If you are very rich and your weight weenie obsession takes you in to beast mode, with all the nuts and bolts in a car (about 3500), replacing them with aluminium for the majority, titanium for a bit more strength where needed and stainless steel for the components your safety depends on, you can save a lot of weight. You'd need a good set of calipers and a lot of time on your hands to work out your order before handing part of your fortune over to Pro-Bolt.

Titanium bolts typically weigh around 1/3 less than steel and aluminium bolts are lighter still - less than 1/2 the weight.

Here is some data comparing the 3 metals:





Aluminium bolts
https://www.pro-bolt.com/aluminium-r...ncy&page_num=2
Titanium bolts
https://www.pro-bolt.com/titanium-ra...drilled-bolts/
Stainless steel bolts
https://www.pro-bolt.com/stainless-s...drilled-bolts/

If you take your obsession this far: https://shop.easyelox.de/carbon-fiber-bolts it's probably time to see a psychiatrist

 

Formula 1 paint job anyone? In one link they say a car paintjob usually weighs 25-30 kg and a Formula 1 car requires just 1.5 Kg. If similar paint is used on a big passenger car like the Jag, it looks like there are big weight reductions to be achieved.

https://www.scuderiaalphatauri.com/e...erformance-f1/

AERO | Sustainable Paint Technology

Remove all of the paint like that polished aluminium Jag XJ8 mentioned in a previous post, just paint the bumpers and lacquer the body, looks like there is potentially a 20 Kg weight reduction.

 

I found more information on carbon ceramic brake rotors:

https://www.rebrake.de/en/faq/

"2. Less weight
The weight savings of using lightweight carbon ceramic brakes can amount up to 35 kg per car. The important fact is, that this mass is part of the rotating and unsprung mass. Saving weight at these masses is critical, because they are subject to the moment of inertia. Rotating brake discs, that have to be accelerated or braked, or suspension that moves up and down are subject to the law of inertia. In professional Motorsport there is a saying: “1kg saved at the rotating/unsprung mass is equivalent to about 5kg at the chassis.” Saving up to 35 kg at the brakes alone would mean a theoretical weight loss of up to 175 kg at the chassis."

So a revised new curbweight with carbon ceramic rotors:

1604 Kg - 10 Kg (Magnesium calipers) - 30 kg (largest size carbon ceramic rotors probably not needed) = 1564 Kg

 

Another curb weight update with the other weight saving guesstimates

Weight
Saving
15 Kg - Sports exhaust + tubular exhaust manifold
15 Kg - Jaguar Space saver spare tyre removal (need a more accurate weight if possible)
32 Kg - Rear seat removal
20 Kg - bare aluminium body finish with lightweight paint/lacquer
82 Kg - Total

1564 Kg - 82 Kg = 1482 Kg (3260 lbs) - we are entering Porsche (992) Carrera 4 territory!

Power to weight ratio = 270 BHP/Tonne (with standard XJR engine)- That is the same as a 2014 Aston Martin V8 Vantage N430 and the 2013 BMW M3 (F80)
0-60 mph should be somewhere in the mid 4s with an LSD fitted.

 

Has anyone removed some of the plastic and soundproofing from the engine compartment?
What kind of weight savings are there?

If you ceramic coat the exhaust manifold, and exhaust system, do you think that some heat shielding could be removed?

 

I thought that this guy is the kind of person who would buy those carbon fibre bolts until he mentioned that the engineers had made his latest creation lighter than he was expecting and he wasn't bothered about the even lighter weight the chief engineer was suggesting it could be. (from 12:25)

 

I mentioned that these weight subtractions would improve performance once your engine power upgrades had been maxed out.
Lets have a look at what the lighter weight + more power means in comparison with other performance cars, which cars will you be able to embarrass with your big old sleeper limo?

This is a list of engine power outputs ranging from the standard 400 Bhp to 700 Bhp (Avos' Twin screw XKR mod) in increments of 50 BHP and based on the reduced curb weight so far of 1482 Kg

400 BHP - standard engine
PTW ratio = 270 BHP/Tonne

2013 BMW M3 (F80) - 1595 Kg - 425 BHP - 266 BHP/Tonne
2014 Aston Martin V8 Vantage N430 - 1610 Kg - 430 BHP - 267 BHP/Tonne
2014 Mercedes-Benz S 63 AMG Coupé - 2070 Kg - 577 BHP - 279 BHP/Tonne
2012 Jaguar XFR-S - 1987 Kg - 542.5 BHP - 273 BHP/Tonne
2004 BMW M5 (E60) - 1830 Kg - 500 BHP - 273 BHP/Tonne

