How competitive can the 3.2 Carrera be in F Class?

[Ho Hum 74]

Folks,

Toying with the idea of selling my 74 and buying a 3.2 Carrera car with PCA logbook. Car is in F class. Any idea how competitive these cars can be with all legal mods?

Thanks
Tristan

[304065]

Well, they can win the class! With the C2 moved to E, they are the clear favorite vs. the 944.

[Ho Hum 74]

Oh, yes. That's right, the C2 is no more in F class. Just have to worry about well driven C4s.

[304065]

Class Year Model Weight HP Ratio (lb./hp.)
F 81-83 911SC (Euro) 2552 204 12.51
F 84-86 911 Carrera 2662 207 12.86
F 84-86 911 Carrera (Turbo-look) 2866 207 13.85
F 85-86 928S (5-speed) 3351 288 11.64
F 85-86 928S (Automatic) 3439 288 11.94
F 86-88 944 Turbo 2899 217 13.36
F 87-88 944S (Club Sport/Firehawk) 2822 200 14.11
F 87-89 911 Carrera 2756 217 12.70
F 89-91 944S2 2932 208 14.10
F 89-94 911 C4 3197 247 12.94
F 90-94 911 C2/C4 (Turbo body) 3252 247 13.17
F 96-97 Boxster 2822 201 14.04
F 98-02 Boxster 2779 217 12.80
F All 968 3086 236 13.08

[Ho Hum 74]

Euro SC looks like a good choice as well. Thanks for the info John.

[304065]

http://www.pca.org/pca/clubrace/2004_results/index.htm

[Ho Hum 74]

What's the difference between the 84-86 3.2s vs. the 87-88? 207HP vs 217HP. Are they the same motor internally or is it just a difference in ECU, induction or exhaust?

[304065]

ECU. Different part number. Very hard to find used, the Club Racers snap them up. I had a water leak in my '88 and had to spend $1700 for a new one from Bosch.

And, obviously, the G50 Trans, with the different torsion bar tube and different sized access holes. Different dashboard cover. I think headlights different.

Me, I'd rather have 94 pounds than 10 more HP.

[cbeers]

As I understand it, they are the same motor, just tuned differently to compensate for the heavier G-50 transmission. I'm sure somone with more expertise will clarify exactly WHAT is different.

EDIT - John was faster to post than I

Also, I could swear that my '87 weighs in over 3400 lbs, not the 2756 listed above?? Maybe due to the fact that I have power items, but 700 pounds? No wonder it's called a pig

I'll have to check again tonight.


-Chris

[nostatic]

that's a lot of ballast you're carrying if it weighs in at 3400lbs. My SC with power windows, sunroof, ac was 2660 before we started ripping stuff out.

[304065]

Chris,

I am interested to see your Carrera's actual weight.

The weights are funny, few cars actually rolled out of the dealer that light, but you end up going to lightweight fiberglass bumpers, carrera spoiler, lighter seats, etc., so that often lead weight is added to MAKE weight. The difference is, it's usually bolted to the floor of the car on the passenger side, for the lowest, most central CG.

Likewise, the HP figures are the minimum output the factory claimed. With headers and free exhaust the RWHP is close to those figures.

[cbeers]

OK. I'll check the tag again tonight after work. Right now she's sleeping to get rested up for the AutoX this weekend

I'm sure I am not remembering it correctly.

-Chris

[joey bagadonuts]

I took a quick count and out of 24 PCA sprint races this year, the 1st place finishes were distributed as follows:

11 - 911 SC (prepared)
4 - 944 Turbo (86-88)
3 - 944S2
2 - 964 C4
1 - 911 3.2
1 - 968
1 - '70 911 (prepared)
1 - '75 911 (prepared)

While the numbers suggest that a Prepared SC is the way to go in F Class, it's difficult to draw such a conclusion since not all of these cars battled head to head at every event. Also, there are simply more 951's, S2's and SC's in Club Racing so the odds of nabbing the top spot are definitely in their favor.

Food for thought.

[304065]

Interesting, I wish there was a combined database of all the years, that must have taken some time to compile.

My experience around here with the "F-Troop" is that there was a group of guys that all ran Carreras. Scotto, Burger, etc., who are OUTSTANDING drivers (they all bought Cup cars). If you check the F podiums for 2000, they dominated that class. Now, query whether that's car or driver. . .

Interesting that the prepared SCs have done so well. The good engine builders can get a lot of power out of a 3.0, the chassis is 110 pounds lighter than the near-identical early Carrera (915 box), tires and wheels the same. PLUS you can slot the suspension and run huge brakes, a 3.8 RSR wing, crank trigger and a different R&P.

What's not to love about THAT? (. . . the budget!)

[Ho Hum 74]

The good engine builders can get a lot of power out of a 3.0, the chassis is 110 pounds lighter than the near-identical early Carrera (915 box), tires and wheels the same. PLUS you can slot the suspension and run huge brakes, a 3.8 RSR wing, crank trigger and a different R&P.

