design flaw : F20A 's air intake gets useless heat from radiator*coolant

  • via thermostat is [i] steel-piped next to & heat is transferred into rocker cover's breather hose
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    , this heated air is then sucked through PCV valve & into intake manifold.chamber [ii] rubber-hosed into bottom of throttle body
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    , & heat flows into the air passing throttle. Both designs make air intake & cylinder head unduly hot
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    : whenever intake manifold heats up ( esp in long trips ), torque drops & warm-starts are difficult , both because hot air cannot expand much when heated. Ideal temperature of air to receive injectors' spray of petrol is just 40°C =
104°F (
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para 10.2[7] ). Intake manifold where injectors spray petrol ( near cylinder head ) & chamber already get heat from manifold's contact with cylinder head, EAC & Fast Idle valves ( both heated by * ), certainly do not need more heat. If designer wanted manifold to heat up fast, then throttle body must have a thermostat to stop * inflow when throttle is heated to 40°C. These 2 designs make steep hill climbing slow & weak ; * & air intake will both be @ their hottest, & torque will be lowest ( ironically, when torque is needed most ). After I disabled these 2 designs, in 28°C air, [i] chamber, manifold & cylinder head are cooler, benefits are many e.g. 1 can use ( cheaper ) mineral oil & lower viscosity [ii] torque ( 5% > before ) does not drop after * heats up [iii] warm-starts are easier.
Reply to
TE Chea
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There isn't supposed to be much air flowing through a PCV system.

Maybe the thermostat for your throttle body, if it has one, is faulty. It's supposed to keep it warm, not hot.

Maybe you fixed a symptom, not a problem? Your posting is hardly clear.

Reply to
Kevin McMurtrie

you need to stop drinking the "cold air intake" coolaid there guy. it may be fine for you kidz in the nice warm county of l.a. to run about with disabled de-icing equipment, but anywhere else in the country, it becomes a bit of an issue when your car sputters to a halt because of ice buildup.

as an aside, i had my air intake cover off the other day, and forgot to screw it on tightly. the screws worked their way out after a few hundred miles, and the air intake cover popped off. it was noticeable by two things:

  1. increased noise. ok, ho hum.

  1. big /decrease/ in power. the "ultimate" cold air intake, i.e. no intake at all produces /less/ power???!!! yep, you better believe it.

now, it's possible that some aftermarket manufacturers of air intakes know what they're doing and understand airflow resonance dynamics and the effect it has on engine air induction, but somehow i doubt most of them do. but hey, most of this stuff is not for performance, it's just for show...

Reply to
jim beam

does not drop after * heats up [iii] warm-starts are easier.

--------------------------------------

I looked at your other posts. Why do you own such a badly designed car?

'Curly'

Reply to
'Curly Q. Links'

"'Curly Q. Links'" wrote in news: snipped-for-privacy@interbaun.com:

His post makes no sense. I read it twice and still can make neither head nor tail out of it.

Reply to
TeGGeR®

jim beam wrote in news:lrWdnX4uvr91awrZnZ2dnUVZ snipped-for-privacy@speakeasy.net:

Uh,the air intake is still from the hot under-hood air.All you did was shorten the intake runner length,which reduces torque. If you don't believe cold air enables more power,then explain why racers put scoops and ducts on their race cars.It wouldn't make sense,adding more drag to get cold air that doesn't produce more power.

Reply to
Jim Yanik

uh, i understand how it works thanks. what i'm saying is that it's not so simple as most of the "cai" crowd believes. if the intake tubing is tuned correctly, i.e. resonances are set specifically, it enhances the air charge entering the engine. done right, it flattens/broadens power/torque curves. otherwise you're stuck with huge flat spots in the engine's performance, exactly what i was experiencing.

"tuning" the air charge has /way/ more effect than the minor density differences made by a few degrees of ambient air temperature.

Reply to
jim beam

I think one of your modifications is allowing carbon monoxide into the cabin.

Reply to
Gordon McGrew

jim beam wrote in news:OuqdnUjFs9QaPAXZnZ2dnUVZ snipped-for-privacy@speakeasy.net:

If Honda Tuning Magazine still has the article,they did flow bench and dyno tests on an RSX for several different brands of short rams and two cold air intakes.They did a reference test on the unaltered vehicle,then tested each intake system.Both CAIs got 20HP and modest torque increases.The short rams only got 5-7 HP gains. They included their graphs in the magazine article.They also discussed the effect of intake air temperature WRT making power.

It was a very informative article.Maybe you can get a back issue.

