Riccardo

[quote]Originally posted by George Stevens:
<strong> ...maintain the basic integrity of the car's handling, ie as close as possible to an optimum 50/50 weight balance. </strong><hr></blockquote>

George, what's the 964's factory weight distribution though? I am quite sure it wasn't 50/50!

I guess what David is suggesting is to try and achieve this 50/50 balance by removing rear weight in first instance. Good idea, but how? Apart from the a/c, I can't think of any obvious things which can be removed from the rear...

Robert Linton

Not to open Pandora's Box, but there are numerous potential (albeit expensive) areas of rear weight reduction other than the A/C. But a few are:

1.removing power steering (both front and rear weight reduction);

2.replacing engine sheet metal with carbon fiber equivalent;

3.replacing the heavy motor bracket with a carbon fiber/titanium equivalent;

4.replacing the two motor mounts with a caerbon fiber/titanium equivalent;

5.replacing the right engine shroud/A/C compressor braket with a carbon fiber/titanium equivalent;

6.lightweight hoses;

7.numerous titanium fasteners and studs for the engine;

8.numerous lightweight engine components (e.g., titanium con rods, lightweight wrist pins, lightweight pistons, lightweight gears, titanium pulleys, drilled camshafts, titanium intake and exhaust valves, different cam deck and, in turn, plastic valve covers, etc.);

9.lightweight starter;

10.lightweight transmissions output flanges;

11.lightweight shocks;

12.titanium springs;

13.carbon fiber engine cover lid and/or wing;

14.titanium spring plates with titanium adjuster pieces;

15.carbon fiber/titanium swing arms;

16.titanium hubs;

17.lightweight CV's with drilled 300M drive shafts and ceramic *****;

18.4130 tube rear anti roll bar;

19.titanium drop links;

20.titanium suspension fasteners;

21.lightweight calipers;

22.eventually, ceramic rotors with aluminum bells;

23.lightweight wheels.

johnfm

This sort of lightening would lead to massless wallet!!

George Stevens

Riccado

I don't know off the top of my head what the weight distribution is.

However the point I am trying to make is that 50/50 ususally is the target (thats why the 968 club sport was such a great drivers car)

Porsche themselves have always understood this, thats why in 1967 they lengthened the wheel base of the 911

Robert Linton

How do I attach pictures?

Cupcar

All of the suggestions above have been utilized by Porsche for either street or competition vehicles. A frend of mine had a 906 with one-off front uprights and springs made of Titanium by Porsche in 1967. The technology is not a problem, cost is. The Mclaren F1 road car is a tour de force of carbon fiber and titanium but for over 1 million $$.

What dissapoints me is the lightweight technologies Porsche has abandoned that have been (and could still be) appplied to road cars. Forged alloy wheels, use of magnesium, aluminum body panels are all technologies that were introduced in the late 60's early 70's by Porsche but are gone in the new cars. Some of the new cast 18 inch wheels weigh in at almost 30 pounds! The market isn't demanding it so why provide it, todays Porsche management is in it for the money not the art of building sports cars.

jonfkaminsky

According to the scales my C2 (with a 200 lb weight in the driver seat and a 1/2 tank of gas) weighs 1352 lbs in front, and 1943 lbs in back for a 41%/59% weight distribution.

Pietro

What I do not understand is how the weight of 911's changes by ~200Kg from an SC to a C2. I can figure about 30Kg of A/C system and another 15Kg of the second muffler, 5-10 for the engine lower lid, another 10? for power steering.... but 200Kg is mistery for me. The earlier 3.2's also were also rated as 1160 like the SC's.

kgorman

I just thought I would update with what I did to get to about 2840 in a C4:

- removed stereo, amp, speakers, crossovers
- removed rear deck, rear speakers, rear seats, rear seatbelts, rear bolsters
- removed all leather from center console (just black plastic now)
- removed door panels, pockets, and replaced with RS door panels.
- removed interior sound padding, floor mats replaced with RS carpet kit
- replaced seats with race seats
- removed air conditioning, rear plumbing
- Cup steering wheel ( I have no airbags )
- Lightweight wheels (BBS RE)
- Cat Bypass + secondary bypass
- Lightweight battery and mount
- removed everything from front area; spare tools, added RS washer system
- removed fog lights; replaced with ducts
- removed undertray, tranny undertray, and front wheel liners
- removed electric spoiler and motor, replaced with fiberglass RS wing
- replaced stock heavy shocks with JIC's (minimal savings)
- I lost 15 lbs since I bought it.

Not yet done:
- remove rear/front bumper mounts
- remove guts/motor from sunroof
- remove heater blower

axl911

Robert Linton, you forgot the carbon fiber door handles!!!

Anyway, this is what I am doing for my 993 (similar to 964) with the goal of being able to put the car back to its porkly stock self.

- remove spares & jack
- lightweight Deka battery (20 lbs saving & cost less)
- RS door panels (15 lbs saving for the 993 /w hi-fi)
- fiberglass hood (~20 lbs saving)
- fiberglass ducktail (~15 lbs saving)
- remove back seat, rear deck, rear sea tbelts (20 lbs saving)
- trying to find light & reasonable (non-racing) seats (est. 30-50 lbs saving)
- also looking for lightweight wheels

Since my car is a daily driver, I have to keep the AC & radio.

Anyone has idea of what is a good & reasonable cost seat to be used for daily driving?

Marc Shaw

Remove power steering pump/pipes and go manual?

Marc

TR6

2840 is pretty impressive for a C4!

911addict

Great thread!
Not sure if particular to the turbo, but we have an air injection system (for emmissions at idle) which is heavy and often removed, maybe 20lbs. Do you Carrera guys have this?

Also, headers, even with heat, much lighter than OEM (30lbs on a turbo!)

and of course, LW clutch & flywheel.

kos11-12

Mr Robert Linton ,I am quite impressed with the list that you dressed as for my experience with racing motorcycles I know for a fact that some parts become stress members and help the chassis to be stronger and handle better I have friends who have bikes 10 kg lighter then mine and lap faster( I am talking about bikes that wheight between 107 to 116kg ) also drilled camshaft are prone to disater that is a fact,anathor think titanium witch grade it can be very dangerous to use titanium even with the right grade if you don't know were it comes from as also magnesium,I have seen as well lightweight gearboxes ( drilled gears ) exploded my point here is to finish in the top 6 you have to last and a race is long unless you do drag racing and you rebuild every 1/4 of a mile so in my opinion wheight is not just about that number, as a matter of intereste I would love to see some parts that you mentions sorry if you have already show those parts in this forum.
Konstantin C4

springer3

Robert has been very generous in sharing his developments with this forum. I share your concerns about reliability versus weight, but I am sure if you read his postings you will see he is maintaining or improving on the factory reliability as he develops his modifications.