3/24/2011

03-24-11 - Some Car videos I like

Most car racing is just excruciatingly boring. In car time attack videos in crazy fast cars, blah blah boring. Some exceptions :

YouTube - On Board with Patrick Long at Lime Rock 2010
It's cool to actually hear the driver talk about what he's thinking. All throughout racing there's tons of crazy stuff going on, but you can't appreciate it from watching cuz you don't know all the subtle things the drivers are thinking about; it's actually very strategic, one move sets up the next. It's so much more interesting with the voice over.

It's pretty nuts the way the Nurburgring races run cars of all kinds of different speeds. You've got crazy race cars running with just slightly modified road cars, and that leads to lots of passing and action, way better than something like F1 where everyone is the same speed and you can never pass :
YouTube - Corvette Z06 GT3 vs. Porsche Cayman @ N�rburgring Nordschleife VLN
YouTube - BMW Z4 M Coupe vs Porsche 997 RSR @ Nurburgring 24 Hr Race

Then you've got people who take their race car out during normal Nurburgring lapping days : (the Alzen 996 Turbo runs 6:58 on the ring, one of the fastest times ever)
YouTube - Porsche Team Jurgen Alzen Motorsport

The other way you get exciting races is in amateur races where you have some very fast cars, and some cars that are woefully bad and spinning out - especially when the fast cars fail to quality and have to start at the back of the back and move forward :
YouTube - Scott Goodyear On Board - 1988 Rothmans Porsche Turbo Cup Series Mont Tremblant Race
NASA GTS Putnam Park, May 15, 2010 on Vimeo

(BTW the Porsche Carrera Cup races are some of the most boring races I've ever seen; all the cars are identical so they can never pass, and the drivers are all rich amateur boneheads who can hardly work their auto-blipping sequential shifter)

The RUF Yellowbird might be the "lairiest" car ever. Take an old Porsche with no traction, lighten it and stick a giant turbo in it. It did at an 8:05 at the ring with the tail sliding the entire time. Completely insane.
YouTube - Ruf Yellowbird DRIFT in Nurburgring
YouTube - 930 Ruf CTR Yellowbird on nurburgring
YouTube - Insane driving in PorscheRUF Yellowbird - Nurburgring Hotlap

I like this video as contrast, it shows how hard it is to drift in the new 911 (even the GT3, which is much easier to drift than the base models). What you have to do is come in to a corner very hot, over 60 mph, brake very hard and very late, continue braking as you turn in ("trail brake"), this should get the weight loaded up on the front wheels and make the rear end light, now you heel and toe into 1st, wait for the nose to get turned in a bit, then on power hard out of the corner. It's much easier going downhill too.
YouTube - Porsche 911 (997) GT3 drifting


Some other random car shite :

Weight distributions :


Porsche 997 C2 : 38% front , 62% rear
Porsche 997 C4 : 40% front , 60% rear
Porsche Cayman : 45% front , 55% rear
Lotus Elise    : 38% front , 62% rear
Lotus Evora    : 39% front , 61% rear

I was surprised how rear-biased the Loti are. So the best handling cars in the world (Loti) have a 911-like rear weight bias. Granted, the weight at the wheels is not the whole story, the location of the engine lump matters a lot for dynamic weight transfer purposes, but still. Weight under acceleration and lateral forces under cornering would tell you a more complete story.

(people often say a car has a 50/50 weight distribution and thus it's "perfectly balanced" - but that's only true when it's not moving; under acceleration it gets more weight in the rear, and under braking it gets more in the front; I think the best cars are slightly rear-biased, like the cayman, because the under braking they becoming only slightly front-biased; front-biased cars get dangerously light in the rear under hard braking)

It's also interesting to compare tire sizes :


Porsche 997 C2 : 235 front , 295 rear
Porsche Cayman : 235 front , 265 rear
Lotus Evora    : 225 front , 255 rear 
Lotus Elise 1  : 185 front , 205 rear 
Lotus Elise 2  : 175 front , 225 rear 
Lotus Exige    : 195 front , 225 rear 
Honda S2000 AP1: 205 front , 225 rear
Mazda RX8      : 225 front , 225 rear

The differences are revealing. The Evora for example weighs about the same as a 911 GT3 and has the same weight distribution, but has much less staggered tire sizes. This means the tail will come out more easily on the Evora, you generally have less rear grip. The Cayman has much less rear weight bias but has the same wide rear tires, which again edges towards understeer. The Elise setup was changed during its life to a much more staggered setup (it's much narrower tires in general are due to its much lower weight).

