotary.com/viewtopic.php?f=4&t=143457

This one is also pertinent
http://www.ausrotary.com/viewtopic.php?f=4&t=185387
including this video for you boys
http://www.youtube.com/watch?v=tvBsjmKpbyg&feature=related
Euro spec F40 Owned by Peter Pless at calder Park drags in early 1990's *see mph*


Enjoy

 

Sorry I can't help you about VBOX data.
But your link is perfect about I'm saying.
The Euro spec F40 has trouble on standing starts, but after the wheelspin, 127.9 mph is shurely a huge terminal 1/4 mile speed considering all. And it's faster than US-spec car.
Time of 12.23 is proof about wheelspin versus the speed.

 

I used to read Fast Lane magazine when it was current. While I cannot comment on the F40 or CGT, I would not trust any data from Fast Lane.

For example, they obtained the highest top speed ever recorded for a Countach QV - using a factory supplied car and a stop watch and mile markers on the highway to get around 190mph!!! Of course, neither Motor, nor Autocar could come close to the top speed or acceleration figures recorded by Fast Lane for that Countach QV- they got around 175 or 180 mph.

The above is just one example, but their road tests were not very scientific. I would not trust any data from Fast Lane. Anybody knowledgeable about the UK motoring press would say the same.

 

I have to agree that the non-scientific method used by Peter Dron to record that Countach QV's top speed means you cannot conclude anything from that data.

However.

Lamborghini had a habit in the days of the Miura and the Countach of not disclosing to journalists that certain cars provided for testing did in fact have tuned engines. By his own accounting, Bob Wallace started this tradition with the Miura, and I can say with confidence that the Countach QV given to Dron to test was a car built specially for Formula One driver Pierluigi Martini. Lets just say that the engine had been 'breathed upon', and in this instance even scientific timing would have recorded a faster speed than that of other Countach QVs. It was routine practice for the works to provide tuned cars to their VIP and sporting customers, something that Dron ruefully notes elsewhere after the fact.

Hope this explains why that particular test was a little fast.

 

Joe, agreed. The QV data is clouded by a non-scientific test and a "special car"

Could the same things be true with Fast Lane's F40 test? After all, a turbocharged car is even easier to make faster by turning up the boost. Any thoughts?

 

From my analysis these cars have more like 520bhp rather than 468~478bhp.

I have compiled all of the test weights (actual measures) and terminal velocities and it all points to a power figure closer to 500+ rather than sub 500.

The USA spec cars that trap 122mph are dead on the 470bhp rating

Also you can see in that best motoring 1994 video that when they put the F40 on the Bosch dyno it read 500+PS.

This is all very fascinating for me as I have a Rare Mazda RX7 which I have been restoring to meet the legendary F40 performance specifications, the cars are very similar indeed. same frontal area, the SP RX7 has a lower Cd (drag coefficient) lighter test weight (I run mine at 1320kg) and at the moment I am putting out ~440bhp region I do 0-100kmh in 4.40 seconds and the other incremental that is a dead give away for the in gear power is the 100kmh to 140kmh Zone, which on the Italian VBOX test of the F40 shows exactly 2.00 seconds covering 67 meters. This is in the meat of the F40's power band 5k to 7+k rpm. (remember the car that trapped 127+mph). My car does this in 2.24 seconds and we have exactly the same rpm band/gearing



The test weight they list was
1421kg
100 to 140 = 2.00 seconds

Mine
1345kg (in this specific test run)
100 to 140 = 2.24 seconds
and I have ~440bhp

From my calculations I need to run my car at 21psi boost pressure to match that figure (currently on 18psi). I have no doubts in my mind that the Euro F40's put out over 500bhp personally, all of the science points to that being the case. if you know the mass, the drag, the frontal area, then its not hard at all to work out the power once you know the velocity.

I work with this stuff every day (I know sad life I have!). I develop all my own formula to derive power from my top line VBOX gear so am very sure of my analysis. This is a great thread and thanks to the people who have posted in it.

I have taken some of the information and collated it in my own thread to do with Kerb Weights, Power and Measured Performance here > http://www.ausrotary.com/viewtopic.php?f=4&t=185387&start=60

 

If you are speaking of this issue using Nick Mason's car, then, according to lore (unconfirmed by me) Mason's engine was a blueprinted unit so perhaps here too we are dealing with a more potent car than the standard production unit.
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My analysis of the numbers agrees with this above, great post F40LM ! In no doubts about the average spread of mph results returned by EURO F40's V's the USA one's point towards greater power, obviously there is a mass difference and the small fact that you can run these cars with up to 80kg more fuel V's another (most testers don't stipulate how much fuel they run) which is why its important to do a proper weight check before the tests like in the Italian F40 test > then its basic to work out the power then given car made on the day of the test.

