Countach, the ultimate supercar

Hi Joe
No what I mean is that there are various views that the Euro QV's produced 455-470bhp. Some said 100bhp was for noise the rest for propulsion!
As i understand it the LP400's had an identical engine to the remaining lambo 4.0 engines in Europe. My recolection of these were that it was commonly thought the 4.0's produced about 300-320bhp in reality. Some commentators were more unkind and suggested it was nearer 275bhp If I recall
The Series I Espada with 40dcoe's had 325 apparently, and the Series II and III had 350 with an identical engine spec? Most people even back then thought it ws lambo puff and not bhp puff for the extra 25bhp!
The LP 400 had 45 dcoe but was otherwise identical? My point is where would 50bhp or an approx 15% increase in power be coming form?
My calclation was therefore on 455-325= 130

there are various tables for calculating power etc
here is a failry well written link:

http://www.pumaracing.co.uk/TOPSPEED.htm

Whilst the be spoliered and arched later Countachs would have more air resitance and rolling resistance with wider tyres, the maths isnt that difficult! If the LP400 and QV are only say 4mph apart as some suggested then the claimed difference of 80bhp being about 21% would without extra drag etc be an extra 38mph as opposed to an apparntly 2% increase meaning presumably that 19% of the QV's extra power was wasted in drag!

I think the commonly accepted fomula for every 1mph above 150mph is 5 extra BHP?

I am not trying to knock these cars or their owners, I love them dearly. However I do become a little concerned about power and top speed claims in ANY car irrespective of make. Years ago I used to be a regular 135+mph driver when roads and traffic cops were very different and have driven a fairy wide variety of cars at 150mph plus, incuding my QV and Espada ( well it was downhill!). I just appreciate that getting beyond that speed isn't easy!

Paul

( awaiting incoming tut tut you worng mail lol)

 

OK, everyone talks about myths and other bs. Joe has already said it.......there is a huge variation from one Countach to another. 90% of Countachs are not tuned perfectly or dialed in at 100%. There are only two or three people in the USA who know how to do this, and most shops just screw them up, so therefore 90% of the data is bad and not representative of properly tuned cars. I know the facts as I have owned and driven them to their maximum. Both LP400 and DD exceed 180 mph. I have done it. Let's quit talking about gauge errors. GPS is accurate, simple, and inexpensive and confirms top speeds. Pics of gauges are just for fun! But I have confirmed speeds in both LP400 and DD exceeding 180mph as explained earlier, using gps.

Paul see my notes in your post.........

 

Paul: "So to get top speed we then get into the calculations of drag x weight x power"

Reply: Weight has nothing to do with top speed.......just how much more time it takes to get there. Top speed is only determined by power vs drag(aero + mechanical). If you put sand bags in your car, it will still reach the same terminal velocity, just takes a little longer to get there.

Paul: The tacho on my CT isnt't accurate. The speedo certianly isn't. I could never work out why the LP400's were apparnetly so much lighter than th later 5000 or QV's?? I appreciate the QV's had a different engine ,but the body steel tubes etc were much the same. 200kg difference???? Well if they were where was the difference? Less tubes? Less hot air????

