BS 996
 

I'm just going to leave this right here...


https://cimg1.ibsrv.net/gimg/rennlis...011729054.jpeg

...and it appears that it may well be that not one of the trophy winners in BS last year at Nats will be back in the class.

How does the 996 have that high of a grip rating? I think it's a good move (as would be 997.1, IMO), but that seems high considering the front tire and camber limitations.

Since the Macan is also in BS, how about adding the model years 2021 and 2022 GTS to the table?

My grip rating is simply weight divided by the sum of the front and rear rim widths. The 996 is by far the lightest of the top 5 in that list but has good rim width with 8s & 10s.

I don't take into account camber capability, nor what tires might actually be fit on the rims or might fit within the space available or might actually be available. That's all way too difficult to figure out for every car. (I do have to choose a rear tire diameter in order to calculate thrust.) I've never found a justifiable way to relate camber capability to cornering capability, for that matter. It's not that I don't think it's a real thing, just that there is no way to generically use it... too much variation from one design to another. Just like Mcpherson struts... we all know they are an undesirable design in a race car, no matter the static camber available, but how much do they really detract from cornering in the real world, 996 vs. Corvette, for instance? Beats me. Too many variables.

The fact that the 996 only has an 8" front rim might seem to justify some sort of special knockdown, except that it has so much less weight on the front that you can make the counter argument that 996 rim widths are more appropriate to the weight distribution than all the other cars when it comes to cornering grip and therefore has an advantage. At one time I actually used a more complicated calculation for grip based on rim size and weight distribution, but it didn't seem to predict anything more accurately so I dropped it.

Once I get some time.

I see that it's over 4400lbs and on 9's & 10's, right? It won't rate well even if we forget about the high CG. Its grip and transient response rating will be very poor. I assume its several inches wider than these others as well. It may be the sportiest of all SUVs, but it's no winning autocrosser.

I've told the story on this forum of when I destroyed the original Macan Turbo, driven by a friend who was a better autocrosser, with my C5. Your can rest assured the new GTS rating will be well below the C5 rating in that table.

Is your 997.1 assuming the widest option widths of 8.5" and 11.5" or the most typical 8" and 11"? The reason I poke at that is real world, the Vettes have more grip due to 1) double wishbone front end, giving and 2) more camber adjustability, at least up front. I've yet to be rear grip limited on my 997 but in any slower, >90 deg corners the front is quickly the limit. It should improve some this year going to 255 fronts versus 235 but it'll still retain the light front end traits and thus sweeper & turnaround grip limitations.

As always, the data, number crunches and summary is always appreciated.

Don't forget the '21 Supra is in BS now too. Seems like it should be a similar case to the M2 / M2C where the numbers look impressive on paper, but the delivery and rev range don't translate to a huge gap in the real world. The improved suspension tuning is a far bigger concern, plus there's no way Toyota is "done" with that car. It'll get better every model year, announced changes or not.

My gut rank is OG M2, followed closely and pretty evenly by the Supra / M2C / Z51. I think the Evora is still in the mix on transition heavy courses. I think the rest is filler.

That Z51 scares me. Someone good, prepping a post-refresh car, and doing well with it could do some damage, which IMO would hurt the class. Perception is so important and AXers are sheep. Hope is the 8.5s up front hold it back just enough.

Consider adding the 2023 Nissan Z:
400hp/350lb-ft
9.5F/10R

Rest should be similar to the 370Z Nismo you already have in there, it's the same chassis:
100.4 wheelbase
Similar width
Maybe add 75lb for the turbo plumbing over the 370

It's getting harder to find Porsche data these days, I think because of Porsche tightening restrictions on their order guides.

For the 997.1 I used 8 and 11 and for the 997.2 I have 8.5 and 11 as what I found to be the widest wheel sizes. (I always want to use the widest, not the most common, for any car.) Can you point me to data showing the 8.5/11.5 option? And which years it was available?

Carrera Sport wheels were an option from 2005 on RWD and AWD models.
19x8.5 and 19x11.5, option code XRR.

What would be terrible about the Z51 being competitive? Before now it didn’t have a home to be a good platform and there were so many of them built.

