P-1 performance (petrol)?

[HORNDAWG]

Has the petrol P-1 come up against a rules wall? It seems as though the petrol P-1's have almost flatlined in performance, even when compared to the P-2's much less the diesel's. Also why is that the spirit (application) of article 19 is different between GT and Prototypes? In GT the performance can be adjusted during the season if needed yet in Prototype's it can only be done after or before the season? Shall we call this the Peugeot variant?

L.P.

[Bob Riebe]

Originally Posted by HORNDAWG

Has the petrol P-1 come up against a rules wall? It seems as though the petrol P-1's have almost flatlined in performance, even when compared to the P-2's much less the diesel's. Also why is that the spirit (application) of article 19 is different between GT and Prototypes? In GT the performance can be adjusted during the season if needed yet in Prototype's it can only be done after or before the season? Shall we call this the Peugeot variant?

L.P.

What is the maximum cr allowed.
What octane gasoline is allowed.

Find that and figure in max. intake orifice allowed, and rough absolute limits can be determined.
Even if revolutions are unlimited, with the intake restrictor, at poiint X due lack of air and fuel the engine more or less goes numb.
As there is a point of no returns due to air and fuel, reach that limit and that is all you get.
Power curve can be adjusted, but while that may get you out of corners quicker, you will still hit a point where the car just starts farting due to the engine being deprived of enough air and fuel mixtuire to operate properly.

Bob

[Bentley03]

Originally Posted by HORNDAWG

Has the petrol P-1 come up against a rules wall?

If you take a look at yesterday's P1 qualy at Spa, you'd think so, wouldn't you, certainly for privateers. But I have little doubt that the privateers will continue to cut tenths off their laptimes and would agree with those who say that a big budget manufacturer P1 effort would eek out at least another couple of seconds.

[JAG]

The Charouz Lola is currently the quicket P1 petrol car, and thats based on a 3 year old P2.

I could envisage the new Lola coupe being 1.5-2 seconds quicker from the chassis alone.

A factory engine should gain another 0.5-1 second, then you'd be in the 2.01 range.

Knock the diesals back a second a lap and things would be pretty equal.

[AU N EGL]

Originally Posted by JAG

Knock the diesals back a second a lap and things would be pretty equal.

or increase the displacment of the petrol engines say 6 liters turbo or 7 liters NA.

[vorsprung]

Originally Posted by AU N EGL

or increase the displacment of the petrol engines say 6 liters turbo or 7 liters NA.

Or decrease P1 minumum weight to 875 or 850 kg. Then heavier diesel engine would present some problems.

[Fogelhund]

I don't think pegging back the Diesels is the answer. I'd prefer that they just let the Petrols perform a bit more. Perhaps drop their weight down to 850-875kg or so.

[ger80]

Yes, same weight for LMP1 and LMP2 (maybe 850kg), only different restrictors. This will avoid having LMP2 cars faster than LMP1.

[JAG]

Originally Posted by Fogelhund

I don't think pegging back the Diesels is the answer. I'd prefer that they just let the Petrols perform a bit more. Perhaps drop their weight down to 850-875kg or so.

So would I but diesels are already lapping below 3.30 during the RACE at Le Mans.

At the very least I expect the ACO to keep cars at their current pace, which considering the development still left in the diesels, likely means a smaller restrictor and possibly more weight for them next season.

If I was Zytek or Creation I'd be worried their new cars appear little quicker than the old ones, and slower than Charouz and Pescaolo on a consistent basis.

Pescaolos cars will undoubtedly get quicker and Lola have a coupe ready to unleash.

[AU N EGL]

or there is the power to wt ratio. and the LMP 1 class has the lowerest ratio.

So smaller or light cars with smaller engines could be on equal terms with larger bigger engines as long as that ratio is equal.

[GTfour]

When we were at the Spa LMS race last Sunday,it allmost looked silly to see them Pug's fly away with such a speedadvantage. To be honest,I just don't take 'm serious as competing racecars in the race anymore,just like the Audi R10's at Le Mans last year.
IMHO it is too obvious that the dieselcars have so much of a poweradvantage. This causes other bigname manufacturers,who don't want to run diesels,to stay out of contention. Which is a cryin' shame.

