Brad Bell
Proven Member
- 192
- 5
- Aug 15, 2014
-
Levant,
Maine
I'm running a turbo 420a setup with 440cc injectors, 250lph walbro pump, BEGI/Cartech FMU, no FCD/missinglink, running at 10psi currently. I'm asking this question to those who are familiar with or use rising rate fmu's like vortech or BEGI etc.
With my current setup, I have the stock fuel regulator removed with 440cc injectors, I turned the fuel pressure down using the FMU to around 18-20psi to compensate for the larger volume injectors. Which idles around 12-13 AFR on wideband. The FMU works great from low rpm and speed, i.g. around town, streets, etc. Rising at a rate of around 5:1, stopping at around 70psi fuel pressure on full 10psi boost as it should. However, whenever I drive on the highway where my rpm's are already very high (3k-4k), and speeds 60mph+, Whenever I go to boost or give it light throttle to pass someone for example the fuel pressure rises incredibly fast, more of like a 12:1 rise instead of 5:1. Going sometimes 100psi and above of fuel pressure even before I've hit boost. Making the car pretty much fall on its face. Currently I'm using the compressor housing nipple on the turbo for a source on the FMU. What is causing it do this whenever I drive on the highway? Do I need to restrict the signal line more? Use a one way check-valve?
Thanks guys.
With my current setup, I have the stock fuel regulator removed with 440cc injectors, I turned the fuel pressure down using the FMU to around 18-20psi to compensate for the larger volume injectors. Which idles around 12-13 AFR on wideband. The FMU works great from low rpm and speed, i.g. around town, streets, etc. Rising at a rate of around 5:1, stopping at around 70psi fuel pressure on full 10psi boost as it should. However, whenever I drive on the highway where my rpm's are already very high (3k-4k), and speeds 60mph+, Whenever I go to boost or give it light throttle to pass someone for example the fuel pressure rises incredibly fast, more of like a 12:1 rise instead of 5:1. Going sometimes 100psi and above of fuel pressure even before I've hit boost. Making the car pretty much fall on its face. Currently I'm using the compressor housing nipple on the turbo for a source on the FMU. What is causing it do this whenever I drive on the highway? Do I need to restrict the signal line more? Use a one way check-valve?
Thanks guys.