Flemke - Is this your McLaren? (Vol 5)

Flemke - Is this your McLaren? (Vol 5)

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chris333

1,034 posts

238 months

Monday 25th August 2014
quotequote all
as ever, thanks for the detailed and complete answer!

flemke said:
chris333 said:
flemke said:
(One should ignore the Autocar "official" 0-200 time, which is about 25% slower than what the car will actually do.)
Why was the Autocar time so slow?
You'd have to ask them what happened - I have no idea.

Background is that a friend (who is more enamoured of straight-line speed than anyone I know) got a Veyron, began using it on the roads, as one will do, and said that he was sure that, in the mid-100s and higher, the Veyron accelerated less quickly than an F1 would do. He then did a side-to-side test ( whistle ) which demonstrated that indeed in the upper half of the speed range the F1 was the faster car.

This induced me to look more carefully at the "official" Autocar numbers from back in 1994.

According to Autocar, the F1's times were:

0-100: 6.3 seconds
0-150: 12.8
0-200: 28.0

The 0-100 makes sense, if you will. I don't know about the 0-150, but the 0-200 time seems a lot.

The Veyron's 0-60 was 2-something. The 0-100 was 5.5, which fits with the F1's 6.3, in that the Veyron's greatly superior 4WD traction under power is going to make itself felt in 0-100 as well as in 0-60.

So far the numbers add up.

I can't readily put my fingers on a 0-150 time for normal Veyron, but the recorded time for Veyron Super Sport is 10.2. Relative to that, Autocar's time for F1 of 12.8 could be right or wrong, but let's give them the benefit of the doubt.

Now, the same Veyron Super Sport appears to have a 0-200 time of 22.2 ( http://fastestlaps.com/cars/bugatti_veyron_164_sup... ), so time from 150-200 is 12.0 seconds.

According to Autocar "official" test, it takes the F1 15.2 seconds to go from 150-200 (they did not take that specific measurement, but I just subtract 0-150 time from 0-200 time).

However, let us not be misled by whatever that magazine claims to have measured 20 years ago. Let us instead GO TO THE TAPE.

https://www.youtube.com/watch?v=wYmIfDAQ9Y0

It is clear here that Andy Wallace is still in the 240s at 18 seconds (he's not really accelerating until the banking starts to flatten), and he hits 322 at 30 seconds. Elapsed time from one to the other: 12 seconds. That is the same elapsed time as the Bugatti Super Sport, which you will know is faster than the normal Veyron. Ergo, my friend, and his side-by-side test, were correct.

If we take Autocar's measured 0-150 time for F1 of "12.8" as correct (although, given the substantial error in their 0-200 time, that time may also be too long), and add the 12 seconds which, as we can see with our own eyes, is the F1's 150-200 time, that gets us to 24.8 seconds, not "28" seconds.

In the past, I have scrutinised the entire Andy Wallace Ehra-Lessien tape on VHS. There is another section in it where he accelerates from low 120s to Vmax. Using that bit, which TBH I cannot be bothered to find ATM, I estimated that the F1's actual 0-200 time was about 22 seconds.

How Autocar got their numbers, I could not say, but clearly they are not entirely accurate.

Cheers.

ETA:

I now see ( http://fastestlaps.com/cars/bugatti_eb_164_veyron.... ) that normal Veyron's times are:

0-100: 5.1 (not sure how it could be faster than Super Sport, but whatever)
0-150: 11.3
0-200: 24.3

which confirm that, from 100 upwards, the F1 is the faster car.



Edited by flemke on Monday 25th August 14:20

zhead

1,180 posts

200 months

Monday 25th August 2014
quotequote all
flemke said:
zhead said:
Just been reading more about the F1 (must admit, was a little confused by the differing types offered) and read this section on Wikipedia:

Wikipedia says said:
The normal McLaren F1 features no wings to produce downforce (compare the LM and GTR editions); however, the overall design of the underbody of the McLaren F1 in addition to a rear diffuser exploits ground effect to improve downforce which is increased through the use of two electric Kevlar fans to further decrease the pressure under the car.[21] A "high downforce mode" can be turned on and off by the driver.[21] At the top of the vehicle, there is an air intake to direct high pressure air to the engine with a low pressure exit point at the top of the very rear.[21] Under each door is a small air intake to provide cooling for the oil tank and some of the electronics.[21] The airflow created by the electric fans not only increase downforce, but the airflow that is created is further exploited through design, by being directed through the engine bay to provide additional cooling for the engine and the ECU.[21] At the front, there are ducts assisted by a Kevlar electric suction fan for cooling of the front brakes.
I had no idea that the F1 effectively ran a ground effect system - I'd never heard of it before. Knowing the approach to design and focus on everything playing it's part I'm sure it contributes but Flemke, is it noticeable when you turn these fans on?

