Best handling....lightness vs. distribution vs....?

[RWebb]

yes, the idea is to strip the car down to nothing

the 964 motor & trans are more HD, powerful but weigh a lot more (unless he tosses the FI and exhaust and uses carbs or something)

the 964 is all set up for, and comes stock with coils and wide wheels & the unit body is stiffer - see Bill's post above

[Superman]

This is indeed a complex subject, and you have heard from Steve Weiner (all rise and bow) who has (this is not a joke) forgotten more about these cars than almost any ten of us have learned.

I'll give you some very simplistic input from my experience: I've lightened my car considerably, but without spending money (I've removed parts and not put them back on.....the radio and speakers came out this weekend, for example). It prolly weighs 2400 lbs without me in it, with 1/4 tank of gas. Maybe 2450.

Stiffer torsion bars (plus the lightening) made this car A LOT more sure-footed. A LOT. When it comes to car handling, think of the car as being either "controlled" or "upset." It is the "upset" part that is the problem. As firm as these cars are with stock suspension, they can still be "upset" which causes you to lose control. With the stiffer torsion bars and anti-sway bars (and shocks), the car probably still tries to get upset, but recovers instantly. My torsion bars are 22/29, and my sways are late-Carrera sways. The car handles nice. If you wanna come down and drive it, I work in Lynnwood. Higgins lives here. We could have a beer. Heck, we could have several beers, then go test the limits of our cars on public highways.,

No, wait.........

[Superman]

Stiffer chassis is HUGE. Apparently, these cars become quite a bit more capable when a roll cage is connecting the four corners. Big difference, in spite of the weight. The car almost refuses to become upset.

I too can second the notion that the first step is to strip the car. This is the easy way. The hard way is to make changes a bit at a time. I've gotten to the point where I'm really not willing to do the piece-at-a-time thing anymore. WAY WAY easier to just begin the project by stripping the car. Completely. Strip the sound deadening and the undercoating and the brittle stuff that lines the floors. Cut the sunroof off, out nearly to the gutters. Install a roll cage and reassemble.

[winders]

Originally Posted by RWebb

yes, the idea is to strip the car down to nothing

the 964 motor & trans are more HD, powerful but weigh a lot more (unless he tosses the FI and exhaust and uses carbs or something)

the 964 is all set up for, and comes stock with coils and wide wheels & the unit body is stiffer - see Bill's post above

When I say nothing, I am talking about a lot more than stripping it down to the chassis. And it still doesn't matter....

Just about anything you do to a 964 to lose weight can be done to an earlier 911 and you will end up much lighter. A torsion bar setup is more than adequate for the street. It is lighter and offers a lower cg.

Get a '73 with RS or SC flares with wheels and tires to match, 22mm/30mm torsion bars, moderate sized Anti-sway bars, use a nice 915 with 8:31 R&P and LSD, and drop a 3.2L or 3.6L motor in. You will have a dynamite car that weigh about 500 lbs less than a 964.

Scott

[DanielDudley]

Supe is right, suspension makes the biggest difference. My SC is stockish, and handles better with a passenger balancing it out. The Carrera is built up, and is crisper, understeers less, and putting a passenger in it doesn't really seem to affect the handling.

[RWebb]

winders, I doubt the early car will be as stiff as a 964. TRE (Dave B.) might know - he has fabbed some add on pieces to weld into early cars to make them stiff. He says they are VERY stiff in one thread. IIRC, it felt comparable to a GT2.

there is also an old post about adding bracing to the front undercarriage by Tyson...

these are all close to pie in the sky for a guy
... on a tight budget

[RWebb]

the next thing to do after you have lightened the car by "throwing things away"

is to think about what new materials can substitute for old materials...

[winders]

Originally Posted by RWebb

winders, I doubt the early car will be as stiff as a 964. TRE (Dave B.) might know - he has fabbed some add on pieces to weld into early cars to make them stiff. He says they are VERY stiff in one thread. IIRC, it felt comparable to a GT2.

there is also an old post about adding bracing to the front undercarriage by Tyson...

these are all close to pie in the sky for a guy
... on a tight budget

Well, the 964 needs to be quite a bit stiffer to flex the same a 911 that weighs 500 lbs less!

Really, light and 964 don't belong in the same conversation.

Scott

[island911]

Balance.

. . .all you can do is shift the balance(s).

Weight dist. 50/50 makes for a more neutral cornering experience. But, considering the drive wheels are in the back, and the stop power is front and back, having the 911 weight bias makes for good stop/go. ...and turn-in.

Suspension: it's more than just stiffness. There is the weigh placement of the springs (coils sit up high) and there is the balance of sprung to unsprung weight. And, every structure has a natural frequencies. (as said, you don't want the spring stiffness to compete with the mounting structure)

IMO, Porsche hit a good balance with these cars. The low hanging fruit is found in lowering and tires. (as the saying goes; where the rubber meets the road)

[gtc]

IMO, the underlying problem with improving handling in the 911 is the chassis' low torsional rigidity. Weight reduction is kind of a backwards way of dealing with this issue.

If I were building a car, I would:
1. Make the chassis as light and stiff as I could, without sacrificing comfort (i.e. no rollcage, and retain sufficient sound deadener).
2. Assemble the rest of the car to a target weight distribution
3. Compute the appropriate spring and damper rates (incluting tires) for my given chassis specs.