Reply: We all agree the gauges aren't accurate. We use gps for real speed, and the gauges are just for fun! My LP400 weighed 2750 with 1/2 tank of gas, weighed at DMV-approved scales. I will post the weight slip tonight. How, you ask, is the LP so much lighter. Here's how: 1.) The body is smaller. 1.a.) Slice a couple of inched out of the bottom of the body (sill area). All that material weighs something and it is that material that was added to make a low-body into a high-body (LP400 vs DD). 1.b.) The fender flares, front spoiler, sills (on 88.5) don't exist on LP400 and weight something. 2) The aluminum thickness on LP400 is 1mm. On all others, it was thickened to 2mm. That doubles the weight of the body by doubling the amount of metal used to make the body. Those with both know how much more fragile and easier-to-bend the LP400 is vs the others. The factory doubled the thickness (and alloy) to address the fragility complaints of the LP400. 3.) LP400 uses magnisium (vs aluminum by other variants which is heavier than mag) on suspension uprights (hub carriers), oil/diff casings, wheels, and many other castings, saving weight. 4) Wheels are smaller in diameter and width which makes them and the tires mounted to them, much lighter. Ditto for the brakes. 5) Simple HVAC system much lighter on LP than the 88.5's climate control system (as used on Diablo) with its myriad of wires, vacuum, lines, actuator, relays, etc. 6) Electric antennae on 88.5 weighs about 4 lbs and doesn't exist on LP400. 7) LP400 used thinner (and more fragile) glass all around. Measure the thichness on an LP and you will see it is thinner than the QV....again for durability reasons. 8) More leather on DD, including dash, headliner, etc. than on LP400, and leather is much heavier than cloth or mousehair. 9) Bigger engine on DD.....bigger pistons, twice as many valves and valve springs, bigger/heavier heads and valve covers, etc. that all go along with increasing an engine from 4 liters to 5.2 liters. 10) Much lighter exhaust without the extemely heavy cats........I could go on and on, as there is much more, but anyway, you get the point.....All these seemingly little things add up to Hell of a lot of weight. The difference is weight is not myth. It is REAL as I have weighed them!!!!! The DMV-certified scales don't lie.

Paul: The relaible car magazines tested these cars a lot and had difficulty matching the factory figures. Individal cars can vary +/- 10% in all cases. But a base LP400 CT doing 180+ ??.

Reply: Yes, Sir, for a properly tuned car. Again, one out of maybe ten will do it because the other nine were set up by others than the handful that really know how to do it.


Paul: Whilst I do not doubt the word of what people are posting, the suggestion that only using the tacho or speedo on a car as a means of measurment isn't relaible. You need to check their accuracy and then determine the readings AT THAT TIME! tyre wear and temp can alter the accuracy.

Reply: I agree, and I've already addressed this.

Paul: I love my CT and other cars, but try not to be hooked up in the myth. My QV is a very fast car. In full tune light fuel load etc it may be very quick even by todays standards. But a 185+ car?? On a level road with no wind and no rear spoiler? Possibly. a LP400? with 130bhp less or thereby? Sorry I don't think so. Do the maths. Will check the formula and post when I can, that is drag x bhp x weight.

Reply: Forget math and calculations. I have done it with gps confirmation, and yes, the 88.5 did it with the wing (albeit the newer little wing). And remember, weight has nothing to do with top speed....just how long it takes you to get there.

 

your certainly correct about the magazines.....the R&T article i saw was dated few month before the infamous 76 "192mph" top speed road test. wallace says it was 2300lbs +change. the photos showed a LP400 in production guise which is notably different from LP500 concept and the red/green preproduction car with the chrome window trim and chunky seats. im just trying to highlight the fact that his comments are sometimes inaccurate or misinterpreted but it becomes ingrained the CT's legacy. i think we can all agree today the LP400 and 400S are the lightest at 2850-3050lbs and gets heavy throughout the production untill the 25th anni?

the carobu miura L400S dyno charts shows a pretty healthy 338hp. although its mostly stock, the specs show the motor was mildly ported. who knows how much the heads were "decked" during the rebuild for increase CR?

dont know much about the burtoni LP400 motors but apparently they ran a heavily "C" modifed CT DD in 2001 that set the world record that stood for 10 years. this car has an extended "superbird" nose, roof fences, fully enclosed fast back, low drag wheel flares, trimmed intake ears and flush moon type wheels.

breaking the record at 201.7 mph... its only 10 more that the infamous 192mph LP400 R&T test.

 

hmmm ..... raymonds euro DD dynoed 397hp and burtoni/carubu LP400 dynoed 380hp.