450 BHP - smaller S/C pulley, ECU tune, Air intake upgrade...etc.
PTW ratio = 304 BHP/Tonne

2014 BMW M5 - 1945 Kg - 592 BHP - 304 BHP/Tonne
2012 Morgan Aero Coupe - 175 Kg - 362 BHP - 308 BHP/Tonne
Audi R8 Spyder 5.2L V10 - [2009] - 300.2 bhp per tonne
Lamborghini Countach LP5000S QV - [1985] - 300.6 bhp per tonne
Aston-Martin DBS V12 2d - [2007] - 300.8 bhp per tonne
Mercedes SL Class 63 AMG Performance Package - [2012] - 301.3 bhp per tonne
TVR Chimaera 500 5.0L V8 - [2001] - 301.8 bhp per tonne
TVR Griffith 500 - [1993] - 301.8 bhp per tonne
Ferrari 512 M - [1994] - 302.4 bhp per tonne
Aston-Martin DB9 GT 5.9 V12 - [2015] - 302.5 bhp per tonne
Lamborghini Diablo VT 5.7 V12 - [1993] - 302.7 bhp per tonne
Aston-Martin Vantage V12 Zagato - [2012] - 303.5 bhp per tonne
BMW 5 Series M5 30 Jahre - [2014] - 304.3 bhp per tonne
Aston-Martin Vantage 600 - [1998] - 304.5 bhp per tonne
Chevrolet Camaro ZL1 6.2L V8 - [2011] - 305.2 bhp per tonne
TVR Cerbera 4.2 - [1996] - 305.8 bhp per tonne
Vauxhall-Opel VXR8 GTS 6.2 V8 - [2013] - 306.2 bhp per tonne
Morgan Aeromax 4.8 V8 - [2008] - 306.7 bhp per tonne
Porsche 911 Turbo 991 - [2013] - 307.1 bhp per tonne
Tesla Model S P85D - [2014] - 308.6 bhp per tonne
Porsche 911 Turbo 997 - [2009] - 309.0 bhp per tonne
Jaguar XK R-S 5.0 V8 - [2011] - 309.1 bhp per tonne

500 BHP - exhaust system, intercooler upgrades, more ECU tuning...etc.
PTW ratio = 337 BHP/Tonne

KTM X-Bow GT 2.0 Turbo - [2013] - 331.7 bhp per tonne
Ferrari 360 Challenge Stradale - [2003] - 332.0 bhp per tonne
Lamborghini Diablo VT 6.0L V12 - [2000] - 334.1 bhp per tonne
Porsche 911 GT2 996 - [2004] - 334.5 bhp per tonne
Mercedes SLS AMG Roadster GT - [2012] - 336.0 bhp per tonne
Audi R8 LMX 5.2 V10 - [2014] - 336.5 bhp per tonne
Ferrari F430 4.3 V8 - [2004] - 336.5 bhp per tonne
Lamborghini Gallardo 5.0 V10 - [2003] - 337.5 bhp per tonne
Mercedes SLR Class McLaren Roadster - [2009] - 338.0 bhp per tonne
Lotus 2-Eleven 1.8 Supercharged - [2007] - 338.2 bhp per tonne
Lamborghini Diablo 6.0 V12 - [2000] - 338.4 bhp per tonne
Aston-Martin Vantage V12 S - [2013] - 339.3 bhp per tonne
Ferrari California T 3.9 V8 Turbo - [2014] - 339.6 bhp per tonne
Nissan Skyline GT-R Nismo R35 - [2015] - 340.7 bhp per tonne
Porsche 911 GT3 4.0 997 - [2011] - 343.5 bhp per tonne
Lamborghini Murcielago 6.2 V12 - [2001] - 346.0 bhp per tonne

