RE: McLaren P1 Nurburgring lap time

[boxerTen]

turbobungle said:

If each of these cars saved the weight of their hybrid systems, they would weigh less giving better cornering and braking as well as being easier on tyres and every other component of the car meaning they could lap for longer and they would no doubt have a better power-to-weight ratio making them quicker as well. The only downside being that they wouldn't now get a good score on the emissions test. To me (and I would imagine most other petrolheads) that would make them better cars.

Edited by turbobungle on Wednesday 23 October 12:38

Or alternatively, lets keep the weight the same, turf out a half-ton of hybrid tech and replace it with ... more engine! At a guess you get 30-odd litres, two or three dozen cylinders, 3000 bhp ...

These hypercars are exercises in hybrid-tech-porn. When we synthesise fuel straight out of sea water, or even the air, all this politically driven battery/hybrid tech will be quitely forgotten as embarrassing and deviant.

[markcoznottz]

Peloton25 said:

garypotter said:

Yes BMW supplied the engine in the infamous Mac F1, 6.1cc V12 N/a, 618bhp and 586 lb torque, very imrpessive figures considering the age it was built and designed.

It was 627bhp and 479 lb-ft of torque.

[quote]I also heard rumours that some of the engines in the GTR were pushing a few more ponies that the official figures.

The GTRs engines produced less horsepower than the road cars as they were all choked by air restrictors to balance the competition. The revisions made elsewhere in the engines did allow them more torque (527 lb-ft) at about 1,000 RPM lower in the rev band. In 1997 with the longtail versions BMW Motorsport had to reduced the displacement of the V12 engine slightly to 5,990cc, or just under the 6.0L barrier, to avoid even more restriction than with the original displacement. This reduced the torque figure slightly to 506 lb-ft.

turbobungle said:

All three would be much better cars without the Hybrid tech.

In the case of the P1 you're wrong - it's hybrid boost is used to provide immediate torque at low RPMs and eliminate any effects of turbo lag. Taking advantage of that low end boost allows them to fit larger turbos which create more high RPM power. To say the car would be better without is rather ignorant. McLaren have been adamant that it would not be and you can be sure in this competitive space they have done all the simulations before settling on the use of a hybrid powerplant.

>8^)
ER

Are the turbo units variable turbine geometry? or some other design. Any idea who manufactures them?.

[anonymous-user]

Peloton25 said:

Have not had the pleasure of a drive or ride in the P1 yet so that will limit some of my comments. There were a couple of great posts on McLarenLife by a future owner who spent time questioning the engineers at the factory. His information offered a detailed description of how it all works but I don't have time to find them at the moment and don't want to paraphrase too much based only on my recollection.

McLaren shared that in a full lap of the Ring the car uses the capacity of the battery twice based on cumulative discharge and recharge rates. The electric motor built inside the P1s engine block is constantly available to recharge the battery pack during part-throttle or off-throttle situations utilizing excess torque from the engine. IIRC the car can also recharge its battery pack at idle in a 10 minute period. It seems there could be some rare situations where you might be able to deplete the battery completely leaving you with only the 727 hp offered by the petrol engine, but in theory that would seem to be quite tough. There are not many places in the world that afford more than 100 seconds of running at max throttle - covering ground at over 200 mph gets you anywhere in a hurry.

Weight of the battery pack is the only figure McLaren have published so far. They list it as 96kg (or 212 lbs), including with that figure that it has the greatest power density of any battery pack on the road today. There would be some additional weight for the electric motor as well as the cabling to the battery pack but given the close positioning of McLaren's hybrid system components that would be fairly limited.

I'll try to add some more details that were shared when I locate the posts that included it.

>8^)
ER

The EMachine isn't "in" the engine block, it's bolted to it, via a 2:1 reduction to the crank. A dual system of clutches allows various modes, and the Emachine to start the ICE. The Emachine itself, with it's inverter weighs well under 50kg (i'm not going to tell you the exact figure, sorry). During braking, KE is recovered from the cars mass and put back into the battery. This gives the systems a really hard time on track because it is either sucking high amounts of power from, or blowing high amounts of power into, the battery system. The Emachine is also used for gearshift engine synchronization, helping to speed up or slow down the ICE during rapid gearshifts (effectively acting to cancel engine inertia). There is a fully Electric only mode and a couple of blended modes, all of which vary with HV battery SOC. Once the driver has made his mode choice (via the dash selector) the amount of electrical torque is automatically blended with the torque produced by the ICE, including having the ICE make excess torque and absorb that with the Emachine to charge the battery system.