1.2 liters more displacement with far better 4valve heads and piston shape only nets 17hp? thats an awful lots for production tooling and engineering for a measly 17hp.

the LP400 should walk away from a DD in the 1/4 mile with the power-to-weight advantage even with the punny xwx's lack standing start traction if this is accurate. i dont know of any cases of this LP400 being quicker.

100hp difference is probably closer to the truth. acceleration and top speed numbers implies this.

there has been some fantastic post and lively debates here in the last couple of days.

much obliged

hf

 

The Miura engine rotates in the opposite direction from the Countach. The cams might have similar profiles but the lobes would likely be in different places. At the very least the firing order would have to change.

There are significant differences in the "setup" of similar vehicles, it's difficult to make any hard and fast rules about anything particularly with "old school" cars. Weber carbs are wonderful devices but the temperature, humidity, and barometric pressure will have a significant effect on performance. Particularly here in the North it is important to set up a car for the type of weather that it will be used in. A car that runs well in the humid Summer will perform differently in the cooler, drier parts of the year.

As far as magazine tests of any car go, I wouldn't put much stock in them beyond "good reading" which is all they were really about anyway.
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Well, that was a fast setup dyno run, we had no fans installed, so the engine ran at about 100 degrees water temp, also I had the inserts in the exhaust tips, that alone makes a difference of 30hp.
Don't forget that hp is a calculated value, more important is the torque curve, the LP400 runs for sure very well, but I didn't find any so far being at least as fast as my QV...

Also don't forget that dynos show nice values when you set the correction parameters to your advantage... the 397hp is the measured value without any correction related to air temperture, altitude, air pressure etc. of course I was a little disappointed but I already felt that the exhaust tips costed a lot of power at high revs. Compared with another QV at the meeting with an Ansa my car was faster 3000-5000rpm but then felt back above 5000, this is now gone with the open tips, it is like day and night... I didn't expect such a huge difference.

Pictures of that run: http://www.countach.ch/Sauerland.html

 

Now we had the inevitable top speed discussion... some arguments were intelligent, some were less intelligent.

My understanding is that a well tuned LP400 is a very fast car - as Vaholtorf stated. I had the unforgettable pleasure of a test drive of LP400 #1120038 through the Alps and at least THIS car must not fear an average QV. It was the AMS test car in 1975 (see below) and still today it is very well tuned and very fast.

A well tuned DD is a very fast car, too - see for example the statement by Vaholtorf.

The incorruptible German test magazine "Auto Motor und Sport" (AMS) measured a QV in the year 1985 at a top speed of 298 kph. In 1975, they stopped LP400 #1120038 at a top speed of 288 kph. And some years before, a Daytona and a Ghibli both reached 274.5 kph, the Daytona probably being an average car while the Ghibli must have been a factory hot rod.

Extremely well sorted DD's and LP400 (and Daytonas) should be able to exceed these top speeds. Average cars probably will be slower. My conclusions are

- that the best QV cars will be faster than 300 kph, that is for sure
- that the best LP400 possibly will come close to that figure or even exceed it (see the Italian car #1120062 - I am not sure whether we can trust in that figure, but it is said to have reached 299 kph - or Vaholtorf's car)
- that the LP400 is aerodynamically clearly superior to the QV and must not fear the QV/DD in the straight lane - a good LP400 has a higher top speed than an average DD...

... but is this really important today? I fear that this is not the case.

This is my first, and hopefully my last statement regarding this issue.

 

I forgot to mention that I meant acceleration rather than top speed, top speed is clearly related to aerodynamical drag which is extremely worse on the S-type Countachs compared with the LP400.

 

lol

not quite, but point taken. Even with the factory figures it would be 80bhp difference.
I know how different these cars can be depending on set up. Furhter that the set up can 'go off' quite quickly.
I Am not sure that weight does not matter to top speed as in the real world there is a finite amount of time to how long one can continue accelerating, eg length of road and consequently weight would practically limit top speed
I am obliged to the poster for explaining the differences between the LP400 in weight terms and didnt know this information.
I remeber Mike PUllen of Carrera sport writing or commentating about the 5000s still being smaller and lighter than the QV. When did the body changes implement?

