Pea Shooter Chronicles (first gen honda insight mods)

[A.K. Boomer]

I like what you're doing to help keep the cold weather mileage figures up there, I believe you are on the right track.

However there are certain aspects of cold weather mileage figures being lower that are simply out of one's control.

We all know that the viscous drag of lubricants and fluids throughout the system will have an impact but it goes beyond that. Things like the tires being less flexible, and then there's winter gasoline, that although more volatile in the winter will also have less energy density by volume. Speaking of tires, they will also loose air pressure so that too will contribute to increased rolling resistance.
Also in spite of your car having a low coefficient of drag, the aerodynamic drag that it and the tires do have will be remarkably greater in cold temps than warm simply because it is more dense, or thicker if you will. Much harder to push a knife through jello that water.
Then there is the increased use of lights, wipers and heaters which all increase the load on the system.

Individually it may not seem significant, add all those factors up together and it turns into a sizable hurdle that can't be ignored or overcome.
Just didn't want you to be discouraged next winter when it gets cold again and anticipated mileage hasn't kept pace with development work expectations.
Some things are just beyond our control.

All good points Willy - i covered what I consider some of the same heavy hitters in post #15,
winter gas not being much as a factor because have had plenty of warm days here during the winter months and just watched my mileage skyrocket --- also fluids not contributing too much to that fact at all because it uses just 10W30 for trans fluid and 0W20 for engine oil...

shorter trips on cold enrichment modes are huge --- and this new system will actually help with that too...

but you are correct in all factors adding up together yet I believe the lions share by far to be what the ambient air temp sensor see's and registers to the computer --- even if it's just half of everything else it's a system worth building and testing, that's what it's about - could be a long Pea shooter chronicle's and that's cool too as time will give up the effects of the changes iv made... it's fun! lol

[dian]

willy, he is increasing therodynamic efficiency by heating the air and thus getting higher combustion temp.

eff. = 1-tc/th

[Willy]

willy, he is increasing therodynamic efficiency by heating the air and thus getting higher combustion temp.

eff. = 1-tc/th

I very much realize what he is doing and why.
The factors I pointed out in post #30 however cannot be eliminated. In order to closely match his summer time MPG figures as he had hoped to, he would need to all but eliminate all of the deleterious effects that cold air temperatures introduce to the equation. It cannot be done.
He can however improve efficiency to some degree but one cannot ignore the realities that I previously outlined. All of those issues play a small role in increasing the volume of fuel required to achieve the same amount of work. Added up these components are significant.

A portion of an article I remember reading a few years ago about how cold dense air affects fuel mileage on transport trucks. I realize the aerodynamics are vastly different however the implications are not. Also consider the fact that air density is just one facet of the puzzle.

https://www.trucknews.com/transporta...rs/1003108264/

Camball made a computer simulation comparing the air drag of a highway truck in warm moist light summer air (90F, 32C) against going through cold dry air (0F, minus 18C). The difference was astounding and far beyond a typical three-percent spread between summer and winter fuel.
While winter winds can howl at high speeds and destroy fuel economy, explained Camball, the more dismal news for winter drivers is that cold, dry air is 20-percent heavier than what you get in the summer months. Who knew?
As Camball explains, at 100 km/h the truck would use 20-percent more force just to push the cold air aside, which means an approximately 14-percent increase in overall vehicle fuel consumption. (In windy conditions, this figure can jump to 20 percent overall when the wind is coming from the front or the side.)
Adding to the 14-percent increase in consumption is the three-percent loss for winter fuel as well as the three-percent loss for a spray chilled driveline, totaling 20-26 percent.

[J Tiers]

Not only all that stuff, but winter pavement is not summer pavement... it has draggy slush on it, snow, etc. All that will add to the rolling friction.

The Ranger drops about 20-30% in winter, for the same long trip, from here up to Minnesota on the same roads, same route.

[A.K. Boomer]

I do know I will not achieve the same summer results, but I do believe I will keep it from taking such a huge winter time hit, like I stated when I bought the car in the fall the all time rating for the cars lifespan was 59.7 and now after winter it's 59.4 that's a huge hit because your going up against changing a mileage rating that's based of off over 145,000 miles!
im sure I will start to see the numbers increase now due to warmer weather, and im pretty sure I will not see them take as big of a hit at the end of next winter,,, it might take a few years but im shooting for an average all time MPG rating of over 60mpg's that's not reaching for the stars - that's attainable....

[A.K. Boomer]

Last nights mod, came up with a couple extra ponies, since It's warm here and I do not need the pre-heat right now I had a piece of plumbing plastic laying around so made and intake "nacelle"
Not really the place for a velocity stack as it's the single inlet for the multi-ports further in the intake system which means the air flow is more at a constant (yes even with only 3 cylinders)
but it is a critical area because it's where the vacuum meets the atmosphere, so smoothing it out is an added benefit...

Velocity stacks work by some of that same principle but they also have an added feature - they have some length to them - this is mostly because they are designed for individual cylinders, this length is critical for the type of power band you want them to perform best at, Iv never liked the term "velocity stacks" as it's really missing out on how they work --- they are better looked at as "pneumatic rams" as that covers their effect of what they do with the individual air impulses --- once that air gets moving from an intake charge to great great speed within the tube, once the valve closes they actually create a positive pressure greater than the atmosphere --- the pressure builds in time for the valve to open again and walla --- Ask Sid --- great power gains can be had....

anyways - pics of my nacelle







the lip matches up with the ID of the intake boxes diameter so it's uninterrupted flow



Taking my pandemic bud up to this brewery today in the pea shooter, Eddyline has a place in buena vista and one in new zealand --- best beer iv ever had IF you get the right type -- and for me - this is the right type - it's a juicy haze IPA and it's spectacular - (although not her favorite she does like others they make)




Hitting the road --- were shooting for 75 mpg's today so should be good unless I have to throw down some diesel repellent on a power joke or something of the like . lol

Cheers

[J Tiers]

Do you think you will get much of that "ram" effect on the intake to the filter box?


