why does everyone crap on the C4?
 

I have been looking for a used c4 for a few months now... It will be a daily driver and sometimes DE and auto x fun car. However, everyone keeps telling me to get a C2 instead because the handling is "soooo much better" and has no understeer. What I dont understand is that no one complains about the turbo having understeer and that is 4 wheel drive... what gives? Isnt it the same system? Also the audi quattro has a great reputation on the track... isnt the c4 gonna at least perform as well as a quattro? Should I really stay away from a c4 if I want to track the car once in awhile and really "learn to drive"? anyway just wanted your thoughts....

You don't say what year C4 you are looking at, but there's always been a distinction drawn between the 964 C4s and the 993 and later C4s. The 964 C4 series has the worst reputation about understeering. If I remember correctly, the 964 has a different design, involving a computerized clutch rather than a simpler viscous coupling (someone will jump in with the details I'm sure). On the track, you'll also have the added weight working against you, if that matters to you. I guess it depends how competitive you plan on being.

I always wondered the same thing. I think the understeer is way overblown. You either have oversteer with a C2 or understeer with a C4. Personally, I've never noticed the understeer. I've also never tracked my car. I can say, however, that there were at least 3 incidences over the past 2 winters in which I am sure that the all wheel drive of my car (90 C4) saved me from a potentially serious accident. A lot of people feel that wagging your tail a little is a desireable Porsche trait. I'm not one of them.

Yes, the early C4s (the 964s, not 993s or 996s) were the ones with problems. They are still not bad cars, and I would imagine that for a DE once and awhile, a C4 would work just fine. However, their 4WD system is a liability. Maybe not a big one, but a liability. However, if you were to have to drive it in the snow, I'd say the utility of the 4WD would completely offset that liability.

I think if you live in an area where you have harsh winters with lots of snow oand or rain/ice, I would go for the C4.

just curious...can a 964 C4 suspension/tires/whatever be adjusted for a more neutral ride, or even for a bit of oversteer?

993 vs 964
 

Yes you are right I should have specified... actually I am looking at both models. I would prefer a 993 c4s which is the best looking 911 ever imo... however finding one for a decent price has been hard and the 964's are pretty in-expensive at the moment (about 1/2 what the 993 are going for as in 25K vs 50K) so I am REAL tempted. Also for a novice driver isnt the c4 a better choice or atleast a safer choice than a c2?

Then again there is the

964 c4
+ super charger
+ exhaust
+big reds

= still 15K to 20K less than a 993 and should be ALOT of fun!!!! By the way is the 964 c4 lighter than the 993 c4?

If you intend to track the car, yes the 964 C4 is not desireable.
A. Extra weight and understeer issues
B. Bleeding brakes requires the Bosch 9288 ("Hammer") tool.
-Chris

On the whole snow and ice thing, I've driven a C4 in the snow and rapidly came to the conclusion that AWD is a performance enhancement for dry or rain-covered roads: it does not make it a snow car.

I wouldn't bag on the C4 for a track car, you just have to drive it differently. . . example:

911E: Hold throttle on straight, apply max brake and downshift, turn-in, apex, throttle, upshift.

C4 (or Audi S4): Hold throttle, max brake and downshift, turn-in, throttle, power understeer through apex, upshift.

The additional accelerative traction can be used much earlier in the sequence to get the car going faster. I know that theoretically that doesn't make sense, friction circle, right, and if you are cornering at max g there is no additional traction available for acceleration, but it seemed to work when I tried it.

As far as the car being heavy, you could say the same thing about the C2, but they were so successful in F they got bumped to E.

I'm not sure about the 964, but the 993 system only puts 5% of the power to the front wheels. Hell, I can't even tell my car has 4WD.

Isnt that 5% increased when the car senses loss of traction in the rear??

I'm not positive about the 964, but in general, I believe the 964 C4's have a set amount of torque that is always being sent to the front wheels, I think it's like 40% front, 60% rear--hence your going to get more understeer than 2wd

The 993 C4, uses an entirely different system which depends on wheel rotation speed to determine how much torque goes to the front wheels. Under full traction conditions the torque split is 5% front 95% rear. If the rear tires are slipping relative to the fronts then more torque is sent to the front axel, to a maximum of 40% front, 60% rear. This system does not control each wheel like the Audi quattro (S4 is my daily) it controls only front to rear bias.
The 993 C4 generaly feels like a RWD car.

This is generaly what happens at the limit.
When you power through a corner hard, the tail will drift out smooth and predictable.....this will transition to a 4 wheel drift as the front wheels get more torque. It all works seamlessly and natural. I have never noticed much understeer in my 993, 4 wheel slides, yes, but never plowing.
It still doesn't let you forget that your driving a 911 with all that weight in the back but it sure does smooth the sharp corners.

31% front
69% rear in a 964.

See this link for a great description of the 964 AWD system

anyone out there track their 964 c4... if so how was it? Any reliability problems under track exposure? Also what is the hammer system? why do you have to bleed the brakes with it? If you upgrade to big reds do you still need this system? Sorry if this is a dumb question... i have never heard of this... thanks

I've never tracked my 964 C4, but I've also NEVER had an issue with the 'dreaded' understeer. Having felt the control that the AWD gives me on the road, I have come to the conclusion that it is the only Porsche I would consider as a year-round daily driver, and our weather doesn't even get that bad (some heavy rain sometimes, no snow). I have not driven a 993 C4, but assume that it would provide the same level of road control.