As will become clear once more people drive the car, the hybrid bits are KEY to how the car performs!

[Peloton25]

Max_Torque said:

The EMachine isn't "in" the engine block, it's bolted to it, via a 2:1 reduction to the crank.

Thanks for that clarification - I had seen it implied that it was built within the block and thought that could be a bad mixture.

The rest of the details are welcomed as well and will save me time for sure. I agree that those who are trying to sell the idea that any of these cars would be much better without the hybrid portion of drivetrains have some learning to do. Yes, less weight is always a good thing, but these cars are game changers. I hope to eventually get my chance for the experience in at least one of them.

>8^)
ER

[wc98]

xRIEx said:

And Ducati was getting 197(.3) out of 989cc 3 years before the SRR.

not from any road legal bike on a dyno .

[Peloton25]

Max Torque - can you also explain the purpose of the 'IPAS' button on the steering wheel - when the driver would use it, what it does and why it would be different than simply flooring the accelerator pedal?

I vaguely recall reading it is for use in situations where you might not be in the proper performance mode but wish to have the full power that can be provided by the EMachine in addition to that of the ICE.

>8^)
ER

[stevesingo]

Peloton25 said:

It was 627bhp and 479 lb-ft of torque.


>8^)
ER

Was it not 627ps, not bhp. Or 461kW=618bhp DIN

[Peloton25]

stevesingo said:

Was it not 627ps, not bhp. Or 461kW=618bhp DIN

If it is, then McLaren need to reprint "Driving Ambition".

I've seen the references online to the figures you quote and it seems to have been made "fact" by wikipedia as well, but McLaren have always quoted 627bhp. Other sources list 636 PS (468 kW / 627 hp).

The spec page from the original AutoCar test of the F1 back in 1994 also shows 627bhp:

http://imageshack.us/photo/my-images/217/f10i.jpg/

EDIT: Another set of facts that seem to make the actual power level quite clear relate all the way back to Gordon's original request to Paul Rosche of BMW Motorsport for an engine that weighed 250kg and produced 550hp. In the end the S70/2 V12 came in at 266kg for a 6.4% weight penalty, but this was offset by a 14% improvement in power. Math says 14% of 550 is 77 - 550+77 = 627.

>8^)
ER

Edited by Peloton25 on Thursday 24th October 02:00

[AER]

Max_Torque said:

The Emachine itself, with it's inverter weighs well under 50kg (i'm not going to tell you the exact figure, sorry)...

It's 42kg. It must be so, since the P1 is the answer to the very question of the meaning of life...

[goodhand]

British Beef said:

"Calibration and final tuning" to deliver the official lap time.... I would love to know what this comprises of!!!

Im sure all the manufacturers do it, but with turbo engines turning the boost up and changing the engine mapping for a "qualifying lap" must be relatively easy to do.

I'm sure I read somewhere earlier in the week, that the first customer car has just been delivered too.

[lesz42]

any of these 3 cars will be nice to have, and tbh, if you could afford them, am sure an ultima gtr would be in the garage too! as for Hybrid, its fine i think, anyone saying its a back would step, you probably said that about, EI, seat belts and windscreen wipers

[stevesingo]

[quote=Peloton25]

If it is, then McLaren need to reprint "Driving Ambition".

I've seen the references online to the figures you quote and it seems to have been made "fact" by wikipedia as well, but McLaren have always quoted 627bhp. Other sources list 636 PS (468 kW / 627 hp).

The spec page from the original AutoCar test of the F1 back in 1994 also shows 627bhp:

http://imageshack.us/photo/my-images/217/f10i.jpg/

EDIT: Another set of facts that seem to make the actual power level quite clear relate all the way back to Gordon's original request to Paul Rosche of BMW Motorsport for an engine that weighed 250kg and produced 550hp. In the end the S70/2 V12 came in at 266kg for a 6.4% weight penalty, but this was offset by a 14% improvement in power. Math says 14% of 550 is 77 - 550+77 = 627.

>8^)
ER

[quote]

Just goes to show how wrong this internet thing is. I'm not using it again, just too embarrassing

[M400 NBL]

turbobungle said:

You're funny.