The other massive variable on turbo cars is the weather!
You need to remember we are talking real world tests here and the effect of ambient temperature has an exaggerated effect on turbocharged vehicles, testing a car in cold England 13 deg C day or in Japan can highly inflate the power on the track on a dyno report it should be corrected by the set engineering standards, but no such standards can be applied in the real world. I experience this all the time with my high accuarcy gear fitted to my vehicle (its not a $800 performance box but rather $30,000 worth of VBOX3i and associated gear), each time I drive and test I make sure to go to the same test location, and target similar ambient conditions, otherwise there can be big spreads in performances. I think this is a big point to raise along with the data people list from one off tests.

The other big thing is terminal speeds at the end of a 400m or 1320ft and how they are measured, in a drag track due to archaic timing beams these are averaged over the last 66ft of the 1320ft, in a high accuarcy VBOX it can be measured exactly at the end of the 1320ft or you can run a report and measure it as an average, this can make an effect. It has a much bigger bearing though on the times! on a drag track you have to take into account the head start you can get by staging 12" or 1 foot further forward of the trigger beam! in a VBOX you have no such problems but testing with a head start v's no head start can make up to 0.3 seconds difference in these types of times

It's a complex game, some don't get all of the factors involved and thus can jump to wrong findings. I'd say the ones that provide the most data and have a reputation for honesty and applying rigorous eng standards to their vehicle testing you can trust. Some times though a good real world head to head test with a video can be worth its weight in gold. Like the 1994 Best Motoring video of the 540bhp Toyota Supra over taking the F40 on the test bowl

 

Traction is all about the tires, driver and surface. I have seen F40's with that trap speed with ET's well in the 11's where they should be.

 

haha that's why I use my own battery packs got caught with that on some race cars myself, very frustrating indeed!

Is it possible for you to do a weight check also? I'll be happy to run my formula over your files and resend it to you with it saved on there.

 

Peter the original cars owner responded in my own thread on the build up of my vehicle when he herd of my performance targets (RX7SP V's F40) and he said he at that meeting had trapped as high as 130mph FYI.

 

Wouldn't surprise me at all.

 

My new best friend I feel ashamed to add my car

 

I think not about the boost up or something special because Mason's car was 100 - 160 mph in 11.6 seconds able.
That's exactly the same as AUTO magazine with private car was able or others curtomers F40s were able (160-260 KMH 11.6 secs)

Take a look about Ruoteclassiche F40 http://www.quattroruote.it/autoclassiche/automoto/protagoniste/visualizza_articolo.cfm?codice=15120&canaleuscita=-1&chiave=&sez=Protagoniste
even as "customers car". Exactly the same 160-240 kmh as AUTO.

My point is, Mason's car was able exactly the same as others customers cars are able.

BusDriver, these cars are all boosted up?
Nope.
FastLane was (trust or not) a good point or perfect test of the F40, like the C&D Carrera GT test, was.
A boosted Up F40 wasn't able of exactly the same 100 - 160 mph as the other, but should be faster.

Marco Brand N-GT MonteShell Michellotto F40 (80742) was a lot quicker than Mason's car during the AutoSprint test sessions here in Italy.
The car was good for "corrected 535hp" in the 1993 N-GT specification as Michelotto saying.
So, Mason's car was no good for N-GT specification engine performance.

 

Corrected dynos seems showing about 470 hp for CAT F40s (and US F40s) and 500 hp for the Euro spec. Obviously, even 520 hp uncorrected, if as you are saying they are TESTED OR DYNOED in better weather conditions than SAE or DIN standard.

That's all, but Mason's Euro-spec car is not so special. It's able as other Euro spec cars are.


The point is, here some (American or something) people are incredulous about straight line Euro F40 performance because they are not really unaware HOW ARE 250 lbs more, 20-30 bhp less and a closed exhaust for their USspec F40s, on exactly the same car!

That's not the only one time, looking the Mecca and the Ameritech F1....

 

I think it is mainly the weight savings of the Eu cars that produces the performance differential don't you?

Do we know how much the F40 LMs weigh? Here is one on the Mulsanne straight circa 1995. The caption reads: "On the Mulsanne Straight - Quick but failed to finish". Pic by Mendaman.
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