What is the volumetric efficiency of a stock ls1?
On The Tree
Joined: Jan 2008
Posts: 109
Likes: 5
From: Where you least expect me
On an optimized setup the pressure is lower in the cylinder up until very close to IVC, which is well after BDC. Intertia is a small role but it doesn't cause 90° of cylinder filling after BDC by itself, at least not at the mass of the atmosphere on our planet. What you are saying is that the force exerted on the air colum from the 180° the piston travels down the bore causes enough inertia to extend that up to and beyond 50% as far... (90°), that's not how the world works.
That's not how the world works either.
Also, show us some arithmetic verifying that the kinetic energy of the inflowing air is not sufficient to compress air that is already in the cylinder.
TECH Enthusiast
Joined: Nov 2004
Posts: 660
Likes: 0
Volumetric efficiency is simply the amount of air being pushed through your motor divided by the displacement and then multiplyed by 100 to give you a percentage. So if you are forcing more air/fuel through the same amount of cubic inches.....???????
VE over rev range Here is some VE information on my 402 that I had dynoed on a superflow 902 a few weeks ago.
ls2-402 dyno.pdf
ls2-402 dyno.pdf
Teching In
Joined: Sep 2008
Posts: 15
Likes: 0
The 402 graph gives a good look at what a VE curve will look like. Remember ve is max at peak torque then diminishes with rpm always, you will never see a larger VE number after peak torque. Also a crude way to get an idea is to use a dyno graph of a sock engine, using the fact that it takes approximately 1 lb/min of air to make 10 hp you could approxiate the airflow over the rpm range. Also 0.069 x CFM = lb/min and (lb/min)/0.069=CFM So using a stock dyno chart you could calculate a very rough approximate airflow versus rpm because dynos aren't the most accurate measuring device. Then take these questimates and divide by the calculated theoretical airflow at the same rpm's at 100%VE then times that by a 100 to give you a percentage. Like I said this is rough but it is a way.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
my current setup (sig) sees 115 at peak tq and then down to 112.
I did a SD tune on a 00' z28 with a lid, ls6 intake, and no muffler that has peak tq at 96 and then down to 95
a stock 00' camaro has a ve map just like that, peak 95
a stock 02' camaro peaks at 99 and then drops to 89
a stock 02 z06 peaks at 99 and then drops to 90
these are all straight from efi live
I did a SD tune on a 00' z28 with a lid, ls6 intake, and no muffler that has peak tq at 96 and then down to 95
a stock 00' camaro has a ve map just like that, peak 95
a stock 02' camaro peaks at 99 and then drops to 89
a stock 02 z06 peaks at 99 and then drops to 90
these are all straight from efi live
