Intake air flow modification

[JanGeo]

Now you can see where you should be going!

[GasSavers_Ryland]

Originally Posted by DaX

If turbulence from the throttle plate is a drawback, then the claims from devices like the Turbonator are definately bunk, as these types of devices do just that - create turbulence.

you need turbulence to mix the fuel and air, an example of that is the intake mainfolds on some carburated engines have a sort of corkscrew like piece of tin in there, AFTER the carburator, there is no point in creating unneeded turbulence befor the carburator, or fuel injectors, of course the finer the mist of fuel you can get, the less turbulence you are going to need as well, but you still need some just to get the fuel mixing, altho, the valves should do some of that as well.
you can get multi barral carburators, and they are great at cutting down turbulance, the wider open they are, the more openings they have, but for a carburator to work, they need restriction, and that is where fuel injection is amazing, it doesn't need the restriction to work properly.
I once tride to make a throttle valve out of a camera iris, I never finished it, but if you could hook that to your TPS and calibrate it, I think it could work great, also useing a thrttle slide, insted of a butter fly valve could work, like motorcycle carburators use, only hook that to a TPS as well, the idea being to keep the throttle opening as smooth, and round as possible, another idea that I had was useing something like a piece if inertube, and air or water presure to close and open the inside of it, thus creating an extreamly smooth opening for your throttle body.

[SVOboy]

you need turbulence to mix the fuel and air, an example of that is the intake mainfolds on some carburated engines have a sort of corkscrew like piece of tin in there, AFTER the carburator, there is no point in creating unneeded turbulence befor the carburator, or fuel injectors, of course the finer the mist of fuel you can get, the less turbulence you are going to need as well, but you still need some just to get the fuel mixing, altho, the valves should do some of that as well.
you can get multi barral carburators, and they are great at cutting down turbulance, the wider open they are, the more openings they have, but for a carburator to work, they need restriction, and that is where fuel injection is amazing, it doesn't need the restriction to work properly.
I once tride to make a throttle valve out of a camera iris, I never finished it, but if you could hook that to your TPS and calibrate it, I think it could work great, also useing a thrttle slide, insted of a butter fly valve could work, like motorcycle carburators use, only hook that to a TPS as well, the idea being to keep the throttle opening as smooth, and round as possible, another idea that I had was useing something like a piece if inertube, and air or water presure to close and open the inside of it, thus creating an extreamly smooth opening for your throttle body.

This reminds me of somender singh's head grooving for FE by swirling up the ****.

[GasSavers_Bruce]

If flow restriction outside of throttle body is more efficient, does this mean that a dirty air filter would _increase_ FE (at the expense of WOT performance)?

[GasSavers_Ryland]

my main question is, when you are doing all this stuff with changing the air intake duct work, are you reducing the size of the duct in just one area, or are you changing the size of the whole thing? because just like exaust, the air intake is tuned, that is why the d15z1 engine has a smaller throttle body, and air intake, is it's running at a lower speed most of the time, requring less air, and you want to keep that air velocity high, this is a very key point in air box, and intake manifold design, in an ideal world, your whole air intake would change in langth, and diametor as your engine speed changed.

[kwtorbe]

I plan on testing this theory on my '97 civic HX with a d15z1 intake manifold. I need a VX intake because I want to maintain the EGR valve.

I will port match the head to manifold ports. Then I will either port the TB area out to accept the larger HX throttle body and use HX injectors and sensors (may need to make an adapter which I can do with a drafter friend of mine and his machinist friends), or I will use the smaller VX TB and the smaller VX injectors and sensors (but then I worry about compatibility of the electronics).

Ford 5.0 guys install larger mass air flow sensors, TBs, and fuel injectors for more horsepower; why not install a smaller TB and injectors for better FE?

The theory I am going off of is Q=VA. mass flow=velocity*area. The VX has smaller runners so the same mass of air with move with a higher velocity. I believe this may increase FE, but I know it will increase my torque and HP at lower rpms and decrease my overall horsepower and torque which is found at higher rpms in a 4 cylinder.

From personal porting experience on mopar 318ci heads to the port size of 360ci heads, I know that heads with smaller ports provide better FE and a lower rpm powerband, while ported heads provide better high rpm power but kill low end performance. This is the reason racers use high stall torque converters and steep gears with massively ported heads and large lift camshafts.

If nothing else I believe my d16y5 will have better low rpm power.

Any suggestions on VX throttle body vs. HX throttle body and there abouts are greatly appreciated.

[jeffreymccoy]

Originally Posted by rh77

I'm hoping that more throttle and the choking effect has an impact on power production, as opposed to what the air is really doing, to reduce the need for fuel. I may be way off, but less air would require less fuel for Stoich, right?

RH77

Any updates on this experiment RH77? Wondering if you have tested and what the results have been?

[rh77]

Originally Posted by jeffreymccoy

Any updates on this experiment RH77? Wondering if you have tested and what the results have been?

Well, it's been a while -- a few conclusions...

I attempted to reduce the airflow by reducing the intake diameter, but it seemed like the PGM-FI controller (on the Honda engine) became confused with the lower Manifold Pressure vs. the Throttle Input. No improvement was noted over several months -- in fact, it seemed to slightly reduce FE performance.

On another note, it was noticed throughout the test that 90-100F intake air temps resulted in optimum FE. I ran 91-octane fuel for 140+ air to prevent detonation, but again, no improvement was noted, and more money was spent on the higher grade fuel.

Too cold, or too hot = decreased FE. First, check a shop manual for IAT response (cold temps force a rich situation -- but too hot: the fuel charge needs cooled to prevent pre-ignition, which equals more fuel injected) -- and each engine design is different. At the same time, hotter engine operation than stock (in my case) has resulted in a a mechanical advantage to increase FE (including a hotter thermostat).

Quicker-to-normal temps from the Block Heater get the engine to closed-loop, and increased efficiency with the automatic transmission. Tightening the throttle-transmission cable has increased hydraulic pressure, quickened and tightened shifts, and increased the torque converter lockup response (places the engine in the optimum RPM range for FE, sooner). Some vehicles, on the contrary, will be quick to downshift with this mod, and decrease FE. Mileage will vary -- only tests can confirm results.

Geez, I think I just summarized most of my major engine experiments

RH77



The conclusion was that each engine series is different. I encourage experimentation and the data

[jeffreymccoy]

Great summary - Thanks RH!

[thisisntjared]

Originally Posted by jeffreymccoy

Great summary - Thanks RH!

bro you are doing really well with your f150!!! congrats! when any newb with a truck is asking how to get better mpg with their v8 i am going to point them to you!