# Tuning questions **URL:** \ **Category:** Shift518 Automotive\ **Created:** [August 21, 2011, 1:48pm UTC](https://forums.speedlife.net/t/tuning-questions/260091 "2011-08-21T13:48:30Z")\ **Posts on this page:** 1\ **Showing post:** 8
**Author:** ![toomanycamaros](https://avatars.discourse-cdn.com/v4/letter/t/7993a0/32.png) [@toomanycamaros](https://forums.speedlife.net/u/toomanycamaros)\ **Post date:** [August 22, 2011, 5:25pm UTC](https://forums.speedlife.net/t/tuning-questions/260091/8 "2011-08-22T17:25:03Z")
> [@When NOT to hyphenate names....](https://forums.speedlife.net/t/when-not-to-hyphenate-names/44802/13): > > :number1 I just ordered a book about it today. I understand firing when the valves are closed but it is still thought to be favorable in high performance apps because the time to fire off an injector decreases as the rpms start to climb. I also found that sequential systems that are used with a performance cam that has 220° of intake duration with. 050 valve lift can only inject ~ 60% of the fuel that a identical batch system can. Which basically means you need to run bigger injectors with a sequential setup in order to get the best fuel delivery. > [@Need help/advice with purchasing a new car](https://forums.speedlife.net/t/need-help-advice-with-purchasing-a-new-car/44689/12): > > Are we talking aftermarket EFI or OEM efi systems? For WOT power I don’t believe sequential to have any benefits other than maybe individual cylinder control. To drastically over simplify things the differences between batch and sequential fire are only apparent at lower RPMs. On a domestic V8 past roughly 3500 RPM your spinning the motor so fast that injectors fired sequentially are firring just about the same as batch fire. Most batch fire OEM stuff went away after the very early 90s because sequential offers much better part throttle drivablitiy and thats where 99% of a street vehicles usage is. I’m spending the extra cash to run the accel DFI setup I have as a sequential, but the cost vs. advantage is going to be different depending on what system your running. Also there has been some debate that the fuel being injected onto the back of the closed valve is actually not a bad thing and can help with difusing it into the intake charge. Basically there are some novel long threads on different forums written by people who know way more then me. My .02 cent is if it’s a street car and you can afford to set it up sequentially then do it you’ll be happy in the long run. --- _[View the full topic](https://forums.speedlife.net/t/tuning-questions/260091)._