Reply to
Jim Yanik

What a laugh! I just read through some as well. I love this one: "Bonnet's rubber seals & felt, front wheels' hub caps too can be removed, to help cool engine."

Sounds like his problem is the loose nut between the steering wheel and the driver's seat.

Steve

Reply to
Steve Mackie

| > Why do you own such a badly designed car? So far all its design flaws ( 3 more & 2 inadequacies which I tell friends & relatives ) can be corrected / mitigated. I love its 4ws ( saves time, very scarce now : no new model has 4ws ), perfect rust proofing. No electric / hybrid / toyota's super 4ws on sale yet.

| "Bonnet's rubber seals Removal of these let air enter & cool intake manifold & chamber , & let out hot air produced by air con's radiator. Torque rose 3%.

| & felt lets heat enter bonnet & escape via convection / radiation

| front wheels' hub caps too can be removed, to help cool engine. My front wheels used to be too hot to touch, caused by this * flow design flaw & cheapo exhaust manifold. Removal of hub cap will let drive shaft & engine cool faster, unnecessary for well cooled engines, but for desparate users with severe overheating, this can help a bit, esp on original steel wheels with 15½" Ø plastic caps.

| loose nut between the steering wheel and the driver's seat. Salesmen / dealers all deny flaws, & denigrate to deter exposers, to protect their bread & butter, just like in 1 thread above ( 11-5-06 ) on ignition switch.

Reply to
TE Chea

i appreciate what you're saying jim, but did they drop a thermistor into the air stream to measure the difference in air temperature between the two? i'll be surprised if they did because i can't say i've ever seen one of those "dyno graph" articles that ever has. without that, they're simply measuring the dynamic air charging effect differences - what i was talking about before. you're right, temperature /can/ make a difference to power yield [an 80 degree difference in air temp gets you roughly 10% difference in air density] but again, have you ever seen temperature reading differences quoted? and what difference does it make for a *moving vehicle* with & without cai? airflow under the hood is, well, you get the picture... just questions to ask.

Reply to
jim beam

You've got to be f***in kidding me.

Plonk.

Steve

Reply to
Steve Mackie

jim beam wrote in news:bM-dncpQr4WtgQfZnZ2dnUVZ snipped-for-privacy@speakeasy.net:

They used the OBDII intake air temp measurements read from the ECU's own sensors.

even with airflow under the hood,the underhood temerature is much higher than outside.There's radiated engine heat that is retained.

You really should get a copy of the article.

Reply to
Jim Yanik

If your wheels are too hot to touch then you probably have a brake problem (or you are riding them/failing to downshift for long descents). Removing the wheel covers could help with brake cooling, but the effect on engine cooling would be negligible.

Hondas have excellent engine cooling. The only time I have ever had a gauge go much above half was when the system had lost coolant. That has happened two or three times in 35 vehicle years of ownership of five Honda cars. I have run these cars in Chicago traffic in ambient temperatures from -28F to 106F and I have never found the cooling system to be inadequate in any way.

So I would suggest that if yours is inadequate, it may need repair or it may be due to one or more of your modifications. If the former, then fix the problem. If the latter, then feel free to make whatever further modifications are necessary to correct these problems. Just don't whine that the car is defective.

Reply to
Gordon McGrew

his best one was about disconnecting the clock because the excessive load on the alternator robbed power...

Reply to
jim beam

great! what were they?

you need to re-phrase that one dude. radiated heat, by definition, is not retained. and a sensor inside the manifold is not going to experience much radiated heat from anything other than the manifold itself.

i think what you mean is that air drawn form under the hood i.e. downwind of the radiator, is warmer, which is true. but in these pics

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in all these cases, the cai's are /all/ downwind of the radiator, so i don't see what the "cold air intake" is achieving in the thermal department, unless it's on a static vehicle with the hood open. and i'd love to see numbers on air temp for a /moving/ vehicle, especially as oem intakes all draw air from up front of the radiator. if all these kiddiez were serious, they'd cut through the fender and/or hood and put a real cold air scoop to the outside world, but i've never seen that on a cai'd civic.

scan it and send it to tegger.

again, i see dyno differences mostly attributable to air charge resonances, not actual air temperature.

Reply to
jim beam

jim beam wrote in news:0PadnVa-YJrl1AbZnZ2dnUVZ snipped-for-privacy@speakeasy.net:

And I'd be delighted to post such results.

And what sort of changes are we talking about here? 5 BHP? Less?

Reply to
TeGGeR®

they never do.

Reply to
SoCalMike

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