Senna [Official] McLaren Senna (P15)

[Matski]

how does the AMG Project 1 and the Aston Martin Valkyrie compare to GT3 cars?

the claimed downforce of the Valkyrie is 4000lb and it weights a bit over 2200lb (1 metric ton) while it has a rumoured power to eclipse 1 to 1 hp/kg

Don't wish to speak for @M.N.D but there aren't any laptimes for either of those cars yet so it's not possible to know accurately.

To echo his informative post, and to back up rants I've made before, it's all about the tyres, the amount of extra performance you need to compensate for running on road legal tyres versus racing slicks is ridiculous. The example I always come back to is a BTCC Ford Focus lapping Silverstone national circuit as quickly as a P1, Laf, 918.

A BTCC car has about 380hp, is FWD, and weighs 1280kg, therefore about 0.29hp/kg

Compared to

918: 0.54 hp/kg
La Ferrari: 0.63 hp/kg
P1: 0.64 hp/kg

Let's call that an average of 0.60 hp/kg.

So with HALF the power-weight the BTCC car is as fast (on a power circuit), put them round a track with more than 4 corners and the Ford Focus would decimate the hypercar trio.

A GT3 car is about 0.42 hp/kg, and on a circuit with corners (Brands GP) is about 5 seconds a lap faster than a BTCC car (1.26 vs 1.31). So a car with a 30ish% increase in power to weight ratio accounts for a 6% decrease in lap-time... And if it takes a hyper Mclaren road car to have a power/weight ratio of 0.64 to catch a FWD, steel bodied, hatchback touring car, then a Mclaren Hyper road car with a power/weight ratio of 0.66 is going to have to be going some to catch a GT3 car.

Just as a reminder, brand new GT3 (and NGTC/TCR Touring car) cars are a fraction of the price of these hyper cars.

 

[Mark ANTAR]

I few quick experimental renderings:

 

[Laurent T]

Looks better if not good with different color combination. What I still fin odd in profile is the postion of the rear wing. Would be much better if pushed more backwards.

 

[M.N.D]

how does the AMG Project 1 and the Aston Martin Valkyrie compare to GT3 cars?

the claimed downforce of the Valkyrie is 4000lb and it weights a bit over 2200lb (1 metric ton) while it has a rumoured power to eclipse 1 to 1 hp/kg

@Matski provided a very well constructed and informative post about how a GT3 race car or any race car in general compares to the road going hypercars. Tyres play a critical role in performance, and the P15 is equipped with a set of Pirelli Trofeo R, and I believe that no matter how much grip it can generate, it won't match the level of a slick racing one. McLaren didn't mention that the P15 Senna is faster than a GT3 car, because this is a very bold claim, and if it's true, the press release will mention such information at least 4 times.

Another example on the effect of tyres can be seen from the Sachsenring once again:

Road car: 1:26.77 / Porsche 918 Spyder / Auto Bild
Race car: 1:26.73 / VW Golf GTI TCR / ADAC TCR Masters 2017 Qualifying

The Golf GTI TCR has around 350 HP and weighs around 1250 KG. Both figures are subject to change due to BoP. According to VW, the TCR version can do the 0-100 KPH in 5.2 seconds.

Race cars are truly built to a single purpose, which is to go around a racing circuit as fast as possible within the regulations. A road going supercar, no matter how power it generates, or the amount of the downforce it's supposed to produce, isn't optimized for a single purpose, because it is built to do a second function, which is being used on the street.

Regarding your question about the Aston Martin Valkyrie and the Mercedes-AMG Project one, it's not logical in my humble opinion to compare them to a GT3 racer due to several reasons. First of all, the two cars you mentioned are purpose built prototypes that didn't go through any sort of performance test as of yet. Their configuration is completely different to the standard GT racer, because they were built from the ground up to have a bespoke chassis, and were optimized to achieve a specific aerodynamic / handling target.

A GT car (GTE/GT3/GT4/TCR/NGTC/etc...) starts its life by using the bodyshell of its road going counterpart, then the engineers start to build the car depending on the regulations that govern each category.

Here is another very good post by @Matski that explains GT racing cars from a DTM thread:
DTM 2017 season

I've taken a look the press release of the AMG and the Aston, and couldn't find what type of tires will be used* or how much downforce can be generated, so I can't provide a thorough comparison. However, while both of these cars use Formula 1 drivetrains, they remind me of an LMP car. In FIA WEC, an LMP1 car (the fastest category) is about 15~20 seconds quicker than a GTE car, which is about 1.5~2 seconds quicker than the GT3 car, while an LMP2 car is about 9~13 seconds quicker than a GTE car.

I believe due to being specific built, these two may go around the track quicker than a GT3 car around the track IF they are equipped with racing slicks. On street tyres, I would say they'll be slower.

My reasoning is based on comparing another set of lap times, this time for the Ferrari FXX-K (it can be categorized in the same class as the Valkyrie and the Project one, even if its performance is assumed to be on a lower level) and the Ferrari 488 Challenge. Around Fiorano circuit, the FXX-K posted a lap time of 1:14.00, while the 488 Challenge posted a lap time of 1:15.5, assuming that both cars are on slick tyres. The FXX-K produces around 1050 PS, while the Challenge car is a race prepped 488 GTB that is simpler and slower than a GT3 car. This means the GT3 car is quicker than the FXX-K. Moreover, the new FXX-K EVO is said to produce a higher downforce level that is similar to the 488 GTE and the 488 GT3, while being lighter than the FXX-K.