On the new Z, I have a bet with a friend on the weight. It'll be over 3500 lbs. The turbos, piping, intercooler, and the additional weight added to other things for robustness/performance with all the added torque and power will add more than 75 lbs. Gearbox, driveline, brakes, mounts, etc will all need a bit of work.

I've always planned to add the new Z when good data was available. Thanks.
A friend just got a '22 Supra and plans to run it this year in BS. I haven't been able to find a good source of info on the suspension changes. I will review the engine dyno info for it and the '21. I found one source that did a back-to-back, same-day test and saw +38hp over the '19. The torque gain was similar.

Thanks. I will update.

On my way today to pick up a 2008 C6Z51.

Two points:

• If it were the garden variety base C6 I'd agree with you pretty easily. Tons of them, fairly cheap, and cheap to run / maintain for the performance. I also advocate for used cars to be moved down a class pretty often when I think it can be beneficial to the membership.
• "Competitive" is a bit loaded. Within noise of course-dependent parity is the ideal, but a really tough mark to hit. More often either a car isn't very competitive, or resets the bar of a class.

The "right" BS C6 is a fairly rare (coupe + z51 + manual) package on a two year run. 08-09 z51, gets the LS3/TR6060 and other improvements. The entry price (well, at least when we began discussion, who knows what the prices are in today's nutty market) is the same as an AS z06, for a far worse car. In '10 the Z51 was replaced with the widebody / wide wheel but otherwise similar Grand Sport. The Grand Sport was right up in the AS mix for a few years before the fastest people swapped to the z06, the LS3 and stubby gearing is pretty raped ape, the LS7 z06 is geared to the moon which negates it's power in slow corners.

We have plenty of Corvette friendly places to play. Making an undesirable, rare / difficult to acquire, and expensive to purchase version as a dominant car is a great way to kill a class. That's why I'm hoping it's either slightly off pace, and/or no top end drivers make a full bore effort with one and clean house.

Ah, now I understand. I was confused at first about the years, but then I remembered that the LS2 was in the prior years C6 (non-Z06) rather than the LS3.

BS Production Numbers: I wanted to see just how rare the Z51 Coupes really were as compared to Supra and M2.

2008-09 Z51 manual coupes: 6,170

There are even more Z51 convertibles and Z51 quick-shifting automatics. I don't think Z51s are difficult to find. I found two Z51 coupes in the week after I sold my C5, both with less than 30K miles, and bought one. There were many other higher-mileage examples on-offer.

2019-20 Supras (all trannys): 8,771

So, calling the Z51 Coupes "rare" and "expensive" is just silly when you are comparing it to 1 or 2 year old (or new) Supras, which very few people actually want (obviously), and the M2 and M2C, which are not at all rare, but which are more expensive, both in initial purchase price, in expected new-car depreciation loss, and, if history is any guide, in maintenance.

Is there any good reason why the LS2 Z51s will be much, if any, slower than the LS3 versions? Even if we throw out the huge 2005 sales and say we don't want the first year, there were 10,147 Z51 coupes sold in 2006-07 and those are much cheaper. Again, even more Z51 convertibles and automatics during those two years.

BMW M2s sold much, much more. Approximately 27,000 from 2016 thru 2018. I couldn't find figures for 2019 or 2020.

The more impactful thing on BS in 2022, I think, is the fact that all used cars are very expensive right now. Not enough other models were put into BS to replace all the SuperPonies that were already bought and moved to FS even if we hadn't had a pandemic used-car squeeze, so I don't foresee a lot of buying of the existing cars in class. There were plenty of other cars, including Porsches (987.2 CS) and other Corvettes (C7Z51) that could/should have been moved that would have brought numbers. (I have never actually seen even one fat C7Z51 on it's narrow little rims run at an SCCA autocross. That's pitiful. 26,000 Z51 coupes were sold in the two years 2014-15 alone. Talk about a popular car with no place to play!)

All this will surely leave BS sorely depleted this year and maybe next as well, barring a convenient recession. The only thing that can save BS now is if the 400Z really has 444hp and weighs 3200lbs like the game says and sells for $40K.