What are the performance car camshafts? Do you need to upgrade yours? Find out this and other information in our comprehensive 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 even four, however, 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 in depth, but at a minimum they’re probably the most misunderstood topic in UK tuning, which leads to a number of common and beautiful serious mistakes when selecting camshafts to your motor.
This article should provide you with an understanding of the performance car camshafts and what’s best to use on your vehicle.
How do you define car camshafts, and what function do they serve?
On the most basic level the camshafts are cylindrical rods made of iron in piston engines , with their lobes protruding out of their ends. They are responsible for opening and close exhaust and inlet valves in the correct amount at the appropriate time.
The quantity duration, the length of time and the time at which cams open the valves contribute to determining how much the power or torque an engine generates and where in the rev range it achieves this, and whether the engine is able to be running at all. As you could envision, with proper modifications, a camshaft change can dramatically improve the performance. However, an error could result in disastrous results not just in terms of the performance but also for reliability too.
Why would I need camshafts for my performance car?
No matter what you decide to do make sure you don’t immediately switch cams now, since the swap of cams isn’t always a good idea! You must be certain the change will enhance the performance of your vehicle before doing because we’ve observed some swaps that reduced power by a significant amount. The thing about camshafts designed for performance vehicles is that they typically remove performance from some point in the rev range in order to bring it into another. However, when you add forced induction to the mix, things could become more complicated.
Don’t believe for a second that the more powerful cam you select, the more powerful your car will be even if it generates more peak power numbers, since this is rarely the situation. From the beginning, the cams of a car are usually extremely light, and are generally designed with a focus on efficiency as well as reliability and, the most important thing, driving. This means there’s nearly all the time room to make improvements however, with low engine specifications and turbocharged engines in particular These standard cams could generally be the most effective all-around choice.
Location and number of the camshafts
It’s not a huge impact on the performance of the engine, but the different engines have different cam positions and also different amounts. The majority of modern engines come with four valves for each cylinder, and they typically include separate cams for exhaust and inlet valves. Therefore, twin cams on straight engines as well as quad cams on flat and V engines.
A lot of older engines had two valves for each cylinder, and one cam operates the entire system. These engines are becoming more rare, but they are made today, including the amazing LS engines found in VXR8s, Corvettes and many more. They LS engines, like some older models, include the camshaft in the block. However, most engines have camshafts in the highest point of the engines located inside the head.
To make things more confusing to make things more complicated, certain engines – typically from Honda are equipped with only one cam that controls all 16 valves. Likewise, there are some engines (a couple of old Ford and Fiat models in particular) with twin cams, but just eight valves. Some engines contain five or three valves per one cylinder. However, overall engines are one cam and 2 valves for each cylinder or twin cams that have four valves per the cylinder.
What is the right amount? Performance car camshafts guide
This is a common issue when it comes to cam swaps, because like we said earlier, the benefits a cam can provide in one region within the rev range usually eliminates in another. Based on how well for the other specifications of the engine and the engine’s spec, it may offer more than it subtracts and produce less than what it takes away. It doesn’t matter if it’s forced or N/A induction, choosing too large a cam without the rest of the engine capable of delivering the same power at the same rpm usually results in a tiny boost in horsepower but at the cost of huge loss of power at lower speed. Overall, the car will be more sluggish.
Did You Know? GSC Power Shop stock the best GSC power division cams UK.
The very wild cams tend to reduce the powerband regardless of the specs racing cars typically sporting a powerband that is about 2000rpm which is in the middle on the speed range. It’s not just that this makes 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 the gear, which could result in a slow acceleration regardless of what the highest power level is.
Cams are often referred to as “Fast road” or “Race specifications, and it is a good reason. While it may offer a bit more top horsepower but a race cam not the most enjoyable on the road and could cause you to be slow overall.
What kind of camshafts are appropriate for my vehicle?
Cams help get air out and in of your engine. However, depending on the way in which your engine gets its air will determine what kind of cams is best for you. Every engine is different, and so are the opinions of people about what’s too wild , and it is essential to conduct thorough research on the effect of different cams on your engine prior to making your decision. You’ve been warned. here’s an overview of the basics…
Naturally-aspirated engines
Since there is no air injected to your vehicle there is no choice other than running quite wild cams and, in the end, have lower and higher rpm powerband when you opt for greater power. The exact distance you want to go is completely up to you, but generally up to 280-290 degrees cams offer a significant increase in power and support modifications, but still suitable for driving on the road.
Turbocharged engines
The engines, as they are out of the box, have much more gentle cams than those normally aspirated since they have air forced into them, which means they won’t compromise on low-down power employing especially wild cams. To maximize gains while maintaining driveability high lift, but short time duration cams would be the best method to go with which is why they’re often called ‘Turbo Cams’. Long-duration cams suffer from two disadvantages on turbo engines, as the small down power loss that you experience in all engines is coupled with an inefficient turbo spool therefore you must be aware of when you’re going to take your turbo cams.
With a typical four valves per engine, you’ll generally get over 200bhp/litre of pump fuel, with relatively light cams with a duration of around 260 that keep the car pliable and at a low. In race turbo engines that run on high-boost, we’ve witnessed approximately 400bhp/litre with similar mild cams. However, this doesn’t mean that more wild cams don’t work in the case of creating an engine designed for full power or high speed usage the super-long duration cams like an N/A engine can give you the power with a less boost, but at the cost of lots of torque and less power.
Another trick used by turbo engines is the use of unicams, in which the inlet cam like 265 length, while that of the exhaust is standard or inlet is 285 length, while the exhaust is 265. As previously mentioned in the unqual cameras section is great method of increasing performance by let the turbo pump through more air, without losing any lower down power.
Overlap is a debated topic regarding turbos as it is a subject that can be based on the preference of the tuner and specifications for the engine. Although overlap results in the air/fuel mix burning as it is released into the turbo and could help the spool, when the engine is able to handle more backpressure than boost pressure, the result is typically reversed, and performance suffers, with small gains in any of the areas.
Supercharged engines
Supercharged engines behave in a similar way to turbo engines in terms of the cam selection, excluding one thing that’s called overlap. With the exception of a few maximum effort applications that only use high-rpm the overlap is not a factor for a turbo engine apart from significantly reducing its performance in some areas or even all in the range of revs.
The reason is that compressed inlet air, as well as the fuel added to it, will be thrown into the exhaust, causing more emissions, exhaust temperatures along with back pressure while the system is wasting huge amounts of energy in the process.
VTEC engines
Due to the fact that VTEC engines employ one cam profile designed for low-rpm use , and another one for high RPM, wild cams can be not as problematic to driveability in a VTEC equipped vehicle, as they are used in different engines. However, Honda fit wild cams in standard configurations on their high performance VTEC engines, such as the EP3 and the FN2 Civic Type Rs, and generally speaking taking them any higher would make the car impossible to drive. On lighter VTEC engines, this provides the chance to boost the top-end power without affecting the car’s driving ability.