Flemke - Is this your McLaren? (Vol 5)

Flemke - Is this your McLaren? (Vol 5)

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Discussion

flemke

22,864 posts

236 months

Wednesday 26th November 2014
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thegreenhell said:
slinky said:
flemke said:
Gearing on F1 is pretty long. I think Vmax in 1st is 65, in 2nd is 90 or 95. It pulls well in 5th.
That's not quite right. The F1 gearbox has an extra bevel gear that converts the longitudinal crank rotation to transverse for the gear shafts, and it isn't 1:1 ratio. This means there is an extra step down factor to apply, which I believe works out as 1.24. This gives the actual speeds in gears @ 7500 rpm as:

1. 66 mph
2. 98 mph
3. 125 mph
4. 154 mph
5. 185 mph
6. 231 mph

For the max speed run at Ehra, Mclaren removed the rev limiter for top gear to allow it to run to approx 7800 rpm.
For Ehra, my reading of the video is that in 6th the engine was getting close to but did not quite reach 8,000 rpm before the aero resistance became insuperable. In the lower gears,I believe that Andy was voluntarily observing an 8,000 rev limit.

I thought that the issue with the Palmer's 231 run at Nardo was that the tyre scrub was taking several mph off the car's accessible Vmax.

The road cars are artificially limited to 7,500. When I did my own "Vmax" run, I kept hitting the limited are 221 mph. This was on half-used tyres. Add on 1% for fresh tyres and you're at 223-224.
Doing the arithmetic, 8,000 is to 240 as 7,500 is to 225, knock off 1% for 3mm of tyre wear so you're down to 223, which implies that on the Ehra run the engine topped out at a bit over 7,900 rpm.

slinky

15,704 posts

248 months

Wednesday 26th November 2014
quotequote all
Yup, I had to spin the redline out to 7900 on my calcs to make it hit 242.17 @ redline in 6th..

Gear Theoretical Vmax/Gear L'RPM Rev Drop
1st 69.73
2nd 102.84 5356 2544
3rd 131.70 6168 1732
4th 162.03 6422 1478
5th 194.15 6593 1307
6th 242.17 6334 1566


thegreenhell

15,115 posts

218 months

Wednesday 26th November 2014
quotequote all
It seems to be difficult to find a definitive answer to this. Although the quoted gear ratios always seem to be the same, I have found two recurring but different sets of data for mph/1000rpm in each gear:

Dataset 1
Gear mph/1000rpm mph @ 7500rpm rpm @ 242mph
1 8.7 65
2 12.7 95
3 16.7 125
4 20 150
5 24 180
6 30 225 8072


Dataset 2
Gear mph/1000rpm mph @ 7500rpm rpm @ 242mph
1 8.2 61
2 12.1 91
3 15.5 116
4 19.1 143
5 23.2 174
6 29.4 221 8237


The worrying thing is that neither of these datasets is 100% consistent with the quoted gear ratios for the car, ie the unknown step down ratio calculates differently for each gear using these numbers.

I have also read an unverified quote attributed to Gordon Murray that the F1 is gearing limited to 221mph, which points more towards the second dataset, but then the revs seems too high for the 242 mph vmax run.

E65Ross

34,947 posts

211 months

Wednesday 26th November 2014
quotequote all
I'd always thought it was limited to 231 by the rpm limiter....?

flemke

22,864 posts

236 months

Wednesday 26th November 2014
quotequote all
E65Ross said:
I'd always thought it was limited to 231 by the rpm limiter....?
It's limited by the rev-limiter to 223-224, assuming new (standard Michelin) tyres. (With the tyres that I have put on my car since I did my run in 2003, the rev-limited Vmax should be about 2 mph more.)

flemke

22,864 posts

236 months

Wednesday 26th November 2014
quotequote all
thegreenhell said:
I have also read an unverified quote attributed to Gordon Murray that the F1 is gearing limited to 221mph, which points more towards the second dataset, but then the revs seems too high for the 242 mph vmax run.
I don't know what Gordon did or did not say, but on well-used tyres I did a number of runs, north and south, up and down gradient, and every one came out at 221, so I am confident that that number was correct unless there was a systematic inaccuracy within the GPS unit. The tyres I was using had roughly 3mm less tread depth than when new.
Also, we have the video evidence of the engine rpms during Andy Wallace's Ehra Leissien run, accompanied by both the McLaren GPS and the facility radar readings. All those things triangulate to a standard car's rev-limited Vmax of approx 224.

