Porsche Air-Cooled Cup USA Series
#61
Rennlist Member
Given that the 996/997 and 987 plus the current rules have basically killed the 993 as a G or H car, I think you should consider allowing the 993 into this class so it has a home where it could be competitive since as we all know, it is the last of the air cooled cars.
#62
Rennlist Member
My previous wish-list was just that and do think weight adjustments can level out the playing field some. 3.2s will have a big (!) gearing advantage w/ 15s but 964s will have better suspensions and brakes and 993s better suspension, brakes and fuel injectors than the 964. 964s in the boot at the Glen are f'g miserable - too fast for 2nd and at around 62-ish mph the tach is around 4k-ish and lugs badly. A E 911 on 15s would probably pass a well driven 964 up the toe right now w/ current weights but of course the 964 will win a drag race down a straight out of 80 mph corner w/ similar drivers.
That said, I think more realistically it would be better to include D&E A.C. cars together and F&G A.C cars together which for the most part would just be convincing F 964 owners to remove 271#s from their cars. Before Clark's post I had been thinking about this over the last few years anyway which was a Spec 964/993 class which would mostly keep stock class rules with a few changes.
But....even though the numbers are small in G at most races the racing is very good and although I haven't raced Anthony in his Cayman yet I watched him and Omar go at it at Summit and they looked very close car-wise and was great racing between completely different platforms so stock class PCA does do a good job with this overall. It does work although it will never be perfect and they have said that in the past (something like PCA stock is a home for every P car sold in the US but there will be some models more competitive than others).
I'm hoping and planning to get back to G for at least a few races this year. Even though the numbers are small I do like G and also really like my car at the current weight of 2,910 with driver.
Dear F 964 racers, please drop 271#s and come race us in G.
Last edited by forklift; 12-17-2018 at 01:01 PM. Reason: clarity
#63
Drifting
#64
Nordschleife Master
Hard to keep racing the air cooled cars at the current values. This seems like a decent attempt, but if you narrow down to just a few classes, I doubt you’ll get many takers.
#65
Drifting
Keep it simple stupid.
That's my motto.
911CUP (911 D, E, F & G stock cars thru 964 only)
* No changes to stock letter class rules except weight
* 911 cars up thru 964
* One (1) spec tire Hoosier R7
* Free tires for winners at 5 select races
That's my motto.
911CUP (911 D, E, F & G stock cars thru 964 only)
* No changes to stock letter class rules except weight
* 911 cars up thru 964
* One (1) spec tire Hoosier R7
* Free tires for winners at 5 select races
#66
Rennlist Member
#67
I'm in....
Rennlist Member
Rennlist Member
I'm all for less classes and this would be great for the air-cooled 911 drivers but what happens to all of the E and F class Boxsters? The numbers keep increasing as air cooled cars decrease but I don't think the numbers are there yet to have classes of their own.
#68
Drifting
#69
Drifting
Let the Chixsters do their own thing. Don't they have their own spec class(es) anyway?
I'm trying to save the old school 911s in pca. These things are disappearing, less and less every year. Need to do something to reverse the trend.
#71
Addict
Rennlist Member
Rennlist Member
If you make these race classes too broad, the whole system falls apart as you can no longer BoP the various cars for the majority of tracks by weight alone. So focus on just ‘77 - ‘88 911s.
#72
Rennlist Member
Nice idea. One thing to consider is using real world HP numbers when doing BoP. Factory numbers listed in rules book are a bit off based on reality. 84-86 E cars for example are supposed to be 2779 weight, 207hp at crank, with a power/weight=13.43. Aren't motors really putting out 220-230 at the wheel. Using 1.15 drivetrain loss, that's about 260hp at the crank, making p/w 10.6. (a solid G class p/w) 964 motors and others are also making more than listed as well. Something to think about to try and make level playing field.
#73
The following is just MY OPINION as an overly cerebral engineering type
Basing BOP on advertized hp to weight(measured or otherwise) or barring 993 because it has a more complicated rear suspension is a canard.
Things that affect performance the most are
1) torque curve, both magnitude and shape, hp is just the result of having torque at higher rpm
2) gearing(which includes tire diameter), this multiplies engine torque and translates the circular motion of the output shaft into push or thrust
3) weight, obviously the less weight the more all aspects of track performance are improved
4) aero, the faster you go the more important this is
How the suspension connects to the pavement is a really minor consideration given that suspension travel is severely limited by the use of high motion rates on whatever suspension is used.
There is a major difference in the potential performance that can be pulled from a water cooled vs an air cooled and I agree that these air cooled cars need a venue separate from the newer water cooled ones. Also the performance potential of a wide body like a 930 vs an SC/Carera is difficult to quantify
Rules should keep stock or at least close to stock aero and gearing, tires free(but w/ compensation made for varying ODs), brake upgrade and weight(including driver and 1/2 tank of gas) compensation added/subtracted, stock type suspension w/ stock attachment points otherwise free(there is an $ argument for limiting the shocks to non adjustable but then the side issue of revalving enters too)
given the above it shouldn't be hard to equalize everything from a '73RS clone to a 993 Cup clone or anything in between
Basing BOP on advertized hp to weight(measured or otherwise) or barring 993 because it has a more complicated rear suspension is a canard.
Things that affect performance the most are
1) torque curve, both magnitude and shape, hp is just the result of having torque at higher rpm
2) gearing(which includes tire diameter), this multiplies engine torque and translates the circular motion of the output shaft into push or thrust
3) weight, obviously the less weight the more all aspects of track performance are improved
4) aero, the faster you go the more important this is
How the suspension connects to the pavement is a really minor consideration given that suspension travel is severely limited by the use of high motion rates on whatever suspension is used.
There is a major difference in the potential performance that can be pulled from a water cooled vs an air cooled and I agree that these air cooled cars need a venue separate from the newer water cooled ones. Also the performance potential of a wide body like a 930 vs an SC/Carera is difficult to quantify
Rules should keep stock or at least close to stock aero and gearing, tires free(but w/ compensation made for varying ODs), brake upgrade and weight(including driver and 1/2 tank of gas) compensation added/subtracted, stock type suspension w/ stock attachment points otherwise free(there is an $ argument for limiting the shocks to non adjustable but then the side issue of revalving enters too)
given the above it shouldn't be hard to equalize everything from a '73RS clone to a 993 Cup clone or anything in between
#74
Rennlist Member
As in NASA, a dyno is essential to all this IMHO. And to flush out the inbred cheaters, a dyno at the track is required also.. Anyone can have their car dynoed, then change cams and ECU to a previous setup, and go race. At the Glen guys in E are hitting well under 2:10's when the fastest D car was squeaking under a 2:13 (wasn't me, I was well above that). I'm not sure a D car can compete but maybe 150-200 lbs will make the difference. It's going to come down to weight/HP/Driver and that's what NASA has been selling for a while.
#75
Nordschleife Master
As in NASA, a dyno is essential to all this IMHO. And to flush out the inbred cheaters, a dyno at the track is required also.. Anyone can have their car dynoed, then change cams and ECU to a previous setup, and go race. At the Glen guys in E are hitting well under 2:10's when the fastest D car was squeaking under a 2:13 (wasn't me, I was well above that). I'm not sure a D car can compete but maybe 150-200 lbs will make the difference. It's going to come down to weight/HP/Driver and that's what NASA has been selling for a while.