However, I'm not a mechanical engineer, so I could be wrong on what I've said.

Another long post...



* EDIT: The AMG is using Michelin Pilot Sport Cup 2

 

[manuelf]

EDIT: The AMG is using Michelin Pilot Sport Cup 2

If this would be a plain vanilla PSC2 without specific vendor tags, I wouldn't expect outstanding performance from the AMG ... but as we maybe all know: There is a broad bandwidth of performance with the PSC2! If you take the more extreme vendor specific variants used by Corvette in the C7 Z06 or the variant of the PSC2 of the AMG GTR, then you have a capable semi slick above the Trofeo R! This seems to be the most aggressive rubber you can go for, if you still need to be street legal ... and those extrem versions of the PSC2 are literally not-driveable under wet conditions....
But even then ... there is still a big gap to a real slick.

 

[Bucketslash11]

from lamborghiniks

 

[Bucketslash11]

i think i know how it's possible to create a faster car than a GT3 car for the road:

this

plus this:

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

"whatever we draw has to respect the laws of physics" - Adrian Newey

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

and as far as i know there are no regulations about suction on road cars

edit:
this video shows the difference between standard and fan car

 

[Matski]

But even then ... there is still a big gap to a real slick.

Yup, I once stuck my thumb into a warm Formula 1 tyre, it was literally tacky, and bore the slight impression of my thumb when I removed it.

 

[M.N.D]

If this would be a plain vanilla PSC2 without specific vendor tags, I wouldn't expect outstanding performance from the AMG ... but as we maybe all know: There is a broad bandwidth of performance with the PSC2! If you take the more extreme vendor specific variants used by Corvette in the C7 Z06 or the variant of the PSC2 of the AMG GTR, then you have a capable semi slick above the Trofeo R! This seems to be the most aggressive rubber you can go for, if you still need to be street legal ... and those extrem versions of the PSC2 are literally not-driveable under wet conditions....
But even then ... there is still a big gap to a real slick.

I've checked the press release of the AMG once again, and it says that the Michelin's compound is developed to specific requirements to suit the car's performance. But then again, there's no way for a street tyre to match a real slick.

So, back to the McLaren. I've noticed that there is no 5 point racing harness, which is odd for a car that's supposed to be a track car for the road

As for how it looks, I feel indifferent. I don't hate it, but it's not beautiful either. The bubble canopy is an interesting touch, and the two piece glass window is a tribute to the F1. However, I think the designers should've at least given it a different headlight shape, as it won't cost them that much for a limited edition car with a price tag of 750,000£.

i think i know how it's possible to create a faster car than a GT3 car for the road:

For the Caparo T1, it won't be enough. Top Gear ran an Aston Martin DBR9 on their test track in one of the old seasons, and its lap time was 1:08.6 seconds according to this video below.

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

Bear in mind that this Aston Martin is a GT1 class car, which was the top GT class in the noughties (not to be confused with the 90's GT1 class, which I think were evolved into the LMP category). They were lighter and more powerful than today's top GT class, the GTE, but due to the advancement in aerodynamics and tyre compound, both categories have virtually the same performance.

I believe we need to open a GT thread on the motorsports section so we can discuss such topics without going off topic here, as this thread is to discuss the McLaren Senna.

 

[Bucketslash11]

I've checked the press release of the AMG once again, and it says that the Michelin's compound is developed to specific requirements to suit the car's performance. But then again, there's no way for a street tyre to match a real slick.

the sucktion will have affect on its grip so add a gearbox driven fan to the caparo T1 and give it the shape of X2010/11/14 in order to reduce unecessary drag, there's a reason brabham BT46b dominated

 

[martinbo]

Let's leave the pipe dreams alone for a moment a focus back on the P15 Senna.

 

[Mark ANTAR]

 

[Laurent T]

Looks better with those renderings... but still annoyed by the rear wing.

 

[Bucketslash11]

can you move the wing further back?

 

[Laurent T]

can you move the wing further back?

I tried it but it did not really solve my "trouble". I guess for me it's a mix between postion and design of this wing and the fixing points which go around it to reach the top. I personnaly would love to see how the P1 LM rear wing fit to this Senna. I feel it would look much better.

 

[Bucketslash11]

I tried it but it did not really solve my "trouble". I guess for me it's a mix between postion and design of this wing and the fixing points which go around it to reach the top. I personnaly would love to see how the P1 LM rear wing fit to this Senna. I feel it would look much better.

try experimenting a bit, maybe you'll reach something that looks better (this includes the LM/GTR wing)

 

[Bucketslash11]

long discussion about the senna

 

[hoffmeister_fan]

it does look better in some of those PS. Still not loving it. I want to love it.

 

[Wunderkind]

Well, McLaren has to find money to fund their F1 team. This must be it.

 

[WBarnes]

long discussion about the senna

I listened to 60s of that and now I have brain damage. Thank you Santa.