This last bit is the most difficult to perform yourself, since it involves a lot of proprietary knowledge and secret formulas that people like Steve have worked out over time.

[Bill Verburg]

No, a 964 will never be able to be as light as a 911 can be made, but they can be dieted down to ~2400# and they do have other advantages that some may be interested in utilizing.

There have also been several interesting projects that were based on a 964 floor pan, lots of work and $ have been invested in these things, Teo's is one example, I believe that it came in ~2200#

[RWebb]

yes, Teo's car is a great example

there was also the 964 that Nashville somebody made up that looked just like an early car on the outside - not as 'advanced' as Teo's

the very most advanced 964 is the America GS car, which can be read about on Rennlist -- it is the most amazing thing I've ever seen

re stiffness, Jim Sims also posted about putting CF sheets on the body panels to stiffen the car - I think it was just an idea & not something he went ahead with tho

[winders]

Originally Posted by Bill Verburg

No, a 964 will never be able to be as light as a 911 can be made, but they can be dieted down to ~2400# and they do have other advantages that some may be interested in utilizing.

There have also been several interesting projects that were based on a 964 floor pan, lots of work and $ have been invested in these things, Teo's is one example, I believe that it came in ~2200#

Bill,

I think any inherent advantages the 964 has over the 911 are easily matched on the 911 at a much lower weight and the end result probably does not cost much, if any, more.

What advantages does the 964 have that cannot be easily matched on a much lighter 911?

Scott

[boba]

Teo's project did not start as a 964, but had a 964 floor grafted in to accommodate the G50/31 gearbox.

Since Al asked for pictures here is a 964 which is being backdated to '72 RSR configuration. In these pics it is about ready to be sent to e-coat. It is now back, has been powder coated (bottom, trunk, interior, engine bay) and is now at the paint shop.








BTW the bare 964 tub is only a couple hundred pounds heavier that an early tub, so you can get it fairly light if you are willing to give up creature comforts.

[boba]

Originally Posted by winders

What advantages does the 964 have that cannot be easily matched on a much lighter 911?

Scott

Scott, the 964 has a more rigid tub to start with, better suspension and brakes. And you get the 964 motor. The weight advantage of the early tub of a couple hundred pounds bare will be somewhat negated if you add the reinforcing to the early tub to stiffen it up.

"Easily matched" is just $$.

There are advantages and disadvantages to both platform choices, it comes down to what you want.

[jmitro]

Originally Posted by boba

BTW the bare 964 tub is only a couple hundred pounds heavier that an early tub, so you can get it fairly light if you are willing to give up creature comforts.

that sounds like a pretty big weight difference if you're talking about a bare tub.

the car looks nice above.

[RWebb]

the numbers I've been give from a couple of people who have weighed them are < 100 lbs.

that is for a bare tub - and IIRC 40 lbs. or so; maybe it was 80

[911st]

Originally Posted by al lkosmal

...What would the "best" weight and distribution goal be for a 911 street rod.? (no track...no auto-X...just street rod, twisties carver)...

Al

My two cents:

Moving the distribuition forward some or working to make it more centered is not going to make any significant differance on the street.

That effort and money might be better invested by shoeing a 3.6 into an SC or adding wider wheels and sticky street tires.

A full race suspention is no fun on a street 911. Also, a stiff suspention that is fast on a track with race tires may not be fast on a bumpy back road with Kumho XS's or such.

Stick with the basics. A good sport torsion bar set up sized for the car, proven spring rates, getting the shocks valved for your use, sport alignment, corner ballance...

If lowering, do it right. If a torsion bar car consider getting the front struts worked by rasing the axels on the strut and make the proper bump steer mods.

Mostly good stuff in making it wider if you like and want to make the investment.

With this you can run bigger street able tires. It adds to the 'look' and improves handeling potental kind of like lowering the car but without as much potental for messing up the geomitry.

A wider car that is not slamed is a lot easyer to get into and out of driveways and not as likely to drag their bellies over speed bumps like a slamed race car.

As to making it light. Yes, lighter is more responsive and improves the power to weight ratio so it is faster. However, fiber bumpers are not a lot of fun if you double park when cafe racing and someone backs into you.

The 964's are heavy, expensive to mod the suspention, but have lots of goodies like working AC, ABS brakes, power steering, and knock sensing. Still, could be a lot of fun if willing to make the investment.

[winders]

Originally Posted by boba

Scott, the 964 has a more rigid tub to start with, better suspension and brakes. And you get the 964 motor. The weight advantage of the early tub of a couple hundred pounds bare will be somewhat negated if you add the reinforcing to the early tub to stiffen it up.

"Easily matched" is just $$.

There are advantages and disadvantages to both platform choices, it comes down to what you want.

All I am saying is that if being light is one of your primary goals, the 964 isn't the likely choice with which to start.

Scott

[911nut]

Originally Posted by winders

All I am saying is that if being light is one of your primary goals, the 964 isn't the likely choice with which to start

In the "light vs. rigid" debate, I'll take rigid every time. Makes for a more predictable and better handling car. Since we are discussing street cars, ultimate 'light" is most likely not the best kind of car to have from a comfort and usability standpoint.