550 BHP - Twin screw supercharger conversion, retune...etc
PTW ratio = 371 BHP/Tonne

Porsche 918 Spyder 4.6 V8 - [2013] - 365.8 bhp per tonne
Mercedes SLR Class McLaren 722 S Roadster - [2008] - 366.2 bhp per tonne
Lamborghini Gallardo 5.0 V10 Superleggera - [2007] - 367.6 bhp per tonne
Lamborghini Gallardo LP560-4 - [2008] - 368.0 bhp per tonne
Lotus Evora GTE 3.5 V6 - [2012] - 368.3 bhp per tonne
Audi R8 5.2 V10 FSI Quattro - [2015] - 369.3 bhp per tonne
TVR Sagaris 4.0 - [2003] - 371.0 bhp per tonne
Ferrari 430 Scuderia - [2007] - 372.5 bhp per tonne
KTM X-Bow R 2.0 Turbo - [2013] - 373.4 bhp per tonne
Aston-Martin Vanquish 5.9 V12 RS - [2009] - 375.0 bhp per tonne
Aston-Martin Vantage GT3 5.9 V12 - [2015] - 377.6 bhp per tonne
Ferrari 458 4.5 V8 - [2009] - 378.4 bhp per tonne
Ford Mustang Shelby GT500 - [2012] - 378.9 bhp per tonne
Lamborghini Murcielago LP640 6.5 V12 - [2006] - 378.9 bhp per tonne

600 BHP - More mods and tuning
PTW ratio = 404 BHP/Tonne

Caterham 7 Superlight R400 - [2006] - 400.0 bhp per tonne
Noble M400 3.0 V6 - [2004] - 400.9 bhp per tonne
Mercedes SLS AMG Black Series 6.2 V8 - [2012] - 401.2 bhp per tonne
McLaren 540C 3.8 V8 Twin Turbo - [2015] - 406.5 bhp per tonne
Chevrolet Corvette Z06 6.2 V8 C7 - [2014] - 406.7 bhp per tonne

650 BHP - Even more mods and tuning
PTW ratio = 438 BHP/tonne

Ferrari F50 4.7 V12 - [1995] - 422.7 bhp per tonne
Chevrolet Corvette C6 ZR1 - [2007] - 423.0 bhp per tonne
Lamborghini Huracan LP 610-4 - [2014] - 423.3 bhp per tonne
Lamborghini Aventador LP700-4 Roadster - [2013] - 424.6 bhp per tonne
McLaren 570 S 3.8 V8 Turbo - [2015] - 428.0 bhp per tonne
McLaren MP4-12C 3.8L V8 Twin Turbo - [2012] - 429.5 bhp per tonne
Pagani Zonda C12 S 7.3 - [2002] - 437.6 bhp per tonne
Lamborghini Aventador LP700-4 - [2011] - 438.0 bhp per tonne
Saleen S7 7.0 V8 - [2000] - 441.0 bhp per tonne
Porsche Carrera GT - [2003] - 442.7 bhp per tonne

700 BHP - Highest recorded AJV8 power?
PTW ratio = 472 BHP/Tonne

Caterham Super 7 JPE - [1992] - 463.8 bhp per tonne
Ferrari Enzo 6.0 V12 - [2002] - 476.1 bhp per tonne
Ferrari F12 Berlinetta 6.3L V12 - [2012] - 478.6 bhp per tonne

So what about Avos' 700+ BHP twin screw engine in a race prepared, 1284 Kg X350?
PTW ratio = 545 BHP/Tonne

That's still not quite quick enough to equal the current production car 1/4 mile king, the McLaren 765LT, which has 564 BHP/Tonne
How does 0 - 60 mph in 2.1 seconds sound and how about the 1/4 mile in the 9s?


You'd need to get the Jag's weight down to 1240 Kg by removing another 44 Kg if possible or increase engine power by another 25 BHP.

I'd love to see that for real, lol.

 

Here is another car list giving BHP/Tonne figures, borrowed from another forum for comparison.

BHP/TONNE List

Highest at the top

Road Legal and Non-Road Legal / Race

Model ----------------- bhp/tonne

Non-Road Legal / Race……

Formula One - Benetton-BMW B186 (+70 kg fuel, +80 kg driver) - 1884
Porsche 917/30 (full 39 psi boost)(dry) - 1767
Formula 1 3.0L 2005 cars – approx 1384
Porsche 917/30 (normal boost)(dry) – 1296
Suzuki Escudo Pikes Peak - 1231 (Race car)
Mercedes Sauber C11 - 1050 (Race car)
Mazda 787B - 828 (Race car)
Ferrari F50 GT1 – 826
Ferrari FXX – 693
Toyota GT1 - 667
Maserati MC12 Corsa – 630
Renault Espace F1 - 615 (Race car)




Road Legal…..

