What are the performance car camshafts? Should you replace yours? Find out this and much more inside our detailed guide to high-performance cams.
If you don’t have a car powered by rotary it is likely that camshafts impact your. The car you drive may have one or perhaps four, but regardless of the number , they’re an essential part of the engine’s performance.
Camshafts are an extremely complex topic that could be high-level physics when you dig deep into it. However, even at the most basic level they’re probably the most misunderstood topic in UK tuning, which leads to some very common and serious mistakes when selecting camshafts to your motor.
This section should give you more understanding of car camshafts, as well as what’s best for the engine you have.
How do you define car camshafts, and what function do they serve?
In the most fundamental sense they are rods that are cylindrical made of iron used in piston engines that have the lobes sticking out of the rods. It is their responsibility to open and close the exhaust and inlet valves in the correct amount at the appropriate time.
The quantity and length of time and the point at which cams open the valves contribute to determining how much the power or torque an engine generates and where in the rev range that it develops this, and whether the engine can operate at all. As you could envision, with proper adjustments, a camshaft swap could dramatically improve the performance. But, a misstep could result in disastrous results not just in terms of performance, but also for reliability too.
Why would I need high-performance car camshafts?
No matter what you decide to do be careful not to immediately switch cams now, since the swap of cams isn’t always a good idea! It is important to ensure that it will benefit the performance of your vehicle before doing and, in the past, we’ve observed some swaps that lost a lot of power. The thing about camshafts for performance cars is that they typically remove performance from an area of the rev range in order to bring it to another. And once you add forced-induction to the mix, things could become even more complicated.
Don’t believe for a second that the more powerful cam you select, the more powerful your car will run, even if it generates more peak power numbers, because this isn’t always the situation. From the beginning, the cams of a car are usually extremely light, and are generally designed with a focus on economics and reliability, but the most important thing, driving. This means there’s nearly every chance to improve however with a low specification engine and turbocharged engines in particular These standard cams could typically be the best all-around choice.
Location and number of the camshafts
It’s not a huge impact on performance, however, the different engines have different cam positions and also different amounts. Most modern engines come with four valves for each cylinder, and they typically come with separate cams for the exhaust and inlet valves. Therefore, twin cams on straight engines and quad cams for flat engines and V.
Some older engines had two valves for each cylinder, and only one cam is operating each. These engines are becoming more rare, but they are made today, including the amazing LS engines that are found in VXR8s, Corvettes and the like. These LS engines, as well as the majority of older engines, include the camshaft in the block, however the majority of engines have camshafts on the highest point of the engines placed within the head.
To make things more complicated there are some engines, most typically from Honda include one cam that operates all 16 valves. However, there are also engines (a couple of more old Ford and Fiat models in particular) with twin cams, but only eight valves. Some engines contain three or five valves in a one cylinder. However, on the whole the majority of engines have or have a single cam with the cylinder has two valves or twin cams that have four valves per the cylinder.
What is the right amount? Performance car camshafts guide
It’s a problem that’s been around for ages with cam swaps as like we said earlier, what a cam provides in one region within the rev range it typically removes from another. Based on how well for the other specifications of the engine and the engine’s spec, it may offer more than it subtracts or generate less than it eliminates. It doesn’t matter if it’s forced or N/A induction, choosing too large a cam without the other components of the engine capable of delivering the same power at the same rpm usually results in a tiny higher bhp but at the cost of huge loss of power at lower speed. In the end, the car will be slow.
Extremely wild cams typically reduce the powerband regardless of the specs and race cars usually sporting a powerband that is about 2000rpm which is in the middle in the range of revs. This can make the car difficult to drive fast on the highway and in the city, but if the gearing is right, you may actually lose a bit of the powerband each when you shift one gear. This would cause acceleration to slow down regardless of what the maximum power level is.
The cams are usually referred to as “Fast road” or “Race specifications, and it is not without reason. Although it could offer a bit more maximum horsepower however, a race cam is not a lot of fun on the road and could even make you more slow overall.
What type of camshaft is appropriate for my vehicle?
Cams are designed to get air into and out of your engine. However, the way your engine gets its air will determine what kind of cams is best for you. Each engine is unique – and so are the opinions of people about what’s wild. Hence, it is essential to conduct thorough research on the impact of various cams on your engine prior to making a final choice. After you’ve been warned, here’s a quick guide…
When shopping for GSC power division cams UK, make sure you visit gscpowershop.co.uk
Naturally-aspirated engines
Since there is no air injected to your vehicle and no air in the car, you are left with nothing other than running rather wild cams, and regrettably, be forced to live with an enlarge and more powerful powerband when you want greater power. The exact distance you want to go is entirely up to you, however, generally the cams can be 280 to 290 degrees and provide a significant power boost as well as the appropriate support modifications, yet remain suitable for driving on the road.
Turbocharged engines
The engines, as they are at the factory, use less sluggish cams than the ones normally used since they have air forced in, which means they don’t need to compromise on low-down power making use of particular wild cams. To maximize gains while maintaining driveability high lift, but short time duration cams would be the recommended method to go with as they are commonly advertised as “Turbo cams”. Long-duration cams suffer from an advantage over turbo engines due to the lower down power loss that you experience in all engines is coupled with the slower turbo spool, which means you have to be aware of in the distance you take your turbo cams.
With a typical four valves per engine, you’ll typically get around 200bhp/litre of pump fuel, with relatively light cams of 260 to 260 minutes that keep the car pliable and at a low. In race turbo engines that run on high-boost, we’ve witnessed about 400bhp per litre using similar mild cams. This doesn’t mean that wilder cams aren’t useful for developing an engine to provide all-out performance or for top speed, the super-long duration cams that are like an N/A engine can give you the power you need at a lower boosts, though at the cost of plenty of torque and lower power.
Another trick used by turbo engines is the use of unicams, in which the inlet cam in the example of 265 in duration and an exhaust cam has a standard or inlet is 285 length, while the exhaust has a lower 265. As we previously mentioned in the unqual cameras section is great method to increase performance by let the turbo pump through more air, without losing any power in the low-down.
Overlap is a debated topic in turbo vehicles as it is a subject that can be based on the preference of the tuner and specifications of the engine. Although overlap results in the air/fuel mix burning as it enters the turbo, and possibly helping the spool, if an engine is more backpressured than boost pressure, the result is usually reversed and the performance suffers, with small gains in any of the areas.
Supercharged engines
Supercharged engines behave exactly like turbo engines in terms of the cam selection, excluding one thing that’s called overlap. With the exception of a few maximum effort high-rpm-only applications the overlap is not a factor for a supercharged engine , aside of reducing the performance in some areas or even all in the range of revs.
The reason for this is that the pressured inlet air, and the fuel added together, will be thrown into the exhaust, causing more the exhaust temperatures, emissions as well as back pressure and using up a lot of energy in the process.
VTEC engines
Because VTEC engines employ one cam profile for low-rpm use , and another one for high RPM, wild cams can be less of a problem to driveability in a VTEC equipped vehicle, as they are with other engine. However, Honda fit wild cams in standard configurations on their high performance VTEC engines, for instance the EP3 and the FN2 Civic Type Rs, and generally speaking taking them any more wild would render the vehicle impossible to drive. On lighter VTEC engines, this offers the chance to boost the top-end power without affecting the driving experience.