And assuming you have the car your 'name' suggests, you should know all about the benefits of light weight.

I haven't got a Noble unfortunately. Just the plate on retention until we've bought our final home!

I'm pretty sure that McLaren know what they are doing, and power/weight isn't the only factor when designing a car that goes quick in a straight line and around bends.

[herebebeasties]

boxerTen said:

These hypercars are exercises in hybrid-tech-porn. When we synthesise fuel straight out of sea water, or even the air, all this politically driven battery/hybrid tech will be quitely forgotten as embarrassing and deviant.

You didn't pay much attention in Chemistry at school, did you?
Electric cars are clearly going to be the way at some point, especially if we ever crack how to make fusion work/economical.

[AreOut]

at some point yeah, at this point they are just a waste of energy

[British Beef]

k-ink said:

British Beef said:

Lets say the P1 achieved 6:40ish on road tyres...

Could the P1 challenge Bellof's 6:11 if the P1 was on racing slicks????

P1 vs 956, P1 has more power but more weight, however over 2 decades more of chasis and aero developmnent.

(I think the circuit has changed in a couple of places and degraded in quite a few more, so this would need to be factored)

I am not convinced two decades makes any difference when you compare a compromised road car against a zero compromise race car. Just look at the aero on those Porsche racers. Their shape is about as simple and aerodynamic as you can get, no matter what stylists may tell you. The downforce is staggering...

Good answer, and I suspect you are quite correct!!

[Gary C]

boxerTen said:

The Vambo said:

boxerTen said:

its one thing to spin a 4-cylinder crank at 9k rpm, quite another when its a longer V12 crank with twice as many cylinders per unit length.

You can almost imagine the Ferrari engineers dreaming of the day that they are allowed to use the that naturally unbalanced inline four configuration rather than the v12 that they are forced to use.

Unbalanced engines aren't a big problem. Performance and racing V8s will typically go for the poorer balance of a flat-plane crank rather than the better balanced cross-plane one for example. Racing engines also routinely have removed or lightened crankshaft counterweights to get weight down at the expense of balance.

Resonances OTOH are a big problem. The resonant frequency of a long V12 crankshaft heavy enough to handle 800 bhp, is going to occur at a lot lower frequency than an inline four handling 'only' 240bhp.

Ferrari is however comprehensively eclipsed by BMW - for a state of the art 4-cylinder engine see the S1000RR motorbike. 1 litre. 193bhp. No typo there .

Edited by boxerTen on Tuesday 22 October 23:50

I believe the 917's engine actually had the drive taken of mid-way down the crank. Allowed it to run almost as two flat 6's. Helping reduce torque induced twisting of the crank down its length reducing resonant vibrations ?

[RobM77]

Is it possible that McLaren are just waiting to see what 'LaFerrari' does before they release a lap time? Perhaps they'll only tell us what the lap time is if they're quicker

[anonymous-user]

I thought this would've been posted here, but I don't think it has.

http://jalopnik.com/did-the-mclaren-p1-get-beaten-...

The salient point is:

McLaren are not releasing the time.

Jalopnik said:

Jalopnik reached out to McLaren and they gave us the same kind of clarification they gave to EVO: McLaren is not releasing a 'Ring time, 'Ring times are pointless, and 'Ring times encourage dangerous behavior. But first McLaren claimed that no one need worry about a lack of speed.

McLaren statement said:

We reckon the Green Hell is one of the most challenging tests in the world of the all-round performance of any supercar. So one of the P1’s engineering targets was to reach a sub-seven time during testing. As you’ll have read, we have achieved that target. Comfortably. But we have no plans to give a time. We didn’t for 12C. We don’t intend to for P1 either.

Whether that's the real reason is another matter. There's more explanation in that article and I think I believe it.

[Cyrus1971]

I have often wondered what the Lap time for the ring was when it lasted hosted Formula 1. I.E. what kind of times did the likes of Lauder and Prost get back then. Curious to know if the P1 and it's hyper car stablemates from Ferrari and Porsche have actually eclipsed the F1 race cars of that era ?

Judging from this Wikipedia page . . .

http://en.wikipedia.org/wiki/List_of_Nordschleife_...

. . . the track has changed a bit over the years so it's hard for me to tell. However from the looks of it I think under 6m 30sec will do the trick. Amazing to think one can buy a road car today with the performance of a 1980's F1 car !