PerformanceTrucks.net Forums - FAST LSXRT and FAST Fuel Rail Question!

PerformanceTrucks.net Forums (https://www.performancetrucks.net/forums/)

- GM Engine & Exhaust Performance (https://www.performancetrucks.net/forums/gm-engine-exhaust-performance-21/)

- - FAST LSXRT and FAST Fuel Rail Question! (https://www.performancetrucks.net/forums/gm-engine-exhaust-performance-21/fast-lsxrt-fast-fuel-rail-question-550817/)

FAST LSXRT and FAST Fuel Rail Question!

I have a LQ4 6.0 out of a 2005 Silverado and I have tons of parts for it, engine is torn down to bare block.

I have the FAST LSXRT intake manifold as well as the FAST anodized fuel rails to accommodate my FAST 33lb injectors.

My QUESTION is that the fuel rail doesn’t seem to have anything for a fuel pressure regulator. Should I use FAST? I’m not sure how to tune it to run with the vacuum line attached to it. Any way around this? Just delete the fuel pressure regulator and plug the outlet on the intake? I’m not sure if the LSXRT even has a spot for the fuel pressure regulator vacuum line...

one more question... the FAST 92mm throttle body doesn’t come with a throttle adapter for cruise control (I can’t use cruise control anyways because I pulled my BRAKE fuse to get rid of the brake light in the dash due to my wheel speed sensor delete/solid axle swap...) Can I just unplug the module on the firewall and forget about it? Or will That cause something funky with the transmission? Again, I don’t have any use for cruise control, just want to delete it and clean up the engine bay a bit.

Thanks in advance!

-Ryan

Bump!

Part nimbers fast gave me for the fuel pressure regulator and adapter fuel line:

Fuel pressure 307030

Adapter 54028

If Your truck had it on the rail, and you removed it, you'll need to replace it. Im used to working on the fbodies where they are in the tank. On the newer trucks the tune in the PCM is designed for a set pressure. It compensates for vacuum by adding less fuel per the MAP reading. Looking at an older tune (02) it shows it needs a vacuum referenced regulator because it flatlines fuel in the tune. Since Im assuming youre gonna have this tuned anyway you could run either/or and have the tune adjusted for the one you install. Either way works fine.

Thanks! I appreciate it. Yeah it’s all being tuned by BBP. I’m assuming I set the fuel regulator to the correct pressure at idle — hook up the vacuum line — then let it do its thing? And yes it’s vacuum controlled.