Yep I am open to bigger injectors.
At the point I stopped, I was making 970 rwhp at only 80-81% injector duty cycle, despite differential fuel pressure falling to about 43 psi. When I increased boost to 28 psi, rail pressure dropped to 65-66 psi, now a dilta of 38psi. The pump was clearly done. With adequate fuel delivery, I was on track for 1,100 rwhp without changing injectors.
So I've got a plan. First, swap Grover's Weldon 2035A pump into Father Time and increase base fuel pressure to 50 psi. Second, upgrade to ARP Custom Age 625+ head studs and probably replace the AFR 205s with modern heads while I'm at it. I've noticed some minor exhaust smoke that smells like oil, possibly from the rings, valve guides, or seals. I'll also have the Box-R intake properly port-matched, since I was disappointed with the previous porting work.
Third, address turbine backpressure. I'll talk with Jose at Forced Inductions about whether a 1.44 A/R housing could bring me closer to a 2:1 pressure ratio without killing spool. If necessary, I'll consider a different turbo and converting to T6.
Restoring differential fuel pressure from 43 to 50 psi alone increases injector flow about 8%. Between that, improved head sealing, and reduced backpressure, I expect to comfortably clear 1,000 rwhp on the existing injectors.
Once those issues are resolved, I'll consider a more aggressive cam, probably a solid roller with duration in the 230s. But first I'm addressing the actual bottlenecks.
At the point I stopped, I was making 970 rwhp at only 80-81% injector duty cycle, despite differential fuel pressure falling to about 43 psi. When I increased boost to 28 psi, rail pressure dropped to 65-66 psi, now a dilta of 38psi. The pump was clearly done. With adequate fuel delivery, I was on track for 1,100 rwhp without changing injectors.
So I've got a plan. First, swap Grover's Weldon 2035A pump into Father Time and increase base fuel pressure to 50 psi. Second, upgrade to ARP Custom Age 625+ head studs and probably replace the AFR 205s with modern heads while I'm at it. I've noticed some minor exhaust smoke that smells like oil, possibly from the rings, valve guides, or seals. I'll also have the Box-R intake properly port-matched, since I was disappointed with the previous porting work.
Third, address turbine backpressure. I'll talk with Jose at Forced Inductions about whether a 1.44 A/R housing could bring me closer to a 2:1 pressure ratio without killing spool. If necessary, I'll consider a different turbo and converting to T6.
Restoring differential fuel pressure from 43 to 50 psi alone increases injector flow about 8%. Between that, improved head sealing, and reduced backpressure, I expect to comfortably clear 1,000 rwhp on the existing injectors.
Once those issues are resolved, I'll consider a more aggressive cam, probably a solid roller with duration in the 230s. But first I'm addressing the actual bottlenecks.
Last edited: