How to get more power out of NA, looking for 400hp ++
01-12-2012, 06:45 PM
#167
Three Wheelin'
The twin counter-rotating vortices shed at the pair of intake valves and persist into the combustion chamber, increasing combustion chamber turbulence and mixing. A single intake valve would simply crash the vortices into each other, creating drag.
Tends to bolster midrange significantly with a very slight penalty at top end.
Plenty of examples of people going to "straight shot" manifolds on 4-valve motors and losing midrange without any other gains. What works on a 2-valve engine doesn't necessarily work on a 4-valve!
Cheers,
Mike
P.S. the explanation of "how" the vortices form is straight forward but I can't be bothered explaining right now. It's related to the tea-leaf paradox solved by Einstein.
http://en.wikipedia.org/wiki/Tea_leaf_paradox
Last edited by mikey_audiogeek; 01-12-2012 at 07:01 PM.
01-12-2012, 07:29 PM
#168
Race Car
Interesting concept. It looks like BMW may have went a similar path with their M50 intake manifolds:
What people tend to skip is the amount of air bouncing around in the intake. Since we are discussing NA power, the harmonics in the intake play a big roll in airflow that's actually delivered. With that said, many OE solutions have a helmholtz resonator built into either the airboxes or the path going into the intake. Reducing that back hit that exits the intake allows for better flow going into the engine. Cold air intakes are actually a negative effect towards this and having a "loud intake" is normally a sign of reduced power and added resistance.
What people tend to skip is the amount of air bouncing around in the intake. Since we are discussing NA power, the harmonics in the intake play a big roll in airflow that's actually delivered. With that said, many OE solutions have a helmholtz resonator built into either the airboxes or the path going into the intake. Reducing that back hit that exits the intake allows for better flow going into the engine. Cold air intakes are actually a negative effect towards this and having a "loud intake" is normally a sign of reduced power and added resistance.
01-13-2012, 06:50 PM
#169
Race Car
01-17-2012, 08:22 PM
#170
Three Wheelin'
The resonators ahead of the throttle body do nothing for performance, they are strictly NVH. Also, tuning increases the density of the aircharge, rather than the airflow in the conventional line of thought. Most swirl is done for emissions, and the most powerful engines will have runners that bifurcate close to the valves, as the greater the surface area in the runner, the greater the losses will be.
Cheers,
Mike
01-18-2012, 05:31 AM
#171
Rennlist Member
I can see why it makes great power , with that almost flat torque curve across the rpm range .
Looking at the graph it is still increasing the power right up to redline and beyond.
GReat work what dry sump pump did you use ?
thanks
JG
Looking at the graph it is still increasing the power right up to redline and beyond.
GReat work what dry sump pump did you use ?
thanks
JG
04-13-2012, 05:05 AM
#173
Are you offset-grinding for this build, Sid? I find myself coming back to this thread too - mostly wondering what a 16v highcompression 2.7 on ITB's would sound like...
04-13-2012, 10:23 AM
#174
Race Car
04-28-2012, 11:57 AM
#175
Pro
Thread Starter
So we put the engine in a while back but only recently got to finishing all detail. Expect to run in a few days. Mew wiring done for the Motec M800, dry sump tank install done etc etc. Here's how it looks.
We're making an additional airbox going to the nose cone for straight feed.
We're making an additional airbox going to the nose cone for straight feed.
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vacuumnoise (04-23-2022)
04-29-2012, 01:31 AM
#179
Beautiful - that lump is a work of art. Wish I could watch you run, also would like to see it in person. Got to Borneo last year, too bad it wasn't this year... best of lu**, sorry, 'break a leg' in your first race!