Caparo Freestream T1 - 1000 (not in production yet)
SSC Ultimate Aero TT (2007) – 946 (production underway)
TVR Cerbera Speed 12 – 903 - (production plans cancelled)
SSC Ultimate Aero - 854
Saleen S7 TT Competition (1035 bhp) - 774
Dauer 962 Lemans – 709
Koenigsegg CCX – 683 (dry weight)
Ultima GTR 640 – 674
Suzuki GSX-R1000 (2006) – 664 (with 170 lb rider)
Koenigsegg CCR – 655
Hennessey Viper Venom SRT-10 1000 Coupe - 643
McLaren F1LM - 641
Radical SR3 Turbo – 640
Kawasaki ZX-14 (plus 170 lb rider) - 640
SSC Aero – 634
Mercedes CLK GTR 1998 – 612
ZX-12R (plus 170 lb rider) - 609
Koenigsegg CC – 596
Gumpert Apollo – 591
Hayabusa (plus 170 lb rider) - 585
Saleen S7 TT (750 bhp) – 561
Radical SR8 - 558
McLaren F1 road car - 550
Ferrari P4/5 by Pininfarina - 550
Stealth B6 – 549
Donkervoort D8 RS06 - 541.09
Pagani Zonda F Clubsport - 539
Caterham R500 Evo - 532
Bugatti Veyron 16.4 - 530 (minimum rating)
Pagani Zonda F – 490
Ariel Atom 2006 1998cc - 483
Ferrari Enzo - 478
Suzuki GSX-R600 (2006) – 470 (with 170 lb rider)
Maserati MC12 - 467
Mosler MT900S Photon – 454
Porsche Carrera GT - 439
Vector W8 TT - 415
Campagna T-Rex – 411
TVR Sagaris - 400
Ferrari F40 – 398
Ferrari F430 Challenge - 395
Jaguar XJ220 – 395
Lamborghini Diablo GT - 394
Ferrari F50 – 389
Lamborghini Murcielago LP640 – 380 (dry, no fuel)
RUF CTR2 - 377
Ferrari 599 GTB Fiorano - 367
Lamborghini Gallardo SE (520 bhp) - 364
Chevrolet C6 Corvette Z06 - 356
Lamborghini Murcielago - 352
TVR Sagaris - 351
Lamborghini Gallardo – 350 (dry, no fuel)
Lamborghini Murcielago Roadster – 349 (dry, no fuel)
Ford GT – 346
Gemballa GT550 - 345
Ferrari F430 - 333
Ferrari 360 Challenge Stradale - 332
Lamborghini Gallardo Spyder (520 bhp) – 332 (dry, no fuel)
Porsche 996 GT2 - 321
Dodge Viper SRT-10 Coupe – 319
Ferrari F430 Spyder - 318
Ferrari 575M – Maranello – 312
Aston Martin V8 Vantage Lemans V600 (2000) - 304
Porsche 997 Twin Turbo - 303
TVR T350 – 295
Ferrari 612 Scaglietti – 294
Porsche 997 GT3 RS (ams 24/06) - 290.61
Ferrari 360 Modena - 288
Mercedes-Benz CL65 AMG - Twin-turbo 6.0 V12 – 287
Mercedes-Benz SL65 AMG - Twin-turbo 6.0 V12 - 285
BMW E63 M6 Coupe (2006) – 285
Ford Shelby GT500 (2006) – 282
Porsche 996 GT3 Carrera RS – 281
Alpina B6 - 279.95
BMW E60 M5 Sedan (2006) - 279
Ariel Atom – 274
Mercedes-Benz S65 AMG (2007) - Twin-turbo 6.0 V12 – 270
Audi R10 - 269
Cadillac XLR-V (2006) – 267
Aston Martin DB9 (2004) - 264
Porsche 996 Twin Turbo - 263
Maybach Exelero – 263
BMW E46 M3 CSL (2003) – 260
Audi RS6 Plus (2004) - 258
Audi RS4 Quattro (2005) – 255
Mercedes CL 63 AMG - 252
Aston Martin V12 Vanguish (2001) – 248
Aston Martin DB7 GT - 242
Cadillac STS-V (2006) - 237
Aston Martin DB7 Vantage (1999-2003) – 236
Ford Mustang SVT Cobra (2003) – 235
BMW E39 M5 (1998-2003) - 233
Audi S8 (2005) - 232
Chrysler 300C SRT-8 (2006) - 232
Cadillac CTS-V (2004) - 230
Dodge Charger SRT-8 (2006) – 226
Chrysler Crossfire SRT-6 coupe (2005) - 225
BMW E46 M3 Coupe (2000) – 223
Audi S6 (2006) – 220
Chrysler Crossfire SRT-6 roadster (2005) – 219
BMW 650i – 213
Porsche Cayman S - 209
Pontiac Firebird Trans Am WS6 (1998-2002) – 206 “conservative”
Lotus Europa S - 201
Nissan 350Z coupe manual (track version)(2006) - 197
Nissan 350Z coupe manual (2006) – 196
Ford Mustang Mach-1 (2003-2004) – 194
Ford Mustang GT Coupe (2006) – 192
Subaru WRX STi (2006) – 188
Opel AStra GTC OPC - 176
BMW E90 330i (2005) – 170
Mazda RX-8 – 168
Mini Cooper S - 145

