Volumetric efficiency

[redliner]

Hey guys. I have pipemax and they have good info about volumetric(?) efficiency but I still dont know how to get a very close estimate of VE for my engine so I can enter the correct info. I can provide list of components etc but as it is a fresh build, no dyno numbers.

[swampbuggy]

Bring on the list. Mark H.

[andyf]

From what I've seen, PipeMax doesn't use the same VE as you'll see on a dyno. I don't recall the reasoning but the VE in PipeMax tends to be higher than what you'll see on a dyno. I run PipeMax for almost every engine I build and I usually have to give it a VE of 110% to get the the numbers to match what we see on the dyno. The VE calculation on the dyno will be a few points lower, maybe 104 or 105.

[redliner]

Bring on the list. Mark H.

Ok, Dart SHP 4.125. Callies Magnum 3.875, Callies Ultra XD 6" rods,11.5 -1 Carrillo Bullet pistons, Mike Jones Solid roller 262/ 268@.050, .715/.700, 110/106,1.7/ 1.7 T&D shaft rockers, 72 cc Speier V2.50 PF/23* 323 @.700, Speier fully ported Motown intake (dom. flange) 1050 Dom. by Mark Whitener, MSD crank trigger MSD 6AL

[redliner]

From what I've seen, PipeMax doesn't use the same VE as you'll see on a dyno. I don't recall the reasoning but the VE in PipeMax tends to be higher than what you'll see on a dyno. I run PipeMax for almost every engine I build and I usually have to give it a VE of 110% to get the the numbers to match what we see on the dyno. The VE calculation on the dyno will be a few points lower, maybe 104 or 105.

I just wanna get as accurate info as I can get so I can build my headers... and have some numbers to think about till I dyno this combo.

[digger]

Input peak hp rpm and use VE as a scale factor that you change until the pipemax hp matches hp on engine dyno or chassis with correction factor

Pipemax VE is not real VE

[BenE64]

103% VE is what lined up with the advertised specs on my engine from factory. I used that as the base line to go from. I am fairly certain it is not that high.

[engineguyBill]

VE is very difficult to determine (or theorize) unless you run the engine on a dyno and even the numbers may be suspect. If you need a VE number to plug into a formula, a maximum effort race engine assumption of 105% at maximum horsepower RPM should get you into the ballpark.

[redliner]

VE is very difficult to determine (or theorize) unless you run the engine on a dyno and even the numbers may be suspect. If you need a VE number to plug into a formula, a maximum effort race engine assumption of 105% at maximum horsepower RPM should get you into the ballpark.

A thats all I need Bill. I want to plug into my pipemax and build some headers.

[MadBill]

In PM, if you have some idea of peak power at RPM you can specify the latter and then adjust the V.E. input to obtain the projected power. You'll then have a better basis for pipe specs.