Well over the last few days I broke down and bought the Spectre intake kit, it was bugging me so I had to try it. Before buying it, I monitored my IAT with my diablo sport programmer and took notes, I have done this before as well and had a decent feeling for what the difference in IAT and ambient temperature is (via mirror, its always been within a degree or two, long as I am moving and not sitting in a parking lot for several minutes with A/C on lol)
Install was easy, the black rubber tubes can be tight, but with some finessing got it all installed. I Noticed the radiator hose was in direct contact, so I placed some foam in between to prevent contact. I then took it for a test drive, noting IAT, and they were much higher, stopping at a light, going as much as 35* above ambient really fast, within in a minute. (stock was about 2-5 in the same situation) I was initially disappointed. I went back home and took a better look at the set up, I felt the tube, and it was untouchable, where the stock set up under driving the same route, was hot, but not untouchable.
I then took and nearly blocked off all "hot air" passages that could get to the filter, including to the hood, so air would nearly exclusively come from the old fender holes and from below.
I preformed my drive, and notice that temperatures still soar in city driving. Going as much as 15-20 degrees hotter than what the factory box had, and being erratic, meaning it would jump in temperature quickly. The factory box I seen temps almost 20 degrees warmer than ambient and would take a long time to get there, where this kit would jump up to 20+ in less than a minute, and stay there for some time, cooling down I would say they are about the same. On the freeway,
after a long time, the Spectre would cool down to within 1 degree of the ambient at times, but typically around 2-3 degrees warmer, the factory box never got lower than about 2 degrees than ambient but mostly within 4-5 degrees.
Each route I took I allowed my truck to cool too point where I could work on it inside our garage, and then drove in the city until it reached normal operating temperature, then took it on the freeway and drove at roughly the same speed for quite some distance, then got off the free way and took the same route, keeping track of temps and how fast things went up.
Before I sealed off the box, I did get the "bog down" feeling using the spectre, watching the IAT, at a light I'm sitting at 100* IAT, ambient around 95 (just got off the freeway) and when I punched it, the temps would jump to 120-130 degrees! (the factory airbox would go maybe, 5-6 degrees, and the spectre blocked off it would still jump 20 degrees) I bet what is happening, is with the IAT so high, the engine now has to make dramatic adjustments, that cause the bog down feeling. My best guess is that when the engine starts sucking more on take off, 2 things are probably happening, 1: more air is being sucked, so some hot air from my sealed box area would get past, 2, the clutch fan is moving more air, and since aluminum is a great conductor, and with the effects of forced convection, it gets heated up really quick.
I also monitored MAP (manifold absolute pressure) and the MAP readings were all the same before, during and after the Spectre intake system. I would of monitored MAF, but the readings were erratic, and the MAP was more stable. Off the line, initially punched it would be 12.5-12.6 PSI, then drop to about 12.3 PSI for most of the range, and then in the 5000 RPM range, drop to 12.2 PSI, with either the K&N with stock air intake system or Spectre kit installed, checked several times and at similar IAT and ambient temps. From this I conclude, correct me if I am wrong, that the Spectre isn't letting anymore air in than normal, and the stock set up is just as good for my stock engine (except magnaflow exhaust and diablo programmer).
So from my experience I stand corrected on my previous statement, saying the aluminum tube maybe better, it seems plastic is the way to go.
When the temps were down around normal in comparison, I had a really hard time feeling any improvements (I felt none), I would just notice more noise (which I liked, but not for the price) MPG seemed unchanged, traveling down a flat open strip of freeway I would check it on the DIC. My truck has 93k miles on it, and recently just did a plug and wire change, and keep up on it maintenance.
I swapped back in my K&N air filter and factory box and took the specter back to the store. But now I am going back to an AC Delco filter, because when I had the factory box and all off, I notice a large amount of dust in the intake tubing, MAF and right be hind the filter, it seems to me the K&N is crappy for filtering dust, and since I drive a lot on dusty roads, and after some more research, I will be sticking to the paper filter, to me a 1-2 hp hit at 5000rpms is worth it for the extra protection.
in conclusion, I know that my tests were informal, and the ambient temp readings can be off, but just seeing how the IAT temps would jump quickly and stay there was more than enough reason to stick with the factory airbox for now, I may, if i fell like it, get the airaid jr. tube to clean up the engine compartment only. The Factory was a couple of degrees warmer on the freeway, but much cooler in the city, and temps far more stable. If you do get a aftermarket intake, I personally would save my money, but if you had to, I would stick with a plastic tube, and some kind of air box that is sealed well against the engine compartment, otherwise you would just get a hot air intake
On sort of a side note, I never been to fond of aftermarket "power adders" did a lot of things on a S10 to get more power, but nothing really seamed to help it, except things that would for sure add, or free up power, such as underdrive pulleys, being one of the few things I did where I felt a difference. Things I tried and could not tell a difference was: Airaid CAI, MSD wires, Accel coil, K&N headers, etc. My MPG never went up on my S10 and power seemed to just stay the same, I didn't dyno it, but honestly If I spend 200-500 dollars on something, I want to feel a difference in my butt dyno or make it sound better or look much better; I'm not racing, so that 1/10th of a second doesn't matter. Honestly at this point, I feel that if GM or some other manufacture in recent years could improve mpg by 1mpg or add 10 hp to an engine, then why didn't they from the factory? I know some of it is cost, but look at the factory airbox on a avalanche, and then an airaid one, which one do you think cost more to make? same thing with coils, wires and all that, sure it may cost more, but when GM can get one more MPG and/or 10hp (think how MPG conscious buyers are now, and all that fun MPG stuff) on the truck and make it cost $5 dollars more then why not? (yes I know aftermarket parts cost a lot more, but when GM is making them and all I doubt their increase in cost is the same as ours)
Other things I think aren't the same, such as the air intake tube or muffler, as these are designed from the factory to be quite, and in which
may increase a small power gain form an aftermarket mod. So now I'm done ranting, and putting my flame suit on, I will end my novel by saying I think my mods from here on out, no matter how tempting, will be things such as stainless handle covers, as put on today
or lifts or stuff like that.
-Sterling