Project C4 Lightweight

I thought I'd start a new topic detailing a bit about my 996 journey. I've always enjoyed "adding lightness" to any car I've owned as it's an excellent way to improve performance in every area. The 996 is no exception and I've taken 100kg out of it already. My only requirements are that it must retain 4-seats (as I sometimes need to transport the boys when my wife's car is in use) and that it needs to look as stock as possible. The car is a 99 C4 and I was attracted to it for 2 main reasons in that: It was Manual and It didn't have a sunroof. I absolutely did NOT want 4WD though and nearly completely overlooked C4's until stumbling on a thread that documented converting the Turbo to RWD and it looked remarkably straightforward. So the C4 was bought and within a month or so the AWD system was removed and coilovers fitted...the slippery road of modification was well underway. Which brings me to the present day: Modifications include: - AWD removal - YSR Coilovers - 15mm/7mm spacers - Carbon Ducktail - Momo Prototipo - 997 Shifter - Custom gear knob (snooker ball) - X-pipe Exhaust (200cell cats) - Low Temp Stat - Metal impeller water pump - Lower Console delete - Rear wiper and 3rd brake light delete - Non-smokers tray And the weight stats are as follows (and thanks to ELA's CLR thread for the part weights and, of-course, inspiration) Parts removed: 4WD removal 35kg (not 50kg as previously thought) Jack 1.3kg Tool roll 0.8kg Spare wheel 11.3kg Rear Wiper assembly 2.2kg Passenger Airbag 3.3kg Drivers Airbag 1.2kg CD Changer 1.9kg Double DIN Radio 3kg Service book holder 0.5kg Boot liner/trim 3kg Speakers x4 1kg Clutch assist spring 0.2kg Floor Mats 2.6kg F/R Low impact bars 6.9 A/C system (most of) 11kg Rear Carpets (behind seats) 6kg Wiper motor panel trim 0.5kg Tracker Module 0.8kg Battery Tray 1.2kg Alarm Siren 0.8 Parts replaced and weight saved: Carbon Ducktail 6kg X-pipe cats 4.5kg MOMO Steering wheel 1.6kg Coilovers 4.5kg Lower Console delete 1kg 993RS Engine Mounts 0.7kg Litronic to Halogen Swap 2.0kg Shido LIfePO4 Battery 15.2 Lightweight mufflers 14 Total weight currently saved = 144kg On the "To Do" list: Remainder of A/C delete 3kg Door Airbags 2.2kg Power steering delete (6kg) GRP Bonnet 8kg GRP Doors 20kg GRP Wings 5kg Lightweight seats 30kg Fuchs 17" Wheels 25kg Polycarbonate windows 5.5kg Main Carpet included Insulation 25kg Rear Side panel insulation 3.6kg LWFW and Clutch 5.9kg This will bring the total weight reduction to around 280kg Already though the performance and handling change is noticeable and without trying to sound too cliché it really does feels more alive and visceral. I just need to make sure I never NEVER add up all the costs!

Some lightweight badgework.

Like it, some good mods. You could save a heap of weight in those wheels, the Sport Designs are heavy.

Thanks! Yes, very true regarding the wheels, and removing unsprung weight is always the best option. As controversial as it might be, I'm not a huge fan on the Fuchs wheels on the 996, which is a shame as I understand they are very light and readily available. I may look down the Enkei or RAYS Volk-Racing route as I've had both of these brands before and they were both superbly made and very light.

You should check out the IslandWorks Lightweight 964 project on youtube. >300kg so far. 8)

Nice work :thumb: Starting with a C4 is good for another reason, in that the chassis is stiffer than the C2 chassis. Well, this is the case on the 997.1 which is why Porsche used the 997 C4 chassis for the 997.1 GT3 and not C2. So I assume it's the same with 996 OZ wheels are worth looking at too, lightweight compared to OEM and not particularly expensive Also seats are another area you could save weight, Recaro Sportsters if you want a light(er) weight folding bucket option. If you didn't need the rear seat functionality then you could save a lot of weight by ditching the OEM seats for fixed buckets like Recaro Pole Positions

@MaxA - Thanks! There goes my afternoon! @Roro - Thanks for the suggestion of the OZ - I'll look into them. As for seat my ultimate desire would be a pair of Tillett B8's however I do still need folding seat access to the rear seats as my kids are still in car seats. That said. I might look into a system where a fixed back carbon seat like the Tillett is fixed onto a base that tilts the whole seat forward.

You can go down the rabbit hole with a fairly obsessed Swedish guy. An amazing project though! Might take more than an afternoon... PS +1 for lightweight OZs.

Re: Project CS2 - A lightweight RWD Carrera 4 115kg's a good start but you've got a way to go to match ELA's CLR. --> http://www.911uk.com/viewtopic.php?t=106137&start=0&postdays=0&postorder=asc&highlight= If you haven't seen this thread hopefully you'll find some further inspiration from it. Have fun :thumbs:

Don't I know it! ELA's thread along with poppopbangbang's is what got me falling down this rabbit hole! A lot of fun though and so much more interesting to drive/own than something fresh from the showroom.

Glad to see that you've ended up keeping it and that your cracking on, I almost contacted you about your ducktail when it was up for sale, Looking forward to the weight saving updates, I hope there's not too much filler in that smoothed rear panel :lol:

Doing a little motivational maths - Based on a standard C4 weighing in at 1375kg then if I can bring total weight down to around 1100kg (Which is about the same that the 996CLR came to IIRC). That coupled with the 340hp from the 3.7L build would produce a power/weight ratio of 309bhp/tonne, which would be the equivalent power/weight of a stock weight C4 producing 425hp. That's using a fairly conservative power output of 340hp, there's every chance it will produce a little more too with reduced load from the A/C delete and the free flowing exhaust. Should make for a rather exciting and unique car although it's going to take me a few years to get to that stage.

Yes I had a little ownership wobble (a BRG Turbo-R was tempting me) however back on the 996 wagon now! The smoothed panel was reinforced fibreglass covering the hole with a light skim of filler; my bodyshop did an amazing job and you wouldn't know it ever had anything else there. Keeping the Ducktail now I'm afraid ;-)

Edited to add that I had the weights wrong for the AWD system - I had been told it was Circa 50kg whereas it actually comes up lighter at 35kg. Quite impressive that the whole system could be made that lightweight. I've now updated my weight figures accordingly.

Lightened flywheel adds power as well as weight loss, :thumb: