[Elastique46]

Do cold air intakes really improve a vehicle's fuel efficiency and horsepower?

[decipha]

they can if its restricted and an actual cai, most of the cheaper kits are hot air intakes and take in engine compartment heat

most fords come factory equipped with cold air intakes, its best to just take out the box and cut the inlet hole bigger where the air silencer is affixed, then simply toss a larger diameter tube through it and call it done

[cgrey8]

Agree with all that. Even my 89 Ranger came stock with an intake system that pulled "cold air." The airbox that held the air filter had a runner in the bottom that pulled air from the grill area right in front of the radiator. But I had to ditch that system to get the V8 to fit...and because that stock runner is way too small for a V8. Unlike Mustangs, Rangers don't have wide fender wells, so you can't duct your filter into the fender. My only EASY option was a cone filter on the MAF thus pulling engine bay air. It's not all bad. Monitoring the ACT sensor, the only time the ACT values are significantly higher than actual outside temps is when I'm idling in traffic for extended periods. The moment the engine starts pulling in more than just idle-amounts of air, the hot air in the engine bay clears pretty quickly. Forward movement also helps with that, but mostly it's just increasing the engine's intake of air. In the summer, I commonly see the ACT rise to the 130-160 range when its only 80s outside. But the moment I push the gas to start moving, the ACTs start dropping into the low 100s. With normal driving by the time I'm in 3rd gear, the ACTs are very near outside temps. If I'm aggressively driving, the ACTs have dropped to near outside air temp before I'm out of 1st.

However datalogged ACT values is not the entire story. There's the heat-soak of the intake manifold. With most Ford EFI systems, there's a significant amount of aluminum on top of the engine that's getting soaked...and it's not just getting soaked from heat conduction being in contact with the engine, but due to the hot air being drawn in from the filter. The cooler the intake air, even idle air, the less soaked the intake will get. So while my at-the-MAF-ACTs may drop like a rock on takeoff, the ACTs, as would-be-measured at the intake port of the heads, are not dropping nearly as fast which can vastly affect an off-idle WOT-blast both in reduced actual oxygen into the engine (hotter air is thinner air) AND in reduced spark advance to avoid ping if you aren't running a sufficiently high enough octane fuel to avoid detonation under these conditions.

I remember back in the 90s when the 5.0s were THE THING at the track, guys would take bags of ice and put them on their intake manifold before they pulled up to the line in hopes they could "cold-soak" their intake. I have no clue how much of that actually had any benefit other than giving them something to do. I'm just thinking they have to queue up, most people would do a pre-takeoff burnout to get the tires hot and sticky, then line up to race. After all that, I'd think any affects of the ice have long since dissipated. But then again, maybe not.

[decipha]

ah yea, back in the day when you didnt race a 5.0 unless you wanted to loose

[cgrey8]

I, personally, don't think the Mustangs got a reputable power plant until the 2000s. Even "built" 5.0s in the 90s were only putting out in the 300hp range. To get anything really impressive, you needed a super/turbocharger to shove-in what the engine couldn't draw in on its own. In the right hands, the Windsors could make block-splitting performance.

Contrast that era to what we have today where L4s and V6s are making ~300hp from the factory on 87 octane. Supercharged 1.6L engines are putting out 200+hp and getting crumb-cruncher sedans over 35 MPG. Minivans with V6s are putting out more power than the stock 93 Cobra did AND have better handling to boot. V8s that don't make at least 350hp in stock form are not really taken seriously as performance power plants. Take the F150s for example where the upgrade to the V8 is the ecoboosted V6.

It's almost depressing to think that I upgraded my old 89 Ranger from its sad 2.9L V6 to a 97 302, then to a 331 high compression stroker with ported GT40p heads, ported Explorer intake, and a mild high lift Crane cam. And as much as I love how much better performance it has as compared to what it was, I doubt it would touch 300hp on a dyno. Relatively speaking to what's available today, it's barely anything to brag about despite all the work that's done to it. That doesn't mean I love it any less.

It's a brave new world.

[decipha]

you do have to consider 1990 was 27 years ago. Back in '90 folks were singing a similar tune as compared to then modern vehicles in comparison to 27 year prior circa 1963 vehicles.

just remember all new technology is old technology, we just have a means to an end now as the supporting technology is being developed to bring some of these theories into fruition.

Such is the case for variable valve timing, variable vane turbos, meth injection, direct injection, etc...

Im really more interested in electric motors these days. A few years back I reprogrammed an eec-V for a guy that put a rewound forklift motor in his crown vic/grand marquis. If I had the opportunity and time Id love to do something similar. I would take it a step further and go AWD with slicks on each corner. That reality of cutting a 0.99 60' has got to be quite the sensation.

Then again Id much rather invest that time and money making a DIY electric quad copter. Something sizeable enough to bodily occupy with seating for four. I have a little rc drone I fly and anyone can operate it with a little practice. I wish someone would take that basic design and just up scale it. If it was reasonably priced 300k or so Id buy one in a heartbeat.

[Elastique46]

Thanks for sharing your opinions. I have learned a lot from reading them all.