Friday 13th June 2014

Rubber 'ring: PH Blog

Why it's the rubber on your wheels not the engine powering them that matters

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Engine stats and performance figures are at the heart of any 'mine's better than yours' debate and yet the key factor in a car's real world performance is often completely overlooked - tyres. And, yes, apologies. At the heart of what follows is the ruddy 'ring again. Blame the fact I'm off out there on Sunday to drive the Megane 275 Trophy aiming for front-driven glory with its unfortunately named '#Under8' campaign.

Track tyres on a Megane = true supercar pace?

Think about that for a second though. This and the SEAT Leon Cupra it's trying to, um, unseat are now lapping the 'ring at a pace that not so long ago was the preserve of Walter Rohrl in a 911 GT3, the 996 version being the first road car he broke that benchmark with. These are hot hatches, albeit seriously souped up, now able to cover that famous 13 miles at a pace only previously achievable by a motorsport influenced 911. The minimum for 'serious' cars is now seven and a half, seven dead now the real target since Porsche ran the 918 Spyder there under that time.

It was chatting with Sport Auto's Horst von Saurma and reading the special issue of the mag celebrating 200 'Super Tests' that really brought it home. In it they picked out the 911 GT3s, BMW M3s, Golf GTIs and V8 mid-engined Ferraris timed since the Super Test started in 1997. Most have improved their lap times by around 30 seconds in that time thanks to incremental improvements in performance and technology.

Cup style tyres now de rigueur for lap glory

And then you look at the BMW M3. E36: 8min 35sec. E46: 8min 22sec. E92: 8:05. F80: 7min 52sec. But among it all an anomaly in 2003 - CSL: 7min 50sec. Four seconds faster than the second-gen 996 GT3 tested the same year. Six seconds faster than the plastic windowed super hardcore Ferrari 360 Challenge Stradale lapped a year later. In an M3. OK, an M3 100kg-odd lighter than the standard one and with another 17hp. But still 'just' an M3.

Even now Sport Auto regards the CSL's time as astonishing, and for good reason. And at the heart of it? The Michelin Pilot Sport Cup tyres. Since that time eight out of the 10 fastest cars ever tested by Sport Auto set their times on sport or 'cup' equivalents.

Those original Pilot Sport Cup tyres did the business on a dry track but were pretty extreme for use off it, even if acceptance (or perhaps expectation) has become more widespread than those early days of CSL owners having to sign their lives away. That a souped-up saloon could be transformed into a proper supercar slayer with a set of fancy rubber proves an important point. Likewise the fact the Carrera GT - a mid-sevens car on original rubber - is widely considered to be 15-20 seconds faster on second-gen Cups. Meaning it's now only 10 seconds or so off the pace of the hybrid/four-wheel drive 918.

Leon wouldn't have gone sub eight on regular rubber

Does this all come at a cost though? We explored that previously in a Megane when we tried out some supposed track-friendly street tyres at Spa. And promptly melted them in a few laps. Are these new Cup tyres any better than a one-shot quali tyre geared for lap time (and now marketing) glory? I did once hear tell of bored tyre testers livening up a dull industry pool session by equipping a Skoda Octavia with a set of racing slicks and black tape over the badges to go harrying Porsche test drivers and raise gossip of a mystery budget mega saloon in development. All it took was a set of rubber. Who's to say similar stunts aren't being pulled in this new obsession with lap times. A question for both Michelin and Renault on Monday I reckon...

What do I know though. You're looking at the man who deliberately put eco tyres on his car in the hope the harder compound would make it do big skids.

Dan

 

 

[renaultgeek]

how did you get your youtube link to start half way in?

[Dan Trent]

renaultgeek said:

how did you get your youtube link to start half way in?

It's in the 'Share' option - you can scroll through the vid, pick a point, check the 'start at' box and job jobbed. You then get a short link with the vid forced to start at the point you picked.

HTH!

Dan

[Kawasicki]

Tyres are not just developing more peak grip, they are also getting more benign past the peak, it's getting easier to drive faster.

[JDMDrifter]

Tires maketh the car. At the end of the day you could spend millions developing high tech suspension and diffs but it wont make bugger all difference if the tyres are naff.

[Kozy]

It's ALL about the tyres, for sure, but everyone knows that surely?