And a boring question - where are the switches to turn these fans on and off?
A couple of separate things going on here.

At the front, there are electric motors inside the brake cooling ducts. They actuate when the brakes are applied at 60 mph or more (at least, that is what the factory told me when I asked last year, although they had to do some digging to ascertain what the actuating protocol was, so the number may be wrong).

At the rear there is an active flap, which is deployed automatically when the brakes are applied above IIRC 40 mph.
When the flap is up, apertures directly underneath it then are open and they allow air to escape from underneath the car. On its way from underneath to above, the flow of air is designed to go past the brakes to supply some cooling.
I am not aware that there are electric fans that accelerate this rear air flow.

In addition to the automatic deployment of the rear flap, it can be raised manually, either "fully" (which just means as far as it will go; the whole thing does not rise; the rear edge rises by rotating off the front, which does not rise) or halfway.

The flap can be manually operated by rotating the upper of the three knobs located behind the steering wheel and to the left of the instrument binnacle. This is the best image I could find:



In this image, one can just make out the top knob, which has an icon with the car silhouette on it. When they put a high-downforce kit on a car, they blank out that portion of the controls, as the HDK has a fixed wing and no flap.

Thanks for the overview, given the specifics - it doesn't sound like there would be any discernible difference here but without the ability to disconnect I'll guess it's not possible to measure. Intriguing that the F1 was using variable aero in any way though, I wasn't aware of that at all.

Given your comments on high speed stability, do you activate the rear flap manually when driving fast or does that unbalance the front more at the gain of rear downforce?

F1GTRUeno

6,335 posts

217 months

Monday 25th August 2014
quotequote all
Just watching the top speed run for about the billionth time.

It does seem to move about a fair bit at the higher echelons, must be such an 'on the edge' feeling when it's doing such a thing.

Also forever thought that 391km/h was 240.1mph but it's not is it? 242.956 according to Google. Must've absolutely blown their minds when they realised just how quick that was back then.

flemke

22,864 posts

236 months

Monday 25th August 2014
quotequote all
zhead said:
flemke said:
zhead said:
Just been reading more about the F1 (must admit, was a little confused by the differing types offered) and read this section on Wikipedia:

Wikipedia says said:
The normal McLaren F1 features no wings to produce downforce (compare the LM and GTR editions); however, the overall design of the underbody of the McLaren F1 in addition to a rear diffuser exploits ground effect to improve downforce which is increased through the use of two electric Kevlar fans to further decrease the pressure under the car.[21] A "high downforce mode" can be turned on and off by the driver.[21] At the top of the vehicle, there is an air intake to direct high pressure air to the engine with a low pressure exit point at the top of the very rear.[21] Under each door is a small air intake to provide cooling for the oil tank and some of the electronics.[21] The airflow created by the electric fans not only increase downforce, but the airflow that is created is further exploited through design, by being directed through the engine bay to provide additional cooling for the engine and the ECU.[21] At the front, there are ducts assisted by a Kevlar electric suction fan for cooling of the front brakes.
I had no idea that the F1 effectively ran a ground effect system - I'd never heard of it before. Knowing the approach to design and focus on everything playing it's part I'm sure it contributes but Flemke, is it noticeable when you turn these fans on?

And a boring question - where are the switches to turn these fans on and off?
A couple of separate things going on here.

At the front, there are electric motors inside the brake cooling ducts. They actuate when the brakes are applied at 60 mph or more (at least, that is what the factory told me when I asked last year, although they had to do some digging to ascertain what the actuating protocol was, so the number may be wrong).

At the rear there is an active flap, which is deployed automatically when the brakes are applied above IIRC 40 mph.
When the flap is up, apertures directly underneath it then are open and they allow air to escape from underneath the car. On its way from underneath to above, the flow of air is designed to go past the brakes to supply some cooling.
I am not aware that there are electric fans that accelerate this rear air flow.

In addition to the automatic deployment of the rear flap, it can be raised manually, either "fully" (which just means as far as it will go; the whole thing does not rise; the rear edge rises by rotating off the front, which does not rise) or halfway.

The flap can be manually operated by rotating the upper of the three knobs located behind the steering wheel and to the left of the instrument binnacle. This is the best image I could find:



In this image, one can just make out the top knob, which has an icon with the car silhouette on it. When they put a high-downforce kit on a car, they blank out that portion of the controls, as the HDK has a fixed wing and no flap.

Thanks for the overview, given the specifics - it doesn't sound like there would be any discernible difference here but without the ability to disconnect I'll guess it's not possible to measure. Intriguing that the F1 was using variable aero in any way though, I wasn't aware of that at all.

