Warmer air

[Toe_cutter]

My vehicle is the old style speed/density system, and on cold days or early mornings my exhaust manifolds, where my intake air comes from, gets hot before my engine is closed loop. This causes some issues with running way way rich from about 2 minutes after start up until about 10 or 12 minutes of drive time. So I'm building a dual intake air cleaner with some flex vents that I can switch from warm air to normal driving and cold air, maybe ram air, for heavy towing duties.
What about ducting the intake air to the radiator? It would warm up right after my block gets hot taking care of my temp rich condition, and reduce the need to use my electric cooling fan and maybe cut out some drag on the alternator. thoughts?

[ConnClark]

If your truck is a diesel warm air intakes are a waste of fuel and time. The colder the intake air the more efficient a diesel becomes

[TXwaterdog]

Search Warm Air Intake and WAI for other threads about this.

http://ecomodder.com/forum/showthrea...ion-16833.html

http://ecomodder.com/forum/showthrea...-cai-8774.html


http://ecomodder.com/forum/showthread.php/wai-3535.html

and on and on..

This video briefly talks about variable intake length relating to torque vs hp...

http://www.youtube.com/watch?v=OW2uS...&feature=feedu

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[jakobnev]

Doesn't it have an IAT that is used to correct the MAF reading?

[Daox]

I'd have to agree with jacobnev. The car should have an intake air temperature sensor that corrects for temperature variation.

Also, I can guarantee that your exhaust manifold gets hot before your radiator even starts to warm up. I did some testing a while back and the warm air intake I made had virtually no benefit to warm up times.

http://ecomodder.com/forum/showthrea...i+warm+testing

[Toe_cutter]

Chevy tbi systems rely only on map and tp inputs to determine fuel strategy, well ignition module input also. No iat. It says the throttle is open this much so it must be sucking this much air. The video talked about intake runner length but not really related to the intake system before the throttle plate, maybe I'm just missing that?

[Toe_cutter]

The problem is that the exhaust gets hot before the engine. The PCM uses ect and o2 sensors to determine when to go into closed loop operation. If the temp sensor says the engine isnt warm it will remain in open loop with a much richer fuel strategy, regardless of wether the o2 sensors are heated up or not.

[mwebb]

depending on the system
there are many things used to determine when to go into "closed loop"

but
none of them can over ride the need for the 02 sensor to report to the ECM
until the 02 sensor begins to cycle , the system does not know how to make a correction to real time fuel trim because there is no "feedback" if no feed back
...
the system can not be in "closed loop" ,
the old POS GM TBi systems will revert to open loop at idle because the 02 sensors did not have heaters , they would go to sleep and not report conditions back to the ECM so the ECM had no "feedback" upon which to make decisions about what to correct .

that is what "closed loop" is , real time corrections to measured conditions , there can be no "closed Loop" if conditions to be controlled can not be measured .

most newer systems are in closed loop in under 1 minute from cold start , even if ECT and IAT says system is cold.
they enter closed loop when the front AFR or 02 sensor begins reporting and they begin to report the second they reach operating temperature

which is why

all new systems have ECM managed heaters on the AFR sensors (front) and 02 sensors (rear)

so
on newer systems with heated AFR or 02 sensors ...
warm / hot air to the intake has zero effect on time to closed loop from cold start.
none the less WAI does have other benefits related to
Fuel Economy

[TXwaterdog]

So, a WAI doesnt help the vehicle reach oporating temp faster, but still helps save gas?

[Daox]

Yes, in my testing it did not seem to improve warm up times.

However, warm air is still a benefit to use for FE. Warm air is less dense and requires a larger throttle opening for the same horsepower output. A larger throttle opening reduces pumping losses and increases efficiency. Warmer air also increases flame speed within the combustion chamber which leads to higher cylinder pressure which improves efficiency.