I get the piss taken out of me for how much interest I take in the rubber but it's by far and away the most important aspect of a performance car.

[TurboHatchback]

Quite so. Even on the road tyres make a huge difference to how hard a car can be driven safely. Whilst there are many defenders of ditchfinders on here who claim that their Nankangs, Events and Goodrides are all the tyre you could possibly need, IMHO they are dead wrong. A set of proper Michelins makes an indescribable difference to a car.

[Mermaid]

Right grooved & construction tyres at the right tyre pressure/temperature (with all the other bits of course) - rather obvious - race cars have been paying attention to this for a few decades.

Cup tyres - perfect track tyres for the dry road.

[Simon866]

Surely, on anything but standing water, the R888 is all you'll ever need?

[Simon866]

Surely, on anything but standing water, the R888 is all you'll ever need?

[Henry Fiddleton]

Simon866 said:

Surely, on anything but standing water, the R888 is all you'll ever need?

The road noise they make, massive side wall stiffness..and the cost.

Mine only come out for track days.

I dont R888s for the station commute.

(But yes, very good tyres!)

[Steven_RW]

I went from Avon Run Flats on the front of my Mini Cooper s (R56) and Hancook run flat rears to Michelin Pilot Super Sports all round. Massive difference in ride quality (improved), stability (improved), initial turn in (similar, as run flats are very stiff so have good initial response) overall grip in dry (improved) and wet (improved). All in all a very great step forward.

What I really want to know is what is the agreed time for that same E46 CSL on something like Pilot Sport 2's, not cups. How many seconds do they think it improved the time by?

:-)

Regards,
Steven_RW

[Sexual Chocolate]

Simon866 said:

Surely, on anything but standing water, the R888 is all you'll ever need?

As long as you don't mind changing tyres every 3K miles.

[Simon866]

Henry Fiddleton said:

Simon866 said:

Surely, on anything but standing water, the R888 is all you'll ever need?

The road noise they make, massive side wall stiffness..and the cost.

Mine only come out for track days.

I dont R888s for the station commute.

(But yes, very good tyres!)

Agreed, I am lucky enough to walk to the station. I only made the mistake of using the sofest compound once and I soon relised that I wasn't rich enough to buy a set of tyres every two track days/sprints!

[JordanTurbo]

article said:

And then you look at the BMW M3.

• E36: 8min 35sec.
• E46: 8min 22sec.
• E92: 8min 05sec.
• F80: 7min 52sec.

I'd like to see a test of the above cars all lapped again on modern rubber to see how much closer the the times would be.

[weed]

Tyre compound and construction of track biased tyres contributes mightily.
However, if they are not kept with the nominal amount of the tread surface in contact with terra firma they will struggle to match a quality road tyre, especially over a longish distance like the ring.
the platform/suspension support is just as important and is also improving with each successive generation of the model.

m

[Debaser]

Tyres don't matter at all, drive to the conditions and you'll be fine on any cheap crap. I read it on PH so it must be true.

[Escort Si-130]

PMSL. Tyres do matter

Debaser said:

Tyres don't matter at all, drive to the conditions and you'll be fine on any cheap crap. I read it on PH so it must be true.

[dukebox9reg]

Amazed at the amount of friends who buy cars like VXR Astra's and then cant afford to stick decent rubber on the 19s so end up with nankangs and infiniti's. Same numpties who tend to go for the cheapest brake pads and wonder why they fall of the road and crash.

Bad enough cheap tyres on 60bhp runabouts let alone performance cars.

[Kozy]

Debaser said:

Tyres don't matter at all, drive to the conditions and you'll be fine on any cheap crap. I read it on PH so it must be true.

It's true, that's why you see so many people struggling to go round corners on NSL roads at anything more than 30mph!

Petrolheads will often take the grip of good tyres for granted, when I was running around with R888s on my daily, I didn't think anything to taking corners at 60mph that would result in a crash at 40mph on a car on budgets. This often scared my unwitting passengers, much to my amusement.

Getting behind the wheel of something on ditchfinders after being spoilt with that much grip is enlightening, you do suddenly realise why so many people drive so slowly!

[mrdemon]

Simon866 said:

Surely, on anything but standing water, the R888 is all you'll ever need?

dated and old design , comes last in the track tyre line up these days.

so no :-)