Porsche 911 GT3 v McLaren 570S Track Pack - DEADLY RIVALS

Porsche 911 GT3 v McLaren 570S Track Pack - DEADLY RIVALS

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Discussion

Phooey

Original Poster:

12,616 posts

170 months

Tuesday 6th November 2018
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Good result for the Porker but reckon a different track or maybe different driver and the Mc'pack would have the edge

https://www.youtube.com/watch?v=bNoq8gvV-go

Juno

4,481 posts

250 months

Tuesday 6th November 2018
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Mclarens just don't lap according to their weight and power,why not??? none of them!!! yet! i think!

Taffy66

5,964 posts

103 months

Tuesday 6th November 2018
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Juno said:
Mclarens just don't lap according to their weight and power,why not??? none of them!!! yet! i think!
Basically what makes one car faster than another around a track is ultimate grip..The GT3 is shod with 245/305 F/R whereas the 570S is on 225/285 F/R. Quite simply the GT3 has more grip and IIRC more downforce..

Juno

4,481 posts

250 months

Tuesday 6th November 2018
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Taffy66 said:
Juno said:
Mclarens just don't lap according to their weight and power,why not??? none of them!!! yet! i think!
Basically what makes one car faster than another around a track is ultimate grip..The GT3 is shod with 245/305 F/R whereas the 570S is on 225/285 F/R. Quite simply the GT3 has more grip and IIRC more downforce..
Yes but with the Macca having more power why don't they tyre them accordingly,surely no manufacturer sets out to produce a slower cars than its competitors that it will be bench marked against.

Taffy66

5,964 posts

103 months

Tuesday 6th November 2018
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Juno said:
Yes but with the Macca having more power why don't they tyre them accordingly,surely no manufacturer sets out to produce a slower cars than its competitors that it will be bench marked against.
Two reasons IMO..The more overtyred a car is relative to its power the higher the strain on all other components such as rims,brakes and all suspension parts due to the increased forces generated by the extra grip,
The other reason is as you increase the car's grip(tyre sizes) the less fun it is at sensible road speeds..A great example is GT4 vs 981 Spyder as i've owned a GT4 and now own a 981 Spyder. The GT4 is a better track car due to more grip(wider tyres) yet the Spyder is more fun and involving as a road car due to its narrower tyres.
Put 245/305s on the 570 and it should be quicker around most tracks as long as the brakes and suspension is strong enough to cope with the extra grip.
Wider tyres also sap power and probably why my Spyder is both slightly quicker and more economical than my GT4 was.

isaldiri

18,631 posts

169 months

Tuesday 6th November 2018
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Taffy66 said:
Wider tyres also sap power and probably why my Spyder is both slightly quicker and more economical than my GT4 was.
The tyre diameter of the 981 spyder (265/35/20) is greater than that on the gt4 (295/30/20)........So I'm not sure how you come up with that being the reason why wider tyres 'sap power' and the spyder being quicker.

Porsche911R

21,146 posts

266 months

Tuesday 6th November 2018
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isaldiri said:
Taffy66 said:
Wider tyres also sap power and probably why my Spyder is both slightly quicker and more economical than my GT4 was.
The tyre diameter of the 981 spyder (265/35/20) is greater than that on the gt4 (295/30/20)........So I'm not sure how you come up with that being the reason why wider tyres 'sap power' and the spyder being quicker.
Started on the gins already!

Purple Man

201 posts

74 months

Tuesday 6th November 2018
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I'm sorry to disappoint you lads, but the basic 570S was faster than my GT3 at Oulton Park and Donnington this year, thats with me driving both cars. Looking at the V box data, it just carries a couple of extra MPH through each corner.
So lets not get to excited because when they have a real test and put them back to back in the dry, well the 570S will be two seconds a lap faster.
Sorry to be the bearer of bad news.

Taffy66

5,964 posts

103 months

Tuesday 6th November 2018
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isaldiri said:
The tyre diameter of the 981 spyder (265/35/20) is greater than that on the gt4 (295/30/20)........So I'm not sure how you come up with that being the reason why wider tyres 'sap power' and the spyder being quicker.
Increasing tyre width results in increased tyre contact patch which has two effects, one positive and one negative.
The positive is increased grip and the negative is higher rolling resistance..By increasing rolling resistance you increase fuel consumption which is the same as sapping power.
Energy cannot be created or destroyed, merely changed from one form to another..Increasing rolling resistance absorbs power..Its simple physics..

Taffy66

5,964 posts

103 months

Tuesday 6th November 2018
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Purple Man said:
I'm sorry to disappoint you lads, but the basic 570S was faster than my GT3 at Oulton Park and Donnington this year, thats with me driving both cars. Looking at the V box data, it just carries a couple of extra MPH through each corner.
So lets not get to excited because when they have a real test and put them back to back in the dry, well the 570S will be two seconds a lap faster.
Sorry to be the bearer of bad news.
Thats truly devastating news..I'm now going out to my garage to set fire to both my GT3 and Spyder.

