The rear weight bias thing...how does one live with it?

[2.7RACER]

Let's not forget that any reference to Formula One cars, Indy cars, or most any other rear engine race car is subject to the force applied by front and rear wings.
I can make my 911 understeer or oversteer depending on how I setup the torsion bars, sway bars, shocks, tire size, pressure or alignment.
I look for a setup that gives me just a little over steer around tight corners with as close as possible to neutral in the high speed sweepers.
I'd set up a 50-50 car for the same characteristics.
With a very high powered car, you need weight or down force to keep the powered tires from spinning. A Porsche 911 does that, with or without wings.
How would a F-1 car get the power down at the start without more weight to the rear? At that point all the aero is doing nothing. Kind of like a dragster.

[Charlie V]

There is no question a 911 feels very different with its rear weight bias. In fact, I was actually a little nervous when I 1st got the car because of all the "stories" non Porsche drivers like to tell.

I am certainly not the fastest guy at our local auto-x or DE (when we can pass), but I can tell you I am getting a better feel for the car and it is a blast to drive hard.

As I told my friend last month - Thanks for talking me into getting a Porsche!!

I've told my dear wife a couple of times - Driving it is better than sex! She feels the same when she gets behind the steering wheel.

[Jeff Alton]

I find my car a dream at the track, but it is well set up. The steering is very accurate and it is very easy to induce oversteer or understeer. Yes, you need to be smooth with the pedals, but I am an intermediate track driver on my best day and I am was able to learn the basics. Now, it has been a very long time since I drove a stock 911 on the track, but I am very partial to basic 911 design. I like the steering feel of the lighter front end and I like the fact that if you have a moderate amount of power you have great traction in the rear when you push the right pedal down. Yes you need to make sure you get good weight transfer to the front wheels at turn in, but if you manage weight transfer well the cars are fabulous.

It is also rewarding to know you really have to "learn" how to drive a 911, it is not for everyone!

Cheers

[alf]

Originally posted by catca

It is also rewarding to know you really have to "learn" how to drive a 911, it is not for everyone!

Cheers

That is one of the reasons why i got a 911. It is not going to be easy to learn to drive it well, but i was not looking for easy, i was looking for a fun challenge.

[look 171]

Originally posted by 911mot
hmm engine at the back cant be all bad,I wonder what the weight distribution of a Formula One car is?

The engine in a F1 is in front of the rear weels right behind the driver.

Dd,

I have push my early Miata much harder then my 930 and was in perfect control, so forgiving. A few weeks ago I smaked my 930 into a curb due to puching it too hard coming out of the corner. A case of Turbo blues. Almost caught it back but ran out of road.

[RoyB]

My guess is that a mid engined car with a rear weight bias would combine the traction/handling benefits of a 911 and the rotating handling prowess of the boxster and 914.

Cayman??

I'm glad someone brought up the fact that F1 cars are more related to airplanes at times, what with all the wings and aerodynamic forces. And these cars are "mid engine", not rear engine......

You buy a Porsche 911 for the WAY it handles. If you want a car to handle differently, there are lots of examples available....but none as much fun......

[Dixie]

When I think about it, these 911s are screwy cars. As gas is depleted from the tank, the rear weight bias of these cars increases, so it becomes apparent the driver has to continually adapt...

This condition really isn’t too bad in a 911. That’s because the gas tank is within the wheelbase. I’ve found the car that suffers from this “phenomena” the most is one you’d suspect the least: a C4 Corvette. In that car, the gas tank is high, and at the very rear of the car. As it empties, you really feel the change.

I find the "trick" with a 911 is when the car spins. Catching a 911 as it spins is like trying to catch a swinging hammer. Once all that weight comes around, you have a lot of physics to deal with...

[masraum]

Just let go of the wheel and let the car catch itself.

[Spud]

Note that whenever you see a current F1 car on the hook it points nose down. The F1 teams purposefully balast them nose heavy to balance the car at speed (when the rear wing produces downforce).

