christian

Took the first and second muffler off today plus catalytic converter and installed fabspeed exhaust system with cat bypass. Sounds (not too loud) and runs great. Probably saves a lot weight.

Robert Linton

In addition to the conventional methods described, with proper engineering, one can reduce weight in a 964 by over an additional 500 pounds.

Adrian

Dear Robert,
This may be so. However I have yet to see a 964 get below 1200kgs. Removing an additonal 250kgs would in my opinion reduce the 964 to pure track work.
The "Lightest 964 series Porsche" never manufactured by Porsche was the 964C4RS and this came in at 1200kgs and was not road legal. Yes I know there was one in 911 and Porsche World but even I do not know how you can register any auto without a VIN, manufactured after 1978. Must be some form of special register in England for such autos.
Ciao,
Adrian
911C4

Robert Linton

If you are interested, I can go into detail -- offline if preferable as it is somewhat time consuming. The short answer is that it involvs very sophisticated engineering (i.e., not "boy racer" or usual after market products) and extensive use of titanium, carbon fiber, MMC and other materials (e.g., one piece cast titanium front uprights, carbon fiber swing arms with bonded titanium ends, carbon fiber A arms, even lightweight drive assemblies with 300M and titanium components and ceramic *****).

Irishdriver

Hi Adrian, others,

The RS was listed at 1220 kgs. We have one hero who turns up for the slaloms with his lightened RS and he weighed in for the German slaloms at 1100 kgs.

However, we believe he filled the tank to max etc., to get this weight.
He runs at a good margin below 1100.

No problem getting cars weight down !!
If only it was as easy for drivers.

Adrian

Dear Robert,
I would be very interested in this data if it was actually a living project. Such a story would fit very nicely into my new book. Especially if the work was carried out on a 964. I am always interested in new technology. I feel high expenses for the average 964 owner as well. Please feel free to email me and let me hear about these things,
Ciao,
Adrian
911C4

Adrian

Dear Irishdriver,
I would love to hear where the extra, over 120kgs were shaved off a genuine RS and still kept road legal,
Ciao,
Adrian
911C4

PS: OZ racing are offering their latest wheels weighing in at a whole 4Kgs each.

George Stevens

Adrian

I do accept that at 1220 kgs the basic sport version of the RS is just bearable for the road, in fact the recent drive in a touring version made me realise how harsh a lightweight RS is.

However I do think it is possible to shave more weight off (although 100kgs would be extreme), the doors and engine cover are still steel,and the standard Recaros are not actually that light compared with proper nomex covered composite racing seats .

I would guess an additional 50kgs could be taken off and it would still be driveable on the road.

Me? I'll leave mine alone thank you!!!!

Flying Finn

I don't think these have been listed yet (I've done these & most of already listed items to my 1975 911, but 993 is still stock, but I think I'll put her on a diet too (propably not so serious diet ;-):

-Remove the stereo, loudspeakers & wiring (all of those are quite heavy)
-remove the heating, all the pipes, heat exhangers etc. (if a daily driver & live in cold climate, think twice)
-Remove under dash elements.
-Remove roof insulation (not easy to put back...).
-Plastic or aluminum fuel tank.

Andrew Wright

I have got rid of all the soundproofing - 30Kgs; one of the seats so far - the replacement weighs 6.5kg plus I have a full RS interior (overall loss around 10kG at huge cost at Autofarm = main problem being £43 per hour!! Even so, they charged me for a fday less labour than they incurred!.

I will not get rid if the "comfort" stuff like A/C, lo-fi or electric windows but I have looked at lightweight bonnet, bumpers & doors. Lots of weight to be saved here.

I intend to replace my wheels with lightweight wheels - unsprung weight loss is definitely the best but I really like the bare RS type interior, not least because it is net and uncluttered. I always hated the stabdard seats and door pockets.

When you first get rid of real weight, it is really noticeable in initial acceleration .. of course you quickly get used to it & want more!!

I also intend to get the 3.8ltr conversion because the difference (mainly excessive torque)is absolutely astounding. I am still deciding whther to go for the lightweight RS flywheel and clutch - tried them on a C2 and they are amazing - do not know anyone that has done the full monty on a C4 - clearly there will be work to be done o the chip, but I am confident the commonly reported stalling issues can be solved.

Any feedback on these ideas??

Andrew
1989 C4

Robert Linton

If you are in the UK, you might speak with Steve Kevlin of the Porsche Club GB. He might be able to get you information ala the factory Carrera 4 Lightweight that was built in the early 1990's.

Christer

Andrew

Understand that you want to keep some 'comfort' items, but you really should get rid if the aircon. Here in the UK when buying a used car with aircon it almost always needs recharging if the car is older than 3-4 years. Why? Because nobody uses it regularly. How many days per year do you use it? That system weighs a hell of a lot, especially if you only use it on say 20 days a year!!

Irishdriver

Adrian,

Remind me in the morning to give you details of the RS in question. The car has spend a significant proportion of its life in the Werkstatt in Stuttgart making sure its owner could be in the top line in the German slalom championship.

It is still TUV'ed and drives to and from slaloms on the road.

He is now complaining as we've introduced a rule for our slaloms that cars must be at least 95% of their factory declared weight and he feels that this rule is just to penalise him. (it's actually safety based as we're afraid people will go too far with lighteneing cars and make them weak.)

Anyway most of us could do better if we lost the weight instead of the car.


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David K.

Keep in mine that the first place to remove weight in a 911 is in the rear. To make your car handle you wont to shift the weight forward. So look to the rear before you start taking weight off the front of your car.

David K.
'93 RS America (Very much put on a diet)

George Stevens

[quote] Keep in mine that the first place to remove weight in a 911 is in the rear. To make your car handle you wont to shift the weight forward. So look to the rear before you start taking weight off the front of your car.<hr></blockquote>

David

Sort of understand the point you are trying to make, but what you say doesn't really apply to the basic theory of car dynamics.

If you shift the weight forward you can induce roll oversteer (the biggest factor in losing control of a car), basically you are weighting up the front so if you are too fast into a corner the car will pivot around the weighted front wheel and unweight the rear wheels causing the car to lose traction and spin.

Any weight reducing programme should involve resetting the corner weights of the car, to maintain the basic integrity of the car's handling, ie as close as possible to an optimum 50/50 weight balance.