best compression ratio
While the charts can help provide direction, nothing beats actual testing. If the means used to achieve this ultra-high compression ratio reduces the combustion efficiency (percentage of air-fuel mixture burned in the cylinder), a slightly lower compression ratio that doesn’t have this impact will be ideal. Of course, we need to define what is meant by “ideal.” The OEM compression ratio is ideal for the minimum octane rating of gasoline recommended, for the factory power output levels, for factory boost levels, for emission compliance and for a driving pattern that the OEM believes will be driven. best practices to improve compression ratio, do not compress specific file types, most efficient compression, compare compression strategies, optimal compression, how to optimize maximum file compression ratio, what is best compression algorithm, file archiving tips & tricks, remove duplicates, hints for best compression options, While the engine would be more fuel efficient with a higher compression ratio, a ¼-mile course without pit stops wouldn’t benefit. When looking at the impact to power output, one needs to adjust for the impact made by the change to the engine’s volumetric efficiency. Since forced-induction wasn’t common until the early ‘90s and it was mostly fitted on imports, many old-timers never dealt with the negative performance tradeoffs of increasing the compression ratio on a boosted engine. If your application desires more power off-boost and up to about 20psi, raising the compression ratio should be considered if the fuel to be used has the knock-resistance required. Join 350,000 subscribers and get a daily digest of news, comics, trivia, reviews, and more. This reduction in volumetric efficiency is the result of having less unswept volume that could be filled. What you feed your engine has a direct effect on ideal compression ratio. In addition to understanding the effects of raising or lowering an engine’s compression ratio, you also need to understand how fuel octane, alcohol percentages, type of fuel injection (port or direct), boost levels and types of driving will factor into selecting the ideal compression ratio for your application. A fuel’s knock resistance and cooling factor will influence the range of compression ratios that can be run. Look on a forum, blog, Instagram or YouTube account and you can find a number of “engine builders” sharing their thoughts and feelings on the best compression ratio for a particular engine or application. In short, we recommend: If you’re just compressing files for your own use, you can use whatever file format you like. When one only considers the difference that a compression ratio change makes on a engine’s thermal efficiency, this would be the following impact to fuel economy. This could mean that the engine is already accelerating faster before the boost “kicks” in. Long before forced-induction found its way onto factory engines, high-compression pistons were one of the original go-fast upgrades. The opposite occurs when the compression ratio is increased to 10.5- or 11.5-to-1. How to Create and Manage To-Dos in WhatsApp Using Any.Do, © 2020 LifeSavvy Media. Since temperatures of the air-fuel mixture at the time of ignition are elevated with increases in compression ratio, raising compression ratio increases the chance of auto-ignition (ignition due to heat and pressure before the spark actually occurs) and detonation (the uncontrolled explosion of the air-fuel mixture). All Rights Reserved, Zip (Windows 8.1): 746 MB (86.4% of the original size), Zip (WinZip): 745 MB (86.3% of the original size), RAR (WinRAR): 746 MB (86.4% of the original size), 7z (7-Zip): 734 MB (85% of the original size), Zip (Windows 8.1): 316 MB (48.3% of the original size), Zip (WinZip): 314 MB (48% of the original size), RAR (WinRAR): 307 MB (46.9% of the original size), 7z (7-Zip): 301 MB (46% of the original size). This means more energy is extracted from the combustion process and less is wasted to the cooling system and exhaust system. There is no single compressor which does best on all files or even on all files of the same type. Compression ratio isn’t the only factor, of course. For a street application or circuit application, the off-boost and low-boost power increase from the higher compression ratio may be most ideal. We will get into this in more detail later, but the important thing to remember is that increases in boost pressure reduce the ideal compression ratio. Overall, Zip and RAR came pretty close to each other. If you work with Mac or Linux, you could use a .tar format instead. In a drag racing application where the boost levels are 50 to 60psi, running a compression ratio in that range would have a lower power output than running a lower compression ratio.