Hold on John. As I understand the rules, you are not allowed to touch ANY of the engine internals and remain in stock. Only induction and exhaust. Now I know you can knife edge the crank and moon the cylinders, port and polish, shuffle pin, reduce deck height to aid compression and all that kind of stuff but that is cheating. I've heard of guys spending $20k on their 3.0 G-Class engines. Really? What kind of rebuild are you talking about for $20k? Certainly one that involves cheating or one that's done at Bruce Anderson rates?

The SC that Joe is referring to (and he is much more efficient at mining this stuff than any of us ) is the Euro SC or Prepared US SC which seems to be the right car for the class.

[Ho Hum 74]

PS. You cannot even, as I understand it, make internal engine modifications in PREPARED class. You have to take it to GT.

Tristan

[304065]

Holding.

Ready?

Your interpretation of the engine rules is correct. Knife-edging and those other mods you mentioned would certainly be illegal.

There's a difference, however, between a tired SC engine and one that has been refreshed by a builder like Peter Dawe. Such engines are "blueprinted" to the exact specifications in the factory manual, and have been balanced to hundredths of a gram. (Machining for balancing purposes only is permitted). These engines make the EXACT compression ratio specified in the book, and are tested with the "whistler" for compliance when they podium. They have been set up on a dyno and tuned for maximum performance with headers and megaphone exhausts. The CIS is so rich, when they lift off before a corner, fire shoots out of the tailpipes.

In short, there's a very wide variation between one "stock" engine and another, and that variation is usually correlated with the skill of the engine builder.

Also, you cannot have a brake system that was not part of a factory option. And you are not allowed the 3.8 wing either or a different ring and pinion.

Read the rule book carefully.

“Prepared” Cars

Any vehicle meeting the criteria for a “stock” Porsche per the previous rules and having one or more of
the following changes will progress up one stock class except as noted. Cars whose original stock class
is B may not make any of the “prepared” modifications and remain in a “stock” class. Any such
modification will result in reclassification to the appropriate “super class” based on “super class” criteria
alone. Note that prepared cars are classified as stock, and compete in the appropriate Class A-K;
therefore, except as noted below, all stock rules take precedence.

1. Engine

A. Non-factory DME chip. KLR chip must remain as supplied by factory.
B. Substitution of carburetors for electronic fuel injection on 914’s.
C. Modifications/changes/substitutions of carburetors/venturis on carbureted cars.
D. Non-standard ignition system.
E. Substitution of carburetors for CIS or motronic systems on 911’s, engine unmodified from intake port to exhaust port, progresses up two stock classes.
F. Substitution of mass flow system for stock air flow metering system progresses up two stock classes.

2. Suspension

A. Slotting to achieve suspension settings is allowed. Pick-up points cannot be welded or machined.
B. Non-factory shock housings set at factory settings are allowed.

3. Tires and Wheels - Wheels two inches wider than originally supplied and any tire combination which fits under the fender is allowed. Tires and wheels must comply with Stock rules 3A, 3B, 3C and 3D.

4. Brakes - Calipers, rotors and master cylinder are free, except the number of master cylinders must be as supplied by the factory.

5. Transmission

A. Ratio of the ring and pinion may be changed.
B. Non-factory limited slip of any type is allowed.

6. Body/Chassis/Interior

A. Ducting for additional coolers provided it doesn’t change size and shape of factory panels.
B. Slope nose conversions are allowed, however, tire/wheel requirements must remain as per above.
C. Fender flaring is allowed using factory material
D. Rear wings may be added provided they are not any higher, relative to the roofline, than a factory (non-extended) 3.8 RSR wing.

I think what is causing the confusion is you are referring to the rule book for "Stock" classes. In "Prepared" classes you may make any, or all, of the above listed modifications, and progress up one stock class (two for the carbs or MAF).

Therefore, an US-Spec SC, which runs in G-stock, may make all of the prepared modifications I listed above, and be classified in F-prepared.

An EURO SC would be bumped to E-class and suffer a terrible fate at the hands of the C2s. The Euro SC's advantage is the additional power, yes, but I'd take the prepared mods and a US-spec SC motor any day over a stock Euro.

Oh, and WRT cheating, the old joke goes, "How do you know the other guy is cheating? Because you're cheating, and he's faster than you!"

Hope this helps!

[Ho Hum 74]

John,

You're correct. I edited my post to remove the mention of the wing etc..

What do you mean by "tested with the "whistler" for compliance "?

[304065]

964 engine rebuild 11.3:1 compression

[joey bagadonuts]

Boy, I didn't mean to send us too far off topic but John definitely makes a good point about driver ability. In many of this year's races, the winners had multiple wins.

As for a multi-year database, I think broadening it to include the top 3 finishers in sprints, enduros and qualifying heats would be especially beneficial. For example, while the 3.2 only finished on the top spot once this year, there was a racer out of the South who nabbed a 2nd at Road Atlanta, 2nd at Barber and qualified 2nd at Sebring.

These data points certainly suggest that the 3.2 can run with the best of them in F. Anyone have anything else to share?