I agree with AU N EGL that allowing the petrolcars more cc's would be fair.

[brielga]

Originally Posted by JAG

At the very least I expect the ACO to keep cars at their current pace, which considering the development still left in the diesels, likely means a smaller restrictor and possibly more weight for them next season.

No way! No equalization downwards, let the petrols be quicker but do not slow down fast cars!!!!

[ger80]

Originally Posted by brielga

No way! No equalization downwards, let the petrols be quicker but do not slow down fast cars!!!!

Have a look on most of the US tracks. Think the other way is much better from a safety point of view. Maybe reducing the boost of the diesels and using the wastegate air for a device that generates some noise would a good way ?

[jhansen]

It would be nice to have a petrol factory P1 car to compare against. I think the result would surprise a few. But certainly the P2 cars have more potential than most would have imagined.

[chewymonster]

Originally Posted by jhansen

It would be nice to have a petrol factory P1 car to compare against. I think the result would surprise a few. But certainly the P2 cars have more potential than most would have imagined.

truth in the quoted post

[FLGTFAN]

Originally Posted by chewymonster

truth in the quoted post

A factory petrol P1 (heavier) does not necessarily equal the overall performance of a factory petrol P2 (lighter).

[chernaudi]

That fact is highly dependant on the make/model of car(how good the vehicle is), how good the team is, the drivers, and the equipment(tires and the like). The best package is the most likely to win. And Audi and Penske Porsche have the best chances right now. Penske rightfully(seemingly) had Audi's number at Lime Rock. But only circumstances(luck) has kept Audi from winning elsewhere aside from Sebring and St.Pete.

In the ALMS' LMP1 category, Intersport has had to deal with getting their Creation late, and the horrid Kumho tires(which they waived bye-bye to last week), and Autocon is staffed with paydrivers. Audi, Penske, Dyson, and the Acura teams are factory supported, run Michelin tires, have pro(paid) drivers, and equal equipment.

But then again, on the issue on LMP1 vs LMP2 equivalancy(which is why it seems that there's a problem-being at best the meat in the diesel LMP1 and factory LMP2 sandwich, or backmarkers at worst), is that the rules are designed for the LMP2 cars to be less reliable due to their more frail construction and highly stressed engines. But the reliablitly is there now-at least for 2.75-4 hour races.

Remember, it wasn't all that long a go that LMP2's rarely finished a 2.75 hour ALMS sprint race, as the 2 liter cars fried a turbocharger, or the 3.4 flat crank V8s threw a rod out the oil pan or sucked a valve(valve spring failure) due to the high RPMS and resultant hamonic vibrations. Or chewed up transmissions like bubble gum.

But then again, the same was basically said by many about the diesels, and look at what's happening now.

[Mal]

I know it is not the ACO's intention, but I really like the scenario we are getting of heavier powerful cars competing with lighter more nimble cars for overall wins. It means that different cars will be suited to different tracks, clever strategy is more important and regular lead changes are likely.

Not sure its good for Audis marketing though as it try to promote diesel as a greener more efficient fuel!!

[HORNDAWG]

Has the petrol P-1 come up against a rules wall? It seems as though the petrol P-1's have almost flatlined in performance compared to their previous years performance.

L.P.

[AU N EGL]

Originally Posted by HORNDAWG

Has the petrol P-1 come up against a rules wall?
L.P.

YES. The allowable displacement of a Petrol fueled NA or Turbo engine, plus the air restrictor size for the P1 cars does not allow enough HP/TQ to match the Diesels. The added attempt to limit the diesels fuel capacity, so it might stop more, was not sufficient.

So the Diesels HP/Wt ratio is much lower then the Petrol HP/Wt ratios hense a much faster car in the P1 class.

[Adam43]

Originally Posted by HORNDAWG

It seems as though the petrol P-1's have almost flatlined in performance compared to their previous years performance.