Purple Man

201 posts

74 months

Tuesday 6th November 2018
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A GT3 and a Spyder will probably get you a GT3RS.
Panic over, cancel the fire brigade!
PMx

APOLO1

5,256 posts

195 months

Tuesday 6th November 2018
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Purple Man said:
I'm sorry to disappoint you lads, but the basic 570S was faster than my GT3 at Oulton Park and Donnington this year, thats with me driving both cars. Looking at the V box data, it just carries a couple of extra MPH through each corner.
So lets not get to excited because when they have a real test and put them back to back in the dry, well the 570S will be two seconds a lap faster.
Sorry to be the bearer of bad news.
Be interesting to see the V-Box data. I dont do Oulton very often. But I do know Silverstone well, and have driven both round there. Whist the 570s will have the advantage on the straight's. But in the corners its restricted by its lack of lateral Grip along side the GT3.2. Due to its narrow 285 rears and lack of a Proper LSD, and RWS. Dont forget the GT3.2PDK Did ring time of 7.12. 570s wont get even close to this. Also round Anglesey the 570s is long way behind the GT3.2 time, though I accept its not same day driver etc.



Edited by APOLO1 on Tuesday 6th November 19:56

isaldiri

18,631 posts

169 months

Tuesday 6th November 2018
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Taffy66 said:
Increasing tyre width results in increased tyre contact patch which has two effects, one positive and one negative.
The positive is increased grip and the negative is higher rolling resistance..By increasing rolling resistance you increase fuel consumption which is the same as sapping power.
Energy cannot be created or destroyed, merely changed from one form to another..Increasing rolling resistance absorbs power..Its simple physics..
Ok. That would explain why Sport Auto/Autobild had the gt4 faster to 100 and 200km/h than the Spyder and why every performance car puts on a stickier tyre (with more rolling resistance) in order to get better acceleration numbers.

And I repeat, the rolling radius of the Spyder is larger than the gt4. Simple physics also states in that case the power applied to the ground is going to be less than with a smaller tyre and that effect is likely to be a lot more consequential than higher rolling resistance.

Taffy66

5,964 posts

103 months

Tuesday 6th November 2018
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Purple Man said:
A GT3 and a Spyder will probably get you a GT3RS.
Panic over, cancel the fire brigade!
PMx
The insurance payout will pay for a GT2 RS..

Porsche911R

21,146 posts

266 months

Tuesday 6th November 2018
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Agree you never see fast macca laptimes, it’s under tyred out back to use any of it's power.
It’s a Pretty dull car to drive and a bit of a one trick pony, hence you see a lot at vmax and drag time days.

Let’s hope the 600lt brings more to the party.

Taffy66

5,964 posts

103 months

Tuesday 6th November 2018
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isaldiri said:
Ok. That would explain why Sport Auto/Autobild had the gt4 faster to 100 and 200km/h than the Spyder and why every performance car puts on a stickier tyre (with more rolling resistance) in order to get better acceleration numbers.

And I repeat, the rolling radius of the Spyder is larger than the gt4. Simple physics also states in that case the power applied to the ground is going to be less than with a smaller tyre and that effect is likely to be a lot more consequential than higher rolling resistance.
Performance cars are fitted with sticky tyres to increase GRIP not SPEED..More grip will help getting off the line but on a roll increasing rolling resistance saps power/fuel..Ask any engineer and he'll be able to explain it better than i can..
A measly 5mm is nothing compared to increasing the width of wheels and tyres by 30mm..Are you able to discern the difference in power on your cars with new tyres compared to slightly worn ones.....thought not..!

isaldiri

18,631 posts

169 months

Tuesday 6th November 2018
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Taffy66 said:
A measly 5mm is nothing compared to increasing the width of wheels and tyres by 30mm..Are you able to discern the difference in power on your cars with new tyres compared to slightly worn ones.....thought not..!
No but I can guarantee you my car is quicker on Cup2s than with a Primacy tyre that has much lower rolling resistance.....

And for some strange reason, both Porsche own numbers and every other mag test I can think of had the gt4 being quicker in a straight line. So unless your definition of 'quicker' is different from mine I'm somewhat unsure how you reckon your spyder was quicker than the gt4.

CrashBang

225 posts

156 months

Tuesday 6th November 2018
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Genuine question - Why are the Porsche forums so full of self serving BS?

av185

18,523 posts

128 months

Tuesday 6th November 2018
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CrashBang said:
Genuine question - Why are the Porsche forums so full of self serving BS?
Feel free not to be amused.

av185

18,523 posts

128 months

Tuesday 6th November 2018
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By coincidence parked next to mine at the gym the other day