Well, in an effort to make sure I check everything at the track I've been working on a post run checklist to go through between rounds. During this process I've been digging into my datalog from the last run at Duct Tape Drags. I noticed the fuel pressure seemed to stay flat through the run rather than raise with boost pressure, I changed the scaling to make it stand out better and I came to the realization that I'm running out of fuel pump.
It was making 9.4psi of boost on the 2 step and fuel pressure was great, but once boost got to 12.5 with the nitrous also coming on it couldn't keep up anymore. CL comp saved my butt, but it was hitting 15% added fuel by the time I let off. I'm not certain I can trust the EGT temps since they seemed to be erratic, but 3 cylinders peaked at just over 1500°F which isn't good.
I have the 3.5gpm Fuel Lab pump, unfortunately I have tried to use their 5gpm pump twice and both times it didn't last more than an hour. The 3.5GPM pump seems to be rock solid.
Amber and I brainstormed about this and I think there is a fairly simple solution. When I built my fuel cell I put a 6an drain on the bottom, I can hook a fuel line to this and run an external pump for a dedicated nitrous fuel system. This will remove the nitrous load from the main fuel pump and I could even add more fuel than needed for the nitrous to help out the main fuel pump at WOT. The main fuel pump has 3 ORB fittings for return lines, I'm currently only using one so I can easily add a second. I already have the fuel solenoid from before, so I just need to get everything plumbed up. This has the added benefit of cooling the intake charge down even more.
I checked my day zero log from Michigan Miles as I ran that one NA. Even there fuel pressure was short by a couple PSI, so I'm on the borderline with the party pulley.
I'm going to try to get something set up so I can test Friday, that way I'll be able to do the 10.50 bracket, otherwise I'll need to drop down to the 11.50 bracket to save the engine.
It was making 9.4psi of boost on the 2 step and fuel pressure was great, but once boost got to 12.5 with the nitrous also coming on it couldn't keep up anymore. CL comp saved my butt, but it was hitting 15% added fuel by the time I let off. I'm not certain I can trust the EGT temps since they seemed to be erratic, but 3 cylinders peaked at just over 1500°F which isn't good.
I have the 3.5gpm Fuel Lab pump, unfortunately I have tried to use their 5gpm pump twice and both times it didn't last more than an hour. The 3.5GPM pump seems to be rock solid.
Amber and I brainstormed about this and I think there is a fairly simple solution. When I built my fuel cell I put a 6an drain on the bottom, I can hook a fuel line to this and run an external pump for a dedicated nitrous fuel system. This will remove the nitrous load from the main fuel pump and I could even add more fuel than needed for the nitrous to help out the main fuel pump at WOT. The main fuel pump has 3 ORB fittings for return lines, I'm currently only using one so I can easily add a second. I already have the fuel solenoid from before, so I just need to get everything plumbed up. This has the added benefit of cooling the intake charge down even more.
I checked my day zero log from Michigan Miles as I ran that one NA. Even there fuel pressure was short by a couple PSI, so I'm on the borderline with the party pulley.
I'm going to try to get something set up so I can test Friday, that way I'll be able to do the 10.50 bracket, otherwise I'll need to drop down to the 11.50 bracket to save the engine.
