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TOP 10 WAYS TO MAKE YOUR CAR LIGHTER

Posted by Matt Bell on 9th February 2021

With newer cars getting bigger and heavier each year, we list the top 10 ways to make your car lighter and faster for any budget. 

No, don’t worry, we’re not about to suggest attending the local zumba class to, ahem, shake your booty like a Polaroid picture. What we’re really interested in here is finding that perfect weight-loss programme for your pride and joy. And, why’s that? Well, arguably it’s the easiest way to improve performance and handling.

Yep, when you think about it, shedding pounds could be even more important than tuning itself. In the real world it’s exactly the same as gaining horsepower… and God knows we’ve all spent plenty of cash over the years trying to gain a little extra grunt, right?

So, that’s why this month we’ve mostly been thinking about fighting that flab and freeing up some healthy, usable power. You can get the obligatory Xmas pigging out of the way first of course, we’re not total monsters. But, when you’ve sung the last words of Old Lang Syne, here’s some tips to get you fighting fit for 2020…

Power to weight – why do I want to make my car lighter?

Power to weight ratios are everything in the pursuit of ultimate performance. They’re the reason you don’t see many race cars with 15-subs in the boot, and why a nuclear-powered oil tanker with 60000bhp will still be beaten off the line by my nan on her mobility scooter.

When you’re looking at weight vs power think about this: If you’ve got a car that weighs 2000kg with 200bhp, that’s a ratio of 2000:200 or 10:1. This also means every single horsepower has to push along 10kg. If you can save 200kg in mass, the ratio becomes 9:1 – a 10-percent increase in acceleration and real-world power.

In braking terms, a small, light car has less mass to slow down and will often be able to out-brake a much larger cruiser with significantly bigger brakes. Handling will also be improved because there’s less weight for the suspension and tyres to control. And, if you’re clever, you can also influence balance, tweaking oversteer and understeer according to where you take the weight from. With less weight your car will be more reliable due to less stress on components, you’ll enhance that magical driver ‘feel’ and you’ll get more MPG too.

1) Need it? No, then shift it!

The easiest, not to mention cheapest, way of saving weight is the most obvious – stripping out all the old guff that you don’t need. The thing to think about is how far you want to go, especially if you want to keep your car usable on the road.

Obviously the most hardcore dieting regimes, chiefly the ones where you’re looking to ditch all the trim, cut away excess metal and scrape away any sound deadening, will always yield the most impressive gains. On plenty of cars just removing the carpet can save a good few kilos for starters.

Of course, no one’s forcing you to go mad, something as simple as clearing out all the old tools and rubbish knocking around your boot can save more weight than you might think. It’s also worth knowing that the full-size spare steelies on some of the more retro Jap motors can weigh up to 15kg, while a can of Tyreweld weighs next to nothing. There’s two reasons why new cars don’t come with full-size spares nowadays – performance and economy.

Weight loss: From a few kg to a lot!
Cost: £mostly free

2) Get some bucket seats

Standard seats weigh an absolute ton especially those big electric, heated jobs you get in the luxury VIP cruisers. In fact, many modders in the US and Japan strip their seats of all the electric motors and fit manual sliders in a bid to shed a few pounds.

The average car seat can weigh 16-25kg so the best solution will always be fitting some lightweight aftermarket buckets. These are available in both reinforced fibreglass and posh composites like Kevlar and carbon fibre. Some aftermarket seats can weigh as little as 4kg and, even with the added subframes, that’s a significant drop in weight – especially if you only need the one.

When you’re making your choice don’t forget to consider that leather generally weighs more than cloth too, just try to pick up a cow sometime…

Weight loss: up to 25KG per seat
Cost: from £165
Start looking: cobra-seats.com

3) Remember that not all rims are equal

Steel wheels, along with the larger sized alloys, can weigh anything up to 20kg a corner with the tyres on, and that’s what’s scientifically know as ‘a lot’. Even an average set of 18-inch alloys can weigh over 12kg a corner. So, do your research and be careful of what aftermarket alloys you choose. The design, construction and materials used can have a huge impact on the overall weight. Problems are always compounded with wheels too, because when they’re rotating, this magnifies the effect of the mass. Some experts say that this can be up to 10-times the original weight and, again, that’s quite a bit of heft pulling your car around.

Obviously budget is always a consideration here, but forged rims, along with rotary forged (flow formed) wheels will always be the ultimate in lightness over more common cast wheels. OK actually, the ultimate would be full-on carbon fibre wheels, but who’s got the cash lying around to pay 4-grand-plus per corner? We’ll just have to wait for those six little numbers to come in!

Weight loss: up to 45kg (4 wheels)
Cost: from £650 (set)
Start Looking: srbpower.com

4) Plastic is pretty fantastic

Due to its complex chemical makeup, glass is a particularly heavy material – handy for seeing through when you’re driving, but heavy none the less. In fact, the glass in an average hatchback can come in at up to 50kg, and that’s why race cars use polycarbonate windows which weigh up to 60-percent less, are super-strong and are pretty much shatter proof. It’s not common with the Jap stuff of course, but in the wider motoring world, a few production cars run polycarbonate here and there. It’s not just the performance specials either, the first to do this was the Smart Fourtwo, and that was way back in 1998.

Anyway, the switch to polycarbonate windows also helps lower the centre of gravity for a bonus improvement in handling, they’re also relatively cheap compared to many performance mods out there.

Everything from replacement windscreens to quarter lights are on the market and with side windows you can often specify race-car style vents and sliders. And,  while you’re at it, take a look at your sunroof – you won’t believe how weighty the glass and mechanism can be there, luckily plenty of these can be replaced too.

