http://www.autoblog.com/2014/12/14/j...ay-race-video/

 

Well there is some aero and maybe as much as 1000 pounds lighter + tires are probably almost the same section width, could make this car work much better with even the same tires. I know that at ORP an RS America lightened and with a wing and highpo Rothsport motor was a good 4 seconds faster per lap than my .2 GT3. So yeah- don't discount the older 911's!

 

Good points. Not knowing details of the car, I forgot to account for the possibility of much better aero on the '72.

 

Great feat on the track but we truly are not talking a true 72 , b/c of the engine change, wheels not stock, different brakes, added aero packages etc.....

 

aero: Front Splitter, large wing, and skirts!

He doesn't mention the size of the tires in the autoblog video but at least 325 on 11" rims.

Quite the track special!

 

Thanks for posting this. I've been studying Jack's Big Willow videos, doing the same caparison since my last day there Dec 14. He's freaking fast in that 72 and he's has years of experience. He's a full 14 seconds in front of me, although I've only done two days there, one in the GT3. Turns 2, 8 and 9 are pretty high speed requiring a great deal of trust, which as a relative novice takes some time acquire.

 

Great video. Thanks for posting. The GT3 is a great dual purpose car, but a highly optimized track machine is hard to beat for pure track driving enjoyment.

 

Pretty sure Jack's on NT01s there, so not hugely sticky rubber. The biggest difference is tire to weight- he's got just under 1000 lbs on a 991 GT3, but his car has more rubber section width on the ground. He's also running a much more aggressive aero package than the GT3, and it's far more effective because the car is so light. The car is definitely dialed for that track.

Still it's a highly street able car that's carrying the weight of a bolt-in cage in that video, not a track only monster. It could likely still be recreated for under 100k, and it would be lucky to break 300 hp. Goes to show that it's all about grip in the end, isn't it?

 

As I suspected. It's really a shame that the GT3 at 3250 lbs approx. is one of the lightest modern cars out there for track work. Light is fast.

 

The other shoe drops, http://www.roadandtrack.com/motorspo...ws&date=122614

If this is the case, by comparison, I think the 991GT3 is still doing "OK" - specially considering the comparative lap times & details in Hoopumpers #16 post to the AutoBlog link above.

 

Thanks for the kind words. There are some aspects of this comparison that are misleading. But I'm pretty confident with the following:

The 991 GT3 has a curb weight of 3,152 pounds. As a European curb weight, it would include 165 pounds for the driver. My car is 2,654 pounds with gas and me sitting in it. So my take on the weight difference would be that I'm 498 pounds lighter.

The MPSC2 is pretty significantly faster (according to the manufacturer) than the MPSC. And I don't know many people who thought the MPSC was slower than the Nitto NT01, which is what I ran in the fast lap. They were about 8 months old at that point, and I drive the same tires around town and to (and then on) the track. If anyone wants to gift me a set of MPSC2s, I'm pretty sure I could improve on my lap time.

Randy Pobst has won multiple SCCA World Challenge GT Championships, twice in Porsche 911 GT3 Cup Cars. He is a Porsche factory supported driver, and was chosen by them to make the attempt on the production car track record at Willow Springs in the 2015 Porsche 918, which he set. I think it would be laughable to say I am a better driver than he is.

The pre-1974 911 body generates about 250# of lift at 130 mph. My home-made wing and splitter cancel that out, I believe. But not by a wide margin. Without a wing, the 991 chassis has pretty great aero numbers, and I would be very surprised if the GT3 configuration with its additional fixed wing is not significantly better than my $80 beer-cooler-foam setup.

So until someone convinces me otherwise, I'll stand by the advanatage of aero, tires and driver go to the GT3 in the video. I have a 500# weight advantage, but the GT3 has 475 hp to my 272 hp. I do have 3/8" wider tires, front and rear.

My car is mostly street driven, without the bolt-on wing and splittler. I don't have special tires I take out to the track with me. I have single-adjustable front and rear shocks, coil springs, and some one-off mods to the geometry of my suspension that Tyson Schmidt came up with.

So what would I consider misleading about the comparison? The track. Willow Springs is probably the fastest track in North America (neck-and-neck with Mosport) -- so people think of it as a horsepower track. But it doesn't have any 2nd-gear turns on it, which really makes it a momentum track. My power deficit gets miminized at this track in a way it wouldn't at any other California track. And the same goes, to some extent, for the weight advantage. It's slightly magnified at this track, since so much of the track is made up of corners with sustained high speeds. I can't say it with certainty, but I don't believe I could come close to the 991 GT3's lap times at any other track in California. In that sense, I'm lucky that Willow Springs is my home track.

But still, it's kind of surprising to me that all these years of development have not produced a 911 that is able to maintain speeds through a 90-mph sweeper like my old 911 can. Even when Pobst set the track record for a production car in the new 918, my speeds through most of the track's corners were faster.

I'm not defying any laws of physics. Lots of 911s are MUCH faster than me at Willow Springs. But they're usually track-dedicated cars on Hoosiers or slicks. I made the comparison with the GT3 because my car does most of its driving on public roads, not tracks. As a 'race car for the street,' I thought a comparison with the GT3 would be fair game.

It was also interesting to make the comparison because this new GT3 is so FAST. The previous best lap for a 997 GT3 RS with pro driver Steve Millen at the wheel was a 1:33. This new 991 GT3 has taken a huge leap forward.

 

I haven't studied numbers on it in detail, but my general impression is that NT01 is faster than MPSC, and I'd guess that NT01 and MPSC2 will be close.

 

Weight matters. Have pounded the table on this from day one.

Fingers crossed the new RS maximizes the inherent weight savings in the new 991/9A1 platform.

Nice work Jack. Thanks for posting.

 

I agree. Imagine what this comparison would look like if the GT3 weighed 2,500 pounds. I think that's within Porsche's capabilities (the Miata manages it), but they keep making the 911 bigger...



Maybe there's no getting around the propensity of the broad demographic of their GT3 buyers. I think if it were up to the Rennlist GT3 owners, the vote would be to make the thing a 2,300-pound car.

If anyone's interested in the same clip without my irritating voiceover and frequent pauses, then here's a version where you can hear the two flat sixes uninterrupted:

 

I like this guy's^^^thinking...