Doesn't sound like it defied your logic.

This exact setup will be tested on Articfriends' 540 dyno session. I will likely be running this setup next year.

Testings not done yet, we'll see what happens when it goes on the 540, i have a hard time grasping that there was zero gain on the modified plenum w bigger throttle body, i saw consistent gains putting bigget throttle bodys on modified 502 intakes. Again, will be testing open plenum short runner intake vs stock 500 vs modified 500, Smitty

I have my own dyno and ill pull the 540 100 ways from sunday till we find any/every gain to be had with every intake test. Norm schenk who owns the dyno in my shop is also providing a 1050 dominator thats been modified to flow 1380cfm, what ever intake shines the best will be whats on my new 540s next season in the scarab. I might buy a full cncd super victor to test too, i will sell off what ever i dont use in end. If somone has a dominator flange cnc'd super victor efi intake they dont have bolted on something i wouldnt mind testing it!

So can we conclude that the MPI Mag intake responds better than the 500 EFI intake to modifications? It seems you had the modded Mag intake doing pretty well, but I don't remember if it was any better than the stock 500 EFI manifold.(and maybe there was never a direct comparison). I think the 500 EFI manifold was Jim Shoffner's (ASM) design as I bought one back in the 90's (pre HP500 EFI). He had an option of long and short runners, the long runners were just cast into the upper plenum I believe and the bases were the same. I definitely remember him saying that there was little difference between the long and short runners, so I opted for the long runners because I was running a small Ultradyne HR and was rev limited sub 5500....this was before good springs and lifters HA HA. Shoffner may have just meant there would be little difference in my case (small cam) though. We always appreciate you posting up your findings Smitty!

Im not convinced yet completely that it doesnt respond to mods, talking to SB we both agree maybe with more cam this would have ran out further on the top. The way these mpi things go normally is guys will add cam trying to raise hp BUT a cam that peaks at lets say 6200 still peaks at 5500/5600, just tq goes away and tq peak ends up going to around 4800 plus and overall tq is LESS. in this case my dyno program shows it peaking at 5600, add more intake, already AT 5600 so wheres it going to go. IF we had a cam that would peak at 6200 and we were at 5600 w stock intake, its possible with more intake/air flow we could have saw the hp peak gain,. My 540 im going to test this on has alot of cam and should show a gain IF there is one to be had stock to modded, we'll see!!

the std 4150 TB will make more power than this deal from test I have seen..

RPM is cubic inches. :D

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As an example

We have both TB types to test so we shall see! What will be interesting effect will be if the engine likes/dislikes the added plenum volume the elbow provides. One I have is 4500 flange and 102mm TB.