Lightning Lap 2018

[GoCougs]

InvalidPremiseSPIN and TireAnecdoteSPIN.

[MexicoCityM3]

And I can show you plenty of data that says otherwise, and that your Camaro 1LE on Z28 tires example is an exception, not the rule.

2009 C&D Lightning lap:  Their 2010 Mustang GT PP came with the wrong tires.  They ran a few laps on whatever the car came with while waiting for Ford to show up with the correct Pirelli PZero performance tires for the car.  From the article:

As an additional data point, the following year, C&D ran the new 5.0L Mustang GTPP.  97 more horespower and 65 lbs-ft more torque and an extra ratio in the transmission (same chassis, tires, suspension, brakes...).  That lapped just under 5 seconds faster than the 2010 model.  So tires alone had as much of an effect as adding a lot more power.  Which do you think would cost more:  Adding 30%+ more power to a car or replacing the tires?

From my own experience actually participating in sanctioned auto competitions and playing around with different tires in my first few seasons of auto-x...

2012 I was competing with my '11 Mustang.  The car was showroom stock, right down to the OEM wheels and tires (17x7" rims with 235 wide all-seasons).  That year, I ran against a guy with an '04 WRX.  He had some very light modification that pushed him out of the stock class (I think maybe lowering springs).  I beat his raw times by 2-3% (e.g. 1-1.5 second faster on a 50 second course), consistently, all season.

In the off season, I invested ~$1200 in a set of 18x8 Pony Package wheels and some 255 wide summer performance tires (budget tires, a tier below something like a Pilot SuperSport and 2 tiers below the Rivals or Star Specs that the fast guys ran).  My competitor showed up having sunk probably twice that into suspension and engine mods (a fully adjustable set of coilovers, swaybars, and a Cobb Stage I kit netting ~20-25% more power), but the same tires he'd been running on the year before.  At the first event, I beat him by a larger margin than I'd beat him all the previous season.  At the next event, his car was wearing a set of sticky summer tires (at least 1 tier up on mine in terms of performance class and a much lower TR rating).  I didn't beat him again the rest of the season.  His average margin of victory through the rest of the season was 2%.  Another meter stick would be one of the more seasoned competitors (runs the Pro class) who was running the exact same car and tire setup both years.  The year I was on my OE tires, he beat me by an average of 1.5%.  After changing my tires, I beat him by an average margin of 1%.  That's a 1.75 second swing assuming a 50 second course just from upgrading tires.  In this sport, that's huge.  To put it into perspective, if the runner up in this year's championship had run an average of just .226 seconds faster per event, he'd have won the title.  If you're not already at the pointy end of the tire performance spectrum, a tire upgrade can yield an improvement of an order of magnitude on that, as I've both seen and personally experienced.

I couldn't agree more. But, that's a lot of effort to argue with Cougs who never ever concedes an argument here.

UnshakeableSpin

[Xer0]

Looking at their data, C&D hasn't had a non R GT350 on VIR yet.  I wonder how close that PP2 would be to it.  They have one in their long term fleet currently, kinda bummed they didn't take it out.

[12,000 RPM]

InvalidPremiseSPIN and TireAnecdoteSPIN.

Much better than BenchRaceSPIN, DenyDataSPIN and DieBeforeConcedeSPIN

Tires are 100% the most effective way to boost lap time performance and the biggest driver of dropping lap times at LL

[MrH]

Looking at their data, C&D hasn't had a non R GT350 on VIR yet.  I wonder how close that PP2 would be to it.  They have one in their long term fleet currently, kinda bummed they didn't take it out.

That's actually a really interesting comparison.  You get a much fancier, better sounding, exotic engine, but I'm guessing the performance difference is pretty minimal.

[GoCougs]

Looking at their data, C&D hasn't had a non R GT350 on VIR yet.  I wonder how close that PP2 would be to it.  They have one in their long term fleet currently, kinda bummed they didn't take it out.

It needs tires and pads and probably springjs, exhaust and intake, lest it be showed up by a lowly Camaro SS (automakers botch these things you know).

[MX793]

It needs tires and pads and probably springjs, exhaust and intake, lest it be showed up by a lowly Camaro SS (automakers botch these things you know).

The only differences between the GT350 and GT350R are wheels/tires, aero (the rear wing and splitter on the R), and the R has had the interior partially gutted (no radio, AC, carpets, or rear seat) to save some weight.

[MexicoCityM3]

The only differences between the GT350 and GT350R are wheels/tires, aero (the rear wing and splitter on the R), and the R has had the interior partially gutted (no radio, AC, carpets, or rear seat) to save some weight.

No cooling differences?

[CaminoRacer]

Are all the cars just running the stock tires? They should run the same tires, or at least the same level of tire. Keep the stock wheels and tire size, but it's a bit ridiculous to compare a Miata running normal-ish tires to a GT2 RS running Pilot Sport Cups

[MX793]

No cooling differences?

Not anymore.  The previously optional "Track Pack" equipment (which included additional coolers) for the non-R model was made standard equipment last year.  I suspect due to complaints about overheating of non-Track Pack GT350s by owners who tracked their cars.

[MX793]

Are all the cars just running the stock tires? They should run the same tires, or at least the same level of tire. Keep the stock wheels and tire size, but it's a bit ridiculous to compare a Miata running normal-ish tires to a GT2 RS running Pilot Sport Cups

They run with whatever the manufacturer fits on the cars with from the factory.

