Handling: 912 vs 911

Patronus · 02-13-2002, 12:44 PM

I previously had a 1977 911 with '74S engine. I now have a 1968 912 with '74S engine. No modifications were made to the body or chassis of either of the cars.

The 911 had 195x60x15 Bridgestones in the front and 205x60x15 Bridgestones at the back, respectively on 6" and 7" cookie cutters.

The 912 has 195x65x15 Bridgestones all round, on 6" Fuchs.

On a dry road, the 911 was a pleasure. But on a wet road it became a nightmare. The back would break loose without warning, anywhere, at any speed. This includes parking lots, intersections, even in a slight curve. It was basically useless in the rainy season. Trying to correct a sudden oversteer was very difficult. It created a fear in me that kept me from driving any 911 for many years.

Now I have the 912. No anti-roll bars, small brakes, thin (high) tyres, a light body, with the same 2.7S engine. Yet, this time, the car is a pleasure to drive in the dry and in the wet. I've had it for almost a year now, and it never let me down. The fear of the previous car is still in me, but with every day that passes I trust the 912 a little bit more. The rear is easy to catch during oversteer (and it only happens when I want it to), it sticks to a wet road, and it hides nothing from me. I can anticipate its limits of cohesion, whereas the 911 would loose the tail (in the wet), without the slightest warning, even when I'm not acellerating.

I'm now scared to upgrade to anything else.

Was there something wrong with the 911? All I can think is that it perhaps had a limited slip diff, that I wasn't aware of.
Any ideas/theories/comments?

Don Wohlfarth · 02-13-2002, 01:24 PM

Wild guess is there was something wrong with the suspension/alignment on the 911. As you no longer own the car it's pretty hopeless to try and diagnose or fix the problem.
Concentrate on the car you have now. Pretty interesting comparison as I believe your 68 is a short wheelbase car which should be a "little" more twitchy than the 77, yet you describe the 68 as handling well. If anything it would be the opposite.
Suggest you try autocrossing to push the car a little more so you become more comfortable with the way it handles. Also understand from your location that finding a ax every other weekend could be a problem.

82SC · 02-13-2002, 02:00 PM

aren't the 912 bodys Short Wheel Base compared to the 911???

I could be wrong...MJ

CamB · CamB's Garage

Similar experience here.

69T difficult to get out of line, despite terrible shocks.

75S would let go quick in the wet. I put it down to 10 year old tyres. It was fine in the dry.

So - is that a possibility?

ClayMcguill · 02-13-2002, 05:18 PM

912=Lower Polar Moment of Inertia. (Less mass hanging pendelum-like ouside the wheelbase.)

Plus, there have been a rear toe-out problem with the 911.

Tyson Schmidt · 02-13-2002, 06:46 PM

But Clay, he put a 911 motor in the 912, so essentially we're comparing a SWB 911 to a LWB 911.

I'm in agreement with the others above. The other car likely had suspension/alignment issues or tire issues.

911's vary a great deals from one another and respond to changes to a greater degree than other cars. Because of this, set-up is critical. Heck, get the wrong tires on ANY 911 and they are awful to drive.

jperry · 02-13-2002, 07:39 PM

Definitely must have been a suspension or alignment issue with the 911. I agree that the light SWB body is easily controllable. I wish I had a 6 cylinder in my 912.

masraum · 02-13-2002, 10:04 PM

I vote suspension/alignment problems and or tires. Tires can make a huge difference. I have Dunlop SP9000's on my 3.2L car and the stick they have in the wet scares me. I have to try to get them to break loose in the wet.

Matt Holcomb · Matt Holcomb's Garage

Modern rubber -- it's a wonderful thing! I can relate to Steve: my car is shod with Dunlop FM901s, and the grip in the wet continues to confound me.

In the dry, the grip is AWD-like; the whole pendulum thing doesn't seem to apply to my car, and believe me, I've tried to induce LTO, which, as we know, is the bad kind of oversteer.

Matt Holcomb
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stlrj · 11:24 PM

I noticed my rear end sticks a lot better without the rear sway bar, so that may be the answer.

Since your car came without swaybars front or rear, it seems reasonable that it would also be more predictable, compliant and forgiving to drive in all conditions including rain.

Joe