koenig_roland

hi Guys,
i`ve a question.

I own my C4 for some years and i did - and actual do - some modifications on my car to reduce weight.

Yesterday, i had a discussion with some of my friends, and they donīt believe my current values and my estimates for current spring.

I started with my C4 with sunroof and Cup-Pipe with a half tank of fuel with 1405kg.

After that, i did some wheight relevant changes

rear fan in the engine bay -4,5 kg
lower engine cover/undertray -4,8 kg
RS rear glas -2 kg
RS carpet instead the orig. carpet and insulation -20 kg
back shelf with speakers -7 kg
RS-seats -30 kg
remove rear seats/belts -7 kg
light weight flywheel/clutch -8 kg

That was a reduction of 83,3kg.

Mathematically, the car should had 1322kg with a half tank of fuel. My mechanic had it on his scales for corner balancing my RS-suspension and he said me, he remembers 1340kg with 3/4 tank of fuel.

During the winter, my car gets still some modifications:

remove spare-wheel and compressor -18 kg
remove carpet in trunk -3 kg
remove clima -20 kg
lightweight front bonnet -9,5 kg
Rennline lower dash and remove passenger airbag -10 kg
RS door-cards without speakers -12 kg
install full equal length header system with heat -20 kg
remove radio -1,5 kg
remove rear bumper undertray -7 kg
5kg AGM starterbattery -10 kg

That`s a minus of 111kg.
So - mathematically that car should weight 1230kg with 3/4 tank of fuel.

It has RS-Brakes, heigo roll-bar and MM Cup1 Style wheels.

So my question: is this possible to see a number, lower than 1250kg with a full tank fuel in spring 2015 with these modifications?

I`m so excitedl about the final result

Whats your opinion or your experiences with C4`s?

regards Thilo

-nick

Some of the numbers sound *very* optimistic.

Rear engine fan is more like 1kg. For instance. Good luck!

koenig_roland

thanks for your feedback!
I had the numbers from various porsche forums. I did`t weighted the stuff when i removed it...

Only the initial weight session was done by myself. The second session was done by my mechanic. It a porsche race-shop.... So, the 1340 in this spring should be real...

kos11-12

Maybe a bit optimistic if you keep AC , my C4 is 1330kg , with AC, sun roof, original carpets minus airbags and RS doors ,
I thing I could save another 80 kg inc sun roof delete... But that is a big job and very expensive.

kos11-12

Sorry did not see you removing AC , then that sound about right . If you can go for lithium battery they are about 1,5kg

koenig_roland

-AC gets removed.
-starterbattery - i`m sceptic about the super-light lithium stuff. I just bought a 5kg industrial agm for 40,-€.
The full-race header system (with heat) should save big numbers in the rear. I estimated 20kg.

I`m searching for some superlight wheels in 17-inch - WITH German Tüv!

kreeshp

The 17" Fuchsfelge genuine Fuchs should be on your list then -- TUV certified and lighter even than the magnesium RS Cup 1's.
7" fronts weigh 16.5 lbs (7.5 kg), 9" rears weigh 17.5 lbs (7.9 kg); versus the 8.5 kg, 9.3 kg of the magnesium RS Cup 1's.

The Zuffenhaus Fuchs are slightly lighter than the genuine Fuchs but I don't believe they are TUV certified as of this writing.

sources:
http://www.fuchsfelgeusa.com/wheel/1...felge-fuchs-17
http://www.944racing.de/wheelweights.php

HiWind

1250kg sounds right for what's above although is it a full heigo cage?

i can vouch for the lithium battery - had voltphreaks 2kg for 4 years now - but they are super expensive
... ok if it last 8-10yrs as promised

would be keen to have more details on the 5kg AGM please!

koenig_roland

@kreeshp
thx, but i don`t like the fuchs style on 964`s. Also 7,5 is not that superlight for me :-)

oz alleggerita is 6.x in 17-inch, but not available in 5x130. Something with 6.xx is superlight for me and the only reason i would change wheel-style from my loved cup1 style...

@hwind
yuasa np17 is the agm i recently have bought. It weights 5.1 kg on my scale...
I`ve no cage - only a roll bar. But not standard. It has no cross in rear, only one diagonal strut in the rear like in the old days.

David A

Be careful with removing the spare, it's part of the "crash test".

BLACK-BETTY

Great work!

koenig_roland

what`s the current weight of BB frank? You`ve a quite similar build with a little bit more *blingbling* in the inside of the car :-)

BLACK-BETTY

I have no idea. In fact I'd love a guestimate from you, please. She's quite fat but I'm finally loosing weight.

So weight savings are recaros, all sound deadening removed, no electric heater, lwt wheels, full lwt exhaust, RS door cards, rear seat delete. Although I've kept electric windows, stereo/ speakers and rear parcel shelf.

Your car is really inspiring. Love seeing light weight C4s proving themselves as track cars too.

boxsey911

In my experience the mathematical weight reduction does not equate to the actual weight achieved. With my C2 I have:

Removed entirely:
Rear Seats
Rear shelf and speakers
rear wiper
rear seat belts
engine undertray
air con pump, pipes and radiator
all interior sound proofing
rear side trim panels
redundant wiring
brake protection shields

Swapped:
Comfort seats for recaro pp
door cards for RS door cards (single speaker in each)
Std engine mounts for lighter RS mounts
fog lights for cooling ducts
Normal carpet for lightweight RS carpet
Std cat for de-cat pipe
Front brakes for 993 brakes (weight gain)
Dual mass flywheel for lightweight flywheel
Std suspension for KWV3 (no change?)
Std sway bars for H&R bars (small gain?)

Added:
BK harness guide bar and Scroth harnesses
lwt floor boards at the front
Rennlist gusset to engine carrier

With all those reductions made I was quite disappointed to see that with 3/4 of tank of fuel it weighed 1305 Kg on the scrutineer's scales at Oulton Park. With all the weight reductions made I was expecting it to be a lot lighter.

Mondrian

I looked into this and my understanding was that the standard weight quoted by Porsche does not include options - for example while sunroof was part of the included UK package it was technically a factory option so starting weight in most cases is above 1400kg, more if aircon/fully electrical seats stereo etc were also optional.