Given your comments on high speed stability, do you activate the rear flap manually when driving fast or does that unbalance the front more at the gain of rear downforce?
Apart from when braking, the flap doesn't have a meaningful benefit until you're going well north of 100. One is not often doing those speeds outside of Germany.

Even in Germany, the reality of the Autobahn is that opportunities to put one's foot down for anything except brief bursts are not frequent. Unlike in the good old days, traffic conditions and roadworks are regular obstacles to "derestricted" motoring.




flemke

22,864 posts

236 months

Monday 25th August 2014
quotequote all
F1GTRUeno said:
Just watching the top speed run for about the billionth time.

It does seem to move about a fair bit at the higher echelons, must be such an 'on the edge' feeling when it's doing such a thing.

Also forever thought that 391km/h was 240.1mph but it's not is it? 242.956 according to Google. Must've absolutely blown their minds when they realised just how quick that was back then.
Yes, and my choice of venue for doing my own "Vmax" run was influenced by likelihood of crosswinds. I thought twice when I read that the place that I had chosen was the site of Bernd Rosemeyer's fatal high speed crash in 1938, cause of crash: crosswinds. In the event, the crosswinds weren't bad, although I thought again when, during the initial "moderate" run (which took me to 206 with no effort at all), I came upon one of those yellow signs depicting a leaping stag. eek

There was a disagreement between McLaren (GPS) and VW (radar) as to precise recorded Vmax at Ehra-Lessien. Radar said it was "387", GPS said "391". McLaren decided to adopt the lower number as the official one.




Derek Chevalier

3,942 posts

172 months

Saturday 30th August 2014
quotequote all
Crockefeller said:
It's not like the newest of them are depreciating still, they're actually going up.
I think it is most likely due to there being very few late models available for sale - a large number of them went overseas when the pound was weak a few years back

RenesisEvo

3,602 posts

218 months

Sunday 7th September 2014
quotequote all
I need to get the pictures from the camera out of RAW, but at the Hampton Court Palace Concours of Elegance this weekend, Simon Kidston's Swiss-plated black F1 was in attendance, and it looked fantastic. It was great to have time to look around and take in all the details.

flemke

22,864 posts

236 months

Tuesday 9th September 2014
quotequote all
RenesisEvo said:
I need to get the pictures from the camera out of RAW, but at the Hampton Court Palace Concours of Elegance this weekend, Simon Kidston's Swiss-plated black F1 was in attendance, and it looked fantastic. It was great to have time to look around and take in all the details.
Yes, it is notable how some of the best cars end up being secured by car dealers for themselves. scratchchin

douglas111

60 posts

114 months

Friday 19th September 2014
quotequote all
flemke said:
In reality it makes no odds. My engine supposedly (according to G. Murray) is putting out IRO 660-670 bhp, as opposed to the "627" official figure. As Mika Hakkinen said, if there is one thing the F1 does not need, it is more power.
Hi Flemke,

Just joined. Been ploughing through the thread over previous days. It will take me an awful lot more time to finish. There's one question I can't wait to ask, which Google suggests has not already been asked.

If your engine is outputting 660-670 bhp, does that mean the LM-spec engines, which I believe includes a couple of road cars with HD kit, are outputting significantly more than the quoted 680 bhp, perhaps into 700s? My thinking is that if McLaren won't give you more power without a HD kit, then this suggests the LM modifications will add quite a bit more than just another 10-20 bhp to your own car.

PS A quick thank you for all your time and enthusiasm responding to this forum thread!

flemke

22,864 posts

236 months

Friday 19th September 2014
quotequote all
douglas111 said:
flemke said:
In reality it makes no odds. My engine supposedly (according to G. Murray) is putting out IRO 660-670 bhp, as opposed to the "627" official figure. As Mika Hakkinen said, if there is one thing the F1 does not need, it is more power.
Hi Flemke,

Just joined. Been ploughing through the thread over previous days. It will take me an awful lot more time to finish. There's one question I can't wait to ask, which Google suggests has not already been asked.

If your engine is outputting 660-670 bhp, does that mean the LM-spec engines, which I believe includes a couple of road cars with HD kit, are outputting significantly more than the quoted 680 bhp, perhaps into 700s? My thinking is that if McLaren won't give you more power without a HD kit, then this suggests the LM modifications will add quite a bit more than just another 10-20 bhp to your own car.

PS A quick thank you for all your time and enthusiasm responding to this forum thread!
1) Welcome to PH.