[Xer0]

No cooling differences?

IIRC the non R had a Track pack the first couple years with upgraded engine, trans, and differential cooling that brought it up to R spec.  It's standard equipment now.

[CaminoRacer]

They run with whatever the manufacturer fits on the cars with from the factory.

Yeah, seems a bit silly. No serious track day driver is going to do that.

[MX793]

Yeah, seems a bit silly. No serious track day driver is going to do that.

No serious track day driver is going to run most of these cars as they roll off the showroom floor.  They'll upgrade brakes (pads at least, probably fluid), likely suspension (sways/shocks/springs), wheels/tires.  Very few cars roll out of the factory ready for real track use.

[68_427]

Just watched MT BDC and they were pretty harsh on the Mustang, which I wasn't expecting at all.

[GoCougs]

Just watched MT BDC and they were pretty harsh on the Mustang, which I wasn't expecting at all.

It's a pretty good car, but a GT car nonetheless, esp. compared to the benchmark (Camaro).

[r0tor]

It's a bit odd to read the corvette tested was the personal car of the chief suspension engineer... One has to wonder about that

[GoCougs]

Crushing the subject:  https://www.roadandtrack.com/car-culture/a23391373/theres-a-lot-you-need-to-consider-before-buying-tires/

"Automakers pick tires years before a model debuts and tweak everything from dampers to suspension pickup points around the rubber of their choosing. "It's the most engineered single part on your entire car," says Aaron Link, lead development engineer for Chevrolet Performance Cars. Slap on something more capable, and you increase the load—and wear and tear—on everything from tie-rods to the oil sump. "

[CaminoRacer]

[Galaxy]

Crushing the subject:  https://www.roadandtrack.com/car-culture/a23391373/theres-a-lot-you-need-to-consider-before-buying-tires/

"Automakers pick tires years before a model debuts and tweak everything from dampers to suspension pickup points around the rubber of their choosing. "It's the most engineered single part on your entire car," says Aaron Link, lead development engineer for Chevrolet Performance Cars. Slap on something more capable, and you increase the load—and wear and tear—on everything from tie-rods to the oil sump. "

Regarding that, I saw a video on YouTube about putting tires on classic cars. I had assumed that you basically upgrade the performance on an old sports cars by fitting modern tires like a Cup 2 R on them. But you are not supposed to do that.

http://www.youtube.com/watch?v=wbRr6gzD82I

skip to 5:50.

[CaminoRacer]

Regarding that, I saw a video on YouTube about putting tires on classic cars. I had assumed that you basically upgrade the performance on an old sports cars by fitting modern tires like a Cup 2 R on them. But you are not supposed to do that.

http://www.youtube.com/watch?v=wbRr6gzD82I

skip to 5:50.

Yeah, old cars usually need different alignment specs which may require new suspension parts.

New cars aren't going to crash because you put stickier tires on em.

[12,000 RPM]

The most extreme tire Cougs has bought is a Michelin Primacy MXM4, at the recommendation of his service advisor.

[MX793]

Crushing the subject:  https://www.roadandtrack.com/car-culture/a23391373/theres-a-lot-you-need-to-consider-before-buying-tires/

"Automakers pick tires years before a model debuts and tweak everything from dampers to suspension pickup points around the rubber of their choosing. "It's the most engineered single part on your entire car," says Aaron Link, lead development engineer for Chevrolet Performance Cars. Slap on something more capable, and you increase the load—and wear and tear—on everything from tie-rods to the oil sump. "

Can't be too precisely calibrated/optimized to the tire since you can often get the same car with multiple tire options and nothing else is different.  You can get Civic Sis with either all seasons or much grippier, "max performance" summer-only tires, with no other difference between the cars (same springs, bushings, sway bars, etc).  Non-PP Mustangs, depending on which wheel option you get (18, 19, or 20 inch), come with either Goodyear F1 Asymmetric all seasons, Pirelli P-Zero Nero all seasons, or Pirelli P-Zero hi-po summer tires, with no other differences to the car.  Camaro LTs are available with a couple of different tires, including run-flats, with no other differences to the car.

When you're at the very pointy end of the performance spectrum, yes, the cars are engineered around the OE tires.  Your Shelby GT350Rs, Camaro Z28s, Corvettes, 911 GT3s, Ferraris...  I specifically prefaced my "tires are the most impactful mod per dollar" statement with the words "unless you're already at the pointy end of the performance spectrum".

If you buy a base Mustang GT or Civic Si with whatever crappy, 500TW all-season tires they come with, the first and biggest bang-for-buck mod you should be looking at is better tires.  That will get you more all-around performance gain (will improve cornering, off the line acceleration, and braking) than any other upgrade(s) you could do to the car for the same money.  Of course, those cars were also already engineered to run better tires than what comes from the factory on their base models, so the risk of increased wear and tear is nil unless you go bonkers with tires and put something far beyond anything the factory ever equipped them with (like a set of 305 R-comps at all corners would not be advised without other upgrades).  I knew a guy who threw some really wide gumballs on his S2000, along with some suspension mods (coil overs, sway bars, aggressive alignment/camber settings) and he tweaked something in the suspension from cornering loads because he'd increased the grip level to such an extreme over stock, so it's certainly possible to go too far.  But I would guess his car was set up to generate at least 1.5x, if not closer to double, the grip that any factory S2K would have been capable of.

[AutobahnSHO]

haha I love me some arguing against reality