 

All the different forms of power to weight ratio are confusing, here's a list of cars using the American BHP per imperial ton format.
https://www.carfolio.com/search/spec...1=&y2=&num=200

 

This is a comprehensive weight reduction guide for improved drag racing performance

https://www.dragstuff.com/techarticl...reduction.html

 

Lightweight alloy wheel lug nuts, minor weight savings and have disadvantages but lets add them anyway.
Rediculous Mods: The Problem with Lightweight Lug Nuts | Tuner University

OEM Steel lug nuts = 1.540 Kg
Lightweight Alloy nuts = 0.646 Kg

Saving = 0.894 Kg (close enough to 1 Kg)

 

Huge weight savings by changing your car battery to lightweight lithium:
https://antigravitybatteries.com/pro...tive/ag-h7-rs/ <= this is the recommended battery model for the Jag X350, claims a 40lbs weight saving over lead acid batteries (18 Kg)

"WEIGHT: The ultralight Antigravity RE-START Batteries weigh from 8.5 lbs to 17 lbs (4-7 Kg) depending on the model. On average this equates to a weight loss from 35- 60 lbs (16-27 Kg) over a typical lead/acid battery!"

 

1 Kg - lightweight wheel lug nuts
18 Kg - Lithium battery
19 Kg - Total

1482 Kg - 19 Kg = 1463 Kg (3218.6 lbs)

 

If you have the squirty puncture repair stuff and don't carry a spare wheel, you don't need a car jack - that's about 9 lbs saved. (4 Kg)

 

I haven't found any comparison weights so I'm going to have to make an educated guesstimate:

The Jaguar's reservoir is 4.5 litres (about 1 US gallon) made from aluminium.


(0.9 Kg)

Those 3 elements total 6.56 Kg, remove all the wiring, sensors and assuming the coilover shocks are a similar weight - 10 Kg reduction seems realistic.

 

10 Kg - Coilover suspension conversion (removal of all air suspension wiring and elements)
4 Kg - Car jack removal
14 Kg - Total

1463 Kg - 14 Kg = 1449 Kg (3188 lbs)

210 Kilograms subtracted so far (462 lbs)

 

So far we've saved the same amount of weight as me and my brother getting out of the car...

 

Fitting a carbon fibre prop shaft would be an extreme mod that would have to be made to measure, not only will the part be far lighter but it will reduce drivetrain losses to the wheels and result in improved acceleration.

https://bactechnologies.com/high-per...10-driveshafts



The OEM prop shaft looks seriously heavy duty,



I'm sure there are some engineers that could make a carbon fibre shaft work.

This thread explains the advantages:
https://www.m5board.com/threads/pote...owners.531745/

Main advantages are a possible reduction in vibrations, a responsiveness effect like a lightened flywheel, Weight reduction of 19 lbs (8.6 Kg) on a BMW V10 drive shaft.

The magnesium wheels also have an improved damping effect due to the metal's crystalline structure , if you fit equal length headers, they create a smoother exhaust pulse pattern - less burbly, the lighter weight of the Jag will allow softer suspension damping settings without allowing too much body roll. All these elements combined will produce significant vibration reduction which means less need for sound deadening everywhere, therefore they can be removed without loss of comfort and refinement, probably saving another chunk of mass.

 

Electric cars are inspiring lots of innovative weight saving solutions like this lightweight sound system: https://www.carscoops.com/2020/01/ha...-over-the-air/

"...the Ecotect system is about twice as efficient as a traditional audio system and also half the weight. This means a typical system weighing about 44 lbs (20 kg) could be replaced by an Ecotect setup weighing just 22 lbs (10 kg *corrected)." = 10 Kg reduction

The rear CD changer is pretty obselete and weighs about 7 lbs (3.2 kg)

13.2 Kg savings are possible with an up to date sound system.

 

8.6 Kg - Carbon fibre prop shaft
13.2 Kg - Out with the Alpine sound system, in with the Harman Ecotect lightweight system. (Or no sound system at all for 23.2 Kg subtracted)
21.8 Kg - Total

Updated curb weight:
1449 Kg - 21.8 Kg = 1427.2 Kg (3140 lbs)