2) Of the 3 factors which according to Gordon contributed to the BHP increase over the official quoted number:

- The official quoted number of "627" was specified in the contract between McLaren and BMW but, insofar as 627 was the minimum required, in actuality the engines as delivered to McLaren always had a bit more than that - which is as one would expect. You would not commit to something if you were going to have to strain to achieve it with some examples. I don't know whether there was a subsequent contract between the firms specifying that the LM engines had to have a minimum of 680 BHP, although I tend to doubt it. If there was no such contract, then perhaps "680" was the kind of BHP number typically published by car makers - a level approximated by the engines that leave the factory, with marginal deviations in both directions.

- I don't know how, when BHP is measured with the use of a dyno, the effects of the silencers and cats are factored into the published number.
The standard F1s had that big Ti silencer drum/rear crash structure at the back. The LMs instead had individual silencers which were louder and more free-flowing. Gordon said that 15-20 BHP is gained by going to the free-flowing silencers, which a number of owners of standard F1s including myself have done.
If the LMs came from the factory with that 15-20 BHP increase already achieved with the lighter silencers, it obviously would not be available to them a second time. Whether that 15-20 is embedded in "680", I could not say.

- Another 15-20 BHP, according to Gordon, was achieved by the time that an F1 engine had been run in for IRO 20,000 miles. I would presume that a similar increase was available in the LM engines. The snag with that improvement, however, is that, to date, none of the 8 LM engines has been driven nearly that far, and it is possible that none ever will be. wink

Cheers.


douglas111

60 posts

114 months

Friday 19th September 2014
quotequote all
Fascinating. Thanks Flemke.

Ali2202

3,815 posts

203 months

Tuesday 23rd September 2014
quotequote all
THE Thread!

thumbup

roystinho

3,767 posts

174 months

Tuesday 23rd September 2014
quotequote all
Yeah been a few weeks without some posts in here, sort it out Flemke it's my favourite read wink

flemke

22,864 posts

236 months

Wednesday 24th September 2014
quotequote all
It's pretty rare for me to have taken any pictures of the car.

The best that I can do is that, whilst the car is currently in for a service, they have mounted the new wheels, of which I took a couple of quick-and-dirty photos the other day. Unfortunately, the image hosting site that I have used, Flickr, has changed how it "works", in the sense that it no longer seems to work, and I cannot post the images on here.

Apart from that, all I can say is that the P1 is apparently about 80% done, and when that is done someone will post here images of it and better images of the F1 with its new wheels.

R_U_LOCAL

2,676 posts

207 months

Wednesday 24th September 2014
quotequote all
This may interest you Flemke.

I was browsing a scale model forum the other day and I came across this thread about a chap building a model of the F1...

http://www.britmodeller.com/forums/index.php?/topi...

On the face of it, not a particularly interesting subject - grown man, plastic kit etc. but have a look at the attention to detail he's putting in to it. And it seems he's using your F1 (in its old colour scheme) as a reference for his model.

roystinho

3,767 posts

174 months

Wednesday 24th September 2014
quotequote all
flemke said:
It's pretty rare for me to have taken any pictures of the car.

The best that I can do is that, whilst the car is currently in for a service, they have mounted the new wheels, of which I took a couple of quick-and-dirty photos the other day. Unfortunately, the image hosting site that I have used, Flickr, has changed how it "works", in the sense that it no longer seems to work, and I cannot post the images on here.

Apart from that, all I can say is that the P1 is apparently about 80% done, and when that is done someone will post here images of it and better images of the F1 with its new wheels.
Happy to bring my iPhone along for some quality pics of the P1 and wheels once they're done, just give me a shout biggrin

ecsrobin

17,023 posts

164 months

Wednesday 24th September 2014
quotequote all
R_U_LOCAL said:
This may interest you Flemke.

I was browsing a scale model forum the other day and I came across this thread about a chap building a model of the F1...

http://www.britmodeller.com/forums/index.php?/topi...

On the face of it, not a particularly interesting subject - grown man, plastic kit etc. but have a look at the attention to detail he's putting in to it. And it seems he's using your F1 (in its old colour scheme) as a reference for his model.
Very impressive!!

Mark-C

5,010 posts

204 months

Wednesday 24th September 2014
quotequote all
ecsrobin said:
R_U_LOCAL said:
This may interest you Flemke.

I was browsing a scale model forum the other day and I came across this thread about a chap building a model of the F1...

http://www.britmodeller.com/forums/index.php?/topi...

On the face of it, not a particularly interesting subject - grown man, plastic kit etc. but have a look at the attention to detail he's putting in to it. And it seems he's using your F1 (in its old colour scheme) as a reference for his model.
Very impressive!!
What incredible attention to detail - amazing!

flemke

22,864 posts

236 months

Wednesday 24th September 2014
quotequote all

Here we are:





Wheel nuts will have normal black "F1" logos in centre.

stevesingo

4,848 posts

221 months

Wednesday 24th September 2014
quotequote all
Change of wheel?

Why, brake cooling/clearance?