vettemerica

Hey all,

I'm a former BMW guy. I've owned a '95 325is/5, a '99 540i/6, and an '07 335i/A. I traded my POS 335 for my '06 Z51 a year ago. What...a...difference. There is absolutely no substitute for American muscle, especially when it's in the form of America's only true sports car (the SRT Viper no longer competes internationally, IIRC, though I'd love me a Viper).

It's funny, the internet likes to compare the C6 Z06 with the new BMW M4. It's a joke, really. Of course, it would offend everybody's sensibilities if the M4 were compared to the outgoing C6 base.

The M4 makes 425HP and 406lb ft/tq. The coupe weighs 3,530lbs, the vert 4,055lbs! This makes for a power/weight ratio of 0.120 for the M4 coupe, and 0.13 for the C6 Z51 (3,200lbs, and using a 410 or 411HP SAE correction for the LS2). Even without the SAE net power correction, the Z51 is still at a 0.13 power/weight ratio. To give some perspective, the C6 Z06 is at a 0.16 p/w ratio, and the ZR1 at 0.19 (interesting how the p/w ratio increases by 0.03 for each).

Yet, the official Nurburgring (yes, I know) lap time for the BMW M4 is 7:52. The LS2-powered Z51's time? 7:59.

As an aside, a sub-8 minute time on this track is considered world class. For example, the outgoing M3 coupe could never manage to break the sub-8:00 barrier. Nor did the Aston Martin DBS, V8 Vantage, Audi R8 (V8), Merc CLK 63 AMG Black, Lexus IS-F, Lotus Exige S, nor the previous BMW M5 or even M6! Crazy, right?

For those who care, the primary reason for the M4's 7:52 time, IMHO, is that the Germans take what's called a "fliegende runde," or "flying start," in addition to them being able to pick and choose their weather conditions. From the research I've done (mainly from what I've managed to dig up and read), the LS2 Z51 is absolutely capable of a 7:52 lap time at the 'Ring. What gets me is, what is it about the BMW M4 that makes it parity with the C6 Z51 on the track? It seems to defy physics.

Anyway, I'd like to hear your comments.

Best,

Erik

Dano523

Gm does not do flying laps for Nurburgring official times.

ls1121

So what you are saying is that the Germans cheat?

vettemerica

Yes, yes...I mentioned this. However, how many seconds would a flying lap net over a start from a dig? 7 seconds? Seems a bit high!

The Germans don't cheat, they just time their laps differently.

5knives

There are no regulations on how lap times are measured at The Ring. They're more of unofficial benchmarks between car manufacturers.

Dano523

Flying lap also means that the tires and brakes are up to temps, which makes a huge difference at the start of the time attack.

Also keep in mind that the C6 Z-51 option car was tested with Goodyear f1's (which no one is running any more), and not the new Pilot Super Sport that are stock now on both the C7 and M-4 cars.

vettemerica

Ah...yes, all of this would definitely add up to at least 7 seconds of time savings. Tires included. The F1's they were running were probably runflats as well.

Dano523

If you really want to lean how bad/skewed some of the official OEM Nurburgring times are, do a search on the GT-R time, and how Nissan came up with that skewed time for the car.
Note, don't get me wrong, the GT-R will corner like a monster, but come top end high speed game, that is a different matter.

Bluntly, the numbers don't really mean a thing for most of the OEM times since there are too many variables, and worse, most of the production cars tested there are not set up the same as fresh out of the factory like you would receive them from the dealer if you buy one yourself.

Bluntly, if you want to get an idea of how well a car did, then you need it's time numbers from half track onward (when everything is warmed up, since it will not matter if it was a flying lap or not), and pay close attention to the entry and exit speeds of the last S bend, then the top end speed down the final long straight as well. Also, got to play "what is not like the others" on the tested car as well, hence was it lowered down so low for that track session that it would be stuck trying to go over a standard height sleeping policeman (speed bump) instead.

vettemerica

Enlightening explanation as to why the Nurburgring is viewed as a silly test track to most publications and shows. You are probably spot on.

JaimeVrod

I had never considered the differences in how GM and BMW time their vehicles. I just assumed it was standardized. Now I'm even happier that I have an LS2 Vette.

stillspinnin

Also keep I'm mind the ls2 vette was developed 10+ years ago and the m4 is brand-new. Just shows you how far ahead gm is

vettemerica

I agree! When put into that perspective, it is pretty amazing to think about. The sheer fact that a *9* year old car that costs less than 1/3 - perhaps even 1/4 - of a fully optioned M4, yet outperforms it, is surprising. Granted, I'm sure the M4 has all the frills over the C6, but let's gloss over that, shall we?