I think that driving a 2wd 911 might be a little scary on wet roads, especially after reading the following:

Link

I think that it was a combination of driver error and road conditions, but the comments made by others about 911 'issues' on wet roads have really made me think, and enjoy my C4 all that much more.

Tom

The 924 C4 ABS system needs to be cycled to bleed the system (AFIK). The Bosch hammer runs over $3000 if you can find one.
-Chris

The brake system on a (early?) 964 C4 is a very high pressure system (and I believe is interconnected with the AWD system). Requires a special procedure for bleeding, I think. The Hammer is a Bosch diagnostic tool, which I believe is used to re-set the error codes from the DME after doing any brake work where the hydraulic lines were opened. No different if using big reds.

Edit: And you don't need to buy one, you would just have to use a shop that has one to either do your brake work for you, or reset the DME errors after any applicable brake work you do yourself.

Tom

I already mentioned this once on the board, but there is a 1996 C4S for sale at an independent lot by my house. I think it is still there. They were asking $39,995. Dark blue with about 65K miles. I would really like to test drive it for someone:D :D :D


I have no conection to the car, car lot or anything else related to it...just want a reason to test drive it;)

C4 before 1994 has electronic 4-wheels drive system like the 959. Don't even thinking about replacment if anything goes wrong. After 1995, C4 has mechanical 4-wheel drive system again.

Go drive both and see which one is the one for you. I have a 89' C4 and its been nothing but :D on my face since she came home. I would consider looking at a turbo if its for street use.

Re: why does everyone crap on the C4?
 

This is why I like GT2s, new turbos don't inspire me. In the most recent article of pano, they say that the new 996 C4S cab has understeer in tight turns with the psm off. Now if 996s and 993s still have understeer and 964s are substantially worse, I'd stay away from 964s. However, it shouldn't be so bad in the later models.

This is why I like GT2s, new turbos don't inspire me. In the most recent article of pano, they say that the new 996 C4S cab has understeer in tight turns with the psm off. Now if 996s and 993s still have understeer and 964s are substantially worse, I'd stay away from 964s.

Sounds very technical but for all pratical purpose, does it really mean anything both on track and street? How many Porsche owners really have the actually experience of "understeer in tight turns" in their Porsche? Not not many owners is willing or capable throwing their $100,000 machine around the corner.

Correct me if I'm wrong, but the only meaning I get from this reply is that if most Porsche owners don't know how to drive well, why make a car that drives well? If a large percentage of people who drive the car can't tell the difference, who cares if it has some characteristics that go against the performance aspects of the car? :rolleyes: I find this depressing and I think it's sad if Porsche gets to that point.

If you take corners in a sporting fashion you'll notice it, understeer. These are sports cars. I recently read a post by a fellow who was hired to instruct for a group of individuals who rented a track. He got to drive the wheels off these people's cars. Among the cars was a Carrera 4. He was not impressed. Understeer was the primary complaint. I felt compelled to explain how this doesn't represent Porsche well. I almost said to go find a GT3 (or at least the C4S with a stiffer suspension). But I didn't. While I know that the GT3 would have satisfied him, should we need to go to the special models to have fun? Should the cheaper models be so numb with a level of understeer dialed in or should they be race car neutral?

>>>I've never tracked my 964 C4, but I've also NEVER had an issue with the 'dreaded' understeer.<<

My cousin had a 90 C4 that he put well over 50,000 miles of TRACK time on it. I have never heard of the understeer issue either, I drove it at R/A a few times, it was awesome. It powered out of turns with the peace of mind that it wasnt coming around on you. He routinely beat just about every other 911 out there. (this was in 90-93). It was also a great auto crosser. Now, the cost factor, he had to replace two transfer drives and the front diff, at a cost of @ $12,000 each time. Now keep in mind, this car was abused HARD.

Regardless of the understeer issue, I'm happy to hear a story of someone using a sports car as it is intended to be used, even if it means a bit of maintenance. I'd probably have a ball riding shotgun.

I wonder why I hear so many times that the 964 C4 is better for snow, not track, because of an AWD system that puts too much power up front. Maybe it's not that bad, but the story is repeated so much that it has become lore. (Or just because 2wd porsche owners categorize it as bad just because it drives more like an S4.) I also wonder why the understeer issue can't be fixed with an alignment or adjustable sway bars. It seems that any problem from the factory like a bit of understeer should be easy to dial out if one was so inclined.

If it were that easy then why hasn't it been done?

Usually with seemingly unlimited resources available for some, you could always throw some money at whatever problem you wanted to correct, like the "dreaded understeer" problem and that would be the end of it.

How come nobody has been able to resolve this annoyance by now?

Joe

understeer
 

I guess I will ask the question: anyone with a 964 C4 modify the suspension? If so what was the effect and did it reduce or eliminate the understeer?

Re: understeer
 

Have you checked out John's 964 specific website. Here is a link to the suspension section of that site: http://www.porsche964.co.uk/technical/susp.htm

Some great info and links, and perhaps some names of folks with C4's who you can contact directly.

Tom

Just to clarify, the 993 C4 and S4 are entirely different. The S4 has a torsen center diff set at 50/50 split (but adjusts depending on speed differential), open front and rear diffs, and electronic intervention at the front or rear via brake pulsation. At speeds below 25 mph, it will pulse the brake on a spinning wheel based on the speed difference at that axle. Its a crude system, IMO, and it is disabled above 25 mph.

The 993 system favors RWD behavior due to its 5/95 split.