Paul

 

yes,
it was tested 10 years ago with modern day equipment (quattrotuote equipment for sister ruoteclassiche magazine)
on a stock exhaust made 299 km/h, beating both BB and a bora, and being 5.0 sec in 0-100 Km/h

0-100 in 5 sec is also a believable result for a good car imo


i ABSOLUTELY agree with the statement that countach performances are VERY different one from each other, depending on conditions and good tuning

my mecanic recently rebuilt an LP400 engine and got a 360 around hp on the dyno...the datas were posted here time ago (360 At first try and on stock box muffler)
ok, he is good tuning them, but the car is 99% stock, so or he is a magician or the 400 engine has good potential

i would say a good 4000 engine is around 340 hp, with the best tuned and sport muffler ones over the 375 claimed hp and the poorly tuned engines well under 300 hp

with almost 100 hp of difference btw a good and a bad one (and everything in btw!) it is not hard to understand while some clocked hi top speeds while other cars failed to reach good results

about QV DD: my friend Alex's car, now perfectly tuned for the ANSA sport, is a real beast! QV has a lot of torque also
his car is not much slower than a diablo and i do not doubt for a second it is well over 400hp ...i would say the 455 are all there

 

Paul,

i think Mike Pullen's talked about his serie uno LP400S, that is indeed closer to an LP400 than it is to a QV

the body changed year 1981 with the 400S serie 3 cars

 

ps

like one of the previous posters am enjoying these comments and the debate and sincerly hope no one takes offence at anything i have suggested

Paul
x

 

We can ask the owner at Padova, he is exhibiting in Padiglione 5 if I remember correctly.

 

Thanks Emilio
you are right it was his car and I thought it was a 5000

I have recently driven my QV back to back with a diablo SV, VT roadster and a ciouple of Ferraris over some lovley roads. The SV was faster with more torque low down but i didnt think there was more than 5-10% in it. The other drivers felt the same as we were jumping form one car to the other during the run.

it is great that we have people on here who seem to enjoy thier cars and exploit them!

Paul
x

 

There is some great and informative info on this thread in the past few days. While I cannot offer first hand information I can offer some opinions based on my extensive background in aerodynamics and vehicle dynamics:

1. Aerodynamically the LP400 is a huge advantage over all of the other variants of the Countach. Its frontal area and narrower tires make a really big difference over the later cars in terms of aerodynamic drag. Remember that drag increases cubicly with velocity so it is not a linear rate. This is why the HP advantages of the DD is quickly eaten up over 120mph.

2. The tires also account for a big difference. I do not have exact wheel weights but the larger wheels and tires on the LP400s and newer cars have two huge disadvantages to acceleration and straight line speed. One is their weight. It takes power to turn heavy wheels and race car engineers generally place a 10-1 premium on rotating unsprung mass to spring mass. In other words save 1 pound on a wheel or brake disc and it is the same as saving 10 pounds on the body of the car. For sure the bigger wheels eat up a lot of performance from the engine when travelling in a straight line. Cornering is another topic all together.

Secondly, the rolling resistance and frontal area of the larger tires are big barriers to overcome when trying to go fast. Take a look at top speed run cars that race on the salt flats, they all have narrow tires. Going straight requires very little lateral grip so the wide tires of the later cars become a crutch at speed.

I consider these two main points to be the biggest obstacle to speed over engine power. Wide tires and increased aero drag can easily consume 150+ HP advantages of later cars. as such power is not everything and it is no surprise that the LP400 in the hands of a driver with the stones to go for it is the fastest of the Countaches.

 

good points

also would be worth to add LP400 and LP400S cars had magnesium wheels VS alluminum of later OZs (5000S, QV, anni)

the 400, 400S and 5000S have 205 front tyres while the QV-anni have the 225,
so again more weight and drag for the newer cars