You're sliding closer to "exhaust restriction to add power" territory there.....😉


The "fairing" of the airflow by the smooth curve to final internal diameter can have an effect, although it is larger when the flow is faster.

[A.K. Boomer]

Do you think you will get much of that "ram" effect on the intake to the filter box?

No JT that was my whole point for talking about the differences between the nacelle and the velocity stacks --- even if I had a stack I would not get any ram effect to speak of - that's why the nacelle makes sense...

The "fairing" of the airflow by the smooth curve to final internal diameter can have an effect, although it is larger when the flow is faster.

Yup and it does - makes more power up on top...

trip was fun - what a great brewery, and beer and wood fired pizza. pea shooter ate it mileage wise though - extremely high winds and as slippery as it is sometimes was getting tossed around like a rag doll but really not too bad for all the different directions we were getting blasted from,,,

about 68.1 mpg's for the 225 mile trip... at least its far above the cars lifetime average... I think I bought this car at the right time - filled it up last night and it was over 30 bucks for just a 10 gallon tank that still had a gallon or two in it before filling --- ouch, expensive even on this little sled...

[dian]

a convex surface makes the air speed up (just like on a wing) so in increases velocity and prevents turbulent flow to some extent. how that would translate into any difference in static pressure is another question. they put those curved intakes on turbos or compressors in racing.

[A.K. Boomer]

a convex surface makes the air speed up (just like on a wing) so in increases velocity and prevents turbulent flow to some extent. how that would translate into any difference in static pressure is another question. they put those curved intakes on turbos or compressors in racing.

Yes like I stated in post 36 velocity stacks do both, they increase normal intake flow by smoothing everything out and it does prevent turbulent flow, same as an intake nacelle - but V.stacks have an entirely different purpose too and have length to them for a reason, they are used on individual pulsating cylinders, the length is critical for the type of tuning you want - and when you want the engine to come on strong --- the length is air mass,
air mass that achieved great speed (velocity) on the intake stroke --- that speed has to come to a dead stop (stack) after the intake stroke is complete, pressure then starts to build into the inlet chamber of the cylinder head behind the intake valve --- depending on the RPM's and the stacks length the pressure hits a peak at a pre-designated time and that's when the intake valve starts to open again --- they work so well they are to be considered a mild form of supercharging , although unlike most other forms of supercharging there is no dividend to pay in powering the effect...

They also do not have to be the first "connection" between the engine and the atmosphere, they can actually reside behind a throttle plate and come to life when needed

Iv seen crunched plastic intake manifolds at the Upull and pay salvage yard with little velocity stacks inside them.

[Willy]

And then there is the exhaust side of the equation. It too can be optimized using the same concept, this time creating a slight vacuum at just the right time. Not only does this aid exhaust gas scavenging, it will also assist intake air entering the cylinder.
Very seldom do most engines achieve 100% volumetric efficiency, however when the entire air movement process is optimized thru the use of cam timing, port shape, size, intake and exhaust diameter and length, etc one can achieve volumetric efficiencies well over 100%. A mild supercharging effect if you will.

I've been working with these concepts since I was a kid, got tons of text books on the subject. I have always found this an absolutely fascinating and incredible subject.
Most guys just groan and roll their eyes when I bring it up, heathens!

Glad to see someone else as keenly interested as I. Reach for the stars AKB, you'll never fall in the mud when you reach high.

[A.K. Boomer]

Spoken well from another motorhead lol and yeah lot's of similarities with what you can do on the exhaust end of the flows and how the scavenging works to make the overlap period "hungry" for the intake charge while that charge is getting slightly pressurized,,, it's a beautiful thing and when engines come onto their "pipe" its goosebump time lol

with exhaust it's where they all meet at the "collector" and they too have to have certain length pipes before the collector for the specific RPM range your want all hell to break loose at...

it's becoming kinda a lost art Willy, not many guys into it anymore just slap a turbo on and pressurize the fuque out of everything on the intake side and restrict the hell out of the exhaust -- does not matter --- what goes in will come out so if you stack the dominant side (as in intake) you really can get away with anything you want --- as long as you have a means of getting rid of the heat that is....

[Willy]

I don't really think it's a lost art, well maybe at the grass roots level.
When you look at the efficiency numbers coming out on engines designed in the last 20 years you just know that the volumetric efficiency is heads and tails above anything produced before 2000. With an ever tightening mileage and emissions focus, engine designers simply can't ignore the easily obtained efficiency from simple air flow dynamics.
Not something that can be left on the table. I think it was probably one of the first low hanging fruits to be capitalized on and still being refined on.

[J Tiers]

It's not really true that there is no price to pay.....

Even with the velocity stack (tuned intake) there is energy added to the incoming air mass. That has to come from somewhere, and the only "somewhere" from which to get that energy is the engine. So yes, there IS some power loss in the intake, just as there is with any form of supercharger.

The "energy deal" made in either case is that the tuned intake, or the supercharger, add more engine power than they use, so the net power output comes out ahead.

[A.K. Boomer]

It's true --- I was just talking on an individual basis as in guys tuning stuff in their own garages,,, but still there is actually plenty of that going on just not as much "per capita" was what used to be,,,

as far as mass produced vehicles id like to see the V.E. stats on the honda S-2000 240 ponies out of a normally aspirated 2 liter rapping out at well over 9 grand, what an engine to be proud of....