(I also tossed in the AP1 S2000 and the RX8 since they are just about the only OEM cars that are tweaked for oversteer; the newer S2000's are on a 255 rear cuz honda pussed out; note that unlike the Elise, the S2000 actually weighs close to the same as the Cayman and Evora, yet is on much narrower tires; that provides more "driving pleasure")

(BTW it's risky to try to learn too much from Lotus because they do things so differently from any other car maker; they use stiff springs, *NO* sway bar or very weak sway bar, no LSD, generally narrow front tires for quick steering, etc.)


For my reference :


BMW M coupe (E86) (2007)
330 hp , 262 lb-ft
3230 curb weight (manufaturer spec)

Cayman S (987.2) (2009)
320 hp, 273 lb-ft
2976 curb weight (manufaturer spec)

I really like the M coupe ; I think it's the last great BMW, reasonably light weight, and tuned for oversteer from the factory. But it is just not as good as the Cayman in pretty much any way. It's also got a much smaller interior and much less cargo space. It's also really not much cheaper, because it's rare and is holding value well, while used Porsche values fall fast. The only real advantage is that the BMW engine is a bit better (it has more potential), and the OEM suspension setup is more enthusiast-oriented. The M coupe would be so much better if they hadn't separated the boot from the cabin; it should have been a proper hatchback; that would provide more feeling of space in the cabin, and much more cargo room. Instead you get a small claustrophobic cabin, and a small boot.

Sometimes I lust after the really old BMW's, like the E28 M5 or the E30 M3, I love how small and boxy they are, and the downward-pointed noses, but they are just so far off modern performance, you would have to do a lot of work on them (suspension, engine). So then I look at newer ones, like the E43 M3, but they really have most of the disadvantages of a new car - big, heavy, tuned for safety, etc. I wind up at the M coupe as sort of the sweet spot of old values and new engineering, but then it just doesn't make sense compared to the Cayman either.

BTW the 2009 Cayman is a big improvement over the earlier cars. It's got a new engine that is really much better; if you just look at the figures it doesn't look like a big improvement (20 hp or something) but that hides the real value - it doesn't blow up like the old ones do; the older ones have power steering problems, air-oil separator problems, oil starvation problems, all of which is fixed in post-2009 cars. But you have to wait until 2013 because the real values in used Porsches come after the lease returns start showing up - when the cars are 4 years old.

Continuing the for my reference theme :


Porsche GT3 (997.1) (2007)
415 hp, 300 lb-ft
3075 - 3262 curb weight (manufaturer spec)

note 1 : it's very hard to find accurate weights of cars. Wikipedia is all over the place with innacurate numbers. For one thing, the US and European official standards for how weight are measured differ, (eg. what kind of fluids are required, standard driver weight added or not, etc), also the weights differ with options, and one of the tricks manufacturers play is they measure the weight without options, but then make those options mandatory. This is another one of those things you would like to see car magazines report on, give you true weights, but of course no they don't do that.

note 2 : the GT3 is more than 2X the price of the M Coupe or Cayman, but in terms of depreciation I'm not sure it costs much more (and the M Coupe is actually cheaper than the Cayman I believe because it will depreciate less). In some sense, you should measure car cost not by initial outlay, but rather by the annual depreciation + opportunity cost of the money sunk. There are some classic cars that have expected ZERO depreciation - that is, other than opportunity cost and transaction cost, they are completely free to own (Jag E-types, classic Ferraris, etc.)

However, buying a car based on expected depreciation sucks as a life move. You have to be constantly worried about how your usage is affecting possible resale value. It's like the future purchaser is watching your every move and judging you. OMG you parked outside in the rain? That's $5k off. You drove in a gravel parking lot? That's $5k off. You put too many miles on it? That's $10k off. It's a horrible feeling. It's much more fun to buy a car and assume you will never sell it and just do as you please with it. (of course many people allow this disease to affect their home ownership experience - they are constantly thinking about how what they do their home will affect resale, which is a sad way to live).

So for example I think a $70k GT3 is actually "cheaper" than a $50k base 997 at the moment, that thinking sucks you into depreciation horror.


