sjfehr

Now that Ryan Clark won a BS national championship in a 987.1S, I don't think there's much chance we'll see 987.2S, 981, or 718 dropped to BS anytime soon. 718 has less HP than 987.1S/987.2S, but doesn't the better torque curve give better overall accelleration? Though I still think they all make more sense in BS than AS. 718 won't be able to hang with the Z06 on power or sweeper-heavy courses, but could still do well on slalom/transition-heavy courses.

burglar

I think it's cool you can get PTV on a base car. Also yeah, that torque curve should help the car punch WAY above its numbers, especially with the out-of-the-powerband digs we get in AX. Don't know how different the gearing is, but the base 718 just crushes a 918S until 4750rpm.

Is there much turbo lag to try and time? Granted my Mini is a budget car with 10 year old tech, but it's still a twin scroll. Timing the gap between when I hit the pedal and when max torque gets to the front tires is an extra challenge.

chriswd62

Apparently the 718 has some anti-lag technology that is programmed into sport/sport plus modes. I have yet to truly test it, so we'll see how well it works in an autocross situation. I'm still anticipating a need to adjust my throttle timing to account for the lag of the turbo.

"To minimize this lag, the new engines precondition the turbocharger under partial loads when the car's drive mode is set to Sport or Sport Plus. This involves closing the wastegate and partially opening the throttle valve, which increases the flow of air through the engine. This allows it to maintain a higher level of boost (since that air flows through the engine and out to the turbocharger downstream of the exhaust valves). This way, if you do give it some beans, the turbo is already spooled up."

User 52121

Yes, it does - I discovered it a few months ago when I had a 718S service loaner.

I made a quick video to send to some 924 Turbo buddies of mine as we were just talking about turbo lag a few days prior.

Here's the video:

The more I've driven the new 718S - the more I think it'll be the cheater platform to run in 2018 autocross.

burglar

The more I read the more I want to drive a Boxster / Cayman. Any Boxster / Cayman.

sjfehr

I was really impressed with the 718S I drove; no hint of turbo lag and lots of torque even at low RPM. I wasn't able to autocross it, but I was impressed with the engine.

mopar bob

How does the base 718 stand up to the Vette in AS? I think that the 718 would do great in the thin air up here.

edfishjr

Giving the C6Z06 a rating of 100, I show the 987.2CS, a car I might like to own, at 96.8, the way I rate things. The 718 base would be similar: it's slightly lighter, has better low RPM torque, same gearing, same width, big unknown is if it has any wheels available wider (or as wide) than 8.5/10? (I haven't researched it.)

As a comparison, in BS, giving the C5 a rating of 100, I calculated a rating of 100.4 (EDITED) for 987.1CS. (So, no, I wasn't surprised that a CS could win.)

So, by my rating system, the 987.2CS and 718 non-S are probably not as competitive in AS as the 987.1CS is in BS.

sjfehr

Out of curiosity, how would your equation compare 987.2CS and 718-base in BS vs C5 and 987.1CS?

edfishjr

I took a look and found an inconsistency in what weights I was using. I hadn't looked at this stuff in a long time and have played with it in the meantime.
Here is the complete list of B-Street that I've done.

B-Street Ratings
2017 M2______105.0
2009 Cayman S 102.3 (AS)
'15 Mustang GT PP 101.8 (FS)
2001 C5 Coupe 101.2
2006 Cayman S 100.6
2000 C5FRC __100.0
E92 M3 _______98.6 (FS)
2008 Cayman__98.4
2008 Boxster___98.0
986 Boxster S _96.5
S2000 ________94.9

I haven't tried to rate the 718, but, as I said, I think it would rate slightly higher than the 987.2CS, assuming you can get 8.5's and 10's. It has slightly higher peak torque, slightly less weight, same width. (If wider wheels are available that would create a big increase for the 718.) As usual, the actual dimensions of the optional wheels seems very difficult to figure out and Porsche has a history of publishing figures that differ from what is actually delivered. According to the build page, you can order 911 turbo wheels for a 718, but do you just get things that look the same or do you get the same widths? In the past, you just got the look.

My simple system uses a factor based on weight to wheel width ratio, 2nd gear thrust at peak torque, and width of the car without mirrors. The thrust factor is only given 70% importance compared to the other two. Here, I don't try to include diffs, mid-enginedness, lack of camber, better match of wheel width to weight distribution, or other hard to quantify effects, as I sometimes have in the past. All Porsche weights are based on official DIN weight + 33lbs. It's just an estimate. C5 and S2000 weights are actual measured values of real autocross cars.

Edit: What would be cool is if Sprockett could tell us the actual race weight of his 987.1CS.

Edit: updated numbers after finding some errors in the spreadsheet, added some other cars not in class by request

sjfehr

My 2010 987.2S PDK weighed 3064lbs, competition weight after the state championship a few years ago (low fuel light was on or about to ding on), with OZ wheels, 55% rear weight bias. I have PSE and the fancy directional headlights, but not PASM. Most of the other options on this car are the lightest possible, so, there's room to lose a few pounds, but not a whole lot.

edfishjr

That puts your car 27lbs lighter than my system would set it. That helps all the P-cars slightly.

I just added the BMW M2 to the list. It gets much less grip than the C5, in theory (but it pulled .99g on the stock tires in C&D's test), slightly better narrowness number, but blows all the other cars in the class away with huge 2nd gear thrust that's 16% more than the C5. In spite of the porkiness, it has more thrust at 1450rpm (24.8" tire) than a C6Z06 (25.9" tire) at the torque peak. Such a number skews everything so bad I think it renders the method unusable. And remember, I degrade the thrust factor by 30% compared to grip and width. But, I don't think I'd want to be in anything else in BS if I wanted the best chance to win.

Any course with 2 digs and not too high a top speed (so it doesn't have to shift to 3rd) and the M2 will run away from everything in the class. I think BS just got killed with the addition of the M2 if it can put that power down. Just like the present generation of tires allowed the C5 to drive the S2000 out, certainly the next generation of tires will allow the M2 to drive all the other cars out of BS, if not already.

I think a classing mistake has been made.

edit: I made a correction to the calculations and the M2 rating in post 25 came down a lot. I didn't change the above words, but I don't feel as strongly about it being a class killer any more. It still pulls as hard as a C6Z06 in 2nd, however.

sjfehr

Course dependency, ugh. I hate how we're trying to cram too many cars into too few classes.

burglar

I don't hear people suggest there's too few classes very often. I'm fairly good with Street with the exception of a big group of late model enthusiast cars buried in AS under the old z06s. Almost needs to be something between AS and BS, or break out the C5z and C6z to a SSC-like spec class, as that's what AS is now. I *think* there would be enough Porsches / GT350s / 1LEs / M4s / C7s to fill grids.

I do think all of SP/P/SM could be partitioned into 6-8 classes total instead of 16 though.

mopar bob

You also need to spit SS when you have a 997.1 base or even an 997.1 S and 991 GT3 in the same class. They are not even in the same zip code with a GT3. There still should be a class for cars like the GT3 or the GTR to run in street. look at nationals almost none of these cars come out any more. Does any body think that a 2011 Boxster Spyder can run with a GT3? This is a big market that no longer comes out to run. I know that you have to fill classes but Porsche is not the only make that this effects.