How much weight reduction to actually notice it?

[gareth h]

Sitting at home with a stinking cold and idly musing how much weight I’d have to take out of the 993 to make an appreciable difference to how it drives, any thoughts or experiences?

[XMA Simon]

Don't let the Mrs hear about you asking that.

[Glassman]

gareth h said:

Sitting at home with a stinking cold and idly musing how much weight I’d have to take out of the 993 to make an appreciable difference to how it drives, any thoughts or experiences?

I replaced the glass back window on a 997 with a plastic one (RS spec). You can do the same on a 993 but you'll lose the hotlines and wiper hole. There are further weight savings to be made on the remaining windows which also means window regulators can be defenestrated.

The chap with the 997 was on a mission though, verging on obsession! He went through all the nuts and bolts he could to replace with titanium. Carpets, rear seats, trims...

Be careful what you start

Edited by Glassman on Monday 21st October 15:02

[gareth h]

I wondered whether binning the front seats (and the wife!) for pole positions and losing the rears would make a noticeable difference, I don’t think I’d be committed enough to start changing glass, my mantra is minimum cost / hassle, maximum gain.

[Orangecurry]

gareth h said:

Sitting at home with a stinking cold and idly musing how much weight I’d have to take out of the 993 to make an appreciable difference to how it drives, any thoughts or experiences?

Bonnet, engine lid (and electric spoiler), plus seats are the easy reversible starting points (costs are anywhere from cheap to expensive depending on your replacement choices). I started with the engine lid just to see how much the metal one weighs, but I haven't decided on the spoiler replacement so I put it back as I'm using the car more.
Next step is carpets and sound deadening, which to remove properly is horrible, and not easy to put back; though a new carpet set would certainly lift the look of any tired interior, plus seats = big difference (in look or weight).

However as you allude to in your question, you have to keep going and going otherwise you won't notice much difference.

I started a spreadsheet (obviously) on actual weights, but it's too messy to post here - however, here is a teaser of what the stuff in the boot weighs.... note I actually gained weight from changing the lower PU corners from standard to (unpainted) aero.

Be prepared to commit, and ensure you have a very good storage solution planned so you are able to put it all back by knowing what-goes-back-where in numbered bags and cross-referenced spreadsheets

Front total weight reduction = 24.5kgs

• spare wheel = 12900
• 6 CD changer + base that sits in spare-wheel = 5212
• boot carpet = 2300
• tool roll without towing eye = 1684
• compressor = 1196
• aluminium jack = 1030
• towing eye = 380
• number-plate - changed to sticker = 197
• spare wheel clamp and bolt = 121
• number-plate plinth = 112
• change front PU corners to Aero = -612

[Orangecurry]

I forgot to post the weight of the OE metal engine lid (I think I'm reading my notes correctly) the lid including spoiler and motor and loom is 12.3kgs
Fibreglass engine lid replacement plus SSteel mesh was 4kgs - I'm sure I could reduce this, but obviously increases if you stick any aero on there.

Probably the most noticeable weight reduction 'feel' was going to lightweight 17" wheels; rotating weight and all that.

[Orangecurry]

gareth h said:

I wondered whether binning the front seats (and the wife!) for pole positions and losing the rears would make a noticeable difference, I don’t think I’d be committed enough to start changing glass, my mantra is minimum cost / hassle, maximum gain.

The below are taken from the internet.....

4 way electrical seats = 23150gs
Cobra Nogaro = 10200gs

6170g pair of faux-leather seat backs including outboard bolt
2098g pair of rear seatbelts including mounting bolts/washers

[Yellow491]

You need at least 100kg reduction to notice the weight gone,if no where near this saving,dont waist your money or time unless you are compelled to.

[Crudeoink]

gareth h said:

Sitting at home with a stinking cold and idly musing how much weight I’d have to take out of the 993 to make an appreciable difference to how it drives, any thoughts or experiences?

You'd notice the biggest difference going to lighter wheels, tyres and brakes. It's been a while since I studied vehicle dynamics but IIRC the rule of thumb was 1kg of unsprung mass equates to 3kg of sprung mass. There is always variables, like how far the mass is from the centre of rotation so tyres can make a big difference. But if it were me id change to a decent set of lightweight wheels, go for a slightly more pointy alignment (less toe in, slightly more camber) and if possible a corner weighted setup

[Discombobulate]

Simple trick is to assess any benefit is to run your car with a near empty fuel tank. Then fill it and drive it back home on the same road. Obviously the weight loss if from the front only, but will give you an idea how 50kg of so saving affects performance and braking.

[MDL111]

Assuming you have "normal" seats, I think bucket seats will make a big difference how the car feels when driving (even though the weight difference is not all that material as a % of car weight). Same for lightweight rims.

[Panamax]

Multi-way electric seats are staggeringly heavy. Air conditioning is also weighty.

I reckon you can start to notice from about 25kg if it's all one end, clearly from 50kg and definitely by the time you get to 100kg.

Bear in mind a typical passenger weighs around 70 kg and you'll certainly notice that - at least they sit in the centre of the car, not up one end.

Wasn't part of the hilarity that people were buying lightweight "Spyder" cars at an elevated price and then adding back massive amounts of weight from the options list? Spyder started out only 30kg lighter than base models in the first place!

[marine boy]

Crudeoink said:

You'd notice the biggest difference going to lighter wheels, tyres and brakes. It's been a while since I studied vehicle dynamics but IIRC the rule of thumb was 1kg of unsprung mass equates to 3kg of sprung mass. There is always variables, like how far the mass is from the centre of rotation so tyres can make a big difference. But if it were me id change to a decent set of lightweight wheels, go for a slightly more pointy alignment (less toe in, slightly more camber) and if possible a corner weighted setup

This, this and this...

I've removed 200kgs from my 964 C2

Not started to get serious yet as I've spent nothing so far and restrained myself to only unbolting stuff or removing redundant wiring

Only lightweight parts added are wheels and a CAT delete pipe

Lighter wheels improved the driving dynamics as much/maybe more than removing the 1st 100kgs of chassis weight

Drives like a completely different car now, much more nimble, dynamic and raw

[gareth h]

marine boy said:

This, this and this...

I've removed 200kgs from my 964 C2

Not started to get serious yet as I've spent nothing so far and restrained myself to only unbolting stuff or removing redundant wiring

Only lightweight parts added are wheels and a CAT delete pipe

Lighter wheels improved the driving dynamics as much/maybe more than removing the 1st 100kgs of chassis weight

Drives like a completely different car now, much more nimble, dynamic and raw

I managed to pick up a set of 18” hollow spokes which although probably not the lightest maintain a factory look, from my primitive bathroom scales they seemed to weigh similar to the Cup 2s that were fitted, but are wider, so I’ve sort of covered that angle

[LennyM1984]

Yellow491 said:

You need at least 100kg reduction to notice the weight gone,if no where near this saving,dont waist your money or time unless you are compelled to.

This^^

I've taken probably 30kg out of my race car (which was only 850kg to begin with) and from feel alone I really can't tell any difference. Even from a lap time perspective, a new set of tyres makes a far bigger difference.