The Boss 302 Mustang has layed down some great lap times, in M3 / Porsche territory, for about half the price. The old "retard's wisdom" is that European cars may be slower in a straight line (than cheaper American cars), but they go faster around corners - is no longer true. (In fact a recent comparo of the Porsche Turbo S vs. the Corvette ZR1 found the Porsche to be faster in a straight line, but the Vette to be faster around a bendy track! That's the exact opposite of the old stereotype which people still deeply associate with these cars). That said, I'm totally uninterested in this car (the Mustang). It weighs over 3600 pounds (the GT500 is over 3800). It's got those damn tall doors and tiny glass that makes it feel like a coffin. I drove a standard mustang with the same body style recently as a rental car, and it was just awful, it felt so huge, so unweildly. The whole high-power giant heavy car thing is such a turn off. The only American sports cars is the Pontiac Solstice. But the other reason I don't like the 302 is Aero.

I believe Aero is a very bad thing for road cars. Much of the speed of the 302 comes from aerodynamic bits (henceforth Aero). The same is true of the Viper ACR, and even the Porsche GT3. These cars have layed down much faster track times than their progenitors, and the main difference is the Aero (the other big difference is stiff track suspension). You look at the lap time and think the car is much improved, but the fact is you will never actually experience that improvement on the road. Aero only has a big effect over 100 mph; you are not taking corners at 120 on the road.

And furthermore - even if you *are* taking fast corners I contend that aero is a bad thing. The reason is that amateur drivers don't know how to handle aero and can get unpredictable effects from it. For example if you are going through a corner at 120 steady state and you brake, you decrease your downforce and suddenly can lose grip and either spin out or understeer. Aero can create false confidence because the car feels very stable and planted, but that's only there as long as you keep on the gas. So IMO when a car is improved by getting better Aero, that is not actually a benefit to the consumer.

Take a car and slap a big wing on it; the lap time goes down by 3 seconds. Is it a better road car? No, probably not. But if you look at lap time rankings it seems much better than its rivals.

I believe that lap times in general are not a great way to judge cars. Granted it is much better than 0-60 or 1/4 mile times, the way the US muscle mags compared cars in the old days, but lap times can be gamed in weird ways (tires, aero, suspension, etc) that aren't actually beneficial to the buyer. (of course, even worse is looking at top speeds, which that moron Clarkson seems to fixate on; he even does the most lol-worthy thing of all which is to compare top speeds of cars that are *limitted*, like he'll say that some shit sedan with a top speed of 160 is "faster than a BMW M5" ; umm that's because the M5 is limitted at 155 you giant fucking moron, and even if it wasn't top speed is totally irrelevant because it depends so much on drag and gearing; you can actually greatly improve most cars by regearing them to lower their top speed to 120 or so).

Another issue is that lap times heavily reward grip. And grip is not really what you want. You want a bit of tail sliding fun, and ideally at a safe speed in a predictable way, which means reasonably low grip. This is part of what makes the Miata so brilliant, they intentionally designed it with low grip, so that even though it doesn't have much power, you could still get the tail out (the original was on 185 width tires).

I love the Best Motoring car reviews ; for example in this one :
YouTube - Boxster S vs Elise vs S2000 Touge Test & Track Battle - Best Motoring International
Tsuchiya rates the cars by how progressively they go from stable to spinning ; the ideal is a car that is steady and gives you lots of feedback, the worst is a car that suddenly goes to spinning without warning you.

If you just look at lap times, you will favor cars with aero downforce, stiff suspension, and wide tires. That's not really what you want. You want cars with "driving pleasure". For some reason, the Japanese seem to be the only manufacturers who get this; cars like the Miata, S2000, RX8 are not about putting up figures, they are about balance, and all those little things that go into a car making you happy (such as shift feel and getting the rev ranges right and so on).

13 comments:

Kevin Pancrazio said...

One of my favorite nürburgring videos:

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

The drivings pretty meh... but the commentary is awesome.

Tom Forsyth said...

> This means the tail will come out more easily on the Evora, you generally have less rear grip.

Weight distribution is a good way to determine whether the back end will come out. The real question is how easy it is to recover, i.e. STOP the rear end continuing to move out. Easy move, easy recover = fun. Hard move, hard recover = death machine.

cbloom said...

The real death machines are "easy move, hard recover" (eg. Porsche 930's and Gen 1 MR2's).

The thing that really bugs me is I want to know something like - is the Evora actually easy to kick into a drift and catch? does it surprise you with unexpected tail slides in the wet? is it progressive and warn you when it's going to let go?

Zero information. None. Not one single car review site that says anything more useful than "this car is great!" in stupid flowery language and metaphors.

Tom Forsyth said...

Gotta read the right mags:

http://www.evo.co.uk/carreviews/evocarreviews/260026/lotus_evora_supercharged_review.html

"With DPM off, the nose runs a little wide at first, but keep the throttle on and the torque will tip the balance rearwards towards the end of the corner until the rear is slipping slightly. You now have options that weren’t open to you in the stock Evora, and although the weight can carry the rear if you back off sharply into a turn, it won’t keep going, the chassis feeling flat and poised and recovering to neutral as the speed scrubs away."

cbloom said...

Nah, I disagree, I read Evo and I find them to be as bad as anyone.

They just love to call everything "poised" or "focused". For example their review of the 911 :

"There’s plenty of feedback from the front end and huge traction from the rear, but you also get brilliant poise when you want to make fast progress, and throttle adjustability when fun is more important. Basically the harder you drive it, the better it feels."

Can you tell the difference between the Evora and the 911 from those two reviews? No, not at all.

They are actually devoid of information. There are actually 0 bits of content in all that writing, because it is 100% predictable.

To actually provide information, they have to say something negative once in a while, which they almost never do, because car reviewers are in the pocket of the car makers.

Thatcher Ulrich said...

What do all you car enthusiasts think of the Tesla Roadster?

cbloom said...

Uh, in terms of driving dynamics the Elise that it's based on is just a lot better, right? I guess the electric motor has great low down acceleration which is probably a hoot. I haven't driven it so I can't really say. But you can't take it on road trips, and you can't take it to the track, so what can you really do with it as a petrol-head?.

One thing for sure is that it's absurdly expensive. You can buy a Prius *and* a Lotus Elise for the price of a Roadster, and actually have a lot left over.

IMO there's no reason for it to have a sports car body. It should have a hatchback body and thus be more useful as a general purpose city car.

Thatcher Ulrich said...

Yeah, I know it's a lot heavier than the Elise, but then the drivetrain is totally different so I don't know what the bottom line on that is.

Re taking it to the track, why not? I've heard of people doing it.

I think the reasoning behind the sports car body is twofold: 1) very low wind resistance enabling long range (about 2/3 the energy consumption of a Nissan Leaf), and 2) can charge a lot of money for it, enabling a big battery.

cbloom said...

I certainly am very curious to try it.

Aaron said...

It's a mountain of power... in a straight line: http://www.youtube.com/watch?v=gXfV2hw_2Xo

I love the idea of cramming electric engines into all kinds of body shapes (the weirder the better... electric Avalanche anyone?). Nothing is worse than everything looking like a Prius.

cbloom said...

So the problem I've read about the Tesla on the track is that it overheats, supposedly it can only do 2-3 laps before going into limp mode. (and please, ignore all journalists, search for owner forums)

To be fair, there are plenty of petrol cars that do the same thing, including the great GTR and BMW N54 engine cars. In both of those cases, the cars can be pretty easily fixed by outfitting better cooling (larger/more radiators), so maybe the Tesla can be similarly fitted. Though I sort of doubt it's as easy because the batteries and electric motor don't have coolant and oil cycling through them the way normal engines do.

But it's sort of irrelevant because if you buy a Tesla it's not to take to the track. It's for shooting off of stop-lights and weaving around commuter traffic.

cbloom said...

"Nothing is worse than everything looking like a Prius."

I actually think *every* car should be a hatchback. There's really not much point to any other body shape. Sure, sports cars could be low-slung hatchbacks (aka shooting brakes), but you don't pay any aero penalty for the bulge behind the drivers, so why not have it?

Every other car shape is pretty much sheer vanity. For example, why would you buy a Subaru WRX sedan when you could have the hatch which performs identically? Oh no, I don't want useful space that makes my car more practical, I care more about whether 14 year old boys will think I'm cool.

Aaron said...

Because cars are art and blood lust and sex appeal. Or at least they should be for how expensive they are.

Is the marginal increase in utility and aerodynamics worth cars all looking the same?

God I really need to sell my Civic :)

old rants