Quite possibly. What do we put this down too? The teams have found the ultimate performance of a petrol LMP1? Or none of the Petrol cars being developed in an significant manner? I suspect the later. The current LMP class is relatively new and I feel that there is potential for more from all the cars, given time, money and effort. The last two being of short supply!

Originally Posted by AU N EGL

YES. The allowable displacement of a Petrol fueled NA or Turbo engine, plus the air restrictor size for the P1 cars does not allow enough HP/TQ to match the Diesels. The added attempt to limit the diesels fuel capacity, so it might stop more, was not sufficient.

So the Diesels HP/Wt ratio is much lower then the Petrol HP/Wt ratios hense a much faster car in the P1 class.

Despite all the big fonts, I'm unsure what we are discussing. Are we (again) discussing the relative performance of petrol and diesel, or are we discussing the performance gains, or lack of, in the petrol cars? The big fonts made me think the latter!

[gwyllion]

Don't forget that the aero rules for LMP1 imply more drag than LMP1 Hybrid (because the full second rollover bar). This explains why the petrol cars did not make such a big performance improvement:

• Creation C07 (LMP1) vs Creation C06/H (LMP1 Hybrid)
• Dome S101.5 (LMP1) vs Dome S101-Hb (LMP1 Hybrid)
• Pescarolo 01 (LMP1) vs Pescarolo C60 Hybrid (LMP1 Hybrid)
• Zytek 07S (LMP1) vs Zytek 06S (LMP1 Hybrid)

[paul-collins]

I tend to think that P1 reg engines may be close to theoretical maximum simply because they've been the engine of serious competition for 8 years now. (Minor restrictor changes being the only fluctuating parts)

Basically, no one really threw any resources at developing the P2 powerplants until Porsche came along - let's face it, AER and Judd are great companies, but they're small fry compared to Porsche and Honda. So it should be no surprise that P2 has made leaps in performance over the last couple of years.

Add to that, that with current regs, power to weight is pretty close for petrol P1s and P2s (assuming target hp of 650 and 550) and it's no surprise that the factory teams are beating the privateers. I suppose the real shocker is that no factory took up the P675 challenge when they had the opportunity!

[jhansen]

Originally Posted by AdamAshmore

Quite possibly. What do we put this down too? The teams have found the ultimate performance of a petrol LMP1? Or none of the Petrol cars being developed in an significant manner? I suspect the later. The current LMP class is relatively new and I feel that there is potential for more from all the cars, given time, money and effort. The last two being of short supply!

I agree with this. Even Audi didn't have to develop the R8 as much as they could have. I don't think any of the petrol P1 cars are close to their potential. The primary reason being money, as you pointed out. The privateers just cannot develop the cars at the pace of a factory.

[Bob Riebe]

Originally Posted by jhansen

I agree with this. Even Audi didn't have to develop the R8 as much as they could have. I don't think any of the petrol P1 cars are close to their potential. The primary reason being money, as you pointed out. The privateers just cannot develop the cars at the pace of a factory.

It really boils down to not if anyone can afford it, rather that factories might be able to put hundreds of thousands of dollars in special cylinder heads dedicated to restrictors, but for what reason?

The cylinder heads Chevrolet had developed for the Corvette were for the factory boys only.
Beyond racing, they have zero purpose on the street as they were created soley for the restricted engines.
WHY, keep driving down a street that is dead-end?
Sadly it is the small engine manufacturers who can profit, as they care squat about street engines, but they cannot compete against factories who do care about street relevance, and spend only as much as they have to for their purposes, which is more than any small comp. engine builder can compete with.

As I said for inlet size, comp.ratio combined with octane, and gasoline allowed plus obviously engine size for type, there is a theoretical point of no return in gasoiline engines.
Reach that with the engine, and the dollars spent are being flushed down the drain.
Restictor racing is expensive to start with, at that point it becomes extraordinarily expensive.
It becomes a matter of return for investment.
Bob