Weight loss: up to 25kg
Cost: From £80
Start looking: acwmotorsportplastics.co.uk

5) Sort your chassis

You know in The Fast and The Furious when they’re designing that orange Supra and saying using aftermarket suspension can save 10-pounds (4.5kg) a corner? Well they were right. In fact, with the advancements in technology, the savings nowadays can be significantly more, in some cases over 10kg can be saved just by switching to a set of coilovers.

It doesn’t stop at shocks and springs either, there are loads of other chassis parts that can shave off a few kgs, sometimes a whole lot more. Lightweight adjustable control arms are also a popular choice, especially those super-hardcore alloy jobs you find on many a Honda, simply because they also do a great job of helping you set up your chassis geometry.

When it comes to your brakes, you may think that big brake conversions will always weigh a whole lot more than standard, but plenty of times that’s just not the case. Nowadays plenty of the top end items will offer quite the saving. Multi-pot alloy brake calipers and discs with alloy bells can weigh a lot less than standard cast iron jobs, and obviously, they’ll work much more effectively too.

Weight loss: up to 40kg
Cost: From £150
Start Looking: bc-racing.co.uk, ksport.co.uk, bilstein.de

6) Get the body you’ve always dreamed of

Lightweight panels, particularly fibreglass replacements, have been a racing staple for decades now. In the more hardcore fraternities it’s pretty common to totally replace front ends, or even the whole body, swapping out all the steel panels over a custom-fabricated, lightweight, tubular chassis.

Of course, we also now have the wonders that are carbon fibre and Kevlar, and everything from bonnets and tailgates, to front wings, bumpers and even complete floor pans are on offer. The best thing is that prices are coming down all the time too.

That said, always be aware of what you’re buying and, if possible, check the weight first. Some cheaper parts are reinforced with steel structures or seriously thick fibreglass underneath, and that can actually be heavier than the standard part altogether. Be especially mindful of this on cars like Subarus which often come with lightweight aluminium bonnets in the first place. You don’t want to make your car heavier, do you? That’s just defeating the object.

Weight loss: up to 25kg
Cost: F Weight loss – anything up to a ton, maybe more!
Cost from £30
Start Looking: tarmacsportz.co.uk

7) Remember it all adds up

When it comes to standard parts, most are made to a budget, so there’s plenty of areas where shaving off a few grams here and there can add up. Take your standard exhaust manifold, it’s most likely cast iron, a stainless steel tubular replacement will not only save a few kilos, but will improve the gasflow for more power too.

It can be a modification as small as a lightweight pulley set or racing steering wheel. Then again, it could be as bonkers as a carbon propshaft, aluminium diff or lightweight gearbox housing – it all makes a difference. We’ve even heard of people emptying their washer bottles and keeping their fuel to a minimum on a trackday. It may sound crazy but it makes sense – 3 litres of washer water weighs 3kg while 40-litres of petrol nearly 30kg.

Of course if you’re looking for the ultimate in lightweight bolt-on performance you could bag yourself a full-on titanium exhaust. Titanium is comparable to steel in strength but has less than half the overall weight. It also looks pretty damn tasty too!

Weight loss: 200grams to 20kg
Cost: from £50
Start Looking: scorpoion-exhausts.co.uk

8) Get the right electricals

Obviously most of us aren’t looking to go that far on a road car, but there are plenty of other easier options. Take your car battery for example. Normal lead-acid items are really, really heavy, but these can easily be replaced with more lightweight units, perhaps even a super-compact racing item if you’re not running too many electrical systems.

Then there’s the audio. If you like to hear your music properly I’ve always been an advocate of a sound system with a dedicated woofer. But, it’s always worth thinking about the gear you’re fitting – do you really need that 18-inch woofer and 4000Watt amp outside of an SPL competition?

Some manufacturers have made a massive impact with lightweight audio over the past few years, and nowadays you can get some serious performance and exceptional sound quality out of tiny subs and even tinier amplifiers. Of course there’s also the age-old option of ripping out the standard system altogether, or fitting a compact Bluetooth receiver instead of a headunit. It all works.

Cost: from £free
Start Looking: jlaudio.co.uk

9) Step away from the fast food!

Let’s just say that one of the heaviest things in your motor is you. In other words, it’s no use trying to shave 20g off the wiring harness and immediately reaching for that second cheeseburger – take this from a rather portly, salad-dodger who knows!

If you already look like you’ve been on the cover of Men’s Health then well done you, but the rest of us will probably admit we could all do with being a little fitter. So, maybe getting your laptimes down a bit could be your motivation to dodge a future heart attack? Then again, maybe life’s just too short for eating steamed cabbage anyway!

Cost: Free

10)  Don’t put it back on again!

You have to feel a little sorry for all those F1 engineers. These guys spend all year trying to shave half a gram off a brake caliper, then Lewis Hamilton turns up with a nose ring that probably weights five times that. My point is to be mindful of what you’re putting back in your car – there’s pros and cons for almost everything.

A roll-cage can add a significant amount of weight but it can also save your life in a smash. Then again, with the rigidity and safety a cage provides, it’s possible to remove a whole lot more metal from the car – along with things like side impact bars.

Think of it like this, cages always look great but racecars have to have them because of the safety regulations, some drivers would happily do without them just to get the performance edge. I know it’s a random one, but in 1952 NASCAR driver Tim Flock was disqualified from a race for having a cage made from painted wood – how’s that for a serious set of spuds, eh?

As with any other modification, it’s all about balance, so make sure you thoroughly (excuse the pun) weigh-up your options before you start pulling stuff apart.