[oldE]

Doug,

The attitude of an F1 car on the hook has got less to do with its weight distribution on all four wheels than it has to do with the position of the slots for the lifting sling. Don't think for a minute the teams are wasting ballast at the nose when there is aero-downforce to be had.

In 2004, Renault got superior drive out of some corners and off the starting line, by putting more of their weight on the rear axle, thereby improving traction under acceleration. They gambled on getting track position and being able to keep other (ultimately faster) cars behind them. Sometimes it worked.

Les

[AES]

Note that whenever you see a current F1 car on the hook it points nose down. The F1 teams purposefully balast them nose heavy to balance the car at speed (when the rear wing produces downforce).

they may hang down in front but only because of the pick point

[DARISC]

A basic fact: Porsche chose to design it's current top of the line model putting the engine amidships. Anyone out there question their wisdom in doing so as opposed to hanging the engine out back as they did in my dearly beloved 82 SC coupe daily driver?

That's a sincere question. Anyone?, Anyone?

[RallyJon]

You guys talk a lot about cornering behavior, but the weirdest handling IMO is over crests. Even worse is a corner over a crest. Definitely not confidence inspiring. And God help you if you get the rear end off the ground. It does not land gracefully.

[Spud]

..."they may hang down in front but only because of the pick point"

Thats not what I've read:

"Last year, Renault had light-ning quick starts. It was
rumored that they had a novel launch control mechanism.
Eventually, it was discovered the secret came out that not only
did they have a trick clutch, but they placed 55 percent of the
weight on the rear wheels (10 percent more than the other cars’
averages). This helped them get off the starting line quickly
because there was more grip available for accel-eration."

So I guess the question is does this mean the other teams on average had a 45% rear bias? Or did they have a 50.5% rear bias?

Also of note, Steve Matchett of the speed channel believes they have a forward weight bias...

Article from here:
http://filebox.vt.edu/users/forum/issue%20archive/2005_3_September/Images/PDF/DesignConsiderations.pdf

[masraum]

Originally posted by DARISC
A basic fact: Porsche chose to design it's current top of the line model putting the engine amidships. Anyone out there question their wisdom in doing so as opposed to hanging the engine out back as they did in my dearly beloved 82 SC coupe daily driver?

That's a sincere question. Anyone?, Anyone?

Nope, mid engined is better because the polar moment is less which means the car can rotate faster.

Originally posted by tcar
F1 cars are mid engine like a 914, not rear engine like a 911 - big lump hanging out behind the rear wheels.

I could be wrong, but I don't think that 911mot was saying that F1 cars were rear engined, just that the engine and bias was behind the driver which is also true of a 911. A 911, of course, has the engine much farther back.

I think the implication is that a rear weight bias is a good thing.

[Tyson Schmidt]

Originally posted by RallyJon
You guys talk a lot about cornering behavior, but the weirdest handling IMO is over crests.

Or over any effective dentifrice for that matter.



(sometimes I just crack myself up!)

[dd74]

"Dentifrice"

Main Entry: den·ti·frice
Pronunciation: 'den-t&-fr&s
Function: noun
Etymology: Middle French, from Latin dentifricium, from denti- + fricare to rub -- more at FRICTION
: a powder, paste, or liquid for cleaning the teeth

Does this mean rear weight bias is better for spreading Crest?

[Tyson Schmidt]

Dave, what has your therapist told you about dealing with you rear weight bias?

The important thing is that you've come to terms with the fact that you do, in fact, have a rear weight bias. That's the first step to recovery my friend. I'm so proud of you!

[RarlyL8]

"You can't drift a 911 either, at least iv'e never seen it or done it. Maybe a 4wd could, anyone tried it?"

Well I can't but that fella in the 'Ring Video sure could!!

[masraum]

You can't drift a 911 either, at least iv'e never seen it or done it. Maybe a 4wd could, anyone tried it?

What?!? With all of that weight in the back? I'm no expert, but I managed some pretty lurid drifts upon occassion in my old stock '88 3.2L.