E65Ross

34,947 posts

211 months

Wednesday 26th November 2014
quotequote all
flemke said:
I don't know what Gordon did or did not say, but on well-used tyres I did a number of runs, north and south, up and down gradient, and every one came out at 221, so I am confident that that number was correct unless there was a systematic inaccuracy within the GPS unit. The tyres I was using had roughly 3mm less tread depth than when new.
Also, we have the video evidence of the engine rpms during Andy Wallace's Ehra Leissien run, accompanied by both the McLaren GPS and the facility radar readings. All those things triangulate to a standard car's rev-limited Vmax of approx 224.
I bet that was a bit, erm, hairy!

So when you hit 221, was it still pulling reasonably strong and just ran into the rpm limiter (to suggest it'd hit 240) or did it just run out of puff?

flemke

22,864 posts

236 months

Wednesday 26th November 2014
quotequote all
E65Ross said:
flemke said:
I don't know what Gordon did or did not say, but on well-used tyres I did a number of runs, north and south, up and down gradient, and every one came out at 221, so I am confident that that number was correct unless there was a systematic inaccuracy within the GPS unit. The tyres I was using had roughly 3mm less tread depth than when new.
Also, we have the video evidence of the engine rpms during Andy Wallace's Ehra Leissien run, accompanied by both the McLaren GPS and the facility radar readings. All those things triangulate to a standard car's rev-limited Vmax of approx 224.
I bet that was a bit, erm, hairy!

So when you hit 221, was it still pulling reasonably strong and just ran into the rpm limiter (to suggest it'd hit 240) or did it just run out of puff?
It was def still pulling, and instinctively one pressed the throttle harder in the hope that a bit more pressure would eke out another couple of mph. Unfortunately, 7,500 meant 7,500, and it didn't matter how hard I pressed.

E65Ross

34,947 posts

211 months

Wednesday 26th November 2014
quotequote all
Thanks Flemke.

You rate the F1 as your favourite (or right up there!) ever drivers car as an experience etc.... What's your next favourite?

Nezquick

1,453 posts

125 months

Wednesday 26th November 2014
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Chicane-UK said:
I think I read something a few pages back about how a P1 had been painted in a TVR style flip paint, and how it was deemed a 'poor choice' by flemke. At the time I read that and saw the small picture and disagreed... I thought it looked great. Until, that is, these pictures emerged on another forum. I guess the wheels don't help matters but... wow... it really makes the car look *completely* wrong in my humble opinion!

http://imgur.com/a/c9DW3

Edited by Chicane-UK on Wednesday 26th November 09:17
That doesn't look good at all.

flemke

22,864 posts

236 months

Wednesday 26th November 2014
quotequote all
E65Ross said:
Thanks Flemke.

You rate the F1 as your favourite (or right up there!) ever drivers car as an experience etc.... What's your next favourite?
Probably either NSX or LCC Rocket.

ETA: Almost forgot, SLS Black Series is right up there.

Edited by flemke on Wednesday 26th November 22:44

LaurasOtherHalf

21,429 posts

195 months

Wednesday 26th November 2014
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Ouch



andyps

7,817 posts

281 months

Wednesday 26th November 2014
quotequote all
LaurasOtherHalf said:
Ouch
That hit the barrier very hard - seems to have harmed the barrier even more than the car.

Hope the occupants are OK.

Orchardab

440 posts

125 months

Wednesday 26th November 2014
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Will it buff out?

Orchardab

440 posts

125 months

Wednesday 26th November 2014
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Will it buff out?

mclwanB

600 posts

244 months

Wednesday 26th November 2014
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Better to have left the traction control on?

Seriously, hope the occupants aren't too badly hurt

greygoose

8,225 posts

194 months

Thursday 27th November 2014
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That is certainly pretty trashed, wonder if they would be able to repair it?

AlmostUseful

3,276 posts

199 months

Thursday 27th November 2014
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You'd inagine that with a retail price of about £1m it'd be in the insurers interest to rebuild it rather than buy a new one!

E65Ross

34,947 posts

211 months

Thursday 27th November 2014
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Of course it will be rebuilt!

stevesingo

4,848 posts

221 months

Thursday 27th November 2014
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It amazes me that someone with the obvious intelligece to earn enough money to be able to purchase such thing can lack the self control to drive it on the public road without putting themselves and potentially others at risk.