A Guide to Car Mods to Improve Performance

A Guide to Car Mods to Improve Performance

It’s only human to want more. In the context of engines and cars, this means more power and speed. The two are related but not the same.


Modifying the engine with parts that belt out more power won’t necessarily translate to a faster car. Pairing the rights parts and taking things one step at a time will. 

For better performance in any car, look to modifications that start with air intake and exhaust, changes to fueling and timing, and lastly, swapping out the heart of a stock engine, the pistons, connecting rods, and crankshaft.

This is where power is produced. A few tweaks along the way, like forced induction and an ECU remap, can completely change your car. 

Before doing any mods, you need to have realistic expectations as to which parts can be changed and how that will affect the overall take on things.

Also, though doubling the amount of horsepower and torque isn’t unheard of, even in smaller displacement engines, longevity will definitely suffer, and you’ll be reeling into your bank account more often just to keep the wheels turning.

Modest bumps in bhp figures though are manageable in almost every engine, and something that you’ll certainly feel when behind the wheel. 

The goal is to set a budget and realistic power gains, then start looking for performance car parts that best suit your vehicle.  Just remember, this is an ongoing process, but one that rewards you with a grin each time you put your foot down. 

Air Intakes and Exhaust Systems

A Guide to Car Mods to Improve Performance

Getting more air into the engine is necessary to burn more fuel and produce a bigger bang. Air-to-fuel ratios vary in different engines, but a conservative average is 15 grams of air for every gram of fuel.

Stock intakes can be improved upon with aftermarket variants that take into account wider and heat shielded tubing to push cooler and more air into the cylinder head for combustion.

So-called ‘cold’ air intakes with bespoke air boxes and high-spec cotton filters, both clean the air from any impurities and cool it at the same time. Why cooler air? Because it is richer in oxygen and, therefore, more efficient. 

Engines, like all living things, need to breathe. Air taken in needs to be removed. This is the job of exhausts. Stock exhausts do a mediocre job at removing combusted air, in a large part due to the restraints of narrower tubing and sub-par materials that generate a lot of heat.

This also creates more back-pressure or choking, with combusted gases making their way back to the cylinder head and preventing new air to be pulled in. As a result, there’s an immediate loss of power. 

Aftermarket exhausts relieve issues with backpressure and help with exhaust ‘scavenging’ or the vacuum created in exhaust piping to get combusted air out faster and new air in.

This is achieved with wider tubing and in different exhaust configurations. What you ultimately end up with will be based on the stock engine, the cylinder count, whether there’s a turbo under the bonnet, and how much extra power you need. 

Header and turbo-back back exhausts are the ones to go for if performance is your end goal. A side bonus is changing the exhaust note to a raspier sound and adding some shine to the tubes with different finishes. 

Cam Profiles, Fuelling, and Ignition Mods

A Guide to Car Mods to Improve Performance
Source: dsportmag.com

Camshafts are engine parts that actuate the inlet and exhaust valves in the cylinder head. They are tasked to control the amount of air that comes into the engine at a given engine speed.

They also control how the spent and combusted air is expelled. This also ensures correct timing in correlation to the speed of pistons inside the cylinder head and the speed of the crankshaft, which drives the camshaft either by a belt, timing chain, or set of gears. 

Stock camshafts guarantee efficiency and a smooth running engine, void of knocks and backfire. But performance camshafts, often offered in higher quality cast iron or machined steel billet have a slight overlay in the inlet and exhaust cam lobes to burn more fuel within a given time frame.

Plainly speaking, this produces more power with optimal fuel use. A by-product of this is increased fuel economy. 

More air means more fuel. If you’ve already changed out the intake and exhaust and put in a cam with modified lobes, then the next step is to replace the stock fuel injectors.

Higher pressure and larger injectors will spray more fuel to compensate for the increase in air. Again, getting the right air-to-fuel ratio will affect how much pressure is applied to the piston crowns and connecting rods during the combustion cycle. The more the is, the bigger the forces acting on the crankshaft. 

Lastly, to better ignite the air and fuel mixture, you can upgrade your spark plugs. Higher temperatures call for platinum or iridium spark plugs (over stock nickel over cooper variants) and with electrodes producing slightly cleaner sparks.

There’ll be less engine noise at idle, cleaner combustion, and less likelihood of carbon deposits in what is known as engine fouling. Choose ‘cold’ spark plugs to get higher temperatures out of the spark plug tips in engines revving higher.

Delving Deep

Going deep into the engine internals is what will get you the most power. Here you can opt for modified or strengthened pistons with crowns that can more than handle the increases in pressure and temperatures due to bigger combustion cycles. 

Materials and production processes in this respect also matter. Pistons in stock engines are often made of cast iron, and most won’t be able to handle more power without seizing, or piston rings losing lubrication.

For performance engines, look to forged aluminum pistons with higher silicone content to reduce vibrations and offer better sealing.

These performance car parts are essential in higher revving engines and those with forced induction. Pistons act on connecting rods, the elongated shafts that connect the pistons to the crank.

Conrods come in varying designs (I-beams for smaller high spinning units and H-beams in diesel and naturally aspirated V6s and V8s).

Forged aluminum or titanium conrods have better flex and elongation and won’t bend or crack under higher pressure in heavier or modified pistons or at higher engine speeds.

They’re superior to cast steel connecting rods for most street applications. Lastly, all this newly-obtained power turns into the crankshaft.

Replacing the stock crank is one of the more costly mods you can do, but this balances all your efforts thus far. Cranks can be lightened (by reducing metal in counterweights), have better lubrication (with gun-drilled holes in the main journals), and heat treated (nitride cranks are highly sought-after) to increase overall strength.

High-quality forged or billet Chromoly steel cranks, machined to perfection, will outlast anything you currently have, no matter how hard they’re pushed. 

Final Considerations

The modifications listed are carried out in stages. And this usually follows a pre-determined path. Stock air intakes and exhausts are the first to go, followed by camshafts, injectors, fuel pumps, and spark plugs.

Here you may also want to bolt on a turbo to naturally aspirated engines or go for faster-spooling turbines to force more air in for combustion.

The internals is often changed last. These parts entail changes to clutches and the transmission since the increase in power will cause clutch slippage and premature wear.

Pairing is key, as each new part has to work seamlessly with the others. When seeking out aftermarket car parts, go for respected automotive brands and retailers that have a strong background in the business. 

Leave a Reply

Your email address will not be published. Required fields are marked *

You May Also Like