[Tom Vaught]

You can only add as much fuel to any one cylinder as the air available to that cylinder.

If you are air rich, you can add more fuel.
If you are air lean, then you are stuck on how much fuel you can put thru that cylinder.

Distribution of air can only be "Crutched" so much, with fuel nozzle or fuel injector/calibration changes.

Tom V.

[twooldgoats]

Originally Posted by Jack Gifford

Jim- no need to wonder- better distribution of air definitely helped me develop more power with the hemi.

.......

I'm not that worried about power at this point (just .17 seconds from my chassis cert). I'm more curious about how long the engine will last. I wonder what negative effect, if any, is being caused by the unequal power the cylinders may be making. The tune is roughly the same side to side, but not front to back. It's not a huge difference, but it's measurable---different port nozzles needed to achieve the same EGT's on all eight cylinders. Maybe the uneven fuel from the hat nozzles balances out the uneven port nozzles and all eight cylinders make the same power. Just curious, that's all.

Jim

[Tom Vaught]

Originally Posted by twooldgoats

I wonder what negative effect, if any, is being caused by the unequal power the cylinders may be making. The tune is roughly the same side to side, but not front to back. It's not a huge difference, but it's measurable---different port nozzles needed to achieve the same EGT's on all eight cylinders. Maybe the uneven fuel from the hat nozzles balances out the uneven port nozzles and all eight cylinders make the same power. Just curious, that's all. Jim

You say you have the same EGTs, Jim.

If you have 8 different bore sizes and 8 EGTs and each one is the same egt reading, OK you have 8 different power levels pushing down on the piston/crankshaft but each cylinder is tuned to the same BALANCE of Air/Fuel vs exhaust temp comping out of that cylinder.

Yes, you might Pick one cylinder and try to get the other cylinders closer to it (after spending a lot of money) but we were more after each cylinder being tuned for a given average temperature on our dyno testing and we could do individual cylinder tuning with our EFI capabilities.
This is across all drive modes, not just WOT. The air distribution